TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 D Fully Specified for 3.3-V and 5-V Operation D Wide Power Supply Compatibility D OR DGN PACKAGE (TOP VIEW) 2.5 V – 5.5 V Output Power for RL = 8 Ω – 700 mW at VDD = 5 V, BTL – 250 mW at VDD = 3.3 V, BTL Ultralow Quiescent Current in Shutdown Mode . . . 1.5 nA Thermal and Short-Circuit Protection Surface-Mount Packaging – SOIC – PowerPAD MSOP D D D D SHUTDOWN BYPASS IN+ IN– 1 8 2 7 3 6 4 5 VO – GND VDD VO + description The TPA701 is a bridge-tied load (BTL) audio power amplifier developed especially for low-voltage applications where internal speakers are required. Operating with a 3.3-V supply, the TPA701 can deliver 250-mW of continuous power into a BTL 8-Ω load at less than 0.6% THD+N throughout voice band frequencies. Although this device is characterized out to 20 kHz, its operation was optimized for narrower band applications such as wireless communications. The BTL configuration eliminates the need for external coupling capacitors on the output in most applications, which is particularly important for small battery-powered equipment. This device features a shutdown mode for power-sensitive applications with a supply current of 1.5 nA during shutdown. The TPA701 is available in an 8-pin SOIC surface-mount package and the surface-mount PowerPAD MSOP, which reduces board space by 50% and height by 40%. VDD 6 VDD RF VDD/2 Audio Input RI CI 4 IN – 3 IN+ 2 BYPASS CS VO+ 5 – + CB – VO– 8 + 700 mW 7 GND From System Control 1 SHUTDOWN Bias Control 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 1998 – 2003, 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 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 AVAILABLE OPTIONS PACKAGED DEVICES TA SMALL OUTLINE† (D) MSOP SYMBOLIZATION MSOP‡ (DGN) – 40°C to 85°C TPA701D TPA701DGN ABA † In the SOIC package, the maximum RMS output power is thermally limited to 350 mW; 700 mW peaks can be driven, as long as the RMS value is less than 350 mW. ‡ The D and DGN packages are available taped and reeled. To order a taped and reeled part, add the suffix R to the part number (e.g., TPA701DR). Terminal Functions TERMINAL NAME NO. I/O DESCRIPTION I BYPASS is the tap to the voltage divider for internal mid-supply bias. This terminal should be connected to a 0.1-µF to 2.2-µF capacitor when used as an audio amplifier. BYPASS 2 GND 7 IN – 4 I IN – is the inverting input. IN – is typically used as the audio input terminal. IN+ 3 I IN + is the noninverting input. IN + is typically tied to the BYPASS terminal. SHUTDOWN 1 I SHUTDOWN places the entire device in shutdown mode when held high (IDD = 1.5 nA). VDD VO+ 6 5 O VDD is the supply voltage terminal. VO+ is the positive BTL output. VO– 8 O VO– is the negative BTL output. GND is the ground connection. absolute maximum ratings over operating free-air temperature range (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 (see Dissipation Rating Table) Operating free-air temperature range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 40°C to 85°C 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 D TA ≤ 25°C 725 mW DERATING FACTOR 5.8 mW/°C TA = 70°C 464 mW TA = 85°C 377 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. 2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 recommended operating conditions ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Supply voltage, VDD High-level voltage, VIH SHUTDOWN Low-level voltage, VIL SHUTDOWN MIN MAX 2.5 5.5 0.9 VDD Operating free-air temperature, TA UNIT V V 0.1 VDD V 85 °C – 40 electrical characteristics at specified free-air temperature, VDD = 3.3 V, TA = 25°C (unless otherwise noted) ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁ ÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ PARAMETER TEST CONDITIONS |VOO| Output offset voltage (measured differentially) SHUTDOWN = 0 V, RL = 8 Ω, RF = 10 kΩ PSRR Power supply rejection ratio IDD IDD(SD) Supply current VDD = 3.2 V to 3.4 V SHUTDOWN = 0 V, RF = 10 kΩ Supply current, shutdown mode (see Figure 4) SHUTDOWN = VDD, RF = 10 kΩ |IIH| High-level input current |IIL| Low-level input current MIN TYP MAX UNIT 20 mV 1.25 2.5 mA 1.5 1000 nA SHUTDOWN, VDD = 3.3 V, VI = 3.3 V 1 µA SHUTDOWN, VDD = 3.3 V, VI = 0 V 1 µA 85 dB operating characteristics, VDD = 3.3 V, TA = 25°C, RL = 8 Ω PARAMETER PO TEST CONDITIONS MIN Output power, see Note 1 THD = 0.2%, See Figure 9 THD + N Total harmonic distortion plus noise AV = – 2 V/V, PO = 250 mW f = 200 Hz to 4 kHz, See Figure 7, BOM B1 Maximum output power bandwidth THD = 2%, See Figure 7 Unity-gain bandwidth AV = – 2 V/V, Open loop, Supply ripple rejection ratio f = 1 kHz, CB = 1 µF, See Figure 2 Noise output voltage AV = –1 V/V, CB = 0.1 µF, See Figure 19 Vn TYP MAX 250 UNIT mW 0.55% See Figure 15 20 kHz 1.4 MHz 79 dB 17 µV(rms) NOTE 1: Output power is measured at the output terminals of the device at f = 1 kHz. electrical characteristics at specified free-air temperature, VDD = 5 V, TA = 25°C (unless otherwise noted) ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ PARAMETER TEST CONDITIONS |VOO| Output offset voltage (measured differentially) SHUTDOWN = 0 V, RL = 8 Ω, RF = 10 kΩ PSRR Power supply rejection ratio IDD IDD(SD) Supply current VDD = 4.9 V to 5.1 V SHUTDOWN = 0 V, RF = 10 kΩ Supply current, shutdown mode (see Figure 4) SHUTDOWN = VDD, RF = 10 kΩ |IIH| High-level input current |IIL| Low-level input current MIN TYP MAX 20 78 UNIT mV dB 1.25 2.5 mA 5 1500 nA SHUTDOWN, VDD = 5.5 V, VI = VDD 1 µA SHUTDOWN, VDD = 5.5 V, VI = 0 V 1 µA POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 3 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 operating characteristics, VDD = 5 V, TA = 25°C, RL = 8 Ω ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁ ÁÁÁ ÁÁÁ ÁÁÁ ÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁ PARAMETER TEST CONDITIONS MIN PO Output power THD = 0.5%, See Figure 13 THD + N Total harmonic distortion plus noise AV = – 2 V/V, PO = 700 mW f = 200 Hz to 4 kHz, See Figure 11, BOM B1 Maximum output power bandwidth AV = – 2 V/V, Open loop, THD = 2%, See Figure 11 Unity-gain bandwidth See Figure 16 TYP 700† MAX UNIT mW 0.5% 20 kHz 1.4 MHz Supply ripple rejection ratio f = 1 kHz, See Figure 2 80 dB CB = 1 µF, Vn Noise output voltage AV = – 1 V/V, See Figure 20 17 CB = 0.1 µF, µV(rms) † The DGN package, properly mounted, can conduct 700 mW RMS power continuously. The D package, can only conduct 350 mW RMS power continuously, with peaks to 700 mW. PARAMETER MEASUREMENT INFORMATION VDD 6 RF Audio Input RI CI 4 IN – 3 IN+ 2 BYPASS – VO+ 5 + RL = 8 Ω CB – VO– 8 + 7 GND 1 SHUTDOWN Bias Control Figure 1. BTL Mode Test Circuit 4 VDD CS VDD/2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 TYPICAL CHARACTERISTICS Table of Graphs FIGURE IDD Supply ripple rejection ratio vs Frequency Supply current vs Supply voltage 3, 4 vs Supply voltage 5 vs Load resistance 6 PO Output power THD + N Total harmonic distortion plus noise 2 vs Frequency Vn PD 7, 8, 11, 12 vs Output power 9, 10, 13, 14 Open loop gain and phase vs Frequency 15, 16 Closed loop gain and phase vs Frequency 17, 18 Output noise voltage vs Frequency 19, 20 Power dissipation vs Output power 21, 22 SUPPLY RIPPLE REJECTION RATIO vs FREQUENCY SUPPLY CURRENT vs SUPPLY VOLTAGE 1.8 RL = 8 Ω CB = 1 µF BTL –10 –20 SHUTDOWN = 0 V RF = 10 kΩ 1.6 I DD – Supply Current – mA Supply Ripple Rejection Ratio – dB 0 –30 –40 –50 –60 –70 VDD = 3.3 V –80 –100 20 100 1.2 1 0.8 VDD = 5 V –90 1.4 10k 1k 20k 0.6 2.5 f – Frequency – Hz 3 3.5 4 4.5 5 5.5 VDD – Supply Voltage – V Figure 2 Figure 3 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 TYPICAL CHARACTERISTICS OUTPUT POWER vs SUPPLY VOLTAGE SUPPLY CURRENT vs SUPPLY VOLTAGE 1000 10 9 THD+N 1% f = 1 kHz BTL SHUTDOWN = VDD RF = 10 kΩ 800 PO – Output Power – mW I DD – Supply Current – nA 8 7 6 5 4 3 600 RL = 8 Ω RL = 32 Ω 400 200 2 1 0 2.5 3 4 3.5 5 4.5 0 2.5 5.5 3 3.5 Figure 4 Figure 5 OUTPUT POWER vs LOAD RESISTANCE 800 THD+N = 1% f = 1 kHz BTL PO – Output Power – mW 700 600 VDD = 5 V 500 400 300 VDD = 3.3 V 200 100 0 8 16 24 32 40 48 56 RL – Load Resistance – Ω Figure 6 6 4 4.5 VDD – Supply Voltage – V VDD – Supply Voltage – V POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 64 5 5.5 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 TYPICAL CHARACTERISTICS TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 10 THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10 VDD = 3.3 V PO = 250 mW RL = 8 Ω BTL AV = –20 V/V 1 AV =– 10 V/V AV = –2 V/V 0.1 0.01 20 100 1k 10k VDD = 3.3 V RL = 8 Ω AV = –2 V/V BTL PO = 50 mW 1 0.1 PO = 125 mW PO = 250 mW 0.01 20 20k 100 1k f – Frequency – Hz Figure 7 TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER 10 VDD = 3.3 V f = 1 kHz AV = –2 V/V BTL THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10 1 RL = 8 Ω 0.1 0.01 0.05 0.1 20k Figure 8 TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER 0 10k f – Frequency – Hz 0.15 0.2 0.25 0.3 0.35 0.4 f = 20 kHz 1 f = 10 kHz f = 1 kHz 0.1 f = 20 Hz 0.01 0.01 PO – Output Power – W VDD = 3.3 V RL = 8 Ω CB = 1 µF AV = –2 V/V BTL 0.1 1 PO – Output Power – W Figure 9 Figure 10 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 TYPICAL CHARACTERISTICS TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY 10 VDD = 5 V PO = 700 mW RL = 8 Ω BTL THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10 AV = –20 V/V 1 AV = –10 V/V AV = –2 V/V 0.1 0.01 20 100 1k 10k 20k VDD = 5 V RL = 8 Ω AV = –2 V/V BTL 1 PO = 700 mW 0.1 PO = 350 mW 0.01 20 100 f – Frequency – Hz 20k TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER 10 10 THD+N –Total Harmonic Distortion + Noise – % THD+N –Total Harmonic Distortion + Noise – % 10k Figure 12 TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER VDD = 5 V f = 1 kHz AV = –2 V/V BTL 1 RL = 8 Ω 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 f = 20 kHz 1 f = 10 kHz f = 1 kHz f = 20 Hz 0.1 0.01 0.01 VDD = 5 V RL = 8 Ω CB = 1 µF AV = –2 V/V BTL PO – Output Power – W 0.1 PO – Output Power – W Figure 13 8 1k f – Frequency – Hz Figure 11 0.01 0.1 PO = 50 mW Figure 14 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 TYPICAL CHARACTERISTICS OPEN-LOOP GAIN AND PHASE vs FREQUENCY 80 180° VDD = 3.3 V RL = Open BTL 70 140° Phase 100° 50 60° 40 20° 30 Gain 20 – 20° 10 Phase Open-Loop Gain – dB 60 –60° 0 –100° –10 –140° –20 –30 1 101 102 103 104 –180° f – Frequency – kHz Figure 15 OPEN-LOOP GAIN AND PHASE vs FREQUENCY 80 180° VDD = 5 V RL = Open BTL 70 60 140° 100° 60° 40 20° 30 Gain 20 – 20° 10 Phase Open-Loop Gain – dB Phase 50 –60° 0 –100° –10 –140° –20 –30 1 101 102 f – Frequency – kHz 103 104 –180° Figure 16 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 9 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 TYPICAL CHARACTERISTICS CLOSED-LOOP GAIN AND PHASE vs FREQUENCY 1 180° Phase 0.75 170° 0.25 0 160° Gain –0.25 150° –0.5 –0.75 140° –1 –1.25 –1.5 Phase Closed-Loop Gain – dB 0.5 VDD = 3.3 V RL = 8 Ω PO = 250 mW BTL 130° –1.75 –2 101 102 103 104 105 106 120° f – Frequency – Hz Figure 17 CLOSED-LOOP GAIN AND PHASE vs FREQUENCY 1 180° Phase 0.75 170° 0.25 0 160° Gain –0.25 150° –0.5 –0.75 140° –1 –1.25 –1.5 –1.75 –2 101 VDD = 5 V RL = 8 Ω PO = 700 m W BTL 102 130° 103 104 105 f – Frequency – Hz Figure 18 10 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 120° 106 Phase Closed-Loop Gain – dB 0.5 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 TYPICAL CHARACTERISTICS OUTPUT NOISE VOLTAGE vs FREQUENCY 100 VDD = 3.3 V BW = 22 Hz to 22 kHz RL = 8 Ω or 32 Ω AV = –1 V/V Vn – Output Noise Voltage – µV Vn – Output Noise Voltage – µV 100 OUTPUT NOISE VOLTAGE vs FREQUENCY VO BTL Vo+ 10 1 20 100 1k 10k VDD = 5 V BW = 22 Hz to 22 kHz RL = 8 Ω or 32 Ω AV = –1 V/V VO BTL Vo+ 10 1 20 20k 100 f – Frequency – Hz Figure 19 800 BTL Mode VDD = 3.3 V RL = 8 Ω BTL Mode VDD = 5 V 700 PD – Power Dissipation – mW PD – Power Dissipation – mW 20k POWER DISSIPATION vs OUTPUT POWER 350 250 200 150 100 10k Figure 20 POWER DISSIPATION vs OUTPUT POWER 300 1k f – Frequency – Hz RL = 32 Ω 50 RL = 8 Ω 600 500 400 300 200 RL = 32 Ω 100 0 0 200 400 600 0 0 PD – Output Power – mW 200 400 600 800 1000 PD – Output Power – mW Figure 21 Figure 22 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 11 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 APPLICATION INFORMATION bridged-tied load Figure 23 shows a linear audio power amplifier (APA) in a BTL configuration. The TPA701 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 V (rms) + V Power + O(PP) 2 Ǹ2 2 (1) (rms) R L VDD VO(PP) RL 2x VO(PP) VDD –VO(PP) Figure 23. Bridge-Tied Load Configuration In a typical portable handheld equipment sound channel operating at 3.3 V, bridging raises the power into an 8-Ω speaker from a singled-ended (SE, ground reference) limit of 62.5 mW to 250 mW. 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 shown in Figure 24. 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. fc + 12 1 2p R C L C (2) POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 APPLICATION INFORMATION bridged-tied load (continued) 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) CC RL VO(PP) fc Figure 24. Single-Ended Configuration and Frequency Response Increasing power to the load does carry a penalty of increased internal power dissipation. The increased dissipation is understandable considering that the BTL configuration produces 4× the output power of a SE configuration. Internal dissipation versus output power is discussed further in the thermal considerations section. BTL amplifier efficiency Linear amplifiers are 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 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 25). IDD VO IDD(RMS) V(LRMS) Figure 25. Voltage and Current Waveforms for BTL Amplifiers POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 13 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 APPLICATION INFORMATION BTL amplifier efficiency (continued) 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 + where P P L (3) SUP 2 Vp V rms 2 L P + + L R 2R L L V V rms + P L Ǹ2 P I SUP + V rms + DD DD I 2V P rms + DD pR L V 2V DD P pR L ǒ p 2P R L L P + Efficiency of a BTL configuration + 4V 4V DD DD pV Ǔ 1ń2 (4) Table 1 employs equation 4 to calculate efficiencies for three different output power levels. 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. 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. Table 1. Efficiency Vs Output Power in 3.3-V 8-Ω BTL Systems OUTPUT POWER (W) EFFICIENCY (%) PEAK VOLTAGE (V) INTERNAL DISSIPATION (W) 0.125 33.6 1.41 0.26 0.25 47.6 58.3 2.00 2.45† 0.29 0.375 0.28 † High-peak voltage values cause the THD to increase. 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. In equation 4, VDD is in the denominator. This indicates that as VDD goes down, efficiency goes up. 14 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 APPLICATION INFORMATION application schematic Figure 26 is a schematic diagram of a typical handheld audio application circuit, configured for a gain of –10 V/V. VDD 6 RF 50 kΩ Audio Input VDD/2 RI 10 kΩ CI 4 IN – 3 IN+ 2 BYPASS VDD CS 1 µF – VO+ 5 + CB 2.2 µF – VO– 8 + 700 mW 7 GND SHUTDOWN 1 From System Control Bias Control Figure 26. TPA701 Application Circuit The following sections discuss the selection of the components used in Figure 26. component selection gain setting resistors, RF and RI The gain for each audio input of the TPA701 is set by resistors RF and RI according to equation 5 for BTL mode. ǒ Ǔ BTL gain + * 2 R F R I (5) 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 TPA701 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 6. Effective impedance + R R F I R )R F I POST OFFICE BOX 655303 (6) • DALLAS, TEXAS 75265 15 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 APPLICATION INFORMATION component selection (continued) 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 V/V 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 7. –3 dB f c(lowpass) + 1 2 pR C F F (7) fc For example, if RF is 100 kΩ and CF is 5 pF, then fco is 318 kHz, which is well outside of audio range. input capacitor, CI In the typical application an input capacitor, CI, is required to allow the amplifier to bias the input signal to the proper dc level for optimum operation. In this case, CI and RI form a high-pass filter with the corner frequency determined in equation 8. –3 dB f c(highpass) + 1 2pR C I I (8) 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 9. 1 C + I 2p R f c I 16 (9) POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 APPLICATION INFORMATION component selection (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. 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. It is important to confirm the capacitor polarity in the application. power supply decoupling, CS The TPA701 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. midrail bypass capacitor, CB The midrail bypass capacitor, CB, is the most critical capacitor and serves several important functions. During start-up or recovery from shutdown mode, CB determines the rate at which the amplifier starts up. The second function is to reduce noise produced by the power supply caused by coupling into the output drive signal. This noise is from the midrail generation circuit internal to the amplifier, which appears as degraded PSRR and THD + N. The capacitor is fed from a 250-kΩ source inside the amplifier. To keep the start-up pop as low as possible, the relationship shown in equation 10 should be maintained. This insures the input capacitor is fully charged before the bypass capacitor is fully charged and the amplifier starts up. ǒCB 10 250 kΩ v 1 Ǔ ǒRF ) RIǓ CI (10) As an example, consider a circuit where CB is 2.2 µF, CI is 0.47 µF, RF is 50 kΩ, and RI is 10 kΩ. Inserting these values into the equation 10 we get: 18.2 v 35.5 which satisfies the rule. Bypass capacitor, CB, values of 0.1 µF to 2.2 µF ceramic or tantalum low-ESR capacitors are recommended for the best THD and noise performance. 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. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 17 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 APPLICATION INFORMATION 5-V versus 3.3-V operation The TPA701 operates over a supply range of 2.5 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 with respect to supply bypassing, gain setting, or stability. The most important consideration is that of output power. Each amplifier in TPA701 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 of operation from 5-V supplies for a given output-power level. 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 TPA701 data sheet, one can see that when the TPA701 is operating from a 5-V supply into a 8-Ω speaker that 700 mW peaks are available. Converting watts to dB: P dB + 10 Log P P W + 10Log 700 mW + –1.5 dB 1W ref Subtracting the headroom restriction to obtain the average listening level without distortion yields: –1.5 dB – 15 dB = –16.5 (15 dB headroom) –1.5 dB – 12 dB = –13.5 (12 dB headroom) –1.5 dB – 9 dB = –10.5 (9 dB headroom) –1.5 dB – 6 dB = –7.5 (6 dB headroom) –1.5 dB – 3 dB = –4.5 (3 dB headroom) Converting dB back into watts: P W + 10 PdBń10 x P ref + 22 mW (15 dB headroom) + 44 mW (12 dB headroom) + 88 mW (9 dB headroom) + 175 mW (6 dB headroom) + 350 mW (3 dB headroom) 18 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPA701 700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER SLOS229D – NOVEMBER1998 – REVISED MAY 2003 APPLICATION INFORMATION headroom and thermal considerations (continued) 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 700 mW 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, 8-Ω system, the internal dissipation in the TPA701 and maximum ambient temperatures is shown in Table 2. Table 2. TPA701 Power Rating, 5-V, 8-Ω, BTL D PACKAGE (SOIC) DGN PACKAGE (MSOP) MAXIMUM AMBIENT TEMPERATURE MAXIMUM AMBIENT TEMPERATURE 675 34°C 110°C 350 mW (3 dB) 595 47°C 115°C 176 mW (6 dB) 475 68°C 122°C 700 88 mW (9 dB) 350 89°C 125°C 700 44 mW (12 dB) 225 111°C 125°C PEAK OUTPUT POWER (mW) AVERAGE OUTPUT POWER POWER DISSIPATION (mW) 700 700 mW 700 700 Table 2 shows that the TPA701 can be used to its full 700-mW rating without any heat sinking in still air up to 110°C and 34°C for the DGN package (MSOP) and D package (SOIC) respectively. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 19 PACKAGE OPTION ADDENDUM www.ti.com 18-Apr-2006 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty TPA701D ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPA701DG4 ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPA701DGN ACTIVE MSOPPower PAD DGN 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPA701DGNG4 ACTIVE MSOPPower PAD DGN 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPA701DGNR ACTIVE MSOPPower PAD DGN 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPA701DGNRG4 ACTIVE MSOPPower PAD DGN 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPA701DR ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPA701DRG4 ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPA701EVM OBSOLETE TBD Lead/Ball Finish Call TI MSL Peak Temp (3) Call TI (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 1 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Applications Amplifiers amplifier.ti.com Audio www.ti.com/audio Data Converters dataconverter.ti.com Automotive www.ti.com/automotive DSP dsp.ti.com Broadband www.ti.com/broadband Interface interface.ti.com Digital Control www.ti.com/digitalcontrol Logic logic.ti.com Military www.ti.com/military Power Mgmt power.ti.com Optical Networking www.ti.com/opticalnetwork Microcontrollers microcontroller.ti.com Security www.ti.com/security Low Power Wireless www.ti.com/lpw Telephony www.ti.com/telephony Mailing Address: Video & Imaging www.ti.com/video Wireless www.ti.com/wireless Texas Instruments Post Office Box 655303 Dallas, Texas 75265 Copyright © 2007, Texas Instruments Incorporated