Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsLinear IC - Audio amplifier Headphones (2-channel, stereo) Class AB TSSOP 14

TPA6138A2

www.ti.com

SLOS704A –JANUARY 2011– REVISED MAY 2011

DirectPath™ Headphone Driver With Adjustable Gain

Check for Samples: TPA6138A2

FEATURES

DESCRIPTION

• Stereo DirectPath™ Headphone Amplifier

The TPA6138A2 is a pop-free stereo headphone

– 40 mW Into 32 Ω With 3.3-V Supply

amplifier designed to allow the removal of the output

• Low THD+N < 0.01% at 10 mW Into 32 Ω

dc-blocking capacitors for reduced component count

and cost. The device is ideal for single-supply

• High SNR, >90 dB

electronics where size and cost are critical design

• Differential Input and Single-Ended Output

parameters.

• Adjustable Gain by External Gain-Setting

Designed using TI’s patented DirectPath™

Resistors

technology, The TPA6138A2 is capable of driving 25

• Configurable as a Second-Order Low-Pass

mW into a 32-Ω load with 3.3-V supply voltage. The

Filter

device has differential inputs and uses external

– Ideal for PWM Audio Sources

gain-setting resistors that supports a gain range of ±1

V/V to ±10 V/V. Gain can be configured individually

• Low DC Offset, <1 mV

for each channel. The device can also be configured

• Ground-Referenced Outputs Eliminate

as a second-order low-pass filter and is ideal for

DC-Blocking Capacitors

interfacing with PWM audio sources. Audio output

– Reduce Board Area

compiles with ±8-kV IEC ESD protection, requiring

just a simple resistor-capacitor ESD protection circuit.

– Reduce Component Cost

The TPA6138A2 has built-in active-mute control for

– Improve THD+N Performance

pop-free audio on/off control. The TPA6138A2 has an

– No Degradation of Low-Frequency

external undervoltage detector that mutes the output

Response Due to Output Capacitors when the power supply is removed, ensuring a

pop-free shutdown.

• Short-Circuit Protection

Using the TPA6138A2 in audio products can reduce

• Click- and Pop-Reduction Circuitry

component count considerably compared to

• External Undervoltage Mute

traditional headphone amplifiers. The TPA6138A2

• Active Mute Control for Pop-Free Audio On/Off

does not require a split-rail power supply or a dc

Control

blocking capacitor. The TPA6138A2 integrates its

own charge pump to generate a negative supply rail

• Space-Saving TSSOP Package

that provides a clean, pop-free ground-biased audio

signal.

APPLICATIONS

The TPA6138A2 is available in a 14-pin TSSOP.

• LCD and PDP TV

• Blu-ray Disc™, DVD Players

• Set-Top Boxes

• Mini/Micro Combo Systems

• Sound Cards

• Laptops

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2DirectPath, FilterPro are trademarks of Texas Instruments.

3Blu-ray Disc is a trademark of Blu-ray Disc Association.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (18 pages)

PAGE 1
TPA6138A2 SLOS704A – JANUARY 2011 – REVISED MAY 2011 www.ti.com DirectPath™ Headphone Driver With Adjustable Gain Check for Samples: TPA6138A2 FEATURES 1 • 23 • • • • • • • • • • • • Stereo DirectPath™ Headphone Amplifier – 40 mW Into 32 Ω With 3.3-V Supply Low THD+N < 0.
PAGE 2
TPA6138A2 SLOS704A – JANUARY 2011 – REVISED MAY 2011 www.ti.com These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.
PAGE 3
TPA6138A2 SLOS704A – JANUARY 2011 – REVISED MAY 2011 www.ti.com SYSTEM BLOCK DIAGRAM +INL –INL +INR Headphone Driver Headphone Driver –INR OUTL OUTR GND UVP Click and Pop Suppression Short-Circuit Protection GND Mute VSS VDD Bias Circuitry CN CP ORDERING INFORMATION (1) (1) TA PACKAGE DESCRIPTION –40°C to 85°C TPA6138A2PW 14-Pin For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI Web site at www.ti.com.
PAGE 4
TPA6138A2 SLOS704A – JANUARY 2011 – REVISED MAY 2011 www.ti.com THERMAL INFORMATION TPA6138A2 THERMAL METRIC (1) PW UNITS 14 PINS θJA Junction-to-ambient thermal resistance 130 θJCtop Junction-to-case (top) thermal resistance 49 θJB Junction-to-board thermal resistance 63 ψJT Junction-to-top characterization parameter 3.
PAGE 5
TPA6138A2 SLOS704A – JANUARY 2011 – REVISED MAY 2011 www.ti.com ELECTRICAL CHARACTERISTICS VDD = 3.3 V, RDL = 32 Ω, Rfb = 30 kΩ, RIN = 15 kΩ, TA = 25°C, Charge pump: CP = 1 µF (unless otherwise noted) PARAMETER TEST CONDITIONS |VOS| Output offset voltage PSRR Power-supply rejection ratio VOH High-level output voltage VDD = 3.3 V VOL Low-level output voltage VDD = 3.
PAGE 6
TPA6138A2 SLOS704A – JANUARY 2011 – REVISED MAY 2011 www.ti.com TYPICAL CHARACTERISTICS VDD = 3.3 V , TA = 25°C, C(PUMP) = C(VSS) = 1 μF , CIN = 2.2 μF, RIN = 15 kΩ, Rfb = 30 kΩ, ROUT = 10 Ω, COUT = 1 nF (unless otherwise noted) TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT POWER VDD = 3.3 V, RL = 32 Ω 5 1 Gain = 2 V/V, Active Filter THD+N – Total Harmonic Distortion+Noise – % THD+N – Total Harmonic Distortion+Noise – % 1 TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT VOLTAGE VDD = 3.3 V, RL = 16 Ω 0.
PAGE 7
TPA6138A2 SLOS704A – JANUARY 2011 – REVISED MAY 2011 www.ti.com TYPICAL CHARACTERISTICS (continued) VDD = 3.3 V , TA = 25°C, C(PUMP) = C(VSS) = 1 μF , CIN = 2.
PAGE 8
TPA6138A2 SLOS704A – JANUARY 2011 – REVISED MAY 2011 www.ti.com APPLICATION INFORMATION Single-supply line-driver amplifiers typically require dc-blocking capacitors. The top drawing in Figure 7 illustrates the conventional line-driver-amplifier connection to the load and output signal. DC blocking capacitors are often large in value. The headphone load (typical resistive values of 16 Ω to 32 Ω) combine with the dc blocking capacitors to form a high-pass filter.
PAGE 9
TPA6138A2 SLOS704A – JANUARY 2011 – REVISED MAY 2011 www.ti.com CHARGE-PUMP FLYING CAPACITOR AND VSS CAPACITOR The charge-pump flying capacitor serves to transfer charge during the generation of the negative supply voltage. The VSS capacitor must be at least equal to the charge-pump capacitor in order to allow maximum charge transfer. Low-ESR capacitors are an ideal selection, and a value of 1 μF is typical.
PAGE 10
TPA6138A2 SLOS704A – JANUARY 2011 – REVISED MAY 2011 www.ti.com Inverting Input Differential Input R2 C3 R1 R2 C3 C1 R3 –IN C1 R3 R1 –IN – C2 + – C2 + TPA6138A2 TPA6138A2 +IN C3 R1 R3 C1 R2 Figure 8. Second-Order Active Low-Pass Filter The resistor values should have a low value for obtaining low noise, but should also have a high enough value to allow use of a small-size ac-coupling capacitor.
PAGE 11
TPA6138A2 SLOS704A – JANUARY 2011 – REVISED MAY 2011 www.ti.com LAYOUT RECOMMENDATIONS A proposed layout for the TPA6138A2 can be seen in the TPA6138A2EVM User's Guide, and the Gerber files can be downloaded from http://www.ti.com. To access this information, open the TPA6138A2 product folder and look in the Tools and Software folder.
PAGE 12
TPA6138A2 SLOS704A – JANUARY 2011 – REVISED MAY 2011 www.ti.com REVISION HISTORY Changes from Original (January 2011) to Revision A Page • Added Rev A and May 2011 to Header, No other changes to page 1 ................................................................................. 1 • Changed Pin Functions Description for UVP pin from "connect to PVDD with a 10-kΩ resistor if function is unused" to "internal pull-up, unconnected if UVP function is unused". ..........................................
PAGE 13
PACKAGE OPTION ADDENDUM www.ti.
PAGE 14
PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device TPA6138A2PWR Package Package Pins Type Drawing TSSOP PW 14 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 2000 330.0 12.4 Pack Materials-Page 1 6.9 B0 (mm) K0 (mm) P1 (mm) 5.6 1.6 8.0 W Pin1 (mm) Quadrant 12.
PAGE 15
PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TPA6138A2PWR TSSOP PW 14 2000 367.0 367.0 35.
PAGE 16
PAGE 17
PAGE 18
IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46C and to discontinue any product or service per JESD48B. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.