D386

Silicore L ow Voltage Audio Power Amplifier D 386 DESCRIPTION T he D386 is a power am plifier designed for u se in low voltage consum er applications. The gain i s internally s et to 20 to keep external part count l ow, but the addition of an external resistor and c apacitor between pins 1 and 8 will increase the g ain to any v alue from 2 0 to 200. T he inputs are ground referenced while the o utput autom a tically b iases to one-half the supply v oltage. The quiescent power drain is only 2 4 O utline Drawing m illiwatts when operating from a 6 v olt supply , m a king the LM386 ideal for battery o peration. F EAT URE B attery o peration M i n i mu m e x t e r n a l p a r t s W ide supply v oltage range: 4V–12V L ow quiescent current drain: 4m A V oltage gains from 2 0 to 200 A vailable in 8 pin DIP package APPLICATION AM-FM radio amplifiers P ortable tape player am plifiers I ntercom s T V sound sy stem s L ine drivers U ltrasonic drivers S m all servo drivers P ower converters P IN CONFIGURATION SHAOXING SILICORE TECHNOLOGY CO.,LTD www. Silicore. com. cn 1/6 CHMC Silicore E QUIVA LENT SCHEMATIC A ND CONNECTION DIAGRAMS D386 A BSOLUTE MAXIMUM RATINGS ( Ta=25 ° C) Characteristic M axim u m I nput Vo ltage S upply Vo ltage M axim u m P ower Disspation S oldering tem p erature(10 sec.) Junction Te m p erature Operating Te m p erature S t orage Te m p erature Symbol VIN V cc PD TS Tj Ta m b Ts tg Va l u e ± 0.4 15 660 260 1 50 - 10~+70 - 40~125 Unit V V mV °C °C °C °C E LECTRICAL C HARACTERISTICS ( Unless otherwise specified: V cc=6V , R L =8 Ω , f =1kHz , Ta m b =25 ℃ ) Characteristics Operating Supply Voltage Quiescent Current Output Power Voltage Gain Bandwidth Total Harmonic Distortion Power Supply Rejection Ratio Input Resistance Input Bias Current Te s t c o n d i t i o n s V cc=6V ， V I N =0 V cc=6V, R L =8 Ω ， THD=10% V cc=9V, R L =8 Ω ， THD=10% V cc=6V, f=1kHz 1 脚 、 8 脚 间 接 10μ F 电 容 V cc=6V ， 脚 1 、 8 开 路 V cc=6V ， R L =8 Ω ， Po=125mW ， f=1kHz 脚 1、 8 开 路 V cc=6V ， f=1kHz ， C B Y P A S S =1 0 μ F， 1、 8 脚 开 路 、 输 出 为 参 考 V cc=6V ， 2 、 3 脚 开 路 S y m bol Vcc Icc Po Av BW THD PSRR RIN IB Min 250 500 - Ty p 4 325 700 26 46 300 0.2 50 M ax 12 8 U nit V mA mW - dB kHz % dB - 50 250 - kΩ nA 2/6 SHAOXING SILICORE TECHNOLOGY CO.,LTD www. Silicore. com. cn CHMC Silicore A PPLICAT ION H INTS G AIN CONTROL D386 T o m a ke the D386 a m o re versatile am plifier, t wo pins (1and 8) are provided for gain c ontrol. With pins 1 and 8 open the 1.35 kW resistor sets the gain at 20 (26 dB). If a c apacitoris put from p in 1 to 8, by passing the 1.35 kW resistor, the gain will go up to 200 ( 46 dB). If a resistor is placed in series with t he capacitor, the gain can be set to any value f rom 2 0 to 200. Gain control can also be done by c apacitively c oupling a resistor (or FET) f rom p in 1 to ground. A dditional external com ponents can be placed in parallel with the internal feedback r esistors to tailor the gain and frequency r esponse for individual applications. For exam ple, w e can com p ensate poor speaker bass response by f requency s haping the feedback path. T his is done with a series RC from p in 1 to 5 (paralleling the internal 15 kW resistor). F or 6 dB effective bass boost: R . 15 kW, the lowest value for good stable operation is R = 1 0 kW if pin 8 is open. If pins 1 and 8 are by passed then R as low as 2 kW can be used. T his restriction is because the am plifier is o nly c om p ensated for closed-loop gains greater t han 9. I NPUT BIASING T he schem a tic shows that both inputs are bi ased to ground with a 50 kW resistor. The b ase current of the input transistors is about 250 nA, so the inputs are at about 12.5 m V w hen left open. If the dc source resistance d riving the D386 is higher than 250 kW it will c ontribute very l ittle additional offset (about 2.5 m V a t the input, 50 m V a t the output). If t he dc source resistance is less than 10 kW, t hen shorting the unused input to ground will k eep the offset low (about 2.5 m V a t the input, 50 m V a t the output). For dc source r esistances between these values we can elim inate excess offset by putting a resistor from t he unused input to ground, equal in value to the dc source resistance. Of course all offset p roblem s are elim inated if the input is capacitively c oupled. W hen using the D386 with higher gains (by p a ssing the 1.35 kW resistor between pins 1 a nd 8) it is necessary t o by pass the unused input, preventing degradation of gain and p ossible instabilities. This is done with a 0. 1 µF capacitor or a short to ground depending o n the dc source resistance on the driven input. SHAOXING SILICORE TECHNOLOGY CO.,LTD www. Silicore. com. cn 3/6 CHMC Silicore A PPLICAT ION CIRCUIT Vs 6 2 Vin 10K 3 + 4 1 8 D386 7 0.05uF 10 5 250uF Vin 2 6 Vs 1 D386 10K + 3 4 7 旁路 D386 10uF 8 5 250uF 0.05uF 10 F ig1 Am plifier w ith G ain = 2 0 (Minimum Parts) Fig2 Am plifier w ith G ain = 2 00 Vs 6 2 Vin 10K + 4 1.2K 1 8 10uF 250uF 220 热敏电阻 2 6 - Vs 1 10uF 390 8 5 250uF D386 Vo D386 3 旁路 5 7 0.05uF 3 + 4 7 0.05uF ÅÔ· 10 RL 10 4.7K 0.01uF F ig3 Am plifier w ith G ain = 5 0 Fig4 Low D istortion P ower W ienbridge Oscillator Vs 6 2 Vin 7 - 6 Vs 1 30K 8 50uF 5 RL 旁路 0.1uF 2 - 0.033uF D386 3 + 4 8 1 5 250uF Vo 3 + 4 D386 7 Vo 10K 0.05uF 10 RL 1K 10K 10K F ig5 A m plifier w ith B ass B oost Fig6 Square W ave O scillator 4/6 SHAOXING SILICORE TECHNOLOGY CO.,LTD www. Silicore. com. cn CHMC Silicore Cc D386 Vs 0.05uF 6 1 10uF Vin VoL 10K 10K 2 2200pF 8 铁氧体线圈 250uF D386 3 + 4 7 5 47 0.05uF 8 喇叭 10uF Fig7 AM Radio Power Amplifier T YPICAL P ERFORMANCE CHARACTERISTICS SHAOXING SILICORE TECHNOLOGY CO.,LTD www. Silicore. com. cn 5/6 CHMC Silicore D386 SHAOXING SILICORE TECHNOLOGY CO.,LTD www. Silicore. com. cn 6/6 CHMC