TFX12V
Thin Form Factor with 12-Volt Connector
Power Supply Design Guide
Version 2.0
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
Revision History
Version Release Date
Notes
1.0
April, 2002
May, 2002
April, 2003
•
•
•
•
•
•
•
•
•
•
•
•
Public release
1.01
1.2
Added dimension in Figure 5 to clarify location of mounting slot feature
Updated power and current guidance
Added efficiency targets for light and nominal loading
Increased minimum Efficiency at full load from 68% to 70%
Updated guidance for standby efficiency
Added Serial ATA connector
Updated Revision history table
Reformat title page
Added cross loading tables
Added loading tables for efficiency measurement points
Minor modifications to Energy Star
•
Updated power and current guidance
Updated cross regulation graphs
2.0
February, 2004
•
•
•
Updated load tables
Updated required efficiency targets. Added recommended efficiency
targets. Increased required minimum efficiency at typical and light load.
•
•
•
•
•
Required Serial ATA connector
Added Terminology section
Main Power Connector changes to 2x12.
Separate current limit on 2x2 connector for 12V2 rail
12V2 requirements added
3
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
Contents
1 Introduction .....................................................................................................7
1.1 TFX12V Scope ............................................................................................................ 7
1.2 TFX12V Overview ....................................................................................................... 7
Improved Acoustics....................................................................................... 8
1.3 Key Changes for TFX12V Version 2.0......................................................................... 8
1.4 Terminology................................................................................................................. 9
2 Electrical........................................................................................................10
Inrush Current Limiting.................................................................................10
2.2 DC Output ..................................................................................................................12
DC Voltage Regulation.................................................................................12
Typical Power Distribution............................................................................13
Efficiency General........................................................................................16
2.2.10 Closed-loop Stability.....................................................................................20
2.2.12 Voltage Hold-up Time...................................................................................20
2.3 Timing / Housekeeping / Control.................................................................................21
Rise Time.....................................................................................................24
+5 VSB at AC Power-down ..........................................................................24
2.4 Output Protection .......................................................................................................24
Short-circuit Protection.................................................................................25
4
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
No-load Operation........................................................................................25
3 Mechanical.....................................................................................................26
3.1 Labeling /Marking .......................................................................................................26
3.2 Physical Dimensions...................................................................................................26
3.3 Mounting Options .......................................................................................................29
3.4 Chassis Requirements................................................................................................30
3.5 Airflow / Fan ...............................................................................................................31
3.6 AC Connector.............................................................................................................31
3.7 DC Connectors...........................................................................................................32
+12 V Power Connector...............................................................................34
Serial ATA Power Connector........................................................................34
4 Environmental...............................................................................................35
4.2 Thermal Shock (Shipping) ..........................................................................................35
4.3 Relative Humidity........................................................................................................35
4.4 Altitude Requirement..................................................................................................35
4.5 Mechanical Shock ......................................................................................................35
4.6 Random Vibration.......................................................................................................36
4.7 Acoustics....................................................................................................................36
4.8 Ecological Requirements............................................................................................36
5 Safety .............................................................................................................37
5.1 North America ............................................................................................................37
6 Electromagnetic Compatibility ....................................................................38
6.1 Emissions...................................................................................................................38
6.3 Input Line Current Harmonic Content .........................................................................39
6.4 Magnetic Leakage Fields............................................................................................39
6.5 Voltage Fluctuations and Flicker.................................................................................39
8 Reliability.......................................................................................................40
9 Applicable Documents .................................................................................40
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
Figures
Figure 1. TFX12V Power Supply...................................................................................................... 7
Figure 2. Cross Loading Graph for 180W Configuration................................................................. 13
Figure 3. Cross Loading Graph for 220W Configuration................................................................. 14
Figure 4. Cross Loading Graph for 240W Configuration................................................................. 15
Figure 5 Cross Loading Graph for 270W Configuration................................................................. 16
Figure 6. Differential Noise Test Setup.......................................................................................... 19
Figure 7. Power Supply Timing ..................................................................................................... 21
Figure 8. PS_ON# Signal Characteristics...................................................................................... 23
Figure 10. Power Supply Mounting Slot Detail ............................................................................... 28
Figure 11. Fan Right and Fan Left Orientations of Power Supply in a Chassis .............................. 29
Figure 12. Suggested TFX12V Chassis Cutout.............................................................................. 30
Figure 13. Suggested Mounting Tab (chassis feature)................................................................... 30
Figure 14. TFX12V Connectors (Pin-side view, not to scale) ......................................................... 32
Tables
Table 1. AC Input Line Requirements........................................................................................... 10
Table 2. DC Output Voltage Regulation........................................................................................ 12
Table 3. Typical Power Distribution for 180 W TFX12V Configurations......................................... 13
Table 4. Typical Power Distribution for 220 W TFX12V Configurations......................................... 14
Table 5. Typical Power Distribution for 240 W TFX12V Configurations......................................... 15
Table 6: Typical Power Distribution for 270 W SFX12V Configurations ........................................ 16
Table 7: Efficiency Vs Load .......................................................................................................... 17
Table 8. Loading Table for Efficiency Measurements ................................................................... 17
Table 9. Energy Star Input Power Consumption........................................................................... 18
Table 11. DC Output Transient Step Sizes..................................................................................... 19
Table 13. PWR_OK Signal Characteristics..................................................................................... 22
Table 15. Over Voltage Protection.................................................................................................. 25
Table 16. Harmonic Limits, Class D Equipment.............................................................................. 39
6
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
1 Introduction
1.1 TFX12V Scope
This document provides design suggestions for a small form factor power supply that is primarily intended for
use with small form factor system designs (9-15 liters in total system volume). It should not be inferred that all
Thin Form Factor with 12 Volt connector (TFX12V) power supplies must conform exactly to the content of this
document, though there are key parameters that define mechanical fit across a common set of platforms.
Since power supply needs vary depending on system configuration, the design specifics described are not
intended to support all possible systems.
Figure 1. TFX12V Power Supply
1.2 TFX12V Overview
This section provides a brief overview of the unique features of the Thin Form Factor with 12 Volt connector
(TFX12V) power supply design and a summary of the changes included in revision 1.2.
1.2.1 Small System Optimized Profile
The increase in demand for smaller systems results in unique system layout challenges. The Thin Form
Factor with 12 Volt connector (TFX12V) configuration has been optimized for small and low profile microATX
and FlexATX system layouts. The long narrow profile of the power supply (shown in Figure 1) fits easily into
low profile systems. The fan placement can be used to efficiently exhaust air from the processor and core
area of the motherboard, making possible smaller, more efficient systems using common industry ingredients.
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
1.2.2 Improved Acoustics
As desktop systems become smaller, they are placed in more exposed areas in the home and work place.
The smaller systems are no longer confined to the floor or under the desk, but are placed on the desktop next
to the user. In these situations, noise becomes an important factor to the end user. Thin Form Factor with 12
Volt connector (TFX12V) supplies should use fan speed control techniques to provide a low acoustic profile,
while providing ample cooling to internal components when required.
1.3 Key Changes for TFX12V Version 2.0
This section briefly summarizes the major changes made to this document that now defines ATX12V power
supply. With the move to 12V voltage regulators for the processor, ATX guidelines for 5V as main power are
no longer provided.
1.3.1 Increased +12 VDC Output Capability
System components that use 12V are continuing to increase in power. In cases where expected current
requirements is greater than 18A a second 12 V rail should be made available. ATX12V power supplies
should be designed to accommodate these increased +12 VDC currents.
1.3.2 Minimum Efficiency
Minimum measured efficiency is required to be 70% at full, typical (50%) load and 60% at light (20%) load.
New recommended guidance has been added to provide direction for expected future requirements.
1.3.3 Main Power Connector
The 2 x 12 main power connector replaces the 2 x 10 connector. This change was made to support 75 watt
PCI Express* requirements.
1.3.4 Separate Current Limit for 12V2 on the 2x2 Connector
The 12V rail on the 2 x 2 power connector should be a separate current limited output to meet the
requirements of UL and EN 60950.
8
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
1.4 Terminology
The following terms are used in this document:
Term
Description
Required
The status given to items within this design guide, which are required to
meet design guide and a large majority of system applications.
Recommended
Optional
BA
The status given to items within this design guide, which are not required
to meet design guide, however, are required by many system
applications.
The status given to items within this design guide, which are not required
to meet design guide, however, some system applications may optionally
use these features.
Declared sound power, LwAd. The declared sound power level
shall be measured according to ISO* 7779 for the power supply
and reported according to ISO 9296.
CFM
Cubic Feet per Minute (airflow).
Monotonically
A waveform changes from one level to another in a steady fashion,
without intermediate retracement or oscillation.
Noise
The periodic or random signals over frequency band of 0 Hz to 20 MHz.
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
2 Electrical
The following electrical requirements must be met over the environmental ranges as defined in Section 5
(unless otherwise noted).
2.1 AC Input
Table 1, lists AC input voltage and frequency requirements for continuous operation. The power supply shall
be capable of supplying full-rated output power over two input voltage ranges rated 100-127 VAC and 200-
240 VAC rms nominal. The correct input range for use in a given environment may be either switch-
selectable or auto-ranging. The power supply shall automatically recover from AC power loss. The power
supply must be able to start up under peak loading at 90 VAC.
Table 1.
AC Input Line Requirements
Minimum
Parameter
Nominal*
115
Maximum
135
Unit
Vin (115 VAC)
Vin (230 VAC)
Vin Frequency
90
VAC rms
VACrms
Hz
180
47
230
265
--
63
*Note: Nominal voltages for test purposes are considered to be within 1.0 V of nominal.
2.1.1 Input Over Current Protection
The power supply shall incorporate primary fusing for input over current protection to prevent damage to the
power supply and meet product safety requirements. Fuses should be slow-blow–type or equivalent to
prevent nuisance trips.1
2.1.2 Inrush Current Limiting
Maximum inrush current from power-on (with power-on at any point on the AC sine) and including, but not
limited to, three line cycles, shall be limited to a level below the surge rating of the input line cord, AC switch if
present, bridge rectifier, fuse, and EMI filter components. Repetitive ON/OFF cycling of the AC input voltage
should not damage the power supply or cause the input fuse to blow.
2.1.3 Input Under Voltage
The power supply shall contain protection circuitry such that the application of an input voltage below the
1
For Denmark and Switzerland international safety requirements, if the internal over current protective devices exceed 8A
for Denmark and 10A for Switzerland, then the power supply must pass international safety testing to EN 60950 using a
maximum 16A over-current protected branch circuit, and this 16A (time delay fuse) branch circuit protector must not open
during power supply abnormal operation (output short circuit and component fault) testing.
10
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
2.1.4 Regulatory
The power supply is required to be tested and comply with the most current version of the following
regulatory specification requirements and/or standards
2.1.4.1 PRODUCT SAFETY
UL* 60950, 3rd Edition –CAN/CSA-C22.2-60950-00,
EN*60 950, 3rd Edition
IEC*60 950, 3rd Edition (CB Report to include all national deviations)
EU* Low Voltage Directive (73/23/EEC) (CE Compliance)
GB4943-90 CCIB* (China)
2.1.4.2 ELECTROMAGNETIC CAMPATIBILITY
FCC*, Class B, Part 15 (Radiated & Conducted Emissions)
CISPR* 22 / EN55022, 3rd Edition (Radiated & Conducted Emissions)
EN55024 (ITE Specific Immunity)
EN 61000-4-2 – Electrostatic Discharge
EN 61000-4-3– Radiated RFI Immunity
EN 61000-4-4– Electrical Fast Transients.
EN 61000-4-5 – Electrical Surge
EN 61000-4-6 – RF Conducted
EN 61000-4-8 – Power Frequency Magnetic Fields
EN 61000-4-11 – Voltage Dips, Short Interrupts and Fluctuations
EN61000-3-2 (Harmonics)
EN61000-3-3 (Voltage Flicker)
EU EMC Directive ((8/9/336/EEC) (CE Compliance)
2.1.4.3 Other Certifications and/or Declarations
GB925 (China/CCC*)
CNS13438 (Taiwan/BSMI*)
AS/NZ3548 (Australia/C-tick* based on CISPR22)
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
2.1.5 Catastrophic Failure Protection
Should a component failure occur, the power supply should not exhibit any of the following:
•
•
•
•
•
•
•
Flame
Excessive smoke
Charred PCB
Fused PCB conductor
Startling noise
Emission of molten material
Earth ground fault (short circuit to ground or chassis enclosure)
2.2 DC Output
2.2.1 DC Voltage Regulation
The DC output voltages shall remain within the regulation ranges shown in Table 2, when measured at the
load end of the output connectors under all line, load, and environmental conditions. The voltage regulation
limits shall be maintained under continuous operation for any steady state temperature and operating
Table 2.
DC Output Voltage Regulation
Output
Range
5%
Minimum
Nominal
+12.00
+12.00
+5.00
Maximum
+12.60
+12.60
+5.25
Unit
+12 V1DC
+12 V2DC (Note)
+5 VDC
+11.40
+11.40
+4.75
+3.14
-10.80
+4.75
Volts
Volts
Volts
Volts
Volts
Volts
5%
5%
+3.3 VDC
-12 VDC
5%
+3.30
+3.47
10%
5%
-12.00
+5.00
-13.20
+5.25
+5 VSB
Note: At +12 VDC peak loading, regulation at the +12 VDC output can go to 10%.
2.2.2 Remote Sensing
The +3.3 VDC output should have provisions for remote sensing to compensate for excessive cable drops.
The default sense should be connected to pin 11 of the main power connector. The power supply should
draw no more than 10 mA through the remote sense line to keep DC offset voltages to a minimum.
12
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
2.2.3 Typical Power Distribution
DC output power requirements and distributions will vary based on specific system options and
implementation.
Significant dependencies include the quantity and types of processors, memory, add-in card slots, and
peripheral bays, as well as support for advanced graphics or other features. Table 3, through Table 6 show
the power distribution and cross loading tables for power supplies in the range of 180 W to 240 W. It is
ultimately the responsibility of the designer to define a power budget for a given target product and market.
Table 3. Typical Power Distribution for 180 W TFX12V Configurations
Minimum Current
(amps)
Rated Current
(amps)
Peak Current
(amps)
Output
+12 VDC
+5 VDC
1.0
0.3
13.0
15.0
12.0 (Note)
16.7 (Note)
0.3
+3.3 VDC 0.5
-12 VDC
+5 VSB
0.0
0.0
2.0
2.5
Note: Total combined output of 3.3 V and 5 V is 63 W
Peak currents may last up to 17 seconds with not more than one occurrence per minute
180W Cross Regulation
(5V rail + 3.3V rail vs. 12V)
70
60
50
40
30
20
10
0
Combined Power
(5V rail + 3.3V rail)
0
50
100
150
200
12V power (watts)
Figure 2. Cross Loading Graph for 180W Configuration
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
Table 4. Typical Power Distribution for 220 W TFX12V Configurations
Minimum Current
(amps)
Rated Current
(amps)
Peak Current
(amps)
Output
+12 VDC
+5 VDC
+3.3 VDC
-12 VDC
+5 VSB
1.0
0.3
0.5
0.0
0.0
15.0
17.0
13.0 (Note)
17.0 (Note)
0.3
2.0
2.5
Note: Total combined output of 3.3 V and 5 V is 80 W
Peak currents may last up to 17 seconds with not more than one occurrence per minute
220W Cross Regulation
(5V rail + 3.3V rail vs. 12V)
90
80
70
60
50
40
30
20
10
0
Combined Power
(5V rail + 3.3V rail)
0
50
100
150
200
12V power (watts)
Figure 3. Cross Loading Graph for 220W Configuration
14
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
Table 5. Typical Power Distribution for 240 W TFX12V Configurations
Minimum Current
(amps)
Rated Current
(amps)
Peak Current
(amps)
Output
+12 VDC
+5 VDC
+3.3 VDC
-12 VDC
+5 VSB
1.0
0.3
0.5
0.0
0.0
16.0
18.0
18.0 (Note)
17.0 (Note)
0.3
2.0
2.5
Note: Total combined output of 3.3 V and 5 V is 115 W
Peak currents may last up to 17 seconds with not more than one occurrence per minute
240W Cross Regulation
(5V rail + 3.3Vrail vs. 12V)
120
100
80
Combined Power
(5V rail + 3.3V rail)
60
40
20
0
0
50
100
150
200
12V power (watts)
Figure 4. Cross Loading Graph for 240W Configuration
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
Table 6:
Typical Power Distribution for 270 W SFX12V Configurations
Output
Minimum
Current
(amps)
Maximum
Current
(amps)
Peak
Current
(amps)
1.0
1.0
0.3
0.5
0.0
0.0
7.0
13.0
18.0
17.0
0.3
9.0
+12 V1DC
+12 V2DC
+5 VDC
+3.3 VDC
-12 VDC
+5 VSB
2.0
2.5
Note: Total combined output of 3.3 V and 5 V is
20 W
Peak currents may last up to 17 seconds with not more than one occurrence per minute
270W Cross Regulation
(5V rail + 3.3V rail vs. 12V1 +12V2)
120
100
80
60
40
20
0
Combined Power
(5V rail + 3.3V rail)
0
40
80
120
160
200
240
12V power (watts)
Figure 5 Cross Loading Graph for 270W Configuration
2.2.4 Power Limit / Hazardous Energy Levels
Under normal or overload conditions, no output shall continuously provide 240 VA under any conditions of
load including output short circuit, per the requirement of UL 1950/CSA 950 / EN 60950/IEC 950 specification.
2.2.5 Efficiency General
The power supply should be a minimum of 70% efficient under “Full” load, 70% under “typical” load, and 60%
in a “light” load idle condition. The efficiency of the power supply should be tested at nominal input voltage of
16
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
115VAC input and 230VAC input, under the load conditions defined Table 8, and under the temperature and
operating conditions defined in Section 3. The loading condition for testing efficiency shown in Table 7
represents a fully loaded system, a typical (50%) loaded system, and a light (20%) loaded system.
Table 7:
Loading
Efficiency Vs Load
Full load
70%
Typical load
70%
Light load
60%
Required Minimum Efficiency
75%
80%
68%
Recommended Minimum Efficiency
Table 8.
Loading Table for Efficiency Measurements
180W (loading shown in Amps)
Loading
Full
+12V
11
7
+5V
4
+3.3V
5.8
4
-12V
0.3
+5Vsb
1.0
1.0
1.0
Typical
Light
3
0.1
2
0.3
0.5
0.0
220W (loading shown in Amps)
Loading
Full
+12V
13
8
+5V
5
+3.3V
-12V
0.3
+5Vsb
1.0
9
5
Typical
Light
3
0.1
1.0
3
0.5
2.0
0.0
1.0
240W (loading shown in Amps)
Loading
Full
+12V
14.5
7
+5V
7
+3.3V
-12V
0.2
+5Vsb
1.0
7
5
Typical
Light
4
0.1
1.0
3.4
1.0
3.0
0.0
1.0
270W (loading shown in Amps)
Loading
Full
+12V1
+12V2
11.5
+5V
9.4
4.5
0.4
+3.3V
-12V
0.2
+5Vsb
4
2
1
9
4
1.0
1.0
1.0
Typical
Light
5.5
2.4
0.1
0.7
0.0
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
2.2.5.1 Energy Star*
The “Energy Star” efficiency requirements of the power supply depend on the intended system configuration.
In the low power / sleep state (S1 or S3) the system should consume power in accordance with the values
Table 9. Energy Star Input Power Consumption
Maximum Continuous Power Rating of
Power Supply
RMS Watts from the AC Line in Sleep/low-Power
Mode
< 200 W
< 15 W
> 200 W < 300 W
> 300 W < 350 W
> 350 W < 400 W
> 400 W
< 20 W
< 25 W
< 30 W
10% of the maximum continuous output rating
Note: To help meet the “Energy Star” system requirements, it is recommended that the power supply have > 50%
efficiency in standby mode.
2.2.6 Other Low Power System Requirements
*
To help meet the Blue Angel system requirements, RAL-UZ 78, US Presidential executive order 13221,
future EPA requirements, and other low Power system requirements the +5 VSB standby supply efficiency
should be as high as possible. Standby efficiency is measured with the main outputs off (PS_ON# high
state). Standby efficiency should be greater than 50% with a load of 100mA.
2.2.7 Output Ripple/Noise
Ripple and noise are defined as periodic or random signals over a frequency band of 10 Hz to 20 MHz.
Measurements shall be made with an oscilloscope with 20 MHz of bandwidth. Outputs should be bypassed at
the connector with a 0.1µF ceramic disk capacitor and a 10µF electrolytic capacitor to simulate system
Table 10. DC Output Noise/Ripple
Maximum Ripple and Noise
Output
+12 V1DC
+12 V2DC
+5 VDC
(mVpp)
120
200
50
+3.3 VDC
-12 VDC
+5 VSB
50
120
50
18
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
V out
Power Supply
AC Hot
Load must be
isolated from the
ground of the
power supply.
Load
0.1uf
AC Neutral
10uf
V return
AC Ground
General Notes:
1. Load the output with its minimum load
current.
2. Connect the probes as shown.
3. Repeat the measurement with maximum
load on the output.
Scope
Filter Note:
Scope Note:
0.1uf - Kemet, C1206C104K5RAC or equivalent
10uf - United Chemi-con, 293D106X0025D2T or
equivalent
†
Use Tektronix TDS460 Oscilloscope or
equivalent and a P6046 probe or equivalent.
Figure 6. Differential Noise Test Setup
2.2.8 Output Transient Response
Table 11 summarizes the expected output transient step sizes for each output. The transient load slew rate is
= 1.0 A/µs.
Table 11. DC Output Transient Step Sizes
Maximum Step Size
(% of rated output amps)
Maximum Step Size
(amps)
Output
+12 V1DC
+12 V2DC
+5 VDC
40%
60%
30%
30%
+3.3 VDC
-12 VDC
+5 VSB
0.1 A
0.5 A
Note: For example, for a rated +5 VDC output of 14 A, the transient step would be 30% × 14 A = 4.2 A
Output voltages should remain within the regulation limits of Table 2, Section 2.2.1, for instantaneous
changes in load as specified in Table 11 and for the following conditions:
•
Simultaneous load steps on the +12 VDC, +5 VDC, and +3.3 VDC outputs (all steps occurring in the
same direction)
•
•
Load-changing repetition rate of 50 Hz to 10 kHz
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
2.2.9 Capacitive Load
The power supply should be able to power up and operate with the regulation limits defined in Table 2,
Section 2.2.1, with the following capacitances simultaneously present on the DC outputs.
Table 12. Output Capacitive Loads
Output
Capacitive Load
(PF)
+12 V1DC
+12 V2DC
+5 VDC
5,000
3,000
10,000
6,000
350
+3.3 VDC
-12 VDC
+5 VSB
350
2.2.10 Closed-loop Stability
The power supply shall be unconditionally stable under all line/load/transient load conditions including
capacitive loads specified in Section 2.2.9. A minimum of 45 degrees phase margin and 10 dB gain margin is
recommended at both the maximum and minimum loads.
2.2.11 +5 VDC / +3.3 VDC Power Sequencing
The +12 VDC and +5 VDC output levels must be equal to or greater than the +3.3 VDC output at all times
during power-up and normal operation. The time between the +12 VDC or +5 VDC output reaching its
minimum in-regulation level and +3.3 VDC reaching its minimum in-regulation level must be ≤ 20 ms.
2.2.12 Voltage Hold-up Time
The power supply should maintain output regulations per Section 2.2.1 despite a loss of input power at the
low-end nominal range—115 VAC / 57 Hz or 230 VAC / 47 Hz - at maximum continuous output load as
applicable for a minimum of 17 ms.
20
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
2.3 Timing / Housekeeping / Control
T1
T5
~
VAC
PS_ON#
~
~
+12VDC
95%
+5VDC
O/P's
}
+3.3VDC
10%
T2
T3
~
PWR_OK
T6
T4
timing_3_5_12b
PWR_OK Sense Level = 95% of nominal
Figure 7. Power Supply Timing
Notes: T1 is defined in Section 2.3.4. , T2 in Section 2.3.5. ,T3, T4, T5, and T6 are defined in Table 13.
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
2.3.1 PWR_OK
PWR_OK is a “power good” signal. This signal should be asserted high by the power supply to indicate that
the +12 VDC, +5 VDC, and +3.3 VDC outputs are above the under voltage thresholds listed in Table 2 in
Section 2.2.1 and that sufficient mains energy is stored by the converter to guarantee continuous power
operation within specification for at least the duration specified in Section 2.2.12, “Voltage Hold-up Time.”
Conversely, PWR_OK should be de-asserted to a low state when any of the +12 VDC, +5 VDC, or +3.3 VDC
output voltages falls below its under voltage threshold, or when mains power has been removed for a time
sufficiently long such that power supply operation cannot be guaranteed beyond the power-down warning
time. The electrical and timing characteristics of the PWR_OK signal are given in Table 13 and in Figure 7.
Table 13. PWR_OK Signal Characteristics
Signal Type
+5 V TTL compatible
< 0.4 V while sinking 4 mA
Between 2.4 V and 5 V output while sourcing 200 µA
1 kΩ from output to common
100 ms < T3 < 500 ms
T4 ≤ 10 ms
Logic level low
Logic level high
High-state output impedance
PWR_OK delay
PWR_OK rise time
AC loss to PWR_OK hold-up time
Power-down warning
T5 ≥ 16 ms
T6 ≥ 1 ms
2.3.2 PS_ON#
PS_ON# is an active-low, TTL-compatible signal that allows a motherboard to remotely control the power
*
supply in conjunction with features such as soft on/off, Wake on LAN , or wake-on-modem. When PS_ON# is
pulled to TTL low, the power supply should turn on the four main DC output rails: +12 VDC, +5 VDC, +3.3
VDC, and -12 VDC. When PS_ON# is pulled to TTL high or open-circuited, the DC output rails should not
deliver current and should be held at zero potential with respect to ground. PS_ON# has no effect on the +5
characteristics.
The power supply shall provide an internal pull-up to TTL high. The power supply shall also provide de-
bounce circuitry on PS_ON# to prevent it from oscillating on/off at startup when activated by a mechanical
switch. The DC output enable circuitry must be SELV-compliant.
The power supply shall not latch into a shutdown state when PS_ON# is driven active by pulses between
10ms to 100ms during the decay of the power rails.
22
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
Table 14. PS_ON# Signal Characteristics
Parameter
Minimum
Maximum
0.8 V
VIL, Input Low Voltage
0.0 V
IIL, Input Low Current (Vin = 0.4 V)
VIH, Input High Voltage (Iin = -200 µA)
VIH open circuit, Iin = 0
-1.6 mA
2.0 V
5.25 V
Hysteresis ≥ 0.3 V
Disable
≥ 2.0 V
PS is
≤ 0.8 V
PS is
disabled
enabled
Enable
5.25 = Maximum Open-
Circuit Voltage
0.8
2.0
PS_ON# Voltage
Figure 8. PS_ON# Signal Characteristics
2.3.3 +5 VSB
+5 VSB is a standby supply output that is active whenever the AC power is present. This output provides a
power source for circuits that must remain operational when the five main DC output rails are in a disabled
state. Example uses include soft power control, Wake on LAN, wake-on-modem, intrusion detection, or
suspend state activities.
The +5 VSB output should be capable of delivering a minimum of 2.0 A. at +5 V 5% to external circuits.
The power supply must be able to provide the required power during a "wake up" event. If an external USB
device generates the event, there may be peak currents as high as 2.5 A., lasting no more than 500 ms.
Over current protection is required on the +5 VSB output regardless of the output current rating. This ensures
the power supply will not be damaged if external circuits draw more current than the supply can provide.
2.3.4 Power-on Time
The power-on time is defined as the time from when PS_ON# is pulled low to when the +12 VDC, +5 VDC,
and +3.3 VDC outputs are within the regulation ranges specified in Section 2.2.1. The power-on time shall be
less than 500 ms (T1 < 500 ms).
+5 VSB shall have a power-on time of two seconds maximum after application of valid AC voltages.
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
2.3.5 Rise Time
The output voltages shall rise from ≤10% of nominal to within the regulation ranges specified in Section 2.2.1
within 0.2 ms to 20 ms (0.2 ms ≤ T2 ≤ 20 ms).
There must be a smooth and continuous ramp of each DC output voltage from 10% to 90% of its final set
point within the regulation band, while loaded as specified in Section 2.2.1.
The smooth turn-on requires that, during the 10% to 90% portion of the rise time, the slope of the turn-on
waveform must be positive and have a value of between 0 V/ms and [Vout, nominal / 0.1] V/ms. Also, for any
5 ms segment of the 10% to 90% rise time waveform, a straight line drawn between the end points of the
waveform segment must have a slope ≥ [Vout, nominal / 20] V/ms.
2.3.6 Overshoot at Turn-on / Turn-off
The output voltage overshoot upon the application or removal of the input voltage, or the assertion/de-
assertion of PS_ON#, under the conditions specified in Section 3.1, shall be less than 10% above the nominal
voltage. No voltage of opposite polarity shall be present on any output during turn-on or turn-off.
2.3.7 Reset after Shutdown
If the power supply latches into a shutdown state because of a fault condition on its outputs, the power supply
shall return to normal operation only after the fault has been removed and the PS_ON# has been cycled
OFF/ON with a minimum OFF time of one second.
2.3.8 +5 VSB at AC Power-down
After AC power is removed, the +5 VSB standby voltage output should remain at its steady state value for the
minimum hold-up time specified in Section 2.2.12 until the output begins to decrease in voltage. The
decrease shall be monotonic in nature, dropping to 0.0 V. There shall be no other disturbances of this voltage
at or following removal of AC power.
2.4 Output Protection
2.4.1 Over Voltage Protection
The over voltage sense circuitry and reference shall reside in packages that are separate and distinct from
the regulator control circuitry and reference. No single point fault shall be able to cause a sustained over
voltage condition on any or all outputs. The supply shall provide latch-mode over voltage protection as
24
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
Table 15. Over Voltage Protection
Output
Minimum
Nominal
15.0
15.0
6.3
Maximum
Unit
+12 V1DC
+12 V2DC
+5 VDC
13.4
13.4
5.74
3.76
15.6
15.6
7.0
Volts
Volts
Volts
Volts
+3.3 VDC
4.2
4.3
2.4.2 Short-circuit Protection
An output short circuit is defined as any output impedance of less than 0.1 ohms. The power supply shall
shut down and latch off for shorting the +3.3 VDC, +5 VDC, or +12 VDC rails to return or any other rail.
Shorts between main output rails and +5 VSB shall not cause any damage to the power supply. The power
supply shall either shut down and latch off or fold back for shorting the negative rails. +5 VSB must be
capable of being shorted indefinitely, but when the short is removed, the power supply shall recover
automatically or by cycling PS_ON#. The power supply shall be capable of withstanding a continuous short
circuit to the output without damage or overstress to the unit (for example, to components, PCB traces, and
2.4.3 No-load Operation
No damage or hazardous condition should occur with all the DC output connectors disconnected from the
load. The power supply may latch into the shutdown state.
2.4.4 Over Current Protection
Overload currents applied to each tested output rail cause the output to trip before reaching or exceeding 240
VA. For testing purposes, the overloaded currents should be ramped at a minimum rate of 10 A/s starting
from full load.
2.4.5 Over-temperature Protection
As an option, the power supply may include an over-temperature protection sensor, which can trip and shut
down the power supply at a preset temperature point. Such an overheated condition is typically the result of
internal current overloading or a cooling fan failure. If the protection circuit is non-latching, then it should have
hysteresis built in to avoid intermittent tripping.
2.4.6 Output Bypass
The output return may be connected to the power supply chassis, and will be connected to the system
chassis by the system components.
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
3 Mechanical
3.1 Labeling /Marking
The following is a non-inclusive list of suggested markings for each power supply unit. Product regulation
stipulations for sale into various geographies may impose additional labeling requirements.
•
Manufacturer information: manufacturer’s name, part number and lot date code, etc., in human-readable
text and/or bar code formats
•
Nominal AC input operating voltages (100-127 VAC and 200-240 VAC) and current rating certified by all
applicable safety agencies
•
•
DC output voltages and current ratings
Access warning text (“Do not remove this cover. Trained service personnel only. No user serviceable
components inside.”) must be in English, German, Spanish, French, Chinese, and Japanese with
universal warning markings
3.2 Physical Dimensions
The power supply shall be enclosed and meet the physical outline shown in Figure 9, as applicable.
26
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
3.3 Mounting Options
The TFX12V mechanical design provides two options for mounting in a system chassis. The unit can be
mounted using one of the mounting holes on the front end (non-vented end) or a chassis feature can be
designed to engage the slot provided in the bottom of the supply. In order to accommodate different system
chassis layouts, the TFX12V power supply is also designed to mount in two orientations (fan left and fan right)
Figure 11. Fan Right and Fan Left Orientations of Power Supply in a Chassis
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
3.4 Chassis Requirements
To ensure the power supply can be easily integrated, the following features should be designed into a chassis
intended to use a TFX12V power supply:
•
•
EITHER a mounting bracket to interface with the forward mounting hole on the power supply OR a
supply
Figure 12. Suggested TFX12V Chassis Cutout
Figure 13. Suggested Mounting Tab (chassis feature)
30
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
3.5 Airflow / Fan
The designer’s choice of a power supply cooling solution depends in part on the targeted end-use system
application(s). At a minimum, the power supply design must ensure its own reliable and safe operation.
Fan location/direction: In general, exhausting air from the system chassis enclosure via a power supply fan
is the preferred, most common, and most widely applicable system-level airflow solution. The location of the
fan can have a large effect on how efficiently this air is exhausted. The location of the fan shown in Figure 9
allows the fan to be located close to the processor cooling solution when used in the common fan left
configuration shown in Figure 11. This close proximity of the fan will aid in the evacuation of heated air and
helps keep the total system cooler.
recommended that a thermally sensitive fan speed control circuit be used to balance system-level thermal
and acoustic performance. The circuit typically senses the temperature of the secondary heat sink and/or
incoming ambient air and adjusts the fan speed as necessary to keep power supply and system component
temperatures within specifications. Both the power supply and system designers should be aware of the
dependencies of the power supply and system temperatures on the control circuit response curve and fan
size and should specify them carefully.
The power supply fan should be turned off when PS_ON# is de-asserted (high). In this state, any remaining
active power supply circuitry must rely only on passive convection for cooling.
Venting: In general, more venting in a power supply case yields reduced airflow impedance and improved
cooling performance. Intake and exhaust vents should be as large, open, and unobstructed as possible so as
not to impede airflow or generate excessive acoustic noise. In particular, avoid placing objects within 0.5
inches of the intake or exhaust of the fan itself. A raised wire fan grill is recommended instead of a stamped
metal vent for improved airflow and reduced acoustic noise for the intake vent. Figure 9 shows the suggested
TFX12V exhaust vent pattern.
Considerations to the previous venting guidelines are:
•
•
Openings must be sufficiently designed to meet the safety requirements described in Section 5.
sufficiently shields EMI in most power supplies, but the design should always be tested as outlined in
NOTE:
Venting in inappropriate locations can detrimentally allow airflow to bypass those areas where it is needed.
3.6 AC Connector
The AC input receptacle should be an IEC 320 type or equivalent. In lieu of a dedicated switch, the IEC 320
receptacle may be considered the mains disconnect.
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
3.7 DC Connectors
Figure 14 shows pin outs and profiles for typical TFX12V power supply DC harness connectors. The TFX12V
requires an additional two-pin, power connector.
UL Listed or recognized component appliance wiring material rated min 85 °C, 300 VDC shall be used for all
output wiring.
There are no specific requirements for output wire harness lengths, as these are largely a function of the
intended end-use chassis, motherboard, and peripherals. Ideally, wires should be short to minimize
electrical/airflow impedance and simplify manufacturing, yet they should be long enough to make all
necessary connections without any wire tension (which can cause disconnections during shipping and
handling). Recommended minimum harness lengths for general-use power supplies is 150 mm for all wire
harnesses. Measurements are made from the exit port of the power supply case to the wire side of the first
connector on the harness.
1
13
+3.3 V
+3.3 V
COM
+3.3 V
-12V
COM
PS_ON
+5V
COM
COM
+5V
COM
COM
COM
PWR_OK
NC
+5VSB
+5V
+5V
+5V
COM
+12V1
+12V2
+3.3V
Main Power Connector
Figure 14. TFX12V Connectors (Pin-side view, not to scale)
32
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
3.7.1 TFX12V Main Power Connector
*
Connector: MOLEX 39-01-2240 or equivalent
(Mating motherboard connector is Molex 44206-0007 or equivalent)
18 AWG is suggested for all wires except for the +3.3 V supply and sense return wires combined into pin 11
(22 AWG).
Pin
Signal
Color
Pin
13
Signal
Color
1
+3.3 VDC
Orange
+3.3 VDC
Orange
[13]
[+3.3 V default [Brown]
sense]
2
+3.3 VDC
COM
Orange
Black
Red
14
15
16
17
18
19
20
21
22
-12 VDC
COM
Blue
Black
Green
Black
Black
Black
NC
3
4
+5 VDC
COM
PS_ON#
COM
5
Black
Red
6
+5 VDC
COM
COM
7
Black
Gray
COM
8
PWR_OK
+5 VSB
+12 V1DC
Reserved
+5 VDC
+5 VDC
9
Purple
Yellow
Red
10
Red
11
12
+12 V1DC
+3.3 VDC
Yellow
23
24
+5 VDC
COM
Red
Orange
Black
3.7.2 Peripheral Connector(s)
*
*
Connector: AMP 1-480424-0 or MOLEX 8981-04P or equivalent.
Contacts: AMP 61314-1 or equivalent.
Pin
1
Signal
+12 V1DC
COM
18 AWG Wire
Yellow
Black
2
3
COM
Black
4
+5 VDC
Red
3.7.3 Floppy Drive Connector
*
Connector: AMP 171822-4 or equivalent
Pin
1
Signal
+5 VDC
COM
20 AWG Wire
Red
2
Black
3
COM
Black
4
+12 V1DC
Yellow
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
3.7.4 +12 V Power Connector
*
*
Connector: MOLEX 39-01-2040 or equivalent (Mating motherboard connector is Molex
39-29-9042 or equivalent)
Pin
1
Signal
COM
COM
18 AWG Wire
Black
Pin
3
Signal
18 AWG Wire
+12 V2DC
+12 V2DC
Yellow /Black Stripe
Yellow /Black Stripe
2
Black
4
3.7.5 Serial ATA Power Connector
This is an optional connector for systems with Serial ATA devices.
The detailed requirements for the Serial ATA Power Connector can be found in the “Serial ATA: High Speed
Serialized AT Attachment” specification, Section 6.3 “Cables and connector specification”
*
Connector: MOLEX 88751 or equivalent.
Wire Signal
18 AWG Wire
Orange
Black
5
4
3
2
+3.3 VDC
COM
+5 VDC
COM
Red
Black
1
+12 V1DC
Yellow
Wire#
5
4
3
2
1
Figure 15. Serial ATA Connector
34
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
4 Environmental
The following subsections define recommended environmental specifications and test parameters, based on
the typical conditions a TFX12V power supply unit may be subjected to during operation or shipment.
4.1 Temperature
Operating ambient: +10 °C to +50 °C (At full load, with a maximum temperature rate of change of 5 °C/10
minutes, but no more than 10 °C/hr.)
Non-operating ambient: -40 °C to +70 °C (Maximum temperature rate of change of 20 °C/hr.)
4.2 Thermal Shock (Shipping)
Non-operating: -40 °C to +70 °C
15 °C/min ≤ Dt/dt ≤ 30 °C/min. Tested for 50 cycles; Duration of exposure to temperature extremes for
each half cycle shall be 30 minutes.
4.3 Relative Humidity
Operating: To 85% relative humidity (non-condensing)
Non-operating: To 95% relative humidity (non-condensing)
Note: 95% RH is achieved with a dry bulb temperature of 55 °C and a wet bulb temperature of 54 °C.
4.4 Altitude Requirement
Operating: To 10,000 ft
Non-operating: To 50,000 ft
4.5 Mechanical Shock
Non-operating: 50 g, trapezoidal input; velocity change ≥ 170 in/s
Three drops on each of six faces are applied to each sample.
35
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
4.6 Random Vibration
Non-operating: 0.01 g²/Hz at 5 Hz, sloping to 0.02 g²/Hz at 20 Hz, and maintaining 0.02 g²/Hz from 20 Hz to
500 Hz. The area under the PSD curve is 3.13 gRMS. The duration shall be 10 minutes per axis for all three
axes on all samples.
4.7 Acoustics
Sound Power: The power supply assembly shall not produce a declared sound power level greater than 3.8
BA. Sound power determination is to be performed at 43C, 50% of rated load, at sea level. This test point is
chosen to represent the environment seen inside a typical system at the idle acoustic test condition, with the
43C being derived from the standard ambient assumption of 23C, with 20C added for the temperature
rise within the system (what is typically seen by the inlet fan). The declared sound power level shall be
measured according to ISO 7779 and reported according to ISO 9296.
Pure Tones: The power supply assembly shall not produce any prominent discrete tone determined
according to ISO 7779, Annex D.
4.8 Ecological Requirements
The following materials must not be used during design and/or manufacturing of this product:
•
•
•
•
Cadmium shall not be used in painting or plating.
Quaternary salt and PCB electrolytic capacitors shall not be used.
CFC’s or HFC’s shall not be used in the design or manufacturing process.
Mercury shall not be used.
36
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
5 Safety
The following subsections outline sample product regulations requirements for a typical power supply. Actual
requirements will depend on the design, product end use, target geography, and other variables. Consult
your company’s Product Safety and Regulations department for more details.
5.1 North America
The power supply must be certified by an NRTL (Nationally Recognized Testing Laboratory) for use in the
USA and Canada under the following conditions:
•
•
The supply must be recognized for use in Information Technology Equipment including Electrical
Business Equipment per UL 60950, 3rd edition, 2000. The certification must include external enclosure
testing for the AC receptacle side of the power supply.
The supply must have a full complement of tests conducted as part of the certification, such as input
current, leakage current, hi-pot, temperature, energy discharge test, transformer output characterization
test (open-circuit voltage, short-circuit current, and maximum VA output), and abnormal testing (to include
stalled-fan tests and voltage-select–switch mismatch).
•
The enclosure must meet fire enclosure mechanical test requirements per clauses 2.9.1 and 4.2 of the
above-mentioned standard.
100% production HiPot testing must be included and marked as such on the power supply enclosure.
There must not be unusual or difficult conditions of acceptability such as mandatory additional cooling or
power de-rating. The insulation system shall not have temperatures exceeding their rating when tested in the
end product.
The certification mark shall be marked on each power supply.
The power supply must be evaluated for operator-accessible secondary outputs (reinforced insulation) that
meet the requirements for SELV and do not exceed 240 VA under any condition of loading.
The proper polarity between the AC input receptacle and any printed wiring boards connections must be
maintained (that is, brown=line, blue=neutral, and green or green/yellow =earth/chassis).
Failure of any single component in the fan-speed control circuit shall not cause the internal component
temperatures to exceed the abnormal fault condition temperatures per the IEC 60950 3rd ed., 1999
Specification.
5.2 International
The vendor must provide a complete CB certificate and test report to IEC 60950: 3rd ed., 1999 . The CB
report must include ALL CB member country national deviations. CB report must include evaluation to EN
60950: 2000. All evaluations and certifications must be for reinforced insulation between primary and
secondary circuits.
37
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
6 Electromagnetic Compatibility
The following subsections outline applicable product regulatory requirements for the TFX12V power supply.
Additional requirements may be applied dependent upon the design, product end use (e.g., medical
equipment and hazardous locations), target geography, and other variables.
6.1 Emissions
The power supply shall comply with FCC Part 15, EN55022: 1998 and CISPR 22: 1997, meeting Class B for
both conducted and radiated emissions with a 4 dB margin. Tests shall be conducted using a shielded DC
output cable to a shielded load. The load shall be adjusted as follows for three tests: No load on each output;
50% load on each output; 100% load on each output. Tests will be performed at 100 VAC 50Hz, 120 VAC 60
Hz, and 230 VAC 50 Hz power.
6.2 Immunity
The power supply shall comply with EN 55024:1998 and CISPR 24 specifications prior to sale in the EU
(European Union), Korea, and possibly other geographies.
38
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12-V Connector
Version 2.0
6.3 Input Line Current Harmonic Content
For sales in the EU (European Union) the power supply shall meet the requirements of
EN61000-3-2 Class D and the Guidelines for the Suppression of Harmonics in Appliances and General Use
Equipment Class D for harmonic line current content at full rated power. See Table 16 for the harmonic limits.
Table 16. Harmonic Limits, Class D Equipment
Per: EN 61000-3-2
Per: JEIDA MITI
Maximum permissible Harmonic
current at 230 VAC / 50 Hz in Amps
Maximum permissible Harmonic
current at 100VAC / 50 Hz in Amps
Harmonic Order n
Odd harmonics
3
2.3
5.29
5
1.14
2.622
7
0.77
1.771
9
0.4
0.92
11
0.33
0.759
13
0.21
0.483
0.15 x (15/n)
0.345 x (15/n)
15≤ n ≤39
6.4 Magnetic Leakage Fields
A PFC choke magnetic leakage field should not cause any interference with a high-resolution computer
monitor placed next to or on top of the end-use chassis.
6.5 Voltage Fluctuations and Flicker
The power supply shall meet the specified limits of the EN61000-3-3 Specification for voltage fluctuations and
flicker for equipment drawing not more then16 AAC, connected to low voltage distribution systems.
39
Download from Www.Somanuals.com. All Manuals Search And Download.
TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
7 System Cooling Considerations
The power supply fan location allows the system designer to utilize the airflow to help cool critical components
such as the processor and chipset. Please note that the fan pulls air from the system, instead of blowing hot
air in, so components must be placed such that airflow is directed across critical components. Cables, etc
must not impede airflow.
8 Reliability
The de-rating process promotes quality and high reliability. All electronic components should be designed
with conservative device d-ratings for use in commercial and industrial environments.
9 Applicable Documents
The following documents support this design guide as additional reference material.
Document Title
Description
FCC Rules Part 15, Class B
ICES-003: 1997, Class B
Title 47, Code of Federal Regulations, Part 15
Interference-Causing Equipment Standard – Digital Apparatus
EN 55022: 1998 +
Information Technology Equipment – Radio disturbance characteristics –
Amendment A1:2000 Class B
Limits and methods of measurement
Information Technology Equipment – Radio disturbance characteristics –
Limits and methods of measurement
CISPR 22: 1997, Class B
AS/NZS 3548:1995, Class B
EN 55024:1998
Information Technology Equipment – Radio disturbance characteristics –
Limits and methods of measurement
Information Technology Equipment – Immunity Characteristics – Limits and
methods of measurement
IEC 60950, 3rd ed., 1999
EN 60950: 2000
UL 60950, 3rd ed., 2000
Safety of Information Technology Equipment
Safety of Information Technology Equipment
Safety of Information Technology Equipment
Safety of Information Technology Equipment
CSA 22.2 No. 60950-00
40
Download from Www.Somanuals.com. All Manuals Search And Download.
|