TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 D D D D D D OR DGN PACKAGE (TOP VIEW) 150-mW Stereo Output Wide Range of Supply Voltages – Fully Specified for 3.3 V and 5 V Operation – Operational From 2.5 V to 5.5 V Thermal and Short-Circuit Protection Surface Mount Packaging – PowerPAD MSOP – SOIC Standard Operational Amplifier Pinout VO 1 IN1– IN1+ GND 1 8 2 7 3 6 4 5 VDD VO 2 IN2– IN2+ description The TPA112 is a stereo audio power amplifier packaged in an 8-pin PowerPAD MSOP package capable of delivering 150 mW of continuous RMS power per channel into 8-Ω loads. Amplifier gain is externally configured by means of two resistors per input channel and does not require external compensation for settings of 1 to 10. THD+N when driving an 8-Ω load from 5 V is 0.1% at 1 kHz, and less than 2% across the audio band of 20 Hz to 20 kHz. For 32-Ω loads, the THD+N is reduced to less than 0.06% 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 0.01% at 1 kHz, and less than 0.02% across the audio band of 20 Hz to 20 kHz. functional block diagram RF VDD 8 VO1 1 Short-Circuit Protection CI VDD RI LIN– CI RI LIN+ 2 IN1– 3 IN1+ CC RC RO RF To Headphone Jack (See TPA152) VDD/2 CI RIN– CI RI RF 6 IN2– 5 IN2+ VO2 CC 7 RO RI RC RIN+ Over-Temperature Protection 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 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 AVAILABLE OPTIONS PACKAGED DEVICES TA SMALL OUTLINE† (D) MSOP Symbolization MSOP† (DGN) – 40°C to 85°C TPA112D TPA112DGN TI AAD † The D and DGN package is available in left-ended tape and reel only (e.g., TPA112DR, TPA112DGNR). Terminal Functions TERMINAL NAME I/O NO. DESCRIPTION GND 4 I GND is the ground connection. IN1– 2 I IN1– is the inverting input for channel 1. IN1+ 3 I IN1+ is the noninverting input for channel 1. IN2– 6 I IN2– is the inverting input for channel 2. IN2+ 5 I IN2+ is the noninverting input for channel 2. 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 Differential input voltage, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to VDD + 0.3 V Input current, II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±2.5 µA Output current, IO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±250 mA 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 ‡ Please 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 Supply voltage, VDD 2.5 5.5 V Operating free-air temperature, TA –40 85 °C 2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 UNIT TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 dc electrical characteristics at TA = 25°C, VDD = 3.3 V PARAMETER TEST CONDITIONS MIN TYP MAX 5 UNIT VIO PSRR Input offset voltage IDD(q) IDD(SD) Supply current 1.5 3 mA Supply current in SHUTDOWN mode 10 50 µA ZI Input impedance >1 Power supply rejection ratio VDD = 3.2 V to 3.4 V 83 mV dB MΩ ac operating characteristics, VDD = 3.3 V, TA = 25°C, RL = 8 Ω PARAMETER TEST CONDITIONS PO THD+N Output power (each channel) THD ≤ 0.1% Total harmonic distortion + noise BOM Maximum output power BW PO = 70 mW, G = 10, Phase margin Open loop Supply ripple rejection f = 1 kHz Channel/channel output separation f = 1 kHz Signal-to-noise ratio PO = 100 mW SVRR SNR MIN TYP 70† 20–20 kHz 2% THD <5% >20 MAX UNIT mW kHz 58° Vn Noise output voltage † Measured at 1 kHz 68 dB 86 dB 100 dB 9.5 µV(rms) dc electrical characteristics at TA = 25°C, VDD = 5 V PARAMETER VIO PSRR Input offset voltage IDD(q) IDD(SD) Supply current ZI TEST CONDITIONS MIN TYP MAX UNIT 5 mV 1.5 3 mA Supply current in SHUTDOWN mode 60 100 µA Input impedance >1 Power supply rejection ratio VDD = 4.9 V to 5.1 V 76 dB MΩ ac operating characteristics, VDD = 5 V, TA = 25°C, RL = 8 Ω PARAMETER TEST CONDITIONS MIN TYP MAX UNIT PO THD+N Output power (each channel) THD ≤ 0.1% 70† Total harmonic distortion + noise 2% BOM Maximum output power BW PO = 150 mW, 20–20 kHz G = 10, THD <5% >20 Phase margin Open loop 56° Supply ripple rejection f = 1 kHz 68 dB Channel/channel output separation f = 1 kHz 86 dB Signal-to-noise ratio PO = 150 mW 100 dB 9.5 µV(rms) SVRR SNR Vn Noise output voltage † Measured at 1 kHz POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 mW kHz 3 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 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% Total harmonic distortion + noise BOM Maximum output power BW PO = 30 mW, G = 10, Phase margin Open loop Supply ripple rejection f = 1 kHz Channel/channel output separation f = 1 kHz Signal-to-noise ratio PO = 100 mW SVRR SNR MIN TYP 40† 20–20 kHz 0.5% THD <2% >20 MAX UNIT mW kHz 58° Vn Noise output voltage † Measured at 1 kHz 68 dB 86 dB 100 dB 9.5 µV(rms) ac operating characteristics, VDD = 5 V, TA = 25°C, RL = 32 Ω PARAMETER TEST CONDITIONS MIN TYP MAX UNIT PO THD+N Output power (each channel) THD ≤ 0.1% Total harmonic distortion + noise BOM Maximum output power BW PO = 60 mW, G = 10, Phase margin Open loop Supply ripple rejection f = 1 kHz 68 dB Channel/channel output separation f = 1 kHz 86 dB Signal-to-noise ratio PO = 150 mW SVRR SNR 40† 20–20 kHz 0.4% THD <2% >20 Vn Noise output voltage † Measured at 1 kHz 4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 mW kHz 56° 100 dB 9.5 µV(rms) TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS Table of Graphs FIGURE THD+N Total harmonic distortion plus noise vs Frequency vs Power output 1, 2, 4, 5, 7, 8, 10, 11, 13, 14, 16, 17, 34, 36 3, 6, 9, 12, 15, 18 PSSR Power supply rejection ratio vs Frequency 19, 20 Vn Output noise voltage vs Frequency 21, 22 Crosstalk vs Frequency 23 – 26, 37, 38 Mute attenuation vs Frequency 27, 28 Open-loop gain vs Frequency 29, 30 Phase margin vs Frequency 29, 30 Phase vs Frequency 39 – 44 Output power vs Load resistance 31, 32 ICC Supply current vs Supply voltage 33 SNR Signal-to-noise ratio vs Voltage gain Closed-loop gain vs Frequency 39 – 44 Power dissipation/amplifier vs Output power 45, 46 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 35 5 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 10 VDD = 3.3 V PO = 30 mW CB = 1 µ F RL = 32 Ω 1 THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10 AV = 5 AV = 10 0.1 AV = 1 0.01 0.001 20 100 1k 1 VDD = 3.3 V AV = 1 V/V RL = 32 Ω CB = 1 µ F PO = 15 mW 0.1 PO = 10 mW 0.01 PO = 30 mW 0.001 20 10k 20k 100 f – Frequency – Hz Figure 2 TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 10 10 VDD = 3.3 V RL = 32 Ω AV = 1 V/V CB = 1 µF THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10k 20k f – Frequency – Hz Figure 1 20 kHz 10 kHz 1 0.1 1 kHz 20 Hz 0.01 1 10 50 1 VDD = 5 V PO = 60 mW RL = 32 Ω CB = 1 µF AV = 10 mW 0.1 AV = 5 mW 0.01 AV = 1 mW 0.001 20 PO – Output Power – mW 100 1k f – Frequency – Hz Figure 3 6 1k Figure 4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 10k 20k TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER 10 1 0.1 VDD = 5 V RL = 32 Ω AV = 1 V/V CB = 1 µF THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10 PO = 30 mW PO = 15 mW 0.01 PO = 60 mW 0.001 20 100 1k VDD = 5 V AV = 1 V/V RL = 32 Ω CB = 1 µF 20 kHz 1 10 kHz 0.1 1 kHz 20 Hz 0.01 0.002 10k 20k 0.01 Figure 5 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 10 VDD = 3.3 V RL = 10 kΩ PO = 100 µF CB = 1 µF AV = 5 mW 0.01 AV = 2 mW 0.001 20 100 1k 10k 20k THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10 0.1 0.2 Figure 6 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 1 0.1 PO – Output Power – W f – Frequency – Hz 1 VDD = 3.3 V RL = 10 kΩ AV = 1 V/V CB = 1 µF 0.1 PO = 45 µW 0.01 PO = 90 µW PO = 130 µW 0.001 20 f – Frequency – Hz 100 1k 10k 20k f – Frequency – Hz Figure 7 Figure 8 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER 10 VDD = 3.3 V RL = 10 k Ω AV = 1 V/V CB = 1 µF THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10 1 0.1 20 Hz 10 kHz 0.01 20 Hz 1 kHz 0.001 5 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 10 100 1 VDD = 5 V RL = 10 kΩ PO = 300 µW CB = 1 µF 0.1 AV = 5 AV = 1 0.01 AV = 2 0.001 20 200 PO – Output Power – µW 100 Figure 10 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER 10 VDD = 5 V RL = 10 kΩ AV = 1 V/V CB = 1 µF PO = 300 µW 0.1 PO = 200 µW 0.01 PO = 100 µW THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10 0.001 20 VDD = 5 V RL = 10 kΩ AV = 1 V/V CB = 1 µ F 1 0.1 20 Hz 20 kHz 0.01 10 kHz 1 kHz 0.001 100 1k 10k 20k 5 10 100 PO – Output Power – µW f – Frequency – Hz Figure 11 8 10k 20k f – Frequency – Hz Figure 9 1 1k Figure 12 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 500 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 2 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 10 VDD = 3.3 V PO = 75 mW RL = 8 Ω CB = 1 µF 1 AV = 5 AV = 2 0.1 AV = 1 0.01 0.001 100 20 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY THD+N –Total Harmonic Distortion + Noise – % THD+N – Total Harmonic Distortion Plus Noise – % TYPICAL CHARACTERISTICS 1k VDD = 3.3 V RL = 8 Ω AV = 1 V/V PO = 30 mW 1 PO = 15 mW 0.1 0.01 PO = 75 mW 0.001 20 10k 20k f – Frequency – Hz 100 1k 10k 20k f – Frequency – Hz Figure 13 Figure 14 THD+N – Total Harmonic Distortion Plus Noise – % TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER THD+N –Total Harmonic Distortion + Noise – % 10 VDD = 3.3 V RL = 8 Ω AV = 1 V/V 20 kHz 10 kHz 1 1 kHz 0.1 20 Hz 0.01 10m 0.1 0.3 2 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY VDD = 5 V PO = 100 mW RL = 8 Ω CB = 1 µF 1 AV = 2 AV = 5 0.1 AV = 1 0.01 0.001 20 100 1k 10k 20k f – Frequency – Hz PO – Output Power – W Figure 15 Figure 16 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 9 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY TOTAL HARMONIC DISTORTION PLUS NOISE vs POWER OUTPUT 10 THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10 VDD = 5 V RL = 8 kΩ AV = 1 V/V PO = 30 mW 1 0.1 PO = 60 mW 0.01 PO = 10 mW 0.001 20 100 1k VDD = 5 V RL = 8 Ω AV = 1 V/V 20 kHz 1 10 kHz 20 Hz 0.01 10m 10k 20k 0.1 f – Frequency – Hz Figure 18 POWER SUPPLY REJECTION RATIO vs FREQUENCY POWER SUPPLY REJECTION RATIO vs FREQUENCY VDD = 3.3 V RL = 8 Ω to 10 kΩ CB = 0.1 µF –30 CB = 1 µF –40 –50 –60 CB = 2 µF –70 Bypass = 1.65 V –80 –90 –100 20 100 1k 10k 20k 0 PSRR – Power Supply Rejection Ratio – dB PSRR – Power Supply Rejection Ratio – dB 0 –20 VDD = 5 V RL = 8 Ω to 10 kΩ –10 –20 CB = 0.1 µF –30 CB = 1 µF –40 –50 –60 CB = 2 µF –70 –80 –90 –100 20 f – Frequency – Hz Bypass = 2.5 V 100 1k f – Frequency – Hz Figure 19 10 1 PO – Output Power – W Figure 17 –10 1 kHz 0.1 Figure 20 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 10k 20k TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS OUTPUT NOISE VOLTAGE vs FREQUENCY OUTPUT NOISE VOLTAGE vs FREQUENCY 20 10 Vn – Output Noise Voltage – µV Vn – Output Noise Voltage – µV 20 VDD = 3.3 V BW = 10 Hz to 22 kHz AV = 1 V/V RL = 8 Ω to 10 kΩ 1 20 100 1k 10 VDD = 5 V BW = 10 Hz to 22 kHz RL = 8 Ω to 10 kΩ AV = 1 V/V 1 20 10k 20k 100 f – Frequency – Hz Figure 22 CROSSTALK vs FREQUENCY CROSSTALK vs FREQUENCY –60 Crosstalk – dB –75 –50 PO = 25 mW VDD = 3.3 V RL = 32 Ω CB = 1 µF AV = 1 V/V –60 –65 –80 IN 2 TO OUT 1 –85 –90 –95 –70 –75 IN 2 TO OUT 1 –80 –85 –100 IN 1 TO OUT 2 –105 –110 20 PO = 100 mW VDD = 3.3 V RL = 8 Ω CB = 1 µF AV = 1 V/V –55 Crosstalk – dB –70 10k 20k f – Frequency – Hz Figure 21 –65 1k IN 1 TO OUT 2 –90 –95 100 1k 10k 20k –100 20 f – Frequency – Hz 100 1k 10k 20k f – Frequency – Hz Figure 23 Figure 24 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 11 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS CROSSTALK vs FREQUENCY CROSSTALK vs FREQUENCY –60 –50 VDD = 5 V PO = 25 mW CB = 1 µF RL = 32 Ω AV = 1 V/V –65 –65 –60 –65 Crosstalk – dB Crosstalk – dB –75 –55 –80 –85 IN 2 TO OUT 1 –90 –95 VDD = 5 V PO = 100 mW CB = 1 µF RL = 8 Ω AV = 1 V/V –70 IN 2 TO OUT 1 –75 –80 –85 –100 –90 IN 1 TO OUT 2 IN 1 TO OUT 2 –105 –95 –110 20 100 1k –100 20 10k 20k 100 f – Frequency – Hz Figure 25 MUTE ATTENUATION vs FREQUENCY 0 –10 –20 –30 –40 –50 –60 –70 –40 –50 –60 –70 –80 –90 –90 100 1k 10k 20k VDD = 5 V CB = 1 µF RL = 32 Ω –30 –80 –100 20 12 0 VDD = 3.3 V RL = 32 Ω CB = 1 µF Mute Attenuation – dB Mute Attenuation – dB –20 10k 20k Figure 26 MUTE ATTENUATION vs FREQUENCY –10 1k f – Frequency – Hz –100 20 100 1k f – Frequency – Hz f – Frequency – Hz Figure 27 Figure 28 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 10k 20k TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS OPEN–LOOP GAIN AND PHASE MARGIN vs FREQUENCY 150° 100 VDD = 3.3 V TA = 25°C No Load 120° Phase 60 φ m – Phase Margin Open-Loop Gain – dB 80 90° 40 60° Gain 20 30° 0 0° –20 100 1k 10k 100k 1M –30° 10M f – Frequency – Hz Figure 29 OPEN–LOOP GAIN AND PHASE MARGIN vs FREQUENCY 100 150° Open-Loop Gain – dB 80 Phase 60 40 120° 90° 60° Gain 20 30° 0 0° –20 100 1k 10k 100k 1M φ m – Phase Margin VDD = 5 V TA = 25°C No Load –30° 10M f – Frequency – Hz Figure 30 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 13 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS OUTPUT POWER vs LOAD RESISTANCE OUTPUT POWER vs LOAD RESISTANCE 120 300 THD+N = 1 % VDD = 3.3 V AV = 1 V/V 250 PO – Output Power – mW PO – Output Power – mW 100 THD+N = 1 % VDD = 5 V AV = 1 V/V 80 60 40 20 200 150 100 50 0 8 24 16 40 32 48 56 0 64 8 16 RL – Load Resistance – Ω 24 THD+N – Total Harmonic Distortion Plus Noise – % 1.4 I DD – Supply Current – mA 1.2 1 0.8 0.6 0.4 0.2 3 3.5 4 56 64 4.5 5 5.5 1 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY VI = 1 V AV = 1 V/V RL = 10 kΩ CB = 1 µF 0.1 0.01 0.001 20 100 1k f – Frequency – Hz VDD – Supply Voltage – V Figure 33 14 48 Figure 32 SUPPLY CURRENT vs SUPPLY VOLTAGE 2.5 40 RL – Load Resistance – Ω Figure 31 0 32 Figure 34 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 10k 20k TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS 104 THD+N – Total Harmonic Distortion Plus Noise – % SIGNAL–TO–NOISE RATIO vs VOLTAGE GAIN VI = 1 V SNR – Signal–to–Ratio – dB 102 100 98 96 94 92 1 2 3 4 5 6 8 7 9 10 1 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY VDD = 5 V AV = 1 RL = 10 kΩ CB = 1 µF 0.1 0.01 0.001 20 100 AV – Voltage Gain – V/V Figure 35 VDD = 3.3 V VO = 1 V RL = 10 kΩ CB = 1 µF –80 VDD = 5 V VO = 1 V RL = 10 kΩ CB = 1 µF –70 –80 –90 Crosstalk – dB Crosstalk – dB CROSSTALK vs FREQUENCY –60 –70 10k 20k Figure 36 CROSSTALK vs FREQUENCY –60 1k f – Frequency – Hz –100 IN2 to OUT1 –110 –120 –90 –100 IN2 to OUT1 –110 –120 –130 –130 IN1 to OUT2 –140 IN1 to OUT2 –140 –150 20 100 1k 10k 20k –150 20 f – Frequency – Hz 100 1k 10k 20k f – Frequency – Hz Figure 37 Figure 38 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 15 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS CLOSED–LOOP GAIN AND PHASE vs FREQUENCY 200° 180° Phase 140° Phase 160° Closed–Loop Gain – dB 120° VDD = 3.3 V RI = 20 kΩ RF = 20 kΩ RL = 32 Ω CI = 1 µF AV = –1 V/V 30 20 10 100° 80° Gain 0 –10 10 100 1k 10k 100k 1M f – Frequency – Hz Figure 39 CLOSED–LOOP GAIN AND PHASE vs FREQUENCY 200° 180° 160° 140° Closed–Loop Gain – dB 120° VDD = 5 V RI = 20 kΩ RF = 20 kΩ RL = 32 Ω CI = 1 µF AV = –1 V/V 30 20 10 100° 80° Gain 0 –10 10 100 1k 10k 100k f – Frequency – Hz Figure 40 16 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1M Phase Phase TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS CLOSED–LOOP GAIN AND PHASE vs FREQUENCY 200° 180° Phase 140° Phase 160° Closed–Loop Gain – dB 120° VDD = 3.3 V RI = 20 kΩ RF = 20 kΩ RL = 8 Ω CI = 1 µF AV = –1 V/V 40 100° 80° 60° Gain 20 0 –20 10 100 1k 10k 100k 1M f – Frequency – Hz Figure 41 CLOSED–LOOP GAIN AND PHASE vs FREQUENCY 200° 160° 140° Phase 180° Phase Closed–Loop Gain – dB 120° VDD = 3.3 V RI = 20 kΩ RF = 20 kΩ RL = 10 kΩ CI = 1 µF AV = –1 V/V 30 20 10 100° 80° Gain 0 –10 10 100 1k 10k 100k 1M f – Frequency – Hz Figure 42 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 17 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS CLOSED–LOOP GAIN AND PHASE vs FREQUENCY 200° 180° Phase Closed–Loop Gain – dB 140° VDD = 5 V RI = 20 kΩ RF = 20 kΩ RL = 8 Ω CI = 1 µF AV = –1 V/V 120° Phase 160° 100° 80° 60° 40° Gain 20 0 –20 10 100 1k 10k 100k 1M f – Frequency – Hz Figure 43 CLOSED–LOOP GAIN AND PHASE vs FREQUENCY 200° 180° 160° 140° 120° VDD = 5 V RI = 20 kΩ RF = 20 kΩ RL = 10 kΩ CI = 1 µF AV = –1 V/V 30 100° 80° 20 10 Gain 0 –10 10 100 1k 10k 100k f – Frequency – Hz Figure 44 18 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1M Phase Closed–Loop Gain – dB Phase TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS POWER DISSIPATION/AMPLIFIER vs OUTPUT POWER 80 180 VDD = 3.3 V VDD = 5 V 8Ω 70 8Ω 160 140 Amplifier Power – mW 60 Amplifier Power – mW POWER DISSIPATION/AMPLIFIER vs OUTPUT POWER 50 40 16 Ω 30 32 Ω 20 120 100 16 Ω 80 60 32 Ω 40 64 Ω 10 64 Ω 20 0 0 20 40 60 80 100 120 140 160 180 200 0 0 20 40 Load Power – mW 60 80 100 120 140 160 180 200 Load Power – mW Figure 45 Figure 46 APPLICATION INFORMATION gain setting resistors, RF and RI ǒǓ The gain for the TPA112 is set by resistors RF and RI according to equation 1. Gain +* RF (1) RI Given that the TPA112 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 + RRF)RRI 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. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 19 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 APPLICATION INFORMATION 20 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 gain setting resistors, RF and RI (continued) 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 co(lowpass) + 2 p R1 C (3) F F For example, if RF is 100 kΩ and CF is 5 pF then fco(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 co(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 + 2pR f 1 (5) I co(highpass) 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 that the source dc level. It is important to confirm the capacitor polarity in the application. power supply decoupling, CS The TPA112 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. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 21 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 APPLICATION INFORMATION midrail voltage The TPA112 is a single-supply amplifier, so it must be properly biased to accommodate audio signals. Normally, the amplifier is biased at VDD/2, but it can actually be biased at any voltage between VDD and ground. However, biasing the amplifier at a point other than VDD/2 will reduce the amplifier’s maximum output swing. In some applications where the circuitry driving the TPA112 has a different midrail voltage, it might make sense to use the same midrail voltage for the TPA112, and possibly eliminate the use of the dc-blocking caps. There are two concerns with the midrail voltage source: the amount of noise present, and its output impedance. Any noise present on the midrail voltage source that is not present on the audio input signal will be input to the amplifier, and passed to the output (and increased by the gain of the circuit). Common-mode noise will be cancelled out by the differential configuration of the circuit. The output impedance of the circuit used to generate the midrail voltage needs to be low enough so as not to be influenced by the audio signal path. A common method of generating the midrail voltage is to form a voltage divider from the supply to ground, with a bypass capacitor from the common node to ground. This capacitor improves the PSRR of the circuit. However, this circuit has a limited range of output impedances, so to achieve very low output impedances, the voltage generated by the voltage divider is fed into a unity-gain amplifier to lower the output impedance of the circuit. VDD VDD R R + _ Midrail CBYPASS TLV2460 R CBYPASS a) Midrail Voltage Generator Using a Simple Resistor-Divider Midrail R b) Buffered Midrail Voltage Generator to Provide Low Output Impedance Figure 47. Midrail Voltage Generator If a voltage step is applied to a speaker, it will pop. To reduce popping, the midrail voltage should rise at a sub-sonic rate; that is, a rate less than the rise time of a 20-Hz waveform. If the voltage rises faster than that, there is the possibility of a pop from the speaker. Pop can also be heard in the speaker if the midrail voltage rises faster than either the input coupling capacitor, or the output coupling capacitor. If midrail rises first, then the charging of the input and output capacitors will be heard in the speaker. To keep this noise as low as possible, the relationship shown in equation 6 should be maintained. ǒ CB 1 R SOURCE Ǔvǒ ǓƠ 1 CI RI 1 R LC C (6) Where CBYPASS is the value of the bypass capacitor, and RSOURCE is the equivalent source impedance of the voltage divider (the parallel combination of the two resistors). For example, if the voltage divider is constructed using two 20-kΩ resistors, then RSOURCE is 10 kΩ. 22 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 APPLICATION INFORMATION midrail bypass capacitor, CB The midrail bypass capacitor, CB, serves several important functions. During start-up, CB determines the rate at which the amplifier starts up. This helps to push the start-up pop noise into the subaudible range (so slow 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 the resistor divider with equivalent resistance of RSOURCE. To keep the start-up pop as low as possible, the relationship shown in equation 7 should be maintained. ǒ CB 1 R SOURCE Ǔvǒ Ǔ 1 CI RI (7) As an example, consider a circuit where CB is 1 µF, RSOURCE = 160 kΩ, CI is 1 µF, and RI is 20 kΩ. Inserting these values into the equation 9 results in: 6.25 v 50 which satisfies the rule. Bypass capacitor, CB, 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, CC 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 8. f (out high) + 2 p R1 C (8) L C The main disadvantage, from a performance standpoint, is that the typically small load impedances drive the low-frequency corner higher. Large values of CC are required to pass low frequencies into the load. Consider the example where a CC 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 Lowest Frequency 32 Ω 68 µF 73 Hz 10,000 Ω 68 µF 0.23 Hz 47,000 Ω 68 µF 0.05 Hz As Table 1 indicates, headphone response is adequate and drive into line level inputs (a home stereo for example) is very good. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 23 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 APPLICATION INFORMATION 24 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 2000 output coupling capacitor, CC (continued) 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: output pull-down resistor, RC + RO Placing a 100-Ω resistor, RC, from the output side of the coupling capacitor to ground insures the coupling capacitor, CC, is charged before a plug is inserted into the jack. Without this resistor, the coupling capacitor would charge rapidly upon insertion of a plug, leading to an audible pop in the headphones. Placing a 20-kΩ resistor, RO, from the output of the IC to ground insures that the coupling capacitor fully discharges at power down. If the supply is rapidly cycled without this capacitor, a small pop may be audible in 10-kΩ loads. 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 TPA112 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 TPA112 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. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 25 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 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. 26 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 TPA112 150-mW STEREO AUDIO POWER AMPLIFIER SLOS212C – AUGUST 1998 – REVISED MARCH 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. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 27 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. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. 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