Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsLinear IC - Audio amplifier 1-channel (mono) Class AB MSOP 8 PowerPad

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FEATURES DESCRIPTION

SHUTDOWN

BYPASS

IN+

IN–

–

GND

D OR DGN PACKAGE

(TOP VIEW)

Audio

Input

Bias

Control

700 mW

BYPASS

IN–

SHUTDOWN

– 8

GND

From System Control

3 IN+

–

TPA721

SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004

700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER

• Fully Specified for 3.3-V and 5-V Operation

The TPA721 is a bridge-tied load (BTL) audio power

amplifier developed especially for low-voltage appli-

• Wide Power Supply Compatibility 2.5 V – 5.5 V

cations where internal speakers are required.

• Output Power for R

= 8 Ω

Operating with a 3.3-V supply, the TPA721 can

– 700 mW at V

= 5 V, BTL

deliver 250-mW of continuous power into a BTL 8-Ω

– 250 mW at V

= 3.3 V, BTL load at less than 0.6% THD+N throughout voice band

frequencies. Although this device is characterized out

• Integrated Depop Circuitry

to 20 kHz, its operation is optimized for narrower

• Thermal and Short-Circuit Protection

band applications such as wireless communications.

• Surface-Mount Packaging

The BTL configuration eliminates the need for exter-

nal coupling capacitors on the output in most appli-

– SOIC

cations, which is particularly important for small

– PowerPAD™ MSOP

battery-powered equipment. This device features a

shutdown mode for power-sensitive applications with

a supply current of 7 µA during shutdown. The

TPA721 is available in an 8-pin SOIC surface-mount

package and the surface-mount PowerPAD MSOP,

which reduces board space by 50% and height by

40%.

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.

PowerPAD is a trademark of Texas Instruments.

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 (28 pages)

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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER FEATURES • • • • • • DESCRIPTION Fully Specified for 3.3-V and 5-V Operation Wide Power Supply Compatibility 2.5 V – 5.5 V Output Power for RL = 8 Ω – 700 mW at VDD = 5 V, BTL – 250 mW at VDD = 3.
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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure.
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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 DISSIPATION RATING TABLE (1) PACKAGE TA ≤ 25°C DERATING FACTOR TA = 70°C TA = 85°C D 725 mW 5.8 mW/°C 464 mW 377 mW DGN 2.14 W (1) 17.1 mW/°C 1.37 W 1.11 W See the Texas Instruments document, PowerPAD Thermally Enhanced Package Application Report (SLMA002), for more information on the PowerPAD package.
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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 OPERATING CHARACTERISTICS VDD = 5 V, TA = 25°C, RL = 8 Ω PARAMETER TEST CONDITIONS MIN TYP MAX 700 (1) UNIT PO Output power THD = 0.5%, See Figure 13 THD + N Total harmonic distortion plus noise PO = 250 mW, f = 200 Hz to 4 kHz, See Figure 11 BOM Maximum output power bandwidth Gain = 2, THD = 2%, See Figure 11 20 kHz B1 Unity-gain bandwidth Open loop, See Figure 16 1.
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TPA721 www.ti.
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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 TYPICAL CHARACTERISTICS (continued) SUPPLY CURRENT vs SUPPLY VOLTAGE OUTPUT POWER vs SUPPLY VOLTAGE 90 1000 SHUTDOWN = VDD RF = 10 kΩ 80 THD+N 1% f = 1 kHz BTL 800 PO − Output Power − mW I DD − Supply Current − µ A 70 60 50 40 30 20 600 RL = 8 Ω RL = 32 Ω 400 200 10 0 2.5 3 3.5 4 4.5 5 0 2.5 5.5 3 3.5 VDD − Supply Voltage − V 5 5.5 Figure 5.
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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 TYPICAL CHARACTERISTICS (continued) TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT POWER 10 THD+N −Total Harmonic Distortion + Noise − % THD+N −Total Harmonic Distortion + Noise − % 10 VDD = 3.3 V RL = 8 Ω AV = −2 V/V BTL PO = 50 mW 1 0.1 PO = 125 mW PO = 250 mW 0.01 20 10k 0.1 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 f − Frequency − Hz PO − Output Power − W Figure 8. Figure 9.
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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 TYPICAL CHARACTERISTICS (continued) TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT POWER 10 VDD = 5 V RL = 8 Ω AV = −2 V/V BTL THD+N −Total Harmonic Distortion + Noise − % THD+N −Total Harmonic Distortion + Noise − % 10 PO = 50 mW 1 PO = 700 mW 0.1 PO = 350 mW 0.01 20 1k 100 10k VDD = 5 V f = 1 kHz AV = −2 V/V BTL 1 RL = 8 Ω 0.1 0.01 0.1 20k 0.2 0.3 f − Frequency − Hz 0.
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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 TYPICAL CHARACTERISTICS (continued) OPEN-LOOP GAIN AND PHASE vs FREQUENCY 80 180° VDD = 3.3 V RL = Open BTL 70 140° Phase 100° 50 60° 40 20° 30 Gain 20 −20° 10 Phase Open-Loop Gain − dB 60 −60° 0 −100° −10 −140° −20 −30 −180° 1 101 102 103 104 f − Frequency − kHz Figure 15.
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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 TYPICAL CHARACTERISTICS (continued) CLOSED-LOOP GAIN AND PHASE vs FREQUENCY 1 180° Phase 0.75 170° 0.25 0 160° Gain −0.25 150° −0.5 Phase Closed-Loop Gain − dB 0.5 −0.75 140° −1 −1.25 −1.5 −1.75 −2 101 VDD = 3.3 V RL = 8 Ω PO = 250 mW BTL 130° 120° 102 103 104 105 106 f − Frequency − Hz Figure 17. CLOSED-LOOP GAIN AND PHASE vs FREQUENCY 1 180° Phase 0.75 170° 0.25 0 160° Gain −0.25 150° −0.5 −0.75 140° −1 −1.
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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 TYPICAL CHARACTERISTICS (continued) OUTPUT NOISE VOLTAGE vs FREQUENCY 100 VDD = 3.3 V BW = 22 Hz to 22 kHz RL = 8 Ω or 32 Ω AV = −1 V/V Vn − Output Noise Voltage − µV Vn − Output Noise Voltage − µV 100 OUTPUT NOISE VOLTAGE vs FREQUENCY VO BTL Vo+ 10 1 20 100 1k 10k VO BTL Vo+ 10 1 20 20k 100 1k 10k f − Frequency − Hz f − Frequency − Hz Figure 19. Figure 20.
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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 APPLICATION INFORMATION BRIDGE-TIED LOAD Figure 23 shows a linear audio power amplifier (APA) in a BTL configuration. The TPA721 BTL amplifier consists of two linear amplifiers driving both ends of the load. There are several potential benefits to this differential drive configuration, but initially consider power to the load.
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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 APPLICATION INFORMATION (continued) VDD –3 dB VO(PP) CC RL VO(PP) fc Figure 24. Single-Ended Configuration and Frequency Response Increasing power to the load does carry a penalty of increased internal power dissipation. The increased dissipation is understandable considering that the BTL configuration produces 4× the output power of a SE configuration.
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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 APPLICATION INFORMATION (continued) P Efficiency where V P L V L(RMS) L SUP 2 L(RMS) R L Vp 2 2R L VP 2 P SUP V I DD(RMS) P DD I DD(RMS) V DD 2VP RL 2V P RL Efficiency of a BTL configuration (3) 2 PLR L VP 4V DD 4V DD 1 2 (4) Table 1 employs Equation 4 to calculate efficiencies for three different output power levels.
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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 APPLICATION SCHEMATICS Figure 26 is a schematic diagram of a typical handheld audio application circuit, configured for a gain of –10 V/V. VDD 6 RF 50 kΩ Audio Input RI 10 kΩ CI 4 IN– 3 IN+ 2 BYPASS VDD CS VDD/2 1 µF – VO+ 5 + CB 2.2 µF – VO– 8 + 700 mW 7 GND From System Control 1 SHUTDOWN Bias Control Figure 26.
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TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 −3 dB f co(lowpass) 1 2 R C F F fc (7) For example, if RF is 100 kΩ and CF is 5 pF, then fco is 318 kHz, which is well outside of the audio range. Input Capacitor, CI In the typical application an input capacitor, CI, is required to allow the amplifier to bias the input signal to the proper dc level for optimum operation. In this case, CI and RI form a high-pass filter with the corner frequency determined in Equation 8.
PAGE 17
TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 Midrail Bypass Capacitor, CB The midrail bypass capacitor, CB, is the most critical capacitor and serves several important functions. During start-up or recovery from shutdown mode, CB determines the rate at which the amplifier starts up. The second function is to reduce noise produced by the power supply caused by coupling into the output drive signal.
PAGE 18
TPA721 www.ti.com SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004 Converting dB back into watts: PW = 10 PdB/10 = 22 mW (15-dB headroom) = 44 mW (12-dB headroom) = 88 mW (9-dB headroom) = 175 mW (6-dB headroom) = 350 mW (3-dB headroom) This is valuable information to consider when attempting to estimate the heat dissipation requirements for the amplifier system.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com (4) 24-Jan-2013 Only one of markings shown within the brackets will appear on the physical device. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information.
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PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant TPA721DGNR MSOPPower PAD DGN 8 2500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 TPA721DR SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.
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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) TPA721DGNR MSOP-PowerPAD DGN 8 2500 358.0 335.0 35.0 TPA721DR SOIC D 8 2500 367.0 367.0 35.
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