User’s Guide
November 1998
Mixed-Signal Products
SLOU026A
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Preface
Related Documentation From Texas Instruments
TI Plug-N-Play Audio Amplifier Evaluation Platform (literature
number SLOU011) provides detailed information on the evaluation
platform and its use with TI audio evaluation modules.
TPA701 700-mW LOW-VOLTAGE AUDIO POWER AMPLIFIER
(literature number SLOS229) This is the data sheet for the TPA701
audio amplifier integrated circuit.
FCC Warning
This equipment is intended for use in a laboratory test environment only. It
generates, uses, and can radiate radio frequency energy and has not been
tested for compliance with the limits of computing devices pursuant to subpart
J of part 15 of FCC rules, which are designed to provide reasonable protection
against radio frequency interference. Operation of this equipment in other
environments may cause interference with radio communications, in which
case the user at his own expense will be required to take whatever measures
may be required to correct this interference.
Trademarks
TI is a trademark of Texas Instruments Incorporated.
iii
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iv
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Contents
1
2
3
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.1
1.2
1.3
Feature Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
TPA701 EVM Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Quick Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.1
2.2
2.3
Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Quick Start List for Platform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Quick Start List for Stand-Alone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.1
3.2
Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
The TPA701 MSOP Audio Amplifier Evaluation Module . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3.2.1 TPA701 Audio Amplifier IC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3.2.2 BTL Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3.2.3 Module Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3.2.4 Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Using The TPA701 MSOP EVM With The Plug-N-Play Evaluation Platform . . . . . . . . . 3-6
3.3.1 Installing and Removing EVM Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
3.3.2 Signal Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
3.3.3 Mute/Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
3.3.4 Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
3.3.5 Inputs and Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Using The TPA701 MSOP EVM Stand-ALone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
3.4.1 TPA701 MSOP EVM Connected for BTL Output . . . . . . . . . . . . . . . . . . . . . . . . 3-11
TPA701 MSOP Audio Amplifier Evaluation Module Parts List . . . . . . . . . . . . . . . . . . . . 3-12
3.3
3.4
3.5
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Figures
1–1
2–1
2–2
3–1
3–2
3–3
3–4
3–5
3–6
3–7
3–8
The TI TPA701 MSOP Audio Amplifier Evaluation Module . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Quick Start Platform Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Quick Start Module Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
The TI Plug-N-Play Audio Amplifier Evaluation Platform . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
TPA701 MSOP EVM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
TPA701 MSOP EVM Schematic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
TPA701 Audio Amplifier IC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Platform Signal Routing and Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Mute/Mode and Polarity Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
Typical Headphone Plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
TPA701 MSOP EVM Connected for Stereo BTL Output . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Tables
2–1
Typical TI Plug-N-Play Platform Jumper and Switch Settings for the
TPA701 MSOP EVM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2–2
3–1
Platform Jumper and Switch Settings for the TPA701 MSOP EVM . . . . . . . . . . . . . . . . . . . 2-3
TPA701 MSOP EVM Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
vi
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Chapter 1
Introduction
This chapter provides an overview of the Texas Instruments (TI ) TPA701
MSOPAudio Amplifier Evaluation Module (SLOP213). It includes a list of EVM
features, a brief description of the module illustrated with a pictorial diagram,
and a list of EVM specifications.
Topic
Page
1.1 Feature Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–2
1.2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–3
1.3 TPA701 MSOP EVM Specifications . . . . . . . . . . . . . . . . . . . . . . . . . 1–4
1-1
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Feature Highlights
1.1 Feature Highlights
The TI TPA701 MSOP Audio Amplifier Evaluation Module and the TI
Plug-N-Play Audio Amplifier Evaluation Platform include the following
features:
TPA701 Low-Voltage Audio Power Amplifier Evaluation Module
Single channel, bridge-tied load (BTL)
3.3-V and 5-V operation
700-mW output power into 8 Ω at 5 V, BTL
Ultra-low current consumption in shutdown mode
Internal thermal and short-circuit protection
Module gain is set at –4 V/V in BTL mode, –2 V/V in SE mode
Quick and Easy Configuration with The TI Plug-N-Play Audio Amplifier
Evaluation Platform
Evaluation module is designed to simply plug into the platform,
automatically making all signal, control, and power connections
Platform provides flexible power options
Jumpers on the platform select power and module control options
Switches on the platform route signals
Platform provides quick and easy audio input and output connections
Platform Power Options
On-board 9-V battery
External 5-V – 15-V (V ) supply inputs
CC
External regulated V
supply input
DD
Socket for on-board 5 V/3.3 V V
voltage regulator EVM
DD
On-board overvoltage and reverse polarity power protection
Platform Audio Input and Output Connections
Left and right RCA phono jack inputs
Miniature stereo phone jack input
Left and right RCA phono jack outputs
Left and right compression speaker terminal outputs
Miniature stereo headphone jack output
1-2
Introduction
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Description
1.2 Description
The TPA701 MSOP Audio Power Amplifier Evaluation Module is a complete,
low-power single-channel audio power amplifier. It consists of the TI TPA701
700-mW Low-Voltage Audio Power Amplifier IC in a very small MSOP
package, along with a small number of other parts mounted on a circuit board
that is approximately one and a quarter inches square (Figure 1–1).
Figure 1–1. The TI TPA701 Audio Amplifier Evaluation Module
Vdd GND
Shutdown
+
C3
S1
R1
C1
†
U1
C4
OUT–
GND
R2
C2
OUT+
R3
C5
TEXAS
INSTRUMENTS
IN
SLOP213
TPA701 MSOP EVM
GND
†
Due to the very small size of the MSOP IC package, the standard part number TPA701 is replaced with the code TIABA.
Single in-line header pins are mounted to the underside of the module circuit
board to allow the EVM to be plugged into the TI Plug-N-Play Audio Amplifier
Evaluation Platform or to be wired directly into existing circuits and equipment
when used stand-alone.
The platform has room for a pair of TPA701 MSOP evaluation modules and
is a convenient vehicle for demonstrating TI’s audio power amplifier and
related evaluation modules. The EVMs simply plug into the platform, which
automatically provides power to the modules, interconnects them correctly,
andconnectsthemtoaversatilearrayofstandardaudioinputandoutputjacks
and connectors. Easy-to-use configuration controls allow the platform and
EVMs to quickly model many possible end-equipment configurations.
There is nothing to build, nothing to solder, and nothing but the speakers
included with the platform to hook up.
1-3
Introduction
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TPA701 EVM Specifications
1.3 TPA701 EVM Specifications
Supply voltage range, V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 V to 5.5 V
DD
Supply current, I
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450 mA, max
DD
Continuous output power, P : 8-Ω BTL, V =5 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 700 mW
O
DD
Audio input voltage, V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Vpp, max
I
Minimum load impedance, R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Ω
L
1-4
Introduction
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Chapter 2
Quick Start
ThestepsinthischaptercanbefollowedtoquicklypreparetheTPA701MSOP
audio amplifier EVM for use. Using the TPA701 MSOP EVM with the TI
Plug-N-Play Audio Amplifier Evaluation Platform is a quick and easy way to
connect power, signal and control inputs, and signal outputs to the EVM, using
standard connectors. However, the audio amplifier evaluation module can be
usedstand-alonebymakingconnectionsdirectlytothemodulepins, anditcan
be wired directly into existing circuits or equipment.
The platform switch and jumper settings shown in Table 2–1 are typical for the
TPA701 MSOP EVM. They will cause the TPA701 device to shutdown when
a plug is inserted into platform headphone jack J10.
Table 2–1. Typical TI Plug-N-Play Platform Jumper and Switch Settings for the TPA701
MSOP EVM
EVM
JP6
JP7
JP8
S2
S3
TPA701
Mute
X
Hi
Note 2
X
Notes: 1) X = Don’t care
2) Set S2 to ON when signal conditioning board is installed in U1; set S2
to OFF when no signal conditioning board is installed.
Topic
Page
2.1 Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–2
2.2 Quick Start List for Platform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–3
2.3 Quick Start List for Stand-Alone . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–4
2-1
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Precautions
2.1 Precautions
Power Supply Input Polarity and Maximum Voltage
Always ensure that the polarity and voltage of the external power
connected to V
power input connector J1, J2, and/or V
power
CC
DD
input connector J6 are correct. Overvoltage or reverse-polarity
power applied to these terminals can open on-board soldered-in
fuses and cause other damage to the platform, installed evaluation
modules, and/or the power source.
Inserting or Removing EVM Boards
Do not insert or remove EVM boards with power applied – damage
to the EVM board, the platform, or both may result.
Figure 2–1. Quick Start Platform Map
6b
6b
6b
1
10
F1
ICC
JP4
C1+
VR1
6a
DC
6b
Power
In/Out
Power
Input
R2
R1
Audio
Power
Amps
Signal Conditioning
8
9
Audio
Input
Speaker
Output
5
Mode
Mute
4
Polarity
****CAUTION****
Lo
Hi
Do not insert or remove
EVM boards with power
applied
Stereo
Headphone
Output
Plug-N-Play Audio Amplifier
Evaluation Platform
SLOP097 Rev. C.1
HP Out
R3
R4
R5
2
3
2-2
Quick Start
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Quick Start List for Platform
2.2 Quick Start List for Platform
Follow these steps when using the TPA701 MSOP EVM with the TI
Plug-N-Play Audio Amplifier Evaluation Platform (see the platform user’s
guide, SLOU011, for additional details). Numbered callouts for selected steps
are shown in Figure 2–1 and details appear in Chapter 3.
Platform preparations
1) EnsurethatallexternalpowersourcesaresettoOFF andthattheplatform
power switch S1 is set to OFF.
2) Install a TPA701 MSOP module in platform sockets U3 and U4 for stereo
operation (or a module in either U3 or U4 for single channel operation),
taking care to align the module pins correctly.
3) Use switch S2 to select or bypass the signal conditioning EVM (U1).
4) Set control signal Polarity jumper JP8 to Hi.
5) Set jumper JP6 to select the Mute control input (causes the TPA701 to
shutdown if a plug is inserted into platform headphone jack J10).
Table 2–2. Platform Jumper and Switch Settings for the TPA701 MSOP EVM
EVM
JP6
JP7
JP8
S2
S3
TPA701
Mute
X
Hi
Note 2
X
Notes: 1) X = Don’t care
2) Set S2 to ON when signal conditioning board is installed in U1; set S2
to OFF when no signal conditioning board is installed.
Power supply
6) Select and connect the power supply:
a) Connect an external regulated power supply set to a voltage between
2.5 V and 5.5 V to platform V power input connector J6, taking care
DD
to observe marked polarity, or
b) Install a voltage regulator EVM (SLVP097 or equiv.) in platform socket
U6. Install a 9-V battery in B1 or connect a 7 V – 12 V power source
to a platform V
power input (see platform user’s guide).
power input J1 or J2 and jumper the appropriate
CC
Inputs and outputs
7) Ensure that signal source level is set to minimum.
8) Connect the audio source to left and right RCA phono jacks J3 and J5 or
stereo miniature phone jack J4.
9) Connect 8-Ω – 32-Ω speakers to left and right RCA jacks J7 and J9 or to
stripped wire connectors J8.
Power-up
10) Verify correct voltage and input polarity and set the external power supply
to ON. If V and an on-board regulator EVM are used to provide V , set
CC
DD
platform power switch S1 to ON.
Platform LED2 should light indicating the presence of V , and the evaluation
DD
modules installed on the platform should begin operation.
11) Adjust the signal source level as needed.
2-3
Quick Start
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Quick Start List for Stand-Alone
2.3 Quick Start List for Stand-Alone
Follow these steps to use the TPA701 MSOP EVM stand-alone or when
connecting it into existing circuits or equipment. Connections to the TPA701
MSOP module header pins can be made via individual sockets,
wire-wrapping, or soldering to the pins, either on the top or the bottom of the
module circuit board. Numbered callouts for selected steps are shown in
Figure 2–2 and details appear in Chapter 3.
Figure 2–2. Quick Start Module Map
2
Vdd GND
Shutdown
+
C3
5
S1
R1
C1
†
U1
C4
OUT–
GND
6
R2
C2
OUT+
R3
C5
TEXAS
INSTRUMENTS
IN
4
SLOP213
TPA701 MSOP EVM
GND
†
Due to the very small size of the MSOP IC package, the standard part number TPA701 is replaced with the code TIABA
Power supply
1) Ensure that all external power sources are set to OFF.
2) Connect an external regulated power supply set to 5 V to the module Vdd
and GND pins, taking care to observe marked polarity.
Inputs and outputs
3) Ensure that the signal source level is set to minimum.
4) Connect the audio source to the module IN and GND pins, taking care to
observe marked polarity.
5) Connect the Shutdown (S1) pin to V
through a Normally Open switch.
DD
6) Connect an 8-Ω – 32-Ω speaker to the module OUT+ and OUT– pins.
Power-up
7) Verify correct voltage and input polarity and set the external power supply
to ON.
The EVM should begin operation.
8) Adjust the signal source level as needed.
2-4
Quick Start
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Chapter 3
Details
This chapter provides details on the TPA701 IC, the evaluation module, the
steps in the Quick-Start List, additional application information, and a parts list
for the TPA701 MSOP evaluation module.
Topic
Page
3.1 Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–2
3.2 The TPA701 MSOP Audio Power Amplifier Evaluation Module . . 3–3
3.3 Using The TPA701 MSOP EVM With The Plug-N-Play
Evaluation Platform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–6
3.4 Using The TPA701 MSOP EVM Stand-Alone . . . . . . . . . . . . . . . . . . . . 3–11
3.5 TPA701 MSOP Audio Power Amplifier Evaluation
Module Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–12
3-1
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Precautions
3.1 Precautions
Power Supply Input Polarity and Maximum Voltage
Always ensure that the polarity and voltage of the external power
connected to V
power input connector J1, J2, and/or V
power
CC
DD
input connector J6 are correct. Overvoltage or reverse-polarity
power applied to these terminals can open on-board soldered-in
fuses and cause other damage to the platform, installed evaluation
modules, and/or the power source.
Inserting or Removing EVM Boards
Do not insert or remove EVM boards with power applied – damage
to the EVM board, the platform, or both may result.
Figure 3–1. The TI Plug-N-Play Audio Amplifier Evaluation Platform
F1
ICC
JP4
C1+
VR1
DC
Power
In/Out
Power
Input
R2
R1
Audio
Power
Amps
Signal Conditioning
Audio
Input
Speaker
Output
Mode
Mute
Polarity
****CAUTION****
Lo
Hi
Do not insert or remove
EVM boards with power
applied
Stereo
Headphone
Output
Plug-N-Play Audio Amplifier
Evaluation Platform
SLOP097 Rev. C.1
HP Out
R3
R4
R5
3-2
Details
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The TPA701 MSOP Audio Power Amplifier Evaluation Module
3.2 The TPA701 MSOP Audio Power Amplifier Evaluation Module
The TPA701 MSOP Audio Power Amplifier Evaluation Module is powered by
a TPA701 700-mW Low-Power Audio Amplifier IC and includes an on-board
shutdown control signal switch.
The module can be used with the TI Plug-N-Play Audio Amplifier Evaluation
Platform (Figure 3–1) or wired directly into circuits or equipment. The module
has single in-line header connector pins mounted to the under side of the
board. These pins allow the module to be plugged into the TI platform, which
automatically makes all the signal input and output, power, and control
connections to the module.
The module connection pins are on 0.1-inch centers to allow easy use with
standard perf board and plug board-based prototyping systems. Or, the EVM
can be wired directly into existing circuits and equipment when used
stand-alone.
The module appears in Figure 3–2 and its schematic is shown in Figure 3–3.
Figure 3–2. TPA701 MSOP EVM
Vdd GND
C3
Shutdown
+
S1
R1
C1
†
U1
C4
OUT–
GND
R2
C2
OUT+
R3
C5
TEXAS
INSTRUMENTS
IN
SLOP213
TPA701 MSOP EVM
GND
†
Due to the very small size of the MSOP IC package, the standard part number TPA701 is replaced with the code TIABA
Figure 3–3. TPA701 MSOP EVM Schematic Diagram
VDD
2.5 V to 5.5 V
GND
C3
10 µF
+
S1
No
1
2
3
8
7
6
Shutdown V
Shutdown
O–
R1
20 kΩ
Bypass GND
C1
1 µF
OUT–
GND
In+
In–
V
DD
C4
1 µF
4
5
V
O+
OUT+
C2
1 µF
C5
5 pF
R3
39 kΩ
Audio Input–
GND
R2
20 kΩ
3-3
Details
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The TPA701 MSOP Audio Power Amplifier Evaluation Module
3.2.1 TPA701 Audio Amplifier IC
The TPA701 audio amplifier IC is a CMOS device intended for bridge-tied load
(BTL) operation in battery-powered applications. It is supplied in a very small
surface-mount package and has been designed to operate from low supply
voltages (between approximately 2.5 V and 5.5 V) and deliver up to
approximately 700 mW into an 8-Ω, BTL (Figure 3–4). Typical applications
include portable phones, toys, games, and similar hand-held audio
applications.
Figure 3–4. TPA701 Amplifier IC
4
_
+
5
IN –
3
OUT+
IN+
6
V
2
DD
V
DD
/2
_
+
BYPASS
7
8
OUT–
GND
1
Bias Control
SHUTDOWN
The IC includes two separate internal amplifiers. The two amplifiers operate
as mirror images of each other for increased power. BTL operation provides
many benefits, including quadruple the output power of single-ended
operation and no need for bulky output coupling capacitors. For more
information, see the TPA701 amplifier IC data sheet, TI Literature Number
SLOS229.
3.2.2 BTL Operation
The output signal from OUT+ must go through the speaker load and be
returned directly to OUT–, and NOT to system ground. This requires that the
OUT– line be isolated not only from system ground, but also from the OUT–
lines of any other amplifiers in the system. The platform provides such isolated
output lines from the amplifier EVM sockets directly to separate left and right
speaker connectors.
3.2.3 Module Gain
The TPA701 MSOP evaluation module has a set gain of 2. However, the gain
can be adjusted to a maximum of 22 by changing the value of resistor R3
(Figure 3–3). Use the following equation to determine value of R
3:
–R
3
Gain
2 for BTL
R
2
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The TPA701 MSOP Audio Power Amplifier Evaluation Module
The TPA701 amplifier IC, like most other amplifiers, exhibits its best distortion
and noise performance at lower gain levels (see the TPA701datasheet). Even
so, the TPA701 at its highest gain setting has significantly less distortion than
most low-cost speakers.
Gain versus total harmonic distortion (THD) should be considered in each
application. Both the module input signal level and the TPA701 MSOP module
gain should be adjusted to obtain the lowest overall distortion level for a
particular overall gain. A quick rule of thumb (everything else being equal): the
module input signal level should be as high as possible without clipping or
overloading the TPA701 input, and the TPA701 gain should be kept as low as
possible.
3.2.4 Shutdown
When the shutdown terminal of the TPA701 amplifier IC is taken high, the IC
ceases operation and enters an ultra-low power state. This is accomplished
by applying a control signal to the module Shutdown pin or by pressing the
Shutdown switch, S1, on the module. When the control signal goes low or is
removed (or the switch is released), amplifier operation resumes.
The Plug-N-Play platform can generate the shutdown (mute) signal for the
module either when a plug is inserted into the platform headphone output jack
or when the plug is removed, as selected by a platform jumper (JP8).
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Using The TPA701 MSOP EVM With the Plug-N-Play Evaluation Platform
3.3 Using The TPA701 MSOP EVM With the Plug-N-Play Evaluation Platform
The TPA701 MSOP Audio Amplifier Evaluation Module was designed to be
used with the TI Plug-N-Play Audio Amplifier Evaluation Platform. It simply
plugs into socket U3 or U4.
The following paragraphs provide additional details for using the TPA701
MSOP EVM with the platform.
3.3.1 Installing and Removing EVM Boards
TI Plug-N-Play evaluation modules use single-in-line header pins installed on
the underside of the module circuit board to plug into sockets on the platform.
The EVM pins and the platform sockets are keyed such that only the correct
type of EVM can be installed in a particular socket, and then only with the
proper orientation.
Evaluation modules are easily removed from the platform by simply prying
them up and lifting them out of their sockets. Care must be taken, however, to
prevent bending the pins.
3.3.1.1 EVM Insertion
1) Remove all power from the evaluation platform.
2) Locate socket U3 or U4 on the platform.
3) Orient the module correctly.
4) Carefully align the pins of the module with the socket pin receptacles.
5) Gently press the module into place.
6) Check to be sure that all pins are seated properly and that none are bent
over.
3.3.1.2 EVM Removal
1) Remove all power from the evaluation platform.
2) Using an appropriate tool as a lever, gently pry up one side of the module
a small amount.
3) Change to the opposite side of the module and use the tool to pry that side
up a small amount.
4) Alternate between sides, prying the module up a little more each time to
avoid bending the pins, until it comes loose from the socket.
5) Lift the EVM off of the platform.
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Using The TPA701 MSOP EVM With the Plug-N-Play Evaluation Platform
3.3.2 Signal Routing
Signal flow on the platform is controlled by two signal routing switches, as
shown in Figure 3–5.
Figure 3–5. Platform Signal Routing and Outputs
Off
U3
TPA701
Amplifier EVM
+
–
R
R
L
R
J7, J8, J9
Speaker
Outputs
U1
Signal
Conditioning
Audio
Input
S2
U4
TPA701
Amplifier EVM
–
+
L
L
On
U2–U4
R
+
–
R
U5
Stereo
Headphone
Amplifier
J10
Headphone
Output
GND
S3
L
–
+
L
U5
3.3.2.1 Signal Conditioning
The audio signal from the input jacks can be applied to the signal conditioning
socket (U1) if an EVM is installed there, or socket U1 can be bypassed and the
audioinputsignalapplieddirectlytotheinputsoftheTPA701poweramplifiers.
Switch S2 selects signal conditioning or bypasses it
3.3.3 Mute/Mode
The TPA701 MSOP EVM is equipped with a shutdown (mute) control input pin.
When this input is tied to V , the TPA701 amplifier IC on the module shuts
DD
down and assumes an ultra-low power mode. When the EVM control input is
tied to GND or allowed to float, amplifier operation resumes.
In typical applications, as often found in notebook computers, portable audio
products, and such, the internal speakers mute when headphones are
plugged into the headphone jack, or internal speakers mute when external
speakers are connected. In applications using separate speaker and
headphone amplifiers, the one not being used can be shut down (muted) to
conserve power.
3.3.3.1 Headphone Jack Control Signals
The platform headphone output jack (J10) contains an internal switch that
changesthestateofapairofcontrollineswhenaplugisinserted(Figure3–6).
Each control line is pulled down by a 1-kΩ resistor to ground (R4 and R5). The
switch in the headphone jack pulls one line or the other up to V
through a
DD
240 Ω resistor (R3) depending on whether or not a plug is inserted in J10.
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Using The TPA701 MSOP EVM With the Plug-N-Play Evaluation Platform
Figure 3–6. Mute/Mode and Polarity Control
V
DD
R3
240 Ω
Polarity
JP8
JP6
Mode
Mute
Lo
U3, U4
Power
Amplifiers
J10
Headphone
Jack
Hi
R4
1 kΩ
R5
1 kΩ
SPK
(U2–U4)
3.3.3.2 Mute/Mode Select (JP6)
A 3-pin jumper header (JP6) on the platform, functioning as a SPDT switch,
routes the control signal from the headphone jack to either the mute control
input pin or the mode control input pin of the evaluation module.
To mute the TPA701 MSOP amplifier module using the control signal
from the platform headphone jack, jumper JP6 to MUTE.
To not affect the TPA701 amplifier when a plug is inserted into the
headphone jack, jumper JP6 to Mode or leave JP6 unjumpered.
3.3.3.3 Mute/Mode Polarity Select (JP8)
A second 3-pin jumper header (JP8) on the platform selects the control signal
polarity by connecting either the active-high or the active-low line from the
headphone jack to jumper JP6.
When JP6 is set to Mute, use the following JP8 settings for the TPA701:
To mute the TPA701 MSOP amplifier module when a plug is inserted
into the headphone jack, jumper JP8 to Hi (this is the typical setting).
To mute the TPA701 MSOP amplifier module until a plug is inserted
into the headphone jack, jumper JP8 to Lo.
When JP6 is set to Mode, the TPA701 amplifier is unaffected by the inser-
tion of the headphone plug.
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Power Requirements
3.3.4 Power Requirements
The TPA701 MSOP Audio Power Amplifier Evaluation Module can operate
from any voltage between approximately 2.5 V and 5.5 V; however, the
TPA701 amplifier IC on the module is characterized for operation at 3.3 V and
5 V. For best performance (highest output power with lowest distortion), the
module should be operated at approximately 5 V, unless there is a specific
reason for operating it from a lower voltage.
The TI Plug-N-Play Audio Amplifier Evaluation Platform with a voltage
regulator EVM installed on it can provide a regulated V
supply from a wide
DD
variety of unregulated V
voltage inputs between approximately 5.5 V and
CC
12 V, including an on-board 9-V battery. Or, an external regulated power
source can be used to supply V voltage to the platform and the TPA701
DD
MSOP evaluation modules installed on it.
The platform is equipped with overvoltage and reverse-polarity supply voltage
input protection in the form of fused crowbar circuits.
V
voltage applied to platform screw terminals J6 MUST NOT exceed
DD
the absolute maximum rating for the TPA701 amplifier IC installed on the
evaluation module (6 V) or damage to the IC may result. In no case should
V
voltage of the incorrect polarity or in excess of 6.1 V be applied to
DD
screw terminals J6 of the platform, or the power protection circuit on the
V
line will trip.
DD
V
voltage applied to the platform MUST NOT exceed the maximum
CC
voltage input specified for the voltage regulator module installed in socket
U6 (12 V for the SLVP097), or damage to the voltage regulator module
may result. In no case should V
voltage applied to the platform exceed
CC
15 V, or the overvoltage protection circuit on the V
bus will trip.
CC
3.3.5 Inputs and Outputs
The TI Plug-N-Play Audio Amplifier Evaluation Platform is equipped with
several standard conectors for audio inputs and outputs.
3.3.5.1 Inputs
In most cases, audio signals enter the platform through either a pair of RCA
phono jacks (J3 and J5) or a miniature (1/8″) stereo phone jack (J4). Certain
signal conditioning and amplifier EVMs, however, may have additional signal
input connectors mounted on the module circuit board.
The platform audio signal input jacks (J3, J4, and J5) are of the closed-circuit
type, grounding the signal input lines when no plugs are inserted.
3.3.5.2 Outputs
Amplified audio output signals leave the platform through left and right RCA
phono jacks (J7 and J9), left and right pairs of compression connectors for
stripped speaker wires (J8).
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Inputs and Outputs
The audio output lines from the power amplifiers are separate all the way to
the edge of the platform (output jacks J7, J8, and J9)—the OUT– lines from
the power amplifier sockets are not tied to each other or to platform ground.
This allows the TPA701 power amplifier EVMs to operate in the highly-efficient
bridge-tied load configuration.
Figure 3–7. Typical Headphone Plug
Left
Right
GND
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Using The TPA701 MSOP EVM Stand-Alone
3.4 Using The TPA701 MSOP EVM Stand-Alone
Using the TPA701 MSOP Audio Power Amplifier Evaluation Module
stand-alone is much the same as using it with the platform. The same 2.5-V
to 5.5-V power supply range and the isolated OUT+ and OUT– lines for BTL
operation requirement exists.
Note that the mute signal applied to the EVM shutdown pins must be able to
supply enough current to overcome the pulldown resistors on the modules
(20 kΩ || 20 kΩ for two EVMs).
3.4.1 TPA701 MSOP EVM Connected for BTL Output
Figure 3–8. TPA701 MSOP EVM Connected for Stereo BTL Output
5 VDC
Vdd GND
Shutdown
+
C3
S1
R1
C1
†
U1
C4
OUT–
GND
Right
R2
C2
OUT+
R3
C5
TEXAS
INSTRUMENTS
Audio
Input
(Right)
IN
SLOP213
TPA701 MSOP EVM
GND
5 VDC
GND
Vdd GND
Shutdown
External Mute
Control
+
C3
S1
(active high)
R1
C1
†
U1
C4
OUT–
GND
Left
R2
C2
OUT+
R3
C5
TEXAS
INSTRUMENTS
Audio
Input
(Left)
IN
SLOP213
TPA701 MSOP EVM
GND
†
Due to the very small size of the MSOP IC package, the standard part number TPA701 is replaced with the code TIABA.
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TPA701 MSOP Audio Power Amplifier Evaluation Module Parts List
3.5 TPA701 MSOP Audio Power Amplifier Evaluation Module Parts List
Table 3–1. TPA701 MSOP EVM Parts List
EVM
Qty.
Manufacturer/
Part Number
Ref.
C3
Description
Size
Digi-Key Number
Capacitor, 10 µF, 6.3 V
A
1
Panasonic
ECS-TOJY106R
Digi-Key
PCS1106CT-ND
C1, C2, Capacitor, 1 µF,
0603
3
Murata
GRM39-Y5V105Z10PT
C4
+80%/–20%,
nonpolarized
C5
Capacitor, pad only
0603
0
2
R1, R2
Resistor, 20 kΩ, 1/16 W, 0603
5%
Panasonic
ERJ-3GSYJ203
R3
S1
Resistor, 39 kΩ, 1/16 W, 0603
1
1
9
1
Panasonic
ERJ-3GSYJ393
5%
Switch, momentary
Panasonic
P8048SCT-ND
Digi-Key
P8048SCT-ND
Terminal Post Headers
Sullins
PTC36SABN
Digi-Key
S1022-36-ND
†
U1
IC, TPA701DGN , audio MSOP
TI
amplifier, 700 mW,
mono
-8
TPA701DGN
PCB1
PCB, TPA701 MSOP
EVM
1
†
Due to the very small size of the MSOP IC package, the standard part number TPA701 is replaced with the code TIABA.
Note: All items are SMD except as noted.
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