TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 D D D D D D D D OR DGN PACKAGE (TOP VIEW) 150 mW Stereo Output PC Power Supply Compatible – Fully Specified for 3.3-V and 5-V Operation – Operation to 2.5 V Pop Reduction Circuitry Internal Mid-Rail Generation Thermal and Short-Circuit Protection Surface-Mount Packaging – PowerPAD MSOP – SOIC Pin Compatible With TPA122, LM4880, and LM4881 (SOIC) VO1 IN1 – BYPASS GND 1 8 2 7 3 6 4 5 VDD VO2 IN2 – SHUTDOWN description The TPA6111A2 is a stereo audio power amplifier packaged in either an 8-pin SOIC or an 8-pin PowerPAD MSOP package capable of delivering 150 mW of continuous RMS power per channel into 16-Ω loads. Amplifier gain is externally configured by means of two resistors per input channel and does not require external compensation for settings of 0 to 20 dB. THD+N when driving a 16-Ω load from 5 V is 0.03% at 1 kHz, and less than 1% across the audio band of 20 Hz to 20 kHz. For 32-Ω loads, the THD+N is reduced to less than 0.02% at 1 kHz, and is less than 1% across the audio band of 20 Hz to 20 kHz. For 10-kΩ loads, the THD+N performance is 0.005% at 1 kHz, and less than 0.5% across the audio band of 20 Hz to 20 kHz. typical application circuit VDD 8 Rf Audio Input VDD C(S) VDD/2 Ri 2 IN 1– 3 BYPASS 6 IN 2– Ci VO1 1 – + C(C) C(BYP) Audio Input Ri Ci From Shutdown Control Circuit 5 VO2 7 – + SHUTDOWN C(C) Bias Control 4 Rf 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. Copyright 2000, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1 TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 AVAILABLE OPTIONS PACKAGED DEVICES SMALL OUTLINE† (D) TA MSOP Symbolization MSOP† (DGN) – 40°C to 85°C TPA6111A2D TPA6111A2DGN TI AJA † The D and DGN package is available in left-ended tape and reel only (e.g., TPA6111A2DR, TPA6111A2DGNR). Terminal Functions TERMINAL NAME NO. I/O DESCRIPTION BYPASS 3 I Tap to voltage divider for internal mid-supply bias supply. Connect to a 0.1 µF to 1 µF low ESR capacitor for best performance. GND 4 I GND is the ground connection. IN1– 2 I IN1– is the inverting input for channel 1. IN2– 6 I IN2– is the inverting input for channel 2. SHUTDOWN 5 I Puts the device in a low quiescent current mode when held high VDD VO1 8 I 1 O VDD is the supply voltage terminal. VO1 is the audio output for channel 1. VO2 7 O VO2 is the audio output for channel 2. absolute maximum ratings over operating free-air temperature (unless otherwise noted)‡ Supply voltage, VDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 V Input voltage, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to VDD + 0.3 V Continuous total power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . internally limited Operating junction temperature range, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to 150°C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C ‡ Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. DISSIPATION RATING TABLE PACKAGE TA ≤ 25°C POWER RATING DERATING FACTOR ABOVE TA = 25°C TA = 70°C POWER RATING TA = 85°C POWER RATING 377 mW D 725 mW 5.8 mW/°C 464 mW DGN 2.14 W§ 17.1 mW/°C 1.37 W 1.11 W § See the Texas Instruments document, PowerPAD Thermally Enhanced Package Application Report (literature number SLMA002), for more information on the PowerPAD package. The thermal data was measured on a PCB layout based on the information in the section entitled Texas Instruments Recommended Board for PowerPAD on page 33 of the before mentioned document. recommended operating conditions MIN MAX UNIT Supply voltage, VDD 2.5 5.5 V Operating free-air temperature, TA –40 85 °C High-level input voltage, VIH, (SHUTDOWN) 60% x VDD Low-level input voltage, VIL, (SHUTDOWN) 2 V 25% x VDD POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 V TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 dc electrical characteristics at TA = 25°C, VDD = 3.3 V PARAMETER VIO PSRR Input offset voltage IDD IDD(SD) Supply current Zi Input impedance TEST CONDITIONS MIN TYP MAX 10 Power supply rejection ratio VDD = 3.2 V to 3.4 V 70 Supply current in shutdown mode UNIT mV dB 1.5 3 mA 1 10 µA >1 MΩ ac operating characteristics, VDD = 3.3 V, TA = 25°C, RL = 16 Ω PARAMETER TEST CONDITIONS PO THD+N Output power (each channel) THD ≤ 0.1%, f = 1 kHz Total harmonic distortion + noise 20 – 20 kHz BOM Maximum output power BW PO = 40 mW, G = 20 dB, Phase margin Open loop Supply ripple rejection f = 1 kHz, C(BYP) = 0.47 µF PO = 40 mW AV = 1 Channel/channel output separation f = 1 kHz, SNR Signal-to-noise ratio Vn Noise output voltage PO = 50 mW, AV = 1 MIN TYP 60 MAX UNIT mW 0.4% THD < 5% >20 kHz 96° 71 dB 89 dB 100 dB µV(rms) 11 dc electrical characteristics at TA = 25°C, VDD = 5 V PARAMETER VIO PSRR Input offset voltage IDD IDD(SD) Supply current Zi Input impedance TEST CONDITIONS Power supply rejection ratio MIN VDD = 4.9 V to 5.1 V TYP MAX 10 mV 1.6 3.2 mA 1 10 µA 70 Supply current in shutdown mode UNIT dB >1 MΩ ac operating characteristics, VDD = 5 V, TA = 25°C, RL = 16 Ω PARAMETER TEST CONDITIONS PO THD+N Output power (each channel) THD ≤ 0.1%, Total harmonic distortion + noise BOM Maximum output power BW PO = 100 mW, 20 – 20 kHz G = 20 dB, THD < 5% Phase margin Open loop Supply ripple rejection ratio f = 1 kHz, Channel/channel output separation f = 1 kHz, f = 1 kHz TYP 150 MAX UNIT mW 0.6% >20 kHz 96° C(BYP) = 0.47 µF SNR Signal-to-noise ratio PO = 100 mW PO = 100 mW, AV = 1 Vn Noise output voltage AV = 1 POST OFFICE BOX 655303 MIN • DALLAS, TEXAS 75265 61 dB 90 dB 100 dB 11.7 µV(rms) 3 TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 ac operating characteristics, VDD = 3.3 V, TA = 25°C, RL = 32 Ω PARAMETER TEST CONDITIONS PO THD+N Output power (each channel) THD ≤ 0.1%, f = 1 kHz Total harmonic distortion + noise 20 – 20 kHz BOM Maximum output power BW PO = 40 mW, G = 20 dB, Phase margin Open loop Supply ripple rejection f = 1 kHz, C(BYP) = 0.47 µF PO = 25 mW AV = 1 Channel/channel output separation f = 1 kHz, SNR Signal-to-noise ratio Vn Noise output voltage PO = 90 mW, AV = 1 MIN TYP 35 MAX UNIT mW 0.4% THD < 2% >20 kHz 96° 71 dB 75 dB 100 dB µV(rms) 11 ac operating characteristics, VDD = 5 V, TA = 25°C, RL = 32 Ω PARAMETER TEST CONDITIONS MIN TYP PO THD+N Output power (each channel) THD ≤ 0.1%, f = 1 kHz Total harmonic distortion + noise 20 – 20 kHz 2% BOM Maximum output power BW PO = 20 mW, G = 20 dB, THD < 2% >20 Phase margin Open loop Supply ripple rejection f = 1 kHz, C(BYP) = 0.47 µF PO = 65 mW AV = 1 Channel/channel output separation f = 1 kHz, SNR Signal-to-noise ratio Vn Noise output voltage PO = 90 mW, AV = 1 90 MAX UNIT mW kHz 97° 61 dB 98 dB 104 dB 11.7 µV(rms) TYPICAL CHARACTERISTICS Table of Graphs FIGURE THD+N vs Frequency 1, 3, 5, 6, 7, 9, 11, 13, vs Output power 2, 4, 8, 10, 12, 14 Total harmonic distortion plus noise Supply ripple rejection ratio vs Frequency 15, 16 Output noise voltage vs Frequency 17, 18 Crosstalk vs Frequency 19 – 24 Shutdown attenuation vs Frequency 25, 26 Open-loop gain and phase margin vs Frequency 27, 28 Output power vs Load resistance 29, 30, IDD Supply current vs Supply voltage 31 SNR Signal-to-noise ratio vs Voltage gain 32 Power dissipation/amplifier vs Load power 33, 34 Vn 4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 TYPICAL CHARACTERISTICS TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT POWER 10 THD+N – Total Harmonic Distortion + Noise – % THD+N – Total Harmonic Distortion + Noise – % TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY VDD = 3.3 V, PO = 25 mW, CB = 1 µF, RL = 32 Ω, AV = –1 V/V 1 0.1 0.01 0.001 20 100 1k 10 1 VDD = 3.3 V, RL = 32 Ω, AV = –1 V/V, CB = 1 µF 20 kHz 0.1 1 kHz 0.01 0.001 10 10k 20k 50 Figure 1 Figure 2 1 AV = –5 V/V AV = –1 V/V AV = –10 V/V 0.1 0.05 0.01 0.001 20 100 1k f – Frequency – Hz TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT POWER THD+N – Total Harmonic Distortion + Noise – % THD+N – Total Harmonic Distortion + Noise – % TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY VDD = 5 V, PO = 60 mW, CB = 1 µF, RL = 32 Ω, 100 PO – Output Power – mW f – Frequency – Hz 10 20 Hz 10k 20k 10 1 VDD = 5 V, RL = 32 Ω, AV = –1 V/V, CB = 1 µF 20 Hz 20 kHz 0.1 1 kHz 0.01 0.001 10 100 500 PO – Output Power – mW Figure 3 Figure 4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 TYPICAL CHARACTERISTICS TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY 10 THD+N – Total Harmonic Distortion + Noise – % THD+N – Total Harmonic Distortion + Noise – % TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY VDD = 3.3 V, PO = 100 mW, CB = 1 µF, RL = 10 kΩ, AV = –1 V/V 1 0.1 0.01 0.001 20 100 1k f – Frequency – Hz 10 1 VDD = 5 V, PO = 100 mW, CB = 1 µF, RL = 10 kΩ AV = –5 V/V AV = –1 V/V 0.1 AV = –10 V/V 0.01 0.001 20 10k 20k 100 Figure 5 THD+N – Total Harmonic Distortion + Noise – % THD+N – Total Harmonic Distortion + Noise – % TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT POWER 10 VDD = 3.3 V, PO = 60 mW, CB = 1 µF, RL = 8 Ω, AV = –1 V/V 0.1 0.01 0.001 20 100 1k f – Frequency – Hz 10k 20k 10 1 VDD = 3.3 V, RL = 8 Ω, AV = –1 V/V, CB = 1 µF 20 Hz 20 kHz 0.1 1 kHz 0.01 0.001 10 100 PO – Output Power – mW Figure 7 6 10k 20k Figure 6 TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY 1 1k f – Frequency – Hz Figure 8 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 500 TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 TYPICAL CHARACTERISTICS TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT POWER 10 VDD = 5 V, PO = 150 mW, CB = 1 µF, RL = 8 kΩ 1 THD+N – Total Harmonic Distortion + Noise – % THD+N – Total Harmonic Distortion + Noise – % TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY AV = –5 V/V AV = –1 V/V 0.1 AV = –10 V/V 0.01 0.001 20 100 1k f – Frequency – Hz 10 VDD = 5 V, RL = 8 Ω, AV = –1 V/V, CB = 1 µF 1 0.01 20 Hz 100 PO – Output Power – mW Figure 9 VDD = 3.3 V, PO = 40 mW, CB = 1 µF, RL = 16 Ω, AV = –1 V/V 0.1 0.01 100 TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT POWER THD+N – Total Harmonic Distortion + Noise – % THD+N – Total Harmonic Distortion + Noise – % 10 0.001 20 1k f – Frequency – Hz 500 Figure 10 TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY 1 20 kHz 0.1 0.001 10 10k 20k 1 kHz 10k 20k 10 1 VDD = 3.3 V, RL =16 Ω, AV = –1 V/V, CB = 1 µF 20 Hz 20 kHz 1 kHz 0.1 0.01 0.001 10 Figure 11 100 PO – Output Power – mW 500 Figure 12 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 TYPICAL CHARACTERISTICS TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT POWER THD+N – Total Harmonic Distortion + Noise – % THD+N – Total Harmonic Distortion + Noise – % 10 VDD = 5 V, PO = 100 mW, CB = 1 µF, RL = 16 Ω 1 AV = –1 V/V AV = –5 V/V 0.1 AV = –10 V/V 0.01 0.001 20 100 1k f – Frequency – Hz 10k 10 1 VDD = 5 V, RL = 16 Ω, AV = –1 V/V, CB = 1 µF 20 kHz 1 kHz 0.1 0.01 0.001 10 20k Figure 14 SUPPLY RIPPLE REJECTION RATIO vs FREQUENCY SUPPLY RIPPLE REJECTION RATIO vs FREQUENCY VDD = 3.3 V, RL = 16 Ω, AV = –1 V/V 0.47 µF –20 1 µF –30 –40 –50 –60 –70 –80 Bypass = 1.65 V –90 –100 –110 –120 20 100 1k f – Frequency – Hz 10k 20k 0 K SVR – Supply Ripple Rejection Ratio – dB K SVR – Supply Ripple Rejection Ratio – dB 0 0.1 µF 0.1 µF –10 VDD = 5 V, RL = 16 Ω, AV = –1 V/V 0.47 µF –20 1 µF –30 –40 –50 –60 –70 –80 Bypass = 2.5 V –90 –100 –110 –120 20 Figure 15 8 500 100 PO – Output Power – mW Figure 13 –10 20 Hz 100 1k f – Frequency – Hz Figure 16 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 10k 20k TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 TYPICAL CHARACTERISTICS OUTPUT NOISE VOLTAGE vs FREQUENCY OUTPUT NOISE VOLTAGE vs FREQUENCY 100 VDD = 3.3 V, BW = 10 Hz to 22 kHz RL = 16 Ω AV = –10 V/V AV = –1 V/V 10 V n – Output Noise Voltage – µ V(RMS) V n – Output Noise Voltage – µ V(RMS) 100 1 20 100 1k f – Frequency – Hz AV = –10 V/V AV = –1 V/V 10 VDD = 5 V, BW = 10 Hz to 22 kHz RL = 16 Ω, 1 10k 20k 20 100 Figure 17 1k f – Frequency – Hz Figure 18 CROSSTALK vs FREQUENCY CROSSTALK vs FREQUENCY 0 –20 –30 –20 –30 –40 –50 –60 –70 –80 –40 –50 –60 –70 –80 IN2– to VO1 –90 IN2– to VO1 –90 –100 –100 –110 –120 VDD = 3.3 V, PO = 40 mW, CB = 1 µF, RL = 16 Ω, AV = –1 V/V –10 Crosstalk – dB Crosstalk – dB 0 VDD = 3.3 V, PO = 25 mW, CB = 1 µF, RL = 32 Ω, AV = –1 V/V –10 10k 20k IN1– to VO2 20 100 1k f – Frequency – Hz IN1– to VO2 –110 10k 20k –120 20 Figure 19 100 1k f – Frequency – Hz 10k 20k Figure 20 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 9 TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 TYPICAL CHARACTERISTICS CROSSTALK vs FREQUENCY CROSSTALK vs FREQUENCY 0 0 VDD = 3.3 V, PO = 60 mW, CB = 1 µF, RL = 8 Ω, AV = –1 V/V –10 –20 –20 –30 –40 Crosstalk – dB Crosstalk – dB –30 –50 –60 –70 IN2– to VO1 –80 –40 –50 –60 –70 –80 –90 IN2– to VO1 –90 –100 –100 IN1– to VO2 –110 –120 VDD = 5 V, PO = 60 mW, CB = 1 µF, RL = 32 Ω, AV = –1 V/V –10 IN1– to VO2 –110 20 100 1k f – Frequency – Hz –120 10k 20k 20 100 Figure 21 CROSSTALK vs FREQUENCY 0 0 VDD = 5 V, PO = 100 mW, CB = 1 µF, RL = 16 Ω, AV = –1 V/V –10 –20 –20 –30 –40 –50 –60 –70 –80 VDD = 5 V, PO = 150 mW, CB = 1 µF, RL = 8 Ω, AV = –1 V/V –10 Crosstalk – dB Crosstalk – dB –30 –40 –50 –60 –70 IN2– to VO1 –80 IN2– to VO1 –90 –90 –100 –100 IN1– to VO2 –110 20 100 IN1– to VO2 –110 1k f – Frequency – Hz 10k 20k –120 20 Figure 23 10 10k 20k Figure 22 CROSSTALK vs FREQUENCY –120 1k f – Frequency – Hz 100 1k f – Frequency – Hz Figure 24 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 10k 20k TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 TYPICAL CHARACTERISTICS SHUTDOWN ATTENUATION vs FREQUENCY –10 –20 Shutdown Attenuation – dB Shutdown Attenuation – dB 0 VDD = 3.3 V, RL = 16 Ω, CB = 1 µF –10 –30 –40 –50 –60 –70 –20 –30 –40 –50 –60 –70 –80 –80 –90 –90 –100 10 100 1k 10 k VDD = 5 V, RL = 16 Ω, CB = 1 µF –100 10 1M 100 f – Frequency – Hz Figure 25 VDD = 3.3 V RL = 10 kΩ 180 120 150 100 Gain 120 Phase 90 30 Gain 0 40 –30 20 –60 –90 0 Open-Loop Gain – dB 60 60 VDD = 5 V RL = 10 kΩ 90 60 60 30 Phase 0 40 –30 20 –60 –90 0 –120 –120 –20 –20 –150 –150 10 k 100 k 1M –180 10 M 150 120 80 Φ m – Phase Margin – Deg 80 –40 1k 1M OPEN-LOOP GAIN AND PHASE MARGIN vs FREQUENCY 180 120 Open-Loop Gain – dB 10 k Figure 26 OPEN-LOOP GAIN AND PHASE MARGIN vs FREQUENCY 100 1k f – Frequency – Hz Φm – Phase Margin – Deg 0 SHUTDOWN ATTENUATION vs FREQUENCY –40 1k 10 k 100 k 1M –180 10 M f – Frequency – Hz f – Frequency – Hz Figure 27 Figure 28 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 11 TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 TYPICAL CHARACTERISTICS OUTPUT POWER vs LOAD RESISTANCE OUTPUT POWER vs LOAD RESISTANCE 100 250 VDD = 3.3 V, THD+N = 1%, AV = –1 V/V VDD = 5 V, THD+N = 1%, AV = –1 V/V 200 P – Output Power – mW O P – Output Power – mW O 75 50 25 0 150 100 50 0 8 12 16 20 24 28 32 36 40 44 45 52 56 60 64 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 RL – Load Resistance – Ω RL – Load Resistance – Ω Figure 30 Figure 29 SUPPLY CURRENT vs SUPPLY VOLTAGE SIGNAL-TO-NOISE RATIO vs VOLTAGE GAIN 2.5 120 SNR – Signal-to-Noise Ratio – dB VDD = 5 V I DD – Supply Current – mA 2 1.5 1 0.5 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 VDD – Supply Voltage – V 5 5.5 100 80 60 40 20 0 1 2 4 5 Figure 32 POST OFFICE BOX 655303 6 7 AV – Voltage Gain – V/V Figure 31 12 3 • DALLAS, TEXAS 75265 8 9 10 TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 TYPICAL CHARACTERISTICS POWER DISSIPATION/AMPLIFIER vs LOAD POWER VDD = 3.3 V Power Dissipation/Amplifier – mW 70 180 VDD = 5 V 8Ω Power Dissipation/Amplifier – mW 80 60 50 40 16 Ω 30 32 Ω 20 64 Ω 10 POWER DISSIPATION/AMPLIFIER vs LOAD POWER 140 120 100 16 Ω 80 60 32 Ω 40 64 Ω 20 0 0 20 40 60 80 100 120 140 160 180 200 8Ω 160 0 0 20 40 Load Power – mW 60 80 100 120 140 160 180 200 Load Power – mW Figure 33 Figure 34 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 13 TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 APPLICATION INFORMATION gain setting resistors, Rf and Ri ǒǓ The gain for the TPA6111A2 is set by resistors Rf and Ri according to equation 1. Gain +* Rf (1) Ri Given that the TPA6111A2 is a MOS amplifier, the input impedance is very high. Consequently input leakage currents are not generally a concern, although noise in the circuit increases as the value of Rf increases. In addition, a certain range of Rf values is required for proper start-up operation of the amplifier. Taken together it is recommended that the effective impedance seen by the inverting node of the amplifier be set between 5 kΩ and 20 kΩ. The effective impedance is calculated in equation 2. Effective Impedance + RR)fRRi f (2) i As an example, consider an input resistance of 20 kΩ and a feedback resistor of 20 kΩ. The gain of the amplifier would be – 1 and the effective impedance at the inverting terminal would be 10 kΩ, which is within the recommended range. For high performance applications, metal film resistors are recommended because they tend to have lower noise levels than carbon resistors. For values of Rf above 50 kΩ, the amplifier tends to become unstable due to a pole formed from Rf and the inherent input capacitance of the MOS input structure. For this reason, a small compensation capacitor of approximately 5 pF should be placed in parallel with Rf. This, in effect, creates a low-pass filter network with the cutoff frequency defined in equation 3. f c(lowpass) + 2 p R1 C (3) f F For example, if Rf is 100 kΩ and CF is 5 pF then fc(lowpass) is 318 kHz, which is well outside 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 4. f c(highpass) + 2 p R1 C (4) i i The value of Ci is important to consider, as it directly affects the bass (low frequency) performance of the circuit. Consider the example where Ri is 20 kΩ and the specification calls for a flat bass response down to 20 Hz. Equation 4 is reconfigured as equation 5. Ci 14 + 2pR f 1 (5) i c(highpass) POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 APPLICATION INFORMATION input capacitor, Ci (continued) In this example, Ci is 0.40 µF, so one would likely choose a value in the range of 0.47 µF to 1 µF. A further consideration for this capacitor is the leakage path from the input source through the input network (Ri, Ci) and the feedback resistor (Rf) to the load. This leakage current creates a dc offset voltage at the input to the amplifier that reduces useful headroom, especially in high-gain applications (> 10). For this reason a low-leakage tantalum or ceramic capacitor is the best choice. When polarized capacitors are used, the positive side of the capacitor should face the amplifier input in most applications, as the dc level there is held at VDD/2, which is likely higher than the source dc level. Please note that it is important to confirm the capacitor polarity in the application. power supply decoupling, C(S) The TPA6111A2 is a high-performance CMOS audio amplifier that requires adequate power supply decoupling to ensure that the output total harmonic distortion (THD) is as low as possible. Power supply decoupling also prevents oscillations for long lead lengths between the amplifier and the speaker. The optimum decoupling is achieved by using two capacitors of different types that target different types of noise on the power supply leads. For higher frequency transients, spikes, or digital hash on the line, a good low equivalent-series-resistance (ESR) ceramic capacitor, typically 0.1 µF, placed as close as possible to the device VDD lead, works best. For filtering lower-frequency noise signals, a larger aluminum electrolytic capacitor of 10 µF or greater placed near the power amplifier is recommended. midrail bypass capacitor, C(BYP) The midrail bypass capacitor, C(BYP), serves several important functions. During start up, C(BYP) determines the rate at which the amplifier starts up. This helps to push the start-up pop noise into the subaudible range (so low it can not be heard). The second function is to reduce noise produced by the power supply caused by coupling into the output drive signal. This noise is from the midrail generation circuit internal to the amplifier. The capacitor is fed from a 230-kΩ source inside the amplifier. To keep the start-up pop as low as possible, the relationship shown in equation 6 should be maintained. ǒ 1 C (BYP) 230 kΩ Ǔ v ǒC1R Ǔ (6) i i As an example, consider a circuit where C(BYP) is 1 µF, Ci is 1 µF, and Ri is 20 kΩ. Inserting these values into the equation 9 results in: 6.25 ≤ 50 which satisfies the rule. Bypass capacitor, C(BYP), values of 0.1 µF to 1 µF ceramic or tantalum low-ESR capacitors are recommended for the best THD and noise performance. output coupling capacitor, C(C) In the typical single-supply single-ended (SE) configuration, an output coupling capacitor (CC) is required to block the dc bias at the output of the amplifier, thus preventing dc currents in the load. As with the input coupling capacitor, the output coupling capacitor and impedance of the load form a high-pass filter governed by equation 7. fc + 2 p R1 C (7) L (C) POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 15 TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 APPLICATION INFORMATION output coupling capacitor, C(C) (continued) The main disadvantage, from a performance standpoint, is that the typically small load impedances drive the low-frequency corner higher. Large values of C(C) are required to pass low frequencies into the load. Consider the example where a C(C) of 68 µF is chosen and loads vary from 32 Ω to 47 kΩ. Table 1 summarizes the frequency response characteristics of each configuration. Table 1. Common Load Impedances vs Low Frequency Output Characteristics in SE Mode RL CC 68 µF LOWEST FREQUENCY 32 Ω 10,000 Ω 68 µF 0.23 Hz 47,000 Ω 68 µF 0.05 Hz 73 Hz As Table 1 indicates, headphone response is adequate and drive into line level inputs (a home stereo for example) is very good. The output coupling capacitor required in single-supply SE mode also places additional constraints on the selection of other components in the amplifier circuit. With the rules described earlier still valid, add the following relationship: ǒ 1 C (BYP) 230 kΩ Ǔ v ǒC1R Ǔ Ơ R C1 i i (8) L (C) using low-ESR capacitors Low-ESR capacitors are recommended throughout this application. A real capacitor can be modeled simply as a resistor in series with an ideal capacitor. The voltage drop across this resistor minimizes the beneficial effects of the capacitor in the circuit. The lower the equivalent value of this resistance, the more the real capacitor behaves like an ideal capacitor. 5-V versus 3.3-V operation The TPA6111A2 was designed for operation over a supply range of 2.7 V to 5.5 V. This data sheet provides full specifications for 5-V and 3.3-V operation, since these are considered to be the two most common standard voltages. There are no special considerations for 3.3-V versus 5-V operation as far as supply bypassing, gain setting, or stability. Supply current is slightly reduced from 3.5 mA (typical) to 2.5 mA (typical). The most important consideration is that of output power. Each amplifier in the TPA6111A2 can produce a maximum voltage swing of VDD – 1 V. This means, for 3.3-V operation, clipping starts to occur when VO(PP) = 2.3 V as opposed when VO(PP) = 4 V while operating at 5 V. The reduced voltage swing subsequently reduces maximum output power into the load before distortion begins to become significant. 16 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 MECHANICAL DATA D (R-PDSO-G**) PLASTIC SMALL-OUTLINE PACKAGE 14 PINS SHOWN 0.050 (1,27) 0.020 (0,51) 0.014 (0,35) 14 0.010 (0,25) M 8 0.008 (0,20) NOM 0.244 (6,20) 0.228 (5,80) 0.157 (4,00) 0.150 (3,81) Gage Plane 0.010 (0,25) 1 7 0°– 8° A 0.044 (1,12) 0.016 (0,40) Seating Plane 0.069 (1,75) MAX 0.010 (0,25) 0.004 (0,10) PINS ** 0.004 (0,10) 8 14 16 A MAX 0.197 (5,00) 0.344 (8,75) 0.394 (10,00) A MIN 0.189 (4,80) 0.337 (8,55) 0.386 (9,80) DIM 4040047 / D 10/96 NOTES: A. B. C. D. All linear dimensions are in inches (millimeters). This drawing is subject to change without notice. Body dimensions do not include mold flash or protrusion, not to exceed 0.006 (0,15). Falls within JEDEC MS-012 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 17 TPA6111A2 150-mW STEREO AUDIO POWER AMPLIFIER SLOS313 – DECEMBER 2000 MECHANICAL DATA DGN (S-PDSO-G8) PowerPAD PLASTIC SMALL-OUTLINE PACKAGE 0,38 0,25 0,65 8 0,25 M 5 Thermal Pad (See Note D) 0,15 NOM 3,05 2,95 4,98 4,78 Gage Plane 0,25 1 0°– 6° 4 3,05 2,95 0,69 0,41 Seating Plane 1,07 MAX 0,15 0,05 0,10 4073271/A 04/98 NOTES: A. B. C. D. All linear dimensions are in millimeters. This drawing is subject to change without notice. Body dimensions include mold flash or protrusions. The package thermal performance may be enhanced by attaching an external heat sink to the thermal pad. This pad is electrically and thermally connected to the backside of the die and possibly selected leads. E. Falls within JEDEC MO-187 PowerPAD is a trademark of Texas Instruments. 18 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgment, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. 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