UNISONIC TECHNOLOGIES CO., LM386 LINEAR INTEGRATED CIRCUIT LOW VOLTAGE AUDIO POWER AMPLIFIER DESCRIPTION The UTC LM386 is a power amplifier, designed for use in low voltage consumer applications. The gain is internally set to 20 to keep external part count low, but the addition of an external resistor and capacitor between pin 1 and pin 8 will increase the gain to any value up from 20 to 200. The inputs are ground referenced while the output automatically biases to one-half the supply voltage. The quiescent power drain is only 24 milliwatts when operating from a 6 voltage supply, making the LM386 ideal for battery operation. FEATURES *Battery Operation *Minimum External Parts *Wide Supply Voltage Range: 4V~12V *Low Quiescent Current Drain:4mA *Voltage Gains:20~200 *Ground Referenced Input *Self-Centering Output Quiescent Voltage *Low Distortion:0.2%(Av =20,Vs=6V,RL=8Ω,Po=125mW,f=1kHz) ORDERING INFORMATION Normal LM386-S08-R LM386-S08-T LM386-P08-R LM386-P08-T LM386-D08-T Ordering Number Lead Free LM386L-S08-R LM386L-S08-T LM386L-P08-R LM386L-P08-T LM386L-D08-T www.unisonic.com.tw Copyright © 2011 Unisonic Technologies Co., Halogen Free LM386G-S08-R LM386G-S08-T LM386G-P08-R LM386G-P08-T LM386G-D08-T Package Packing SOP-8 SOP-8 TSSOP-8 TSSOP-8 DIP-8 Tape Reel Tube Tape Reel Tube Tube 1 of 8 QW-R107-007.H LM386 LINEAR INTEGRATED CIRCUIT PIN CONFIGURATION UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 8 QW-R107-007.H LM386 LINEAR INTEGRATED CIRCUIT BLOCK DIAGRAM 6 BYPASS 7 15K 15K GAIN GAIN 8 1 150 -INPUT 15K 5 VOUT 1.35K 2 3 50K +INPUT 50K 4 UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw Vs GND 3 of 8 QW-R107-007.H LM386 LINEAR INTEGRATED CIRCUIT ABSOLUTE MAXIMUM RATINGS PARAMETER SYMBOL VCC VIN RATINGS UNIT 15 V -0.4V ~ +0.4V V DIP-8 1250 Power Dissipation PD mW SOP-8 600 TSSOP-8 600 Operating Temperature TOPR -20 ~ +85 °C Junction Temperature TJ +125 °C Storage Temperature TSTG -40 ~ +150 °C Note:1. Absolute maximum ratings are stress ratings only and functional device operation is not implied. The device could be damaged beyond Absolute maximum ratings. Supply Voltage Input Voltage ELECTRICAL CHARACTERISTICS (Ta=25°C, unless otherwise specified.) PARAMETER Operating Supply Voltage Quiescent Current SYMBOL Vss IQ Output Power POUT Voltage Gain GV Bandwidth BW Total Harmonic Distortion THD Rejection Ratio RR Input Resistance Input Bias Current RIN IBIAS TEST CONDITIONS Vss=6V, VIN=0 Vss=6V, RL=8Ω, THD=10% Vss=9V, RL=8Ω, THD=10% Vss=6V, f=1kHz 10μF from pin 1 to pin 8 Vss=6V , Pin1 and pin 8 open POUT=125mW, Vs=6V,f=1kHz RL=8Ω pin1 and pin 8 open Vss=6V, f=1kHz, CBYPASS=10μF pin1and pin 8 open, Referred to output Vss=6V Pin2 and pin 3 open UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw MIN 4 250 500 TYP 4 325 700 MAX UNIT 12 V 8 mA mW 26 46 300 dB dB kHz 0.2 % 50 dB 50 250 kΩ nA 4 of 8 QW-R107-007.H LM386 LINEAR INTEGRATED CIRCUIT APPLICATION NOTES GAIN CONTROL To make the LM386 a more versatile amplifier, two pins(1and 8) are provided for gain control. With pins 1 and 8 open the 1.35 kΩ resistor sets the gain at 20(26dB),If a capacitor is put from pin 1 to 8,bypassing the 1.35 kΩ resistor, the gain will go up to 200(46dB).If a resistor is placed in series with the capacitor, the gain can be set to any value from 20 to 200.Gain control can also be done by capacitively coupling a resistor (or FET) from pin 1 to ground. Additional external components can be placed in parallel with the internal feedback resistors to tailor the gain and frequency response for individual applications. For example we can compensate poor speaker bass response by frequency shaping the feedback path. This is done with a series RC from pin 1 to 5 (paralleling the internal 15 kΩ resistor). For 6 dB effective bass boost: R=15 kΩ, the lowest value for good stable operation is R=10 kΩ, if pin 8 is open, If pins 1 and 8 are bypassed then R as low as 2 kΩ can be used. This restriction is because the amplifier is only compensated for closed-loop gains greater than 9. INPUT BIASING The schematic shows that both inputs are biased to ground with a 50 kΩ resistor. The base current of the input transistors is about 250nA, so the inputs are at about 12.5mW when left open. If the dc source resistance driving the LM386 is higher than 250 kΩ it will contribute very little additional offset (about 2.5mW at the input, 50mW at the output).If the dc source resistance is less than 10 kΩ,then shorting the unused input to ground will keep the offset low (about 2.5mV at the input,50 mV at the output).For dc source resistances between these values we can eliminate excess offset by putting a resistor from the unused input to ground, equal in value to the dc source resistance. Of course all offset problems are eliminated if the input is capacitively coupled. When using the LM386 with higher gains (bypassing the 1.35 kΩ resistor between pins 1 and 8)it is necessary to bypass the unused input, preventing degradation of gain and possible instabilities. This is done with a 0.1μF capacitor or a short to ground depending on the dc source resistance on the driven input. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 5 of 8 QW-R107-007.H LM386 LINEAR INTEGRATED CIRCUIT TYPICAL APPLICATIONS CIRCUIT AM Radio Power Amplifier FROM DETECTOR Cc VOL 10KΩ Vs 10μF + 0.05μF R1 10KΩ 2 C1 2200pF 6 - FERRITE BEAD 1 250μF + 8 5 3 + 4 7 47 +10μF 47Ω + 0.05μF 8Ω SPEAKER Note 1: Twist Supply lead and supply ground very tightly. Note 2: Twist speaker lead and ground very tightly. Note 3: Ferrite bead in Ferroxcube K5-001-001/3B with 3 turns of wire. Note 4: R1C1 band limits input signals. Note 5: All components must be spaced very closely to IC. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 6 of 8 QW-R107-007.H LM386 TYPICAL CHARACTERISTICS Power Supply Rejection Ratio(Referred to the Output) vs Frequency Quiescent Supply Current vs Supply Voltage 60 6 Power Supply Rejection (dB) Supply Current (mA) C7=50μF 5 4 3 2 4 5 6 7 8 9 10 11 50 12 1μF 30 0.5μF 10μF 20 NO BYPASSCAPACITOR 10 100 1K 10K 100K Frequency (Hz) Supply Voltage(volts) Frequency Response With Bass Boost Peak-to -Peak Output Voltage Swing vs Supply Voltage 27 10 RL=∞ 26 16 25 8 8 Voltage Gain (dB) Output Voltage (Volts Peak-To-Peak) Vs=6V Av=26dB 40 0 10 1 6 4 4 2 24 23 22 21 20 19 18 17 20 0 4 5 6 7 8 9 10 11 12 Supply Voltage(volts) 50 100 200 500 1K 2K 5K 10K 20K Frequency (Hz) Total Harmonic Distortion (%) Voltage Gain (dB) LINEAR INTEGRATED CIRCUIT UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 7 of 8 QW-R107-007.H LM386 LINEAR INTEGRATED CIRCUIT TYPICAL CHARACTERISTICS(cont.) Device Dissipaton vs Output Power 4ΩLoad Distortion vs Output Power 2.0 10 8 1.8 1.6 Device Dissipation (W) Total Harmonic Distortion (%) 9 Vs=6V RL=8Ω f=1kHz 7 6 5 4 3 2 1.4 Vs=12V 1.2 Vs=9V 0.8 0.6 0 0.001 Vs=6V 0 0.01 0.1 0 1.0 Power Output (Watts) 10% THD LEVEL 1.6 Device Dissipation (W) 0.3 0.4 0.5 Device Dissipaton vs Output Power -16ΩLoad Vs=16V 1.4 1.2 Vs=12V Vs=9V 0.6 0.4 0.2 Vs=6V 3% THD LEVEL 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Output Power (W) Vs=16V 0.8 Device Dissipation (W) 1.8 0 0.2 1.0 2.0 0.8 0.1 Output Power (W) Device Dissipaton vs Output Power 8ΩLoad 1.0 10% THD LEVEL 0.4 0.2 1 3% THD LEVEL 1.0 3% THD LEVEL 0.6 Vs=12V 0.4 0.2 10% THD LEVEL Vs=9V Vs=6V 0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Output Power (W) UTC assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all UTC products described or contained herein. UTC products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 8 of 8 QW-R107-007.H