Texas Instruments TPA152 User manual

1998 Mixed-Signal Products
TPA152
Audio Power Amplifier
Evaluation Module
User’s Guide

TPA152
Audio Power Amplifier
Evaluation Module
User’s Guide
SLOU019
June 1998
Printed on Recycled Paper

IMPORTANT NOTICE
Texas Instruments (TI) reserves the right to make changes to its products or to discontinue any
semiconductor product or service without notice, and advises its customers to obtain the latest
version of relevant information to verify, before placing orders, that the information being relied
on is current.
TIwarrantsperformanceofitssemiconductorproductsandrelatedsoftwaretothespecifications
applicableatthetimeofsaleinaccordancewithTI’sstandardwarranty.Testingandotherquality
control techniques are utilized to the extent TI deems necessary to support this warranty.
Specific testing of all parameters of each device is not necessarily performed, except those
mandated by government requirements.
Certain applications using semiconductor products may involve potential risks of death,
personal injury, or severe property or environmental damage (“Critical Applications”).
TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, INTENDED, AUTHORIZED, OR
WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT APPLICATIONS, DEVICES
OR SYSTEMS OR OTHER CRITICAL APPLICATIONS.
Inclusion of TI products in such applications is understood to be fully at the risk of the customer.
Useof TIproducts insuch applicationsrequires thewritten approvalof anappropriate TIofficer.
Questions concerning potential risk applications should be directed to TI through a local SC
sales office.
In order to minimize risks associated with the customer’s applications, adequate design and
operating safeguards should be provided by the customer to minimize inherent or procedural
hazards.
TI assumes no liability for applications assistance, customer product design, software
performance, or infringement of patents or services described herein. Nor does TI warrant or
representthatanylicense,eitherexpressorimplied,isgrantedunderanypatentright,copyright,
mask work right, or other intellectual property right of TI covering or relating to any combination,
machine, or process in which such semiconductor products or services might be or are used.
Copyright 1998, Texas Instruments Incorporated

iii
Chapter Title—Attribute Reference
Preface
Related Documentation From Texas Instruments
J 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.
J TPA152 75-mW STEREO AUDIO POWER AMPLIFIER (literature
number SLOS210) This is the data sheet for the TPA152 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
testedforcompliancewiththe limits of computing devicespursuanttosubpart
Jof part15of FCCrules,whicharedesignedtoprovidereasonableprotection
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.

If You Need Assistance
iv
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Dallas, Texas 75266
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†Texas Instruments Product Information Center

Running Title—Attribute Reference
v
Chapter Title—Attribute Reference
Contents
1 Introduction 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.1 Feature Highlights 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 Description 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3 TPA152 EVM Specifications 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Quick Start 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1 Precautions 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 Quick Start List for Platform 2-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3 Quick Start List for Stand-Alone 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Details 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1 Precautions 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 The TPA152 Audio Amplifier Evaluation Module 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.1 TPA152 Audio Amplifier IC 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.2 Module Gain 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.3 Shutdown 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3 Using The TPA152 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 3-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.4 Power Requirements 3-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.5 Inputs and Outputs 3-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4 Using The TPA152 EVM Stand-Alone 3-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.1 TPA152 EVM Connected as a Stereo Headphone Amplifier 3-11. . . . . . . . . . . . . .
3.5 TPA152 Audio Amplifier Evaluation Module Parts List 3-12. . . . . . . . . . . . . . . . . . . . . . . . . .

Running Title—Attribute Reference
vi
Figures
1–1 The TI TPA152 Audio Amplifier Evaluation Module 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–1 Quick Start Platform Map 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–2 Quick Start Module Map 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–1 The TI Plug-N-Play Audio Amplifier Evaluation Platform 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–2 TPA152 EVM 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–3 TPA152 EVM Schematic Diagram 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–4 TPA152 Audio Amplifier IC 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–5 Platform Signal Routing and Outputs 3-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–6 Mute Polarity Control 3-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–7 Typical Headphone Plug 3-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–8 TPA152 EVM Connected as a Stereo Headphone Amplifier 3-11. . . . . . . . . . . . . . . . . . . . . . . .
Tables
2–1 Typical TI Plug-N-Play Platform Jumper and Switch Settings for the TPA152 EVM 2-1. . . . .
2–2 Platform Jumper and Switch Settings for the TPA152 EVM 2-3. . . . . . . . . . . . . . . . . . . . . . . . .
3–1 TPA152 EVM Parts List 3-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-1
Introduction
Introduction
This chapter provides an overview of the Texas Instruments (TI) TPA152
Audio Amplifier Evaluation Module (SLOP123). 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 Features 1–3
1.2 Description 1–4
1.3 TPA152 EVM Specifications 1–4
Chapter 1

1-2
Introduction

Features
1-3
Introduction
1.1 Features
The TI TPA152 Audio Amplifier Evaluation Module and the TI Plug-N-Play
Audio Amplifier Evaluation Platform include the following features:
- TPA152 Stereo Audio Power Amplifier Evaluation Module
J Dual channel, single-ended operation
J 75 mW output power into 32 Ωat 5 V
J 4.5-V to 5.5-V operation
J Verylowdistortion—THD+Nis less than 0.005% into10-kΩloadsat
1 kHz, and less than 0.01% from 20 Hz to 20 kHz
J Low current consumption in shutdown/mute mode
J Internal thermal and short-circuit protection
J Internal pop reduction circuitry
- Quick and Easy Configuration with the TI Plug-N-Play Audio Amplifier
Evaluation Platform
J Evaluation module is designed to simply plug into the platform, auto-
matically making all signal, control, and power connections
J Platform provides flexible power options
J Jumpers on the platform select power and module control options
J Switches on the platform route signals
J Platformprovides quick and easyaudioinputand output connections
- Platform Power Options
J On-board 9-V battery
J External 5-V – 15-V (VCC) supply inputs
J External regulated VDD supply input
J Socket for on-board 5-V VDD voltage regulator EVM
J On-board overvoltage and reverse polarity power protection
- Platform Audio Input and Output Connections
J Left and right RCA phono jack inputs
J Miniature stereo phone jack input
J Left and right RCA phono jack outputs
J Left and right compression speaker terminal outputs
J Miniature stereo headphone jack output

Description
1-4
Introduction
1.2 Description
The TPA152 Audio Power Amplifier Evaluation Module is a complete,
low-power stereo audio power amplifier for high-fidelity line-level output and
headphone applications. It consists of the TI TPA152 75-mW Stereo Audio
PowerAmplifierICinaverysmallpackage,alongwithasmallnumberofother
parts mounted on a circuit board that is approximately one and a quarter
inches square (Figure 1–1).
Figure 1–1.The TI TPA152 Audio Amplifier Evaluation Module
GND
Vo2
C3
IN2
GND
Vdd GND
IN1
SD
GND U1
R4
R3
R1
R6
C5
R2
S1
Shut-
down
C4
Vo1
C7
C1
C6
C2
TEXAS
INSTRUMENTS
SLOP124
TPA152 EVM
GND
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
EvaluationPlatform,ortobewireddirectlyintoexistingcircuitsandequipment
when used stand-alone.
The platform has room for a single TPA152 evaluation module 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 TPA152 EVM Specifications
Supply voltage range, VDD 4.5 V to 5.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Supply current, IDD 80 mA, max. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous output power, PO: 32-Ω, VDD=5 V: 75 mW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Audio input voltage, VIVDD + 3 Vpp, max. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Minimum load impedance, RL32 Ω. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-1
Quick Start
Quick Start
Thestepsinthischapter can be followed toquicklypreparetheTPA152 audio
amplifier EVM for use. Using the TPA152 EVM with the TI Plug-N-Play Audio
AmplifierEvaluationPlatformisaquickandeasywaytoconnectpower,signal
and control inputs, and signal outputs to the EVM using standard connectors.
However, the audio amplifier evaluation module can be used stand-alone by
making connections directly to the module pins, and can be wired directly into
existing circuits or equipment.
TheplatformswitchandjumpersettingsshowninTable2–1 are typical for the
TPA152 EVM and will cause the TPA152 IC to mute when a plug is removed
from platform headphone jack J10.
Table 2–1. Typical TI Plug-N-Play Platform Jumper and Switch Settings for the TPA152
EVM
EVM JP6 JP7 JP8 S2 S3
TPA152 X Lo X Note 2 U5
Notes: 1) X = Don’t care
2) SetS2toONwhen signal conditioning board is installed in U1; setS2
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
Chapter 2

Precautions
2-2
Quick Start
2.1 Precautions
Power Supply Input Polarity and Maximum Voltage
Always ensure that the polarity and voltage of the external power
connected to VCC power input connector J1, J2, and/or VDD power
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
Donotinsert or remove EVMboardswith power applied—damage
to the EVM board, the platform, or both may result.
Figure 2–1. Quick Start Platform Map
3
Signal Conditioning
****CAUTION****
Do not insert or remove
EVM boards with power
applied
ICC
JP4
F1
VR1
R1
JP3 JP2 JP1 AC/DC
(J2)
VCC(J1)
D1 D2 D3
D4 J2
J3 J4 J5
AC/DC
In
VCC
In
+
J1
DC
SOURCE
LED1 VCC
LED2 VDD
R2
JP5 IDD
B1
U6
POWER
SUPPLY
U3 U4
U5
U1
U2
Audio
Power
Amps
OnOff ConditioningS2
J7 J8 Right
Out Left
Out
+–+–
JP6
Mode
Mute
Spk(U2-U4)
JP8
J9 Left
Out
JP7
S3 HP Source
U2-U4
U5
Polarity
Lo
Hi
HP(U5)
C3 C2
++
R3
R4 R5
J10
Stereo
HP Out
TP1
GND
Plug-N-PlayAudioAmplifier
Evaluation Platform
SLOP097 Rev. C.1
Stereo
In
Right
In Left
In
J6 In/Out VDD
F2
VR2
+
DC
Power
In/Out
Speaker
Output
Headphone
Output
Audio
Input
Power
Input
Batt
C1+
Right
Out
On Off Pwr
S1
TEXAS INSTRUMENTS 1997
110
9
8
6b
6b
6a
6b
4
7b
25

Quick Start List for Platform
2-3
Quick Start
2.2 Quick Start List for Platform
FollowthesestepswhenusingtheTPA152EVMwiththeTIPlug-N-PlayAudio
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) Ensurethatallexternalpowersourcesaresetto
OFF andthattheplatform
power switch S1 is set to
OFF.
2) Install a TPA152 module in platform socket U5, 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 JP7 to
Lo.
5) SetHp sourceswitchS3 toU5 toroutetheoutputsignaltotheheadphone
Jack (J10).
Table 2–2. Platform Jumper and Switch Settings for the TPA152 EVM
EVM JP6 JP7 JP8 S2 S3
TPA152 X Lo X Note 2 U5
Notes: 1) X = Don’t care
2) SetS2 to
ON whensignalconditioning board is installed inU1; set S2
to
OFF when no signal conditioning board is installed.
- Power supply
6) Select and connect the power supply:
a) Connectanexternalregulatedpower supply set to avoltagebetween
4.5Vand 5.5 V to platform VDD powerinput connector J6 takingcare
to observe marked polarity, or
b) Install a 5-V 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 VCC power input J1 or J2 and jumper the ap-
propriate power input (see platform user’s guide).
- 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 32-Ωheadphones to headphone jack J10.
- Power-up
10) Verifycorrect voltage and input polarityand settheexternalpowersupply
to
ON. IfVCCandanon-boardregulatorEVMareusedtoprovideVDD,set
platform power switch S1 to
ON.
PlatformLED2shouldlightindicatingthepresenceofVDD,andtheevaluation
modules installed on the platform should begin operation.
11) Adjust the signal source level as needed.

Quick Start List for Stand-Alone
2-4
Quick Start
2.3 Quick Start List for Stand-Alone
Follow these steps to use the TPA152 EVM stand-alone or when connecting
it into existing circuits or equipment. Connections to the TPA152 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
5
2
67
4GND
Vo2
C3
IN2
GND
Vdd GND
IN1
SD
GND U1
R4
R3
R1
R6
C5
R2
S1
Shut-
down
C4
Vo1
C7
C1
C6
C2
TEXAS
INSTRUMENTS
SLOP124
TPA152 EVM
GND
- Power supply
1) Ensure that all external power sources are set to
OFF.
2) Connectanexternal regulatedpowersupplyset to5Vto themoduleVDD
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 IN1, IN2, and GND pins taking
care to observe marked polarity.
5) Connect the Shutdown pin to VDD through a Normally Open switch.
6) Connect 32-Ωheadphones to the module VO1, VO2pins through 33 µF
to1000 µF output-coupling capacitors (figure 3–8) and return to the GND
pin, or
7) For line output, connections to the VO1and VO2pins must be made
through 33 µF to 1000 µF output-coupling capacitors and returned to
GND.
- Power-up
8) Verifycorrect voltage and input polarityand settheexternalpowersupply
to ON.
The EVM should begin operation.
9) Adjust the signal source level as needed.

3-1
Details
Details
This chapter provides details on the TPA152 IC, the evaluation module, the
stepsinthe Quick-StartList,additionalapplicationinformation, andapartslist
for the TPA152 evaluation module.
Topic Page
3.1 Precautions 3–2
3.2 The TPA152 Audio Power Amplifier Evaluation Module 3–3
3.2.1 TPA152 Audio Amplifier IC 3–4
3.2.2 Module Gain 3–5
3.2.3 Mute 3–5
3.3 Using The TPA152 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 3–8
3.3.4 Power Requirements 3–9
3.3.5 Inputs and Outputs 3–10
3.4 Using The TPA152 EVM Stand-Alone 3–11
3.4.1 TPA152 EVM Connected as a Stereo Headphone Amplifier 3–11
3.5 TPA152 Audio Power Amplifier
Evaluation Module Parts List 3–12
Chapter 3

Precautions
3-2
Details
3.1 Precautions
Power Supply Input Polarity and Maximum Voltage
Always ensure that the polarity and voltage of the external power
connected to VCC power input connector J1, J2, and/or VDD power
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
Donotinsert or remove EVMboardswith 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
Signal Conditioning
****CAUTION****
Do not insert or remove
EVM boards with power
applied
ICC
JP4
F1
VR1
R1
JP3 JP2 JP1 AC/DC
(J2)
VCC(J1)
D1 D2 D3
D4 J2
J3 J4 J5
AC/DC
In
VCC
In
+
J1
DC
SOURCE
LED1 VCC
LED2 VDD
R2
JP5 IDD
B1
U6
POWER
SUPPLY
U3 U4
U5
U1
U2
Audio
Power
Amps
OnOff ConditioningS2
J7 J8 Right
Out Left
Out
+–+–
JP6
Mode
Mute
Spk(U2-U4)
JP8
J9 Left
Out
JP7
S3 HP Source
U2-U4
U5
Polarity
Lo
Hi
HP(U5)
C3 C2
++
R3
R4 R5
J10
Stereo
HP Out
TP1
GND
Plug-N-PlayAudioAmplifier
Evaluation Platform
SLOP097 Rev. C.1
Stereo
In
Right
In Left
In
J6 In/Out VDD
F2
VR2
+
DC
Power
In/Out
Speaker
Output
Headphone
Output
Audio
Input
Power
Input
Batt
C1+
Right
Out
On Off Pwr
S1
TEXAS INSTRUMENTS 1997

The TPA152 Audio Power Amplifier Evaluation Module
3-3
Details
3.2 The TPA152 Audio Power Amplifier Evaluation Module
The TPA152 Audio Power Amplifier Evaluation Module is powered by a
TPA15275-mWStereoAudioAmplifierIC,includesamutecontrolsignalinput
with on-board switch, and can drive either 32-Ωheadphones or line-level
outputs.
The evaluation 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,whichautomaticallymakesallthesignalinputandoutput,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.TPA152 EVM
GND
Vo2
C3
IN2
GND
Vdd GND
IN1
SD
GND U1
R4
R3
R1
R6
C5
R2
S1
Shut-
down
C4
Vo1
C7
C1
C6
C2
TEXAS
INSTRUMENTS
SLOP124
TPA152 EVM
GND
Figure 3–3.TPA152 EVM Schematic Diagram
IN 1–
GND
VDD
VO2
VO1
Mute
Bypass
IN 2–
VDD
R6
20 kΩC5
1 µF
R3
20 kΩ
C3
1 µF
R1
20 kΩ
C1
1 µF
S1
NO
C6
1 µF
R4, 20 kΩ
C4, 5 pF
C2, 5 pF R2, 20 kΩ
8
7
6
5
1
2
3
4
Output 1
C7
10 µF
Audio Input 1
Audio Input 2
SD
(VDD to Mute) TPA152 +VDD
4.5 to 5.5 V
GND
Output 2

The TPA152 Audio Power Amplifier Evaluation Module
3-4
Details
3.2.1 TPA152 Audio Amplifier IC
The TPA152 audio amplifier IC is a CMOS device intended primarily for
high-performance line-level output and headphone driver applications. It is
supplied in a very small surface-mount package and has been designed to
operate from low supply voltages (between approximately 4.5 V and 5.5 V)
and deliver up to approximately 75 mW into 32-Ωheadphones with low
distortion. As a line-level driver, distortion levels (THD+N) are below 0.01%
into10-kΩloadsacrosstheaudioband(20Hzto20kHz)(Figure3–4).Typical
applications include portable computers, desktop computers, personal audio,
toys, games, and similar audio applications.
Figure 3–4.TPA152 Amplifier IC
Stereo
RLRL
CC
CC
VO1
VO2
BYPASS
IN2–
IN1–
CB
RF
RF
RI
RI
CI
CI
R
L
Stereo Audio
Input
Mute
Control
From System
Control
CB
VDD
4
3
2
1
8
6
5
Depop
Circuitry
–
–
+
+
The IC includes two separate internal amplifiers, depop circuitry, and a
common mute control. The load for each channel is connected between the
VOpin and GND through a coupling capacitor. For more information, see the
TPA152 amplifier IC data sheet, TI Literature Number SLOS210.

The TPA152 Audio Power Amplifier Evaluation Module
3-5
Details
3.2.2 Module Gain
TheTPA152evaluationmodulehasasetgainof1(inverting)foreachchannel.
However, the gain can be adjusted to a maximum of approximately 10
(inverting) by changing the value of feedback resistors (R2 and R4, Figure
3–3). Use the following equation to determine the value of RF:
Gain +
–RF
RI
The TPA152 amplifier IC, as most other amplifiers, exhibits its best distortion
and noise performance at lower gain levels. In addition, higher gain levels
require a small compensation capacitor to ensure stability (see the TPA152
data sheet).
Gain versus total harmonic distortion (THD) and gain versus signal-to-noise
ratio (SNR) should be considered in each application. Both the module input
signal level and the TPA152 module gain should be adjusted to obtain the
lowestoveralldistortionlevelforaparticularoverallgain.Aquickruleofthumb
(everything else being equal): the module input signal level should be as high
aspossiblewithoutclipping or overloadingtheTPA152input, and theTPA152
gain should be kept as low as possible.
3.2.3 Mute
WhenthemuteterminaloftheTPA152amplifierICistakenhigh,theICceases
operation.Thisis accomplished by applying a control signal to themodule SD
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 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 (JP7).