TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 D D D D D D Desktop Computer Amplifier Solution – 1.75-W Bridge Tied Load (BTL) Center Channel – 500-mW L/R Single-Ended Channels Low Distortion Output – < 0.05% THD+N at Full Power Full 3.3-V and 5-V Specifications Surface-Mount Power Package 24-Pin TSSOP L/R Input MUX Feature Shutdown Control . . . IDD = 5 µA CFC RILC CB 1 2 3 4 5 6 7 8 9 10 11 12 GND/HS NC LOUT LLINEIN LHPIN CIN VDD SHUTDOWN MUTE OUT COUT+ MODE B GND/HS 19 NC CIN GND/HS NC ROUT RLINEIN RHPIN BYPASS VDD NC HP/LINE COUT– MODE A GND/HS COUT+ 10 – BYPASS 9 MUTE OUT 8 SHUTDOWN MODE A 14 CNTL MODE B 11 7, 18 HP/LINE 16 NC RIR 20 21 RHPIN RLINEIN Internal Speaker COUT – 15 + VDD VDD VDD RM2 RM1 VDD COUTR Right MUX – + ROUT 22 RM3 CIR NC RIL CIL 24 23 22 21 20 19 18 17 16 15 14 13 RFC 6 RIRC PWP PACKAGE (TOP VIEW) RFR 5 LHPIN 4 LLINEIN RFL Left MUX – + LOUT 3 COUTL GND/HS 1, 12, 13, 24 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 Incorporated. 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 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 description The TPA0103 is a 3-channel audio power amplifier in a 24-pin TSSOP thermal package primarily targeted at desktop PC or notebook applications. The left/right (L/R) channel outputs are single ended (SE) and capable of delivering 500 mW of continuous RMS power per channel into 4-Ω loads. The center channel output is a bridged tied load (BTL) configuration for delivering maximum output power from PC power supplies. Combining the SE line drivers and high power center channel amplifiers in a single TSSOP package simplifies design and frees up board space for other features. Full power distortion levels of less than 0.25% THD+N into 4-Ω loads from a 5-V supply voltage are typical. Low-voltage application are also well served by the TPA0103 providing 800 mW to the center channel into 4-Ω loads with a 3.3-V supply voltage. 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. A two channel input MUX circuit is integrated on the L/R channel inputs to allow two sets of stereo inputs to the amplifier. In the typical application, the center channel amplifier is driven from a mix of the L/R inputs to produce a monaural representation of the stereo signal. The center channel amplifier can be shut down independently of the L/R output for speaker muting in headphone applications. The TPA0103 also features a full shutdown function for power sensitive applications holding the bias current to 5 µA. The PowerPAD package (PWP) delivers a level of thermal performance that was previously achievable only in TO-220-type packages. Thermal impedances of less than 35°C/W are readily realized in multilayer PCB applications. This allows the TPA0103 to operate at full power at ambient temperature of up to 85°C. AVAILABLE OPTIONS PACKAGE TA TSSOP† (PWP) – 40°C to 85°C TPA0103PWP † The PWP package is available in left-ended tape and reel only (e.g., TPA0103PWPLE). 2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 Terminal Functions TERMINAL NAME BYPASS NO. I/O 19 DESCRIPTION Bypass. BYPASS is a tap to the voltage divider for the internal mid-supply bias. CIN 6 I Center channel input COUT+ 10 O Center channel + output. COUT+ is in an active or high-impedance state unless the device is in a mute state when the MODE A terminal (14) is high and the MODE B terminal (11) is low. COUT– 15 O Center channel – output. COUT– is in an active or high-impedance state unless the device is in a mute state when the MODE A terminal (14) is high and the MODE B terminal (11) is low. GND/HS 1, 12, 13, 24 MODE A, MODE B 14, 11 Ground. GND/HS is the ground connection for circuitry, directly connected to thermal pad. I Mode select. MODE A and MODE B determine the output modes of the TPA0103. TERMINAL 3 CHANNEL MUTE CENTER ONLY L/R ONLY MODE A L MODE B L H L H L H H HP/LINE 16 I Input MUX control input, hold high to select (L/R) HPIN (5, 20), hold low to select (L/R) LINEIN (4, 21). HP/LINE is normally connected to ground when inputs are connected to (L/R) LINEIN. LHPIN 5 I Left channel headphone input, selected when the HP/LINE terminal (16) is held high LLINEIN 4 I Left channel line input, selected when the HP/LINE terminal (16) is held low LOUT 3 O Left channel output. LOUT is active when the MODE A terminal (14) is low and the MODE B terminal (11) is don’t care. MUTE OUT 9 O When the MODE A terminal (14) is high and the MODE B terminal (11) is low, MUTE OUT is high and the device is in a mute state. Otherwise MUTE OUT is low. NC 2, 17, 23 RHPIN 20 RLINEIN ROUT SHUTDOWN VDD No internal connection I Right channel headphone input, selected when the HP/LINE terminal (16) is held high 21 I Right channel line input, selected when the HP/LINE terminal (16) is held low 22 O Right channel output. ROUT is active when the MODE A terminal (14) is low and the MODE B terminal (11) is don’t care. 8 I Places entire IC in shutdown mode when held high, IDD = 5 µA 7, 18 I Supply voltage input. The VDD terminals must be connected together. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 3 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Supply voltage, VDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 V Continuous output current (COUT+, COUT–, LOUT, ROUT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 A Continuous total power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . internally limited Operating virtual junction temperature range, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 40°C to 150°C Operating virtual case temperature range, TC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 40°C to 125°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 PWP‡ TA ≤ 25°C 2.7 W DERATING FACTOR 21.8 mW/°C TA = 70°C 1.7 W TA = 85°C 1.4 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 Supply Voltage, VDD NOM MAX 5 5.5 3 Operating junction temperature, TJ UNIT V °C 125 dc electrical characteristics, TA = 25°C PARAMETER TEST CONDITIONS VDD = 5 V IDD Supply current 3V VDD = 3 3.3 VOO IDD(MUTE) Output offset voltage (measured differentially) Supply current in mute mode VDD = 5 V, VDD = 5 V IDD(SD) IDD in shutdown VDD = 5 V 3 Channel L and R or Center only 3 Channel POST OFFICE BOX 655303 TYP MAX 19 25 UNIT mA 9 15 mA 13 20 mA L and R or Center only 3 10 mA Gain = 2, 5 35 mV NOTE 1: At 3 V < VDD < 5 V the dc output voltage is approximately VDD/2. 4 NOM • DALLAS, TEXAS 75265 See Note 1 µA 800 5 15 µA TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 ac operating characteristics, VDD = 5 V, TA = 25°C, RL = 4 Ω PARAMETER PO TEST CONDITIONS Output power (each channel) (see Note 2) MIN BTL, Center channel 1.75 THD = 1%, BTL, Center channel 2.1 THD = 0.2%, SE, L/R channels 535 THD = 1%, SE, L/R channels 575 f = 20 to 20 kHz THD+N Total harmonic distortion plus noise BOM Maximum output power bandwidth Po = 1.5 W, G = 10, Phase margin Open loop f = 1 kHz f = 20 – 20 kHz Center channel 60 L/R channels 30 Line/HP input separation Input impedance Vn VO = 1 V(rms) Output noise voltage ° 58 f = 1 kHz Signal to noise ratio Signal-to-noise SE, L/R channels BTL, Center channel SE, L/R channels mW 85 L/R channels Center channel W kHz 80 BTL, UNIT >20 Center channel Mute attenuation ZI MAX 0.25% THD < 5 % Supply ripple rejection ratio Channel-to-channel output separation TYP THD = 0.2%, dB 85 dB 95 dB 100 dB 2 MΩ 94 dB 100 20 µV(rms) 9 NOTE 2: Output power is measured at the output terminals of the IC at 1 kHz. ac operating characteristics, VDD = 3.3 V, TA = 25°C, RL = 4 Ω PARAMETER TEST CONDITIONS BTL, Center channel 800 THD = 1% BTL, Center channel 850 THD = 0.2%, SE, L/R channels 215 THD = 1%, SE, L/R channels f = 20 to 20 kHz Output power (each channel) (see Note 2) THD+N Total harmonic distortion plus noise BOM Maximum output power bandwidth Po = 750 mW, G = 10, Phase margin Open loop f = 1 kHz Supply ripple rejection ratio f = 20 – 20 kHz THD < 5 % Signal to noise ratio Signal-to-noise Vn Output noise voltage VO = 1 V(rms) kHz 85 ° 62 Center channel 55 L/R channels 30 Input impedance BTL, Center channel SE, L/R channels mW >20 L/R channels Line/HP input separation UNIT 235 70 f = 1 kHz MAX 0.8% Center channel Mute attenuation ZI TYP THD = 0.2% PO Channel-to-channel output separation MIN dB 85 dB 95 dB 100 dB 2 MΩ 93 100 BTL, Center channel 21 SE, L/R channels 10 dB µV(rms) NOTE 2: Output power is measured at the output terminals of the IC at 1 kHz. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 PARAMETER MEASUREMENT INFORMATION RF CI RL = 4 Ω or 8 Ω RI CB 4.7 µF VDD MODE A VDD MODE B SHUTDOWN MUX HP/LINE MUX Figure 1. BTL Test Circuit CB 4.7 µF VDD MODE A VDD MODE B VDD SHUTDOWN RF CI CO MUX RI RL HP/LINE CI CO MUX RI RL RF Figure 2. SE Test Circuit 6 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS Table of Graphs FIGURE THD + N vs Output power 3, 4, 7, 10–12, 15, 18, 21, 24, 27, 30, 33, 36 vs Frequency 5, 6, 8, 9, 13, 14, 16, 17, 19, 20, 22, 23, 25, 26, 28, 29, 31, 32, 34, 35 Total harmonic distortion plus noise Vn Output noise voltage vs Frequency 37,38 Supply ripple rejection ratio vs Frequency 39, 40 Crosstalk vs Frequency 41, 42 Open loop response vs Frequency 43, 44 Closed loop response vs Frequency 45 – 48 Supply current vs Supply voltage 49 PO Output power vs Supply voltage vs Load resistance 50, 51 52, 53 PD Power dissipation vs Output power 54 – 57 IDD TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER 10 THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10 VDD = 5 V f = 1 kHz BTL 1 RL = 4 Ω RL = 8 Ω 0.1 VDD = 5 V f = 1 kHz SE 1 RL = 8 Ω 0.1 RL = 4 Ω 0.01 0.01 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 0 75 150 225 300 375 450 525 600 675 750 PO – Output Power – mW PO – Output Power – W Figure 3 Figure 4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY VDD = 5 V PO = 1.5 W RL = 4 Ω BTL THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10 1 AV = –10 V/V AV = –20 V/V 0.1 AV = –2 V/V 0.01 20 100 1k 10 VDD = 5 V RL = 4 Ω AV = –2 V/V BTL 1 PO = 1.5 W PO = 0.75 W 0.1 PO = 0.25 W 0.01 10 k 20 k 20 100 f – Frequency – Hz Figure 5 THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY VDD = 5 V RL = 4 Ω BTL 1 f = 20 kHz 0.1 f = 1 kHz f = 20 Hz 10 VDD = 5 V RL = 8 Ω AV = –2 V/V BTL 1 PO = 0.5 W 0.1 PO = 1 W PO = 0.25 W 0.01 0.1 1 PO – Output Power – W 10 20 Figure 7 8 10 k 20 k Figure 6 TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER 0.01 0.01 1k f – Frequency – Hz 100 1k f – Frequency – Hz Figure 8 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 10 k 20 k TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS 10 VDD = 5 V PO = 1 W RL = 8 Ω BTL 1 AV = –20 V/V AV = –10 V/V TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 0.1 AV = –2 V/V 0.01 20 100 1k 10 k 10 VDD = 5 V RL = 8 Ω AV = –2 V/V BTL 1 f = 20 kHz 0.1 f = 1 kHz f = 20 Hz 0.01 0.01 20 k 0.1 1 PO – Output Power – W f – Frequency – Hz Figure 9 Figure 10 TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER 10 TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10 VDD = 3.3 V f = 1 kHz BTL 1 RL = 4 Ω RL = 8 Ω 0.1 0.01 10 VDD = 3.3 V f = 1 kHz SE 1 RL = 8 Ω 0.1 RL = 4 Ω 0.01 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 PO – Output Power – W 1 0 30 Figure 11 60 90 120 150 180 210 240 270 300 PO – Output Power – mW Figure 12 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 9 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS 10 VDD = 3.3 V PO = 0.75 W RL = 4 Ω BTL 1 AV = –20 V/V 0.1 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY AV = –10 V/V AV = –2 V/V 0.01 VDD = 3.3 V RL = 4 Ω AV = –2 V/V BTL 1 PO = 0.75 W 0.1 PO = 0.1 W PO = 0.35 W 0.01 20 100 10 k 1k 20 k 20 Figure 13 Figure 14 f = 20 kHz f = 1 kHz 0.1 f = 20 Hz 10 VDD = 3.3 V PO = 0.4 W RL = 8 Ω BTL 1 AV = –20 V/V 0.1 AV = –10 V/V AV = –2 V/V 0.01 0.1 1 PO – Output Power – W 10 20 100 1k f – Frequency – Hz Figure 15 10 10 k 20 k TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY THD+N –Total Harmonic Distortion + Noise – % VDD = 3.3 V RL = 4 Ω AV = –2 V/V BTL 0.01 0.01 1k f – Frequency – Hz 10 1 100 f – Frequency – Hz TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER THD+N –Total Harmonic Distortion + Noise – % 10 Figure 16 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 10 k 20 k TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER 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 1 0.1 PO = 0.25 W PO = 0.4 W PO = 0.1 W 0.01 20 100 1k 10 VDD = 3.3 V RL = 8 Ω AV = –2 V/V BTL f = 20 kHz 1 0.1 f = 1 kHz f = 20 Hz 0.01 0.01 10 k 20 k 1 0.1 PO – Output Power – W f – Frequency – Hz Figure 17 Figure 18 VDD = 5 V PO = 0.5 W RL = 4 Ω SE 1 AV = –10 V/V 0.1 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 10 10 AV = –5 V/V AV = –1 V/V 10 VDD = 5 V RL = 4 Ω AV = –2 V/V SE 1 PO = 0.5 W PO = 0.25 W 0.1 PO = 0.1 W 0.01 0.01 20 100 1k f – Frequency – Hz 10 k 20 k 20 100 1k 10 k 20 k f – Frequency – Hz Figure 19 Figure 20 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 11 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 10 VDD = 5 V RL = 4 Ω AV = –2 V/V SE THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER 1 f = 20 kHz 0.1 f =100 Hz f = 1 kHz 10 VDD = 5 V PO = 0.25 W RL = 8 Ω SE 1 AV = –10 V/V 0.1 AV = –5 V/V AV = –1 V/V 0.01 0.01 0.001 0.01 0.1 PO – Output Power – W 20 1 100 1k Figure 21 Figure 22 TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER 10 VDD = 5 V RL = 8 Ω SE THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 1 0.1 PO = 0.25 W PO = 0.1 W PO = 0.05 W 0.01 20 100 10 k 20 k 1k 10 VDD = 5 V RL = 8 Ω AV = –2 V/V SE 1 f = 20 kHz 0.1 f = 1 kHz f = 100 Hz 0.01 0.001 f – Frequency – Hz 0.01 Figure 24 POST OFFICE BOX 655303 0.1 PO – Output Power – W Figure 23 12 10 k 20 k f – Frequency – Hz • DALLAS, TEXAS 75265 1 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS 10 VDD = 5 V PO = 75 mW RL = 32 Ω SE 1 AV = –10 V/V AV = –5 V/V 0.1 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY AV = –1 V/V 0.01 VDD = 5 V RL = 32 Ω SE 1 0.1 PO = 50 mW PO = 75 mW PO = 25 mW 0.01 20 100 1k 10 k 20 k f – Frequency – Hz 20 1k f – Frequency – Hz Figure 25 Figure 26 THD+N –Total Harmonic Distortion + Noise – % 10 VDD = 5 V RL = 32 Ω SE 1 f = 20 kHz 0.1 f = 20 Hz f = 1 kHz 0.01 0.001 100 10 k 20 k TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER THD+N –Total Harmonic Distortion + Noise – % 10 10 VDD = 3.3 V PO = 0.2 W RL = 4 Ω SE 1 AV = –10 V/V 0.1 AV = –5 V/V AV = –1 V/V 0.01 0.1 0.01 PO – Output Power – W 1 20 Figure 27 100 1k f – Frequency – Hz 10 k 20 k Figure 28 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 13 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS 10 VDD = 3.3 V RL = 4 Ω SE 1 PO = 0.2 W PO = 0.1 W 0.1 PO = 0.05 W TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 100 1k VDD = 3.3 V RL = 4 Ω AV = –2 V/V SE 1 f = 20 kHz f = 1 kHz 0.1 f = 100 Hz 0.01 0.001 0.01 20 10 10 k 20 k 0.01 f – Frequency – Hz Figure 30 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 10 THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY VDD = 3.3 V PO = 100 mW RL = 8 Ω SE 1 AV = –10 V/V 0.1 AV = –1 V/V 10 VDD = 3.3 V RL = 8 Ω SE 1 PO = 100 mW PO = 50 mW 0.1 PO = 25 mW 0.01 0.01 20 100 1k f – Frequency – Hz 10 k 20 k 20 100 1k f – Frequency – Hz Figure 31 14 1 PO – Output Power – W Figure 29 AV = –5 V/V 0.1 Figure 32 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 10 k 20 k TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 10 THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER VDD = 3.3 V RL = 8 Ω SE 1 f = 20 kHz f = 1 kHz 0.1 f = 100 Hz 0.01 0.001 10 VDD = 3.3 V PO = 30 mW RL = 32 Ω SE 1 AV = –10 V/V 0.1 AV = –5 V/V AV = –1 V/V 0.01 0.01 0.1 PO – Output Power – W 20 1 100 Figure 33 VDD = 3.3 V RL = 32 Ω SE 1 PO = 20 mW PO = 30 mW 0.01 PO = 10 mW 0.001 100 1k TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10 20 10 k 20 k Figure 34 TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 0.1 1k f – Frequency – Hz 10 k 20 k 10 VDD = 3.3 V RL = 32 Ω SE 1 f = 20 kHz 0.1 f = 1 kHz f = 20 Hz 0.01 0.001 0.001 f – Frequency – Hz Figure 35 0.01 0.1 PO – Output Power – W 1 Figure 36 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 15 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS OUTPUT NOISE VOLTAGE vs FREQUENCY OUTPUT NOISE VOLTAGE vs FREQUENCY 100 VDD = 5 V BW = 22 Hz to 22 kHz RL = 4Ω V n – Output Noise Voltage – µ V(rms) V n – Output Noise Voltage – µ V(rms) 100 Center Left 10 Right VDD = 3.3 V BW = 22 Hz to 22 kHz RL = 4Ω Center Left 10 Right 1 1 20 100 10 k 20 k 1k 20 100 f – Frequency – Hz Figure 37 Figure 38 SUPPLY RIPPLE REJECTION RATIO vs FREQUENCY SUPPLY RIPPLE REJECTION RATIO vs FREQUENCY 0 RL = 4 Ω CB = 4.7 µF BTL –20 Supply Ripple Rejection Ratio – dB Supply Ripple Rejection Ratio – dB 0 –10 –30 –40 –50 –60 VDD = 3.3 V –70 –80 VDD = 5 V –90 RL = 4 Ω CB = 4.7 µF SE –10 –20 –30 –40 –50 VDD = 5 V –60 –70 VDD = 3.3 V –80 –90 –100 –100 20 100 1k 10 k 20 k 20 f – Frequency – Hz 100 1k f – Frequency – Hz Figure 39 16 10 k 20 k 1k f – Frequency – Hz Figure 40 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 10 k 20 k TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS CROSSTALK vs FREQUENCY –40 CROSSTALK vs FREQUENCY –40 VDD = 5 V PO = 75 mW RL = 32 Ω SE –50 –50 –60 Crosstalk – dB –60 –70 –80 Left to Right –90 –100 –70 Left to Right –80 –90 –100 Right to Left Right to Left –110 –110 –120 100 1k –120 20 10 k 20 k f – Frequency – Hz 100 1k 10 k 20 k f – Frequency – Hz Figure 41 Figure 42 OPEN LOOP RESPONSE 100 VDD = 5 V BTL 80 180° 60 Phase 90° 40 Phase 20 Gain – dB Crosstalk – dB VDD = 3.3 V PO = 35 mW RL = 32 Ω SE Gain 20 0° 0 –90° –20 –40 0.01 0.1 1 10 100 1000 –180° 10000 f – Frequency – kHz Figure 43 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 17 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS OPEN LOOP RESPONSE 80 180° VDD = 3.3 V BTL 60 Phase 90° Gain 0° 20 Phase Gain – dB 40 0 –90° –20 –40 0.01 0.1 1 10 100 1000 –180° 10000 f – Frequency – kHz Figure 44 CLOSED LOOP RESPONSE 0° 10 VDD = 5 V AV = –2 V/V PO = 1.5 W BTL 9 8 – 45° 7 – 90° 5 – 135° 4 Phase – 180° 3 2 – 225° 1 0 20 100 1k 10 k – 270° 100 k 200 k f – Frequency – Hz Figure 45 18 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 Phase Gain – dB Gain 6 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS CLOSED LOOP RESPONSE 0° 10 VDD = 3.3 V AV = –2 V/V PO = 0.75 W BTL 9 8 – 45° 7 – 90° 5 – 135° 4 Phase Gain – dB Gain 6 Phase – 180° 3 2 – 225° 1 0 20 100 1k 10 k – 270° 100 k 200 k f – Frequency – Hz Figure 46 CLOSED LOOP RESPONSE 0° 0 Gain –1 – 45° –2 – 90° –4 –5 – 135° –6 Phase Gain – dB –3 Phase – 180° –7 VDD = 5 V AV = –1 V/V PO = 0.5 W SE –8 –9 –10 20 100 1k 10 k – 225° – 270° 100 k 200 k f – Frequency – Hz Figure 47 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 19 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS CLOSED LOOP RESPONSE 0° 0 Gain –1 – 45° –2 – 90° –4 –5 – 135° –6 Phase Gain – dB –3 Phase – 180° –7 VDD = 3.3V AV = –1 V/V PO = 0.25 W SE –8 –9 –10 20 100 1k 10 k – 225° – 270° 100 k 200 k f – Frequency – Hz Figure 48 SUPPLY CURRENT vs SUPPLY VOLTAGE OUTPUT POWER vs SUPPLY VOLTAGE 3 30 2.5 ÁÁ ÁÁ PO – Output Power – W I DD – Supply Current – mA 25 20 3 Channel 15 10 L/R or Center Channel 5 4 5 VDD – Supply Voltage – V 2 RL = 4 Ω 1.5 1 RL = 8 Ω 0.5 0 3 THD+N = 1% BTL Center Channel 6 0 2.5 3 4 4.5 Figure 50 POST OFFICE BOX 655303 5 VDD – Supply Voltage – V Figure 49 20 3.5 • DALLAS, TEXAS 75265 5.5 6 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS OUTPUT POWER vs SUPPLY VOLTAGE 1 OUTPUT POWER vs LOAD RESISTANCE 3 THD+N = 1% SE Each L/R Channel 2.5 PO – Output Power – W PO – Output Power – W 0.8 RL = 4 Ω 0.6 RL = 8 Ω 0.4 THD+N = 1% BTL Center Channel 0.2 2 1.5 VDD = 5 V 1 0.5 RL = 32 Ω VDD = 3.3 V 0 0 2.5 3 3.5 4 4.5 5 VDD – Supply Voltage – V 5.5 0 6 4 Figure 51 1.4 RL = 4 Ω 1.2 PD – Power Dissipation – W 0.8 PO – Output Power – W 32 POWER DISSIPATION vs OUTPUT POWER THD+N = 1% SE Each L/R Channel 0.6 0.4 28 Figure 52 OUTPUT POWER vs LOAD RESISTANCE 1 8 12 16 20 24 RL – Load Resistance – Ω VDD = 5 V 1 0.8 RL = 8 Ω 0.6 0.4 0.2 VDD = 5 V BTL Center Channel 0.2 VDD = 3.3 V 0 0 0 4 8 12 16 20 24 RL – Load Resistance – Ω 28 32 0 Figure 53 1.5 0.5 1 PO – Output Power – W 2 Figure 54 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 21 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 TYPICAL CHARACTERISTICS POWER DISSIPATION vs OUTPUT POWER POWER DISSIPATION vs OUTPUT POWER 0.8 0.6 RL = 4 Ω 0.6 PD – Power Dissipation – W PD – Power Dissipation – W 0.5 RL = 4 Ω 0.4 RL = 8 Ω 0.2 RL = 32Ω VDD = 5 V SE Each L/R Channel 0.4 0.3 RL = 8 Ω 0.2 VDD = 3.3 V BTL Center Channel 0.1 0 0 0 0.1 0.4 0.2 0.3 PO – Output Power – W 0.5 0.6 0 0.75 0.25 0.5 PO – Output Power – W Figure 55 Figure 56 POWER DISSIPATION vs OUTPUT POWER 0.6 PD – Power Dissipation – W VDD = 3.3V SE Each L/R Channel RL = 4 Ω 0.4 RL = 8 Ω 0.2 RL = 32Ω 0 0 0.05 0.1 0.15 0.2 PO – Output Power – W Figure 57 22 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 0.25 1 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 THERMAL INFORMATION The thermally enhanced PWP package is based on the 24-pin TSSOP, but includes a thermal pad (see Figure 58) to provide an effective thermal contact between the IC and the PWB. Traditionally, surface mount and power have been mutually exclusive terms. A variety of scaled-down TO-220-type packages have leads formed as gull wings to make them applicable for surface-mount applications. These packages, however, have only two shortcomings: they do not address the very low profile requirements (< 2 mm) of many of today’s advanced systems, and they do not offer a terminal-count high enough to accommodate increasing integration. On the other hand, traditional low-power surface-mount packages require power-dissipation derating that severely limits the usable range of many high-performance analog circuits. The PowerPAD package (thermally enhanced TSSOP) combines fine-pitch surface-mount technology with thermal performance comparable to much larger power packages. The PowerPAD package is designed to optimize the heat transfer to the PWB. Because of the very small size and limited mass of a TSSOP package, thermal enhancement is achieved by improving the thermal conduction paths that remove heat from the component. The thermal pad is formed using a patented lead-frame design and manufacturing technique to provide a direct connection to the heat-generating IC. When this pad is soldered or otherwise thermally coupled to an external heat dissipator, high power dissipation in the ultra-thin, fine-pitch, surface-mount package can be reliably achieved. DIE Side View (a) Thermal Pad DIE End View (b) Bottom View (c) Figure 58. Views of Thermally Enhanced PWP Package POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 23 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 APPLICATION INFORMATION bridged-tied load versus single-ended mode Figure 59 shows a linear audio power amplifier (APA) in a BTL configuration. The TPA0103 center -channel 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. The differential drive to the speaker means that as one side is slewing up the other side is slewing down and vice versa. This in effect doubles the voltage swing on the load as compared to a ground referenced load. Plugging 2 × VO(PP) into the power equation, where voltage is squared, yields 4× the output power from the same supply rail and load impedance (see equation 1). V (rms) + O(PP) 2 Ǹ2 Power + V V (rms) 2 (1) RL VDD VO(PP) RL 2x VO(PP) VDD –VO(PP) Figure 59. Bridge-Tied Load Configuration In a typical computer sound channel operating at 5 V, bridging raises the power into an 8-Ω speaker from a singled-ended (SE, ground reference) limit of 250 mW to 1 W. In sound power that is a 6-dB improvement — which is loudness that can be heard. In addition to increased power there are frequency response concerns. Consider the single-supply SE configuration of the L/R channels as shown in Figure 60. A coupling capacitor is required to block the dc offset voltage from reaching the load. These capacitors can be quite large (approximately 33 µF to 1000 µF) so they tend to be expensive, heavy, occupy valuable PCB area, and have the additional drawback of limiting low-frequency performance of the system. This frequency limiting effect is due to the high pass filter network created with the speaker impedance and the coupling capacitance and is calculated with equation 2. 24 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 APPLICATION INFORMATION fc + 2 p R1 C (2) L C For example, a 68-µF capacitor with an 8-Ω speaker would attenuate low frequencies below 293 Hz. The BTL configuration cancels the dc offsets, which eliminates the need for the blocking capacitors. Low-frequency performance is then limited only by the input network and speaker response. Cost and PCB space are also minimized by eliminating the bulky coupling capacitor. VDD –3 dB VO(PP) fc = 293 Hz, 8 Ω, 68 µF CC RL VO(PP) fc = 73 Hz, 32 Ω, 68 µF fc Figure 60. Single-Ended Configuration and Frequency Response BTL amplifier efficiency Linear amplifiers are notoriously inefficient. The primary cause of these inefficiencies is voltage drop across the output stage transistors. There are two components of the internal voltage drop. One is the headroom or dc voltage drop that varies inversely to output power. The second component is due to the sinewave nature of the output. The total voltage drop can be calculated by subtracting the RMS value of the output voltage from VDD. The internal voltage drop multiplied by the RMS value of the supply current, IDDrms, determines the internal power dissipation of the amplifier. An easy-to-use equation to calculate efficiency starts out as being equal to the ratio of power from the power supply to the power delivered to the load. To accurately calculate the RMS values of power in the load and in the amplifier, the current and voltage waveform shapes must first be understood (see Figure 61). IDD VO IDD(RMS) V(LRMS) Figure 61. Voltage and Current Waveforms for BTL Amplifiers POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 25 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 APPLICATION INFORMATION Although the voltages and currents for SE and BTL are sinusoidal in the load, currents from the supply are very different between SE and BTL configurations. In an SE application the current waveform is a half-wave rectified shape whereas in BTL it is a full-wave rectified waveform. This means RMS conversion factors are different. Keep in mind that for most of the waveform both the push and pull transistors are not on at the same time, which supports the fact that each amplifier in the BTL device only draws current from the supply for half the waveform. The following equations are the basis for calculating amplifier efficiency. Efficiency + PP L (3) SUP Where: + P L(BTL) V Lrms 2 RL 2 2 RL , V PP + ǸPLRL2 V PP 2V PP + Ǹ2 V V P SUP + V DD I DDrms + DD PP p RL V PP I DDrms + pR V Lrms(BTL) + 2 Ǹ2 + V PP V PP V PP 2 Efficiency of a BTE Configuration +P SUP + + VL * VPP Ǹ L PL + 2VP V PP 2 2 RL p RL V DDV PP LR L + 2VVPP p + p 22P V DD (4) DD Equation 4 can also be used for SE operations. Table 1 employs equation 4 to calculate efficiencies for four different output power levels. Note that the efficiency of the amplifier is quite low for lower power levels and rises sharply as power to the load is increased resulting in a nearly flat internal power dissipation over the normal operating range. Note that the internal dissipation at full output power is less than in the half power range. Calculating the efficiency for a specific system is the key to proper power supply design. For a stereo 1-W audio system with 8-Ω loads and a 5-V supply, the maximum draw on the power supply is almost 3.25 W. Table 1. Efficiency Vs Output Power in 5-V 8-Ω BTL Systems OUTPUT POWER (W) EFFICIENCY (%) PEAK-TO-PEAK VOLTAGE (V) INTERNAL DISSIPATION (W) 0.25 31.4 2.00 0.55 0.50 44.4 2.83 0.62 1.00 62.8 4.00 4.47† 0.59 1.25 70.2 † High peak voltages cause the THD to increase. 0.53 A final point to remember about linear amplifiers (either SE or BTL) is how to manipulate the terms in the efficiency equation to utmost advantage when possible. Note that in equation 4, VDD is in the denominator. This indicates that as VDD goes down, efficiency goes up. As the numerator values of RL and PL decrease, efficiency decreases. 26 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 APPLICATION INFORMATION For example, if the 5-V supply is replaced with a 3.3-V supply (TPA0103 has a maximum recommended VDD of 5.5 V) in the calculations of Table 1 then efficiency at 0.5 W would rise from 44% to 67% and internal power dissipation would fall from 0.62 W to 0.25 W at 5 V. Then for a stereo 0.5-W system from a 3.3-V supply, the maximum draw would only be 1.5 W as compared to 2.24 W from 5 V. In other words, use the efficiency analysis to chose the correct supply voltage and speaker impedance for the application. selection of components Figure 62 and Figure 63 are a schematic diagrams of typical computer application circuits. CFC RFC 6 RIRC RILC CB 19 NC 9 8 CIN COUT+ 10 – + BYPASS MODE A 14 MUTE OUT CNTL MODE B 11 SHUTDOWN VDD 7, 18 HP/LINE 16 NC RIR 20 21 RHPIN RLINEIN VDD RM2 VDD 100 kΩ RM1 100 kΩ VDD COUTR Right MUX – + ROUT 22 RM3 1 kΩ CIR NC RIL CIL Internal Speaker COUT – 15 RFR 5 LHPIN 4 LLINEIN RFL Left MUX – + LOUT 3 COUTL GND/HS 1, 12, 13, 24 Figure 62. TPA0103 Minimum Configuration Application Circuit POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 27 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 APPLICATION INFORMATION CFC 5 pF RFC 100 kΩ RIC 10 kΩ 6 Mono CIC 0.1 µF 19 CB 4.7 µF AC97 VDD 11 System Active/Shutdown 16 Control High/Low Gain RIRHP 10 kΩ Right Line 7, 18 CIR 0.1 µF CIN COUT+ 10 – BYPASS 4Ω Internal Speaker COUT – 15 + VDD MODE A 14 MODE B CNTL HP/LINE 20 RHPIN 21 RLINEIN RM2 100 kΩ (see Note A) VDD RM1 100 kΩ MUTE OUT 11 SHUTDOWN 8 Right MUX – + ROUT 22 COUTR 470 µF RM3 1 kΩ RIRL 10 kΩ RFRHP 10 kΩ 4 Ω – 32 Ω Speakers or Headphones RFRL 50 kΩ RILHP 10 kΩ Left Line CIL 0.1 µF 5 LHPIN 4 LLINEIN Left MUX RILL 10 kΩ LOUT 3 – + GND/HS 1, 12, 13, 24 RFLHP 10 kΩ RFLL 50 kΩ NOTE A: This connection is for ultralow current in shutdown mode. Figure 63. TPA0103 Full Configuration Application Circuit 28 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 COUTL 470 µF TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 APPLICATION INFORMATION gain setting resistors, RF and RI ǒǓ ǒǓ The gain for each audio input of the TPA0103 is set by resistors RF and RI according to equation 5 for BTL mode. + *2 BTL Gain RF (5) RI In SE mode the gain is set by the RF and RI resistors and is shown in equation 6. Since the inverting amplifier is not used to mirror the voltage swing on the load, the factor of 2, from equation 5, is not included. SE Gain +* RF (6) RI BTL mode operation brings about the factor 2 in the gain equation due to the inverting amplifier mirroring the voltage swing across the load. Given that the TPA0103 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 are required for proper startup 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 7. Effective Impedance + RRF)RRI F (7) I As an example consider an input resistance of 10 kΩ and a feedback resistor of 50 kΩ. The BTL gain of the amplifier would be –10 and the effective impedance at the inverting terminal would be 8.3 kΩ, which is well 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 when RF is greater than 50 kΩ. This, in effect, creates a low pass filter network with the cutoff frequency defined in equation 8. –3 dB f c(lowpass) + 2 p R1 C (8) F F fc For example, if RF is 100 kΩ and Cf is 5 pF then fc is 318 kHz, which is well outside of the audio range. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 29 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 APPLICATION INFORMATION 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 9. –3 dB + 2 p R1 C f c(highpass) (9) I I fc 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 10 kΩ and the specification calls for a flat bass response down to 40 Hz. Equation 8 is reconfigured as equation 10. CI + 2 p 1R fc (10) I 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. 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, CS The TPA0103 is a high-performance CMOS audio amplifier that requires adequate power supply decoupling to ensure 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 audio power amplifier is recommended. 30 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 APPLICATION INFORMATION midrail bypass capacitor, CB The midrail bypass capacitor, CB, serves several important functions. During startup 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. This noise is from the midrail generation circuit internal to the amplifier. The capacitor is fed from a 25-kΩ source inside the amplifier. To keep the start-up pop as low as possible, the relationship shown in equation 11 should be maintained. ǒ CB ǓW v ǒC1R Ǔ 1 25 k (11) I I As an example, consider a circuit where CB is 0.1 µF, CI is 0.22 µF and RI is 10 kΩ. Inserting these values into the equation 10 we get 400 ≤ 454 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 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 12. –3 dB f c(high) + 2 p R1 C (12) L C fc The main disadvantage, from a performance standpoint, is the load impedances are typically small, which drives the low-frequency corner higher degrading the bass response. Large values of CC are required to pass low frequencies into the load. Consider the example where a CC of 330 µF is chosen and loads vary from 4 Ω, 8 Ω, 32 Ω, to 47 kΩ. Table 2 summarizes the frequency response characteristics of each configuration. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 31 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 APPLICATION INFORMATION output coupling capacitor, CC (continued) Table 2. Common Load Impedances Vs Low Frequency Output Characteristics in SE Mode RL CC LOWEST FREQUENCY 4Ω 330 µF 120 Hz 8Ω 330 µF 60 Hz 32 Ω 330 µF 15 Hz 47,000 Ω 330 µF 0.01 Hz As Table 2 indicates, most of the bass response is attenuated into a 4-Ω load, an 8-Ω load is adequate, headphone response is good, and drive into line level inputs (a home stereo for example) is exceptional. The output coupling capacitor required in single-supply SE mode also places additional constraints on the selection of other components in the amplifier circuit. The rules described earlier still hold with the addition of the relationship shown in equation 13. ǒ CB 1 25 kΩ Ǔvǒ ǓƠ 1 CI RI 1 R LC C (13) mode control resistor network, RM1, RM2, RM3 Using a readily available 1/8-in. (3.5-mm) stereo headphone jack, the control switch is closed when no plug is inserted. When closed, the 100-kΩ/1-kΩ divider (see Figure 64) pulls the MODE A input low. When a plug is inserted, the 1-kΩ resistor is disconnected and the MODE A input is pulled high. When the input goes high, the center BTL amplifier is shutdown causing the speaker to mute. The SE amplifiers then drive through the output capacitors (CO) into the headphone jack. Input MUX operation The HP/LINE MUX feature gives the audio designer the flexibility of a multichip design in a single IC (see Figure 64). The primary function of the MUX is to allow different gain settings for different types of audio loads. Speakers typically require approximately a factor of 10 more gain for similar volume listening levels as compared to headphones. To achieve headphone and speaker listening parity, the resistor values would need to be set as follows: Gain (HP) +* ǒ Ǔ ǒ Ǔ R F(HP) (14) R I(HP) If, for example RI(HP) = 20 kΩ and RF(HP) = 20 kΩ then SE Gain(HP) = –1 Gain (LINE) +* R F(LINE) (15) R I(LINE) If, for example RI(LINE) = 10 kΩ and RF(LINE) = 100 kΩ then Gain(LINE) = –10 32 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 APPLICATION INFORMATION Input MUX operation (continued) RFRHP CIRLINE R IRLINE RFRLINE 21 RLINE IN COUTR – + MUX 20 CIRHP RHP IN Right Channel ROUT 22 RIRHP MID VDD MODE A 14 System Control 16 HP/LINE CNTL MODE B 11 VDD Left Channel Figure 64. TPA0103 Example Input MUX Circuit Another advantage of using the MUX feature is setting the gain of the headphone channel to –1. This provides the optimum distortion performance into the headphones where clear sound is more important. mute and shutdown modes The TPA0103 employs both a mute and a shutdown mode of operation designed to reduce supply current, IDD, to the absolute minimum level during periods of nonuse for battery-power conservation. The SHUTDOWN input terminal should be held low during normal operation when the amplifier is in use. Pulling SHUTDOWN high causes the outputs to mute and the amplifier to enter a low-current state, IDD = 5 µA. SHUTDOWN should never be left unconnected because amplifier operation would be unpredictable. Mute mode alone reduces IDD <1 mA. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 33 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 APPLICATION INFORMATION mute and shutdown modes (continued) Table 3. Shutdown and Mute Mode Functions INPUTS† OUTPUT AMPLIFIER STATE MODE A HP/LINE MODE B SHUTDOWN MUTE OUT INPUT OUTPUT Low Low Low Low Low L/R Line 3 Channel X X — High High X Mute X X High Low High X Mute Low High Low Low Low L/R HP 3 Channel High Low Low Low High L/R Line Mute High High Low Low High L/R HP Mute Low Low High Low Low L/R Line Center BTL Low High High Low Low L/R HP Center BTL High Low High Low Low L/R Line L/R SE High High High Low Low L/R HP L/R SE † Inputs should never be left unconnected. X = do not care using low-ESR capacitors Low-ESR capacitors are recommended throughout this applications section. A real (as opposed to ideal) 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 TPA0103 operates over a supply range of 3 V to 5.5 V. This data sheet provides full specifications for 5-V and 3.3-V operation, as 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 goes. For 3.3-V operation, supply current is reduced from 19 mA (typical) to 13 mA (typical). The most important consideration is that of output power. Each amplifier in TPA0103 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 to VO(PP) = 4 V at 5 V. The reduced voltage swing subsequently reduces maximum output power into an 8-Ω load before distortion becomes significant. Operation from 3.3-V supplies, as can be shown from the efficiency formula in equation 4, consumes approximately two-thirds the supply power for a given output-power level than operation from 5-V supplies. When the application demands less than 500 mW, 3.3-V operation should be strongly considered, especially in battery-powered applications. 34 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 APPLICATION INFORMATION headroom and thermal considerations Linear power amplifiers dissipate a significant amount of heat in the package under normal operating conditions. A typical music CD requires 12 dB to 15 dB of dynamic headroom to pass the loudest portions without distortion as compared with the average power output. From the TPA0103 data sheet, one can see that when the TPA0103 is operating from a 5-V supply into a 4-Ω speaker that 2 W RMS levels are available. Converting watts to dB: P dB + 10 Log + 10 Log + 3 dB ǒǓ PW ǒǓ P ref 2 1 Subtracting the headroom restriction to obtain the average listening level without distortion yields: 3 dB * 15 dB + * 12 dB (15 dB headroom) Converting dB back into watts: + 10PdBń10 Pref P W + * 12 dB + 63 mW (15 dB headroom) PW This is valuable information to consider when attempting to estimate the heat dissipation requirements for the amplifier system. Comparing the absolute worst case, which is 1.5 W of continuous power output with 0 dB of headroom, against 12 dB and 15 dB applications drastically affects maximum ambient temperature ratings for the system. Using the power dissipation curves for a 5-V, 4-Ω system, the internal dissipation in the TPA0103 and maximum ambient temperatures is shown in Table 4. Table 4. TPA0103 Power Rating, 5-V, 4-Ω, Three Channel CONFIGURATION Center only only, PO = 2 W max L/R only only, PO = 500 mW max HEADROOM† POWER DISSIPATION 2 × L/R + CENTER = TOTAL TA (MAX)‡ 35°C/W 25°C/W 0 dB 0 1.25 W 1.25 W 81°C 93°C 15 dB 0 0.6 W 0.6 W 104°C 110°C 0 dB 0.6 W 0 1.2 W 83°C 95°C 15 dB 0.2 W 0 0.4 W 111°C 115°C Center, PO = 2 W max 0 dB 0.6 W 1.25 W 2.45 W 39°C 63°C and 15 dB 0.2 W 0.6 W 1W 90°C 100°C L/R , PO = 500 mW max † The 2 W max at 0 dB is a maximum level tone that is very loud. 15 dB is a typical headroom requirement for music. ‡ This parameter is based on a maximum junction temperature (TJ) of 125°C. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 35 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 APPLICATION INFORMATION headroom and thermal considerations (continued) ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ DISSIPATION RATING TABLE PACKAGE PWP† PWP‡ TA ≤ 25°C 2.7 W DERATING FACTOR 21.8 mW/°C TA = 70°C 1.7 W TA = 85°C 1.4 W 2.8 W 22.1 mW/°C 1.8 W 1.4 W † This parameter is measured with the recommended copper heat sink pattern on a 1-layer PCB, 4 in2 5-in × 5-in PCB, 1 oz. copper, 2-in × 2-in coverage. ‡ This parameter is measured with the recommended copper heat sink pattern on an 8-layer PCB, 6.9 in2 1.5-in × 2-in PCB, 1 oz. copper with layers 1, 2, 4, 5, 7, and 8 at 5% coverage (0.9 in2) and layers 3 and 6 at 100% coverage (6 in2). The maximum ambient temperature depends on the heatsinking ability of the PCB system. Using the 0 LFM and 300 LFM data from the dissipation rating table, the derating factor for the PWP package with 6.9 in2 of copper area on a multilayer PCB is 22.1 mW/°C and 53.7 mW/°C respectively. Converting this to ΘJA: Θ JA For 0 LFM : For 300 LFM : 1 + Derating 1 + 22.1 mW ń°C + 45°CńW 1 + 53.7 mW ń°C + 18°CńW To calculate maximum ambient temperatures, first consider that the numbers from the dissipation graphs are per channel so the dissipated heat needs to be doubled for the two SE channels and added to the center channel dissipation. Given ΘJA, the maximum allowable junction temperature, and the total internal dissipation, the maximum ambient temperature can be calculated with the following equation. The maximum recommended junction temperature for the TPA0103 is 150°C. The internal dissipation figures are taken from the Power Dissipation vs Output Power graphs. T A Max + TJ Max * ΘJA PD + 125 * 45 (0.2 2 ) 0.6) + 80°C (15 dB headroom, 0 LFM) + 125 * 18 (0.2 2 ) 0.6) + 107°C (15 dB headroom, 300 LFM) NOTE: Internal dissipation of 1 W is estimated for a 3-channel system with 15 dB headroom per channel (see Table 4 for more information). Table 4 shows that for most applications no airflow is required to keep junction temperatures in the specified range. The TPA0103 is designed with thermal protection that turns the device off when the junction temperature surpasses 150°C to prevent damage to the IC. However, sustained operation above 125°C is not recommended. Table 4 was calculated for maximum listening volume without distortion. When the output level is reduced the numbers in the table change significantly. Also, using 8-Ω speakers dramatically increases the thermal performance by increasing amplifier efficiency. 36 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA0103 1.75-W 3-CHANNEL STEREO AUDIO POWER AMPLIFIER SLOS167A – JULY 1997 – REVISED MARCH 2000 PWP (R-PDSO-G**) PowerPAD PLASTIC SMALL-OUTLINE 20 PINS SHOWN 0,30 0,19 0,65 20 0,10 M 11 Thermal Pad (See Note D) 4,50 4,30 0,15 NOM 6,60 6,20 Gage Plane 1 10 0,25 A 0°– 8° 0,75 0,50 Seating Plane 0,15 0,05 1,20 MAX PINS ** 0,10 14 16 20 24 28 A MAX 5,10 5,10 6,60 7,90 9,80 A MIN 4,90 4,90 6,40 7,70 9,60 DIM 4073225/F 10/98 NOTES: A. B. C. D. All linear dimensions are in millimeters. This drawing is subject to change without notice. Body dimensions do not include mold flash or protrusions. The package thermal performance may be enhanced by bonding the thermal pad to an external thermal plane. This pad is electrically and thermally connected to the backside of the die and possibly selected leads. E. Falls within JEDEC MO-153 For the latest package information, go to http://www.ti.com/sc/docs/package/pkg_info.htm PowerPAD is a trademark of Texas Instruments Incorporated. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 37 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 acknowledgement, 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. 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