10W Stereo Class D Audio Power Amplifier BA3101 Data Sheet Rev.1.0, 2009.08.01 Biforst Technology Inc. Page 0 of 7 BA3101 10W Stereo Class D Audio Power Amplifier 10W Stereo Class D Audio Power Amplifier GENERAL DESCRIPTION The BA3101 is a 12V class D amplifier from Biforst Technology. BA3101 provide volume control with four selectable gain settings. BA3101 is a 10-W (per channel) with lower supply current and fewer external components for driving bridged-tied stereo speaker directly. BA3101 operates with high efficiency energy conversion up to 89% (8-Ω Load) so that the external heat sink can be eliminated while playing music. Two gain select pins, GAIN0 and GAIN1, control the two controllable gain values, with firm gain selections are 20dB, 26dB, 32dB, 36dB. BA3101 also integrates Anti-Pop, Output Short & Over-Heat Protection Circuitry to ensure device reliability. This device output are completely protected from shorts to ground or supply pin as well as protected from Output Pin to Output Pin short. All the output short protection features are auto restore and auto monitor. FEATURE 9.2W Per Channel Into 8-Ω Speakers (THD+N = 10%@12V) 10.8W Per Channel into 8-Ω Speakers (THD+N = 10%@13V) Operation Voltage From 8V To 15V Maximum Power Efficiency Into 8-Ω, 89% Total four selectable, firm-gain solution Differential input Automatic monitor and restore scheme for short and over heat protection Clock synchronization master/slave for multiple Class D device Eliminates output clamp and bypass capacitors Package is SMD 7mm * 7mm 48 Pins TQFP-with Exposed Thermal Pad APPLICATION LCD TV LCD Monitor Powered Speaker Hi-Fi Audio System Page 1 of 7 BA3101 10W Stereo Class D Audio Power Amplifier These devices have limited built-in ESD protection. The lead should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the device. ABSOLUTE MAXIMUM RATINGS Over operating free-air temperature range, unless otherwise specified (* 1) SYMBOL PARAMETER VALUE UNIT VDD, PVDDL, PVDDR Supply voltage -0.3 to 15 V VI( SHUTDOWN , MUTE) Input voltage -0.3 to VCC+0.3 V Input voltage -0.3 to VREG+0.5 V Operating free-air temperature range -40 ~ +85 o -40 to +150 o o VI(GAIN0, GAIN1, RINN, RINP, LINN, LINP, MSTR/ SLV , SYNC) TA TJ (* 2) Operating junction temperature range C C TSTG Storage temperature range -65 to 85 C R(Load) Minimum load resistance 8 Ω Electrostatic discharge Human body model ±2 kV Electrostatic discharge Machine model ±200 V ( *1): Stress beyond those listed at “absolute maximum rating” table may cause permanent damage to the device. These are stress rating ONLY. For functional operation are strongly recommend follow up “recommended operation conditions” table. ( *2): BA3101 package embedded with an exposed thermal PAD underside of package. The exposed PAD performs the function of heat sink and it have to be connected to a thermally dissipating plane for power dissipation. Failure to do so will result in the device going into thermal protection shutdown. PACKAGE DISSPATION RATINGS PACKAGE θja(junction to ambient air) θjc(junction to case) TQFP 48 pin with Expose Pad 35.24 7.14 UNIT ℃ mW/ *This data was taken using 1 oz copper pad that is soldered directly to FR-4 PCB. The thermal pad must be soldered to the thermal land on PCB. RECOMMENDED OPERATING CONDITIONS Over operating free-air temperature range, unless otherwise specified SYMBOL PARAMETER VDD Supply voltage TEST CONDITION VDD ，PVDDL，PVDDR SPECIFICATION MIN MAX 8 15 UNIT V Page 2 of 7 BA3101 SYMBOL VIH VIL IIH 10W Stereo Class D Audio Power Amplifier PARAMETER High level input voltage Low level input voltage High level input current Low level input current VOH VOL fOSC TA High level output voltage MIN ，MSTR/ SLV ，SYNC，GAIN0， GAIN1，MUTE SHUTDOWN ，MSTR/ SLV ，SYNC MUTE， GAIN0，GAIN1 V =V ，V =15 V MUTE，V =V ，V =15 V V =V ，V =15 V V =V ，V =15 V V =0 V，V =12 V FAULT，I =1 mA， SHUTDOWN I DD REG I DD FAULT 0.8 2 2 DD 1 OL=-1 uA 80 DD ，I V 150 DD OH voltage V DD I Low level output Oscillator frequency DD UNIT MAX 2.0 DD I I IIL SPECIFICATION TEST CONDITION uA V VREG-0.6 ， mA ，MSTR/ SLV = 2 V ROSC Resistor = 100 kΩ Operating free-air temperature AGND +0.4 V 250 300 kHZ - 40 85 o C DC CHARACTERISTICS TA = 25 ℃, VDD= 12V, RL = 8Ω, Gain =20dB (unless otherwise noted) SYMBOL VREG VBYP |PSRR| PARAMETER 5V internal supply voltage Bypass reference for input amplifier DC power supply rejection ratio Drain-Source RDS(ON) TEST CONDITION on –state resistance G TYP MAX No load 4.5 5 5.5 V No load 1.15 1.25 1.35 V VDD=12V, PO=8W, GAIN0=L Gain GAIN0=H UNIT MIN VDD=12V, input AC tie ground, Gain=36dB RL=8Ω SPECIFICATION 70 High Side 365 Low Side 365 GAIN1=L 20 GAIN1=H 26 GAIN1=L 32 GAIN1=H 36 dB mΩ dB Page 3 of 7 BA3101 10W Stereo Class D Audio Power Amplifier SPECIFICATION SYMBOL PARAMETER TEST CONDITION TON Turn-On time C(VBYP)=1µF, SHUTDOWN =H 25 ms TOFF Turn-Off time C(VBYP)=1µF, SHUTDOWN =L 0.1 ms Quiescent MIN SHUTDOWN =H, MUTE=L, no load, no TYP MAX UNIT 24 filter, no snubber ICC Mute mode SHUTDOWN =H, MUTE=H, no load, no mA 11 filter, no snubber Shutdown mode SHUTDOWN =L, no load, no filter, no 200µA snubber AC CHARACTERISTICS TA = 25 ℃, VDD= 12V, RL = 8Ω, Gain =20dB (unless otherwise noted) SYMBOL |Ksvr| THD+N |Crosstalk| PO PARAMETER TEST CONDITION Supply ripple 200mVPP ripple from 20Hz-1kHz, input AC rejection tie ground Total harmonic distortion and noise Crosstalk between L/R channel Continuous output power f=1kHz SPECIFICATION MIN TYP MAX UNIT 70 dB f=1kHz, PO=5W 0.17 % Vo=1VRMS,f=1kHz 90 dB THD+N=1% 7.4 THD+N=10% 9.2 VDD=13V,THD+N=10% 10.8 W SNR Signal to noise ratio THD+N=1%, A-weighted, f=1kHz 93 dB VN Output noise 22Hz to 22kHz, A-weighted filter 150 µV Page 4 of 7 BA3101 10W Stereo Class D Audio Power Amplifier VDD VDD FAULT MUTE SHUTDOWN_B N.C. ROUTP ROUTP ROUTN ROUTN N.C. GND 48 47 46 45 44 43 42 41 40 39 38 37 PIN ASSIGNMENTS GND 1 36 RINN 2 35 PVDDR RINP 3 34 PVDDR GND 4 33 PVSSR LINP 5 32 PVSSR 31 N.C. 30 N.C. BA-3101 Exposed-Thermal PAD GND 23 24 N.C. 22 GND 21 GND LOUTN 25 LOUTN 12 20 GND LOUTP PVDDL 19 SYNC 26 18 PVDDL 11 N.C. MSTR/SLV_B LOUTP PVSSL 27 17 28 10 GND 9 16 GAIN1 VBYP PVSSL VREG 29 15 8 14 GAIN0 13 7 GND 6 ROSC LINN GAIN0 PIN DESCRIPTION Pin No. Pin I/O Pad Function Type Power ground 1 GND POWER 2 RINN Input Right channel negative audio signal input 3 RINP Input Right channel positive audio signal input 4 GND POWER 5 LINP Input Left channel positive audio signal input 6 LINN Power Left channel negative audio signal input 7~8 GAIN0 Input Gain control input to select least significant bit 9 GAIN1 Input Gain control input to select most significant bit 10 MSTR/ SLV 11 SYNC 12 ~ 13 GND Power ground Determine clock operating mode. While this pin is H state, BA3101 operates in clock master mode, SYNC outputs operating clock, otherwise the operating mode is clock Slave mode, SYNC pin accept clock input. Could be input or output clock to synchronize multiple class D devices. Input/Output I/O direction is decided by “MSTR/ SLV ” pin. Input Power Power ground Input/Output External resistor for current control 14 ROSC 15 VREG Output 5V voltage regulation output for internal reference. 16 VBYP Output Bias reference voltage output, need connect an external capacitor. 17 GND Power Power ground 18 NC Page 5 of 7 BA3101 10W Stereo Class D Audio Power Amplifier 19 ~ 20 LOUTP Output Left channel positive output 21 ~ 22 LOUTN Output Left channel negative output 24 ~ 25 GND Power Power ground 26 ~ 27 PVDDL Power Power supply for left channel output 28 ~ 29 PVSSL Power Power ground for left channel output 32 ~ 33 PVSSR Power Power ground for right channel output 34 ~ 35 PVDDR Power Power supply for right channel output 36 ~ 37 GND Power Power ground 39 ~ 40 ROUTN Output Right channel negative output 41 ~ 42 ROUTP Output Right channel negative output 23 NC 30 ~ 31 NC 38 NC 43 NC 44 SHUTDOWN_B Input 45 MUTE Input 46 FAULT Output 47 ~ 48 VDD Exposed Thermal PAD Power Shutdown signal for IC (L state = disabled, H state= normal). TTL logic levels with compliance to VDD. Signal to instantly disable output; Signal is TTL logic level compatible and compliance with VDD. Fault status indicator. HIGH = short-circuit fault. LOW = fault-free. Only reports short-circuit faults. Power supply. The thermal pad have to be soldered and be connect to the PCB large ground copper area. Page 6 of 7 BA3101 10W Stereo Class D Audio Power Amplifier FUNCTIONAL BLOCK DIAGRAM TEST SETUP FOR PERFORMANCE MEASUREMENTS + AP SYS-2722 (Analog Generator) - OUTP INP BA3101 Demo Board OUTN INN + Load AP AUX-0025 AP SYS-2722 - (Analog Analyzer) 10uF Power Supply Page 7 of 7 BA3101 10W Stereo Class D Audio Power Amplifier Note: This connection diagram shows single channel configuration. All graphs were measured by BA3101 demo board. Two 22µH inductors are used in series with load resistor to emulate the speaker for efficiency measurement. TYPICAL CHARACTERISTICS Table of Graphs Figure No. Description 1 THD+N vs. Output Power Gain=20dB,Load=8Ω,VDD=12V 2 THD+N vs. Output Frequency Gain=20dB,Load=8Ω,VDD=12V 3 Crosstalk vs. Frequency 4 Gain and Phase 5 Output Power vs. Supply Voltage Gain=20dB,Load=8Ω 6 Output Power vs. Current Gain=32dB,Load=8Ω 7 Efficiency Gain=32dB,Load=8Ω,VDD=12V Gain=20dB,Load=8Ω,VDD=12V, THD+N=1% Gain=32dB,Load=8Ω,VDD=12V, CIN=10µF,VIN=0.1V Important notice: Power above 10 W may require increased heatsinking. Figure 1. THD+N vs Output Power Page 8 of 7 BA3101 10W Stereo Class D Audio Power Amplifier Figure 2. Figure 3. THD+N vs Frequency Crosstalk vs Frequency Page 9 of 7 BA3101 10W Stereo Class D Audio Power Amplifier Figure 4. Gain and Phase Shift vs Frequency Figure 5. Output Power vs Supply Page 10 of 7 BA3101 10W Stereo Class D Audio Power Amplifier Figure 6. Supply Current vs Output Power Figure 7. Efficiency FUNCTION DESCRIPTION Output Filter Application Note Design the BA3101 without the filter if the traces from amplifier to speaker are short (< 10cm), where the speaker is in the same enclosure as the amplifier is a typical application for class D without a filter. Many applications require a ferrite bead filter. The ferrite filter reduces EMI around 30MHz. When selecting a ferrite bead, choose one with high impedance at high frequencies, but low impedance at low frequencies. Page 11 of 7 BA3101 10W Stereo Class D Audio Power Amplifier Use an LC output filter if there are low frequency (<1 MHz) EMI sensitive circuits and there are long wires from the amplifier to the speaker. Figure 8. Typical LC Output Filter, Speaker Impedance=8Ω Figure 9. Typical Ferrite Chip Bead Output Filter, Speaker Impedance=8Ω Inductors used in LC filters must be selected carefully. A significant change in inductance at the peak output current of the BA3101 will cause increased distortion. The change of inductance at currents up to the peak output current must be less than 0.1µH per amp to avoid this. Also note that smaller inductors than 33µH may cause an increase in distortion above what is shown in preceding graphs of THD versus frequency and output power. In all cases, avoid using inductors which value are less than 22µH. Capacitors used in LC filters must also be selected carefully. A significant change in capacitance at the peak output voltage of the BA3101 will cause increased distortion. LC filter capacitors should have DC voltage ratings of at least twice the peak application voltage (the power supply voltage). In all cases, it is strongly recommended using capacitors with good temperature ratings like X5R. Output Snubbers In Figure 11, the 470pF capacitors in series with 22Ω resistors from the outputs of the BA3101 to switching snubbers. They smooth switching transitions and reduce overshoot and ringing. By doing so they improve THD+N at lower power levels and they improve EMC by 2 to 4 dB at middle frequencies. Page 12 of 7 BA3101 10W Stereo Class D Audio Power Amplifier They increase quiescent current by 3mA to 11mA depending on power supply voltage. Figure 10. Output Snubbers Over-Heat Protection Over-Heat protection on the BA3101 prevents damage to the device when the internal die junction temperature exceeds 150°C. Once the die temperature exceeds the thermal set point, the device enters the shutdown state and the outputs are disabled. The device will back to normal operation when die temperature is reduced without external system interaction. Output Short Protection The BA3101 has output short circuit protection circuitry on the outputs that prevents damage to the device during output-to-output short, output-to-GND short and output-to-VDD short. BA3101 enter the shutdown state and the outputs are disabled when detects output short. This is a latched fault and must be reset by cycling the voltage on SHUTDOWN pin or MUTE pin, or by cycling the power off and then back on. This clears the short circuit flag and allows for normal operation if the short was removed. If the short was not removed, the protection circuitry would active again. Internal 5V reference The VREG terminal (pin 15) is the output of an internally generated 5V supply, used for the oscillator, preamplifier, and gain control circuitry. It is highly recommended to place a 10nF~100nF capacitor close to the pin to keep the internal regulator stable. This regulated voltage should be used to connect GAIN0, GAIN1, MSTR/ SLV , and MUTE terminals only. Do not use it to drive external circuitry. Bypass Capacitor The internal bias generator (VBYP) nominally provides a 1.25V bias for the preamplifier stages using internally. The input coupling capacitors and this internal voltage reference allow the inputs to be biased Page 13 of 7 BA3101 10W Stereo Class D Audio Power Amplifier within the optimal common-mode range of the input preamplifiers. The value of the capacitor on the VBYP terminal (pin 16) is critical related to amplifier performance. During power up or recovery from the shutdown state, this capacitor determines the rate at which the amplifier starts up. Using a larger value of VBYP capacitor can increase amplifier start-up time but should not exceed 10µF. Selection of ROSC The class D output switching frequency can be controlled by ROSC and COSC by the following equation: f OUT = 1 2 × ROSC × C OSC ROSC is an external resistance connected to pin 14 that is nominally 100kΩ. COSC is an internal capacitor that is nominally equal to 18 pF. Variation over fabrication process and temperature can result in a ±15% change in this capacitor value. For example, if ROSC is fixed at 100kΩ, the frequency from device to device with this fixed resistance could vary from 300 kHz to 250 kHz including the variations of ROSC resistor. LOW-ESR Capacitors Low-ESR capacitors are high recommended for this application. Generally a practical capacitor can be modeled simply as a resistor in series with an ideal capacitor. The voltage drop across this unwanted resistor can eliminate the effects of the ideal capacitor. Place low ESR capacitors on supply circuitry can improve THD+N performance. Decoupling Capacitors BA3101 requires appropriate power decoupling to minimize the output total harmonic distortion (THD). Power supply decoupling also prevents intrinsic 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 lines. For higher frequency spikes, or digital hash on the rail, a good low ESR ceramic capacitor, for example 0.1µF to 10µF, placed as close as possible to PVDD_A pins works best. For filtering lower frequency noise, a larger low ESR aluminum electrolytic capacitor of 220µF or greater placed near the audio power amplifier is also recommended. The 220µF capacitor also serves as local storage capacitor for supplying current during heavy duty on the amplifier outputs. The PVDD_A terminals provide the power to the output transistors, so a 220µF or larger capacitor should be placed on each channel PVDD_A terminal. A 10µF ceramic capacitor on each VDD terminal is also recommended. Gain Settings The gain of the BA3101 can be set by GAIN0 and GAIN1 pins. The gain ratios listed in Table are implemented by changing the taps on the feedback resistors in the preamplifier stage. Since the gain settings are controlled by ratios of input resistor and feedback resistor of the preamplifier, the gain ratio may varies with different VDD supply. Note the amplifier gain ratio is obtained at 12V VDD supply. Page 14 of 7 BA3101 10W Stereo Class D Audio Power Amplifier Gain 1 Gain 0 Gain Ratio 1 1 36dB 1 0 32dB 0 1 26dB 0 0 20dB Table 1. BA3101 Gain Ratio Differential Input The differential input stage of the amplifier can cancel any common-mode noise coupled from input paths. To use the BA3101 with a differential signal source, connect the positive output of the audio source to the INP input and the negative output from the audio source to the INN input. To use the BA3101 with a single-ended signal source, ac ground the INP or INN input through a coupling capacitor equal in value to the input capacitor on INN or INP and apply the audio source to either input. In single-ended input configuration, the unused inputs should be ac grounded at the audio source instead of at the IC input for better noise performance. SHUTDOWN OPERATION The BA3101 employs a shutdown mode of operation designed to reduce supply current to the absolute minimum level during periods of nonuse for power conservation. This terminal should be held high during normal operation when the amplifier is in normal operating. Pulling low causes the output drivers shutdown and the amplifier to enter a low-current state. Do not leave it unconnected, because there is no weakly pulling resistor inside the amplifier. Remember that to place the amplifier in the shutdown state prior to removing the power supply voltage so that power-off pop noise can be eliminated. MSTR/ SLV and SYNC Operation The MSTR/ SLV and SYNC terminals can be used to synchronize the frequency of the class D output switching. When the MSTR/ SLV terminal is high, the output switching frequency is determined by the selection of the resistor connected to the ROSC terminal. The SYNC terminal becomes an output in this mode, and the frequency of this output is also determined by the selection of the ROSC resistor. This TTL compatible, push-pull output can be connected to another BA3101, configured in the slave mode. The output switching is synchronized to avoid any beat frequencies that could occur in the audio band when two class D amplifiers in the same system produces switching noises on VDD supply. When MSTR/ SLV terminal is in low state, the output switching frequency is determined by the incoming square wave on the SYNC input. The SYNC terminal becomes an input in this mode and accepts a TTL compatible square wave from another BA3101 configured in the master mode or from an external GPIO. If connecting to an external GPIO, recommended frequencies are 225 kHz to 325 kHz for proper device Page 15 of 7 BA3101 10W Stereo Class D Audio Power Amplifier operation. SAMPLE APPLICATION CIRCUIT Figure 11. Stereo Class D with Differential Inputs Figure 12. Stereo Class D with Single-Ended Inputs Page 16 of 7 BA3101 10W Stereo Class D Audio Power Amplifier PACKAGE DIMENSION TQFP-48-EP Page 17 of 7 BA3101 10W Stereo Class D Audio Power Amplifier CONTACT INFORMATION Biforst Technology Inc. 3F-3, No.32, Tai Yuen St., Jubei City, Hsin-Chu, Taiwan, R.O.C. Tel: 886-3-552-6521; Fax: 886-3-552-6558; Email: [email protected] Revision History Version Date Page Description 0.2 2009.06.24 Preliminary Release 1.0 2009.08.01 Initial Release Page 18 of 7