The LM386 is a power amplifier designed for use in low volt-age consumer applications. The gain is internally set to 20 tokeep external part count low, but the addition of an externalresistor and capacitor between pins 1 and 8 will increase thegain to any value from 20 to 200.The inputs are ground referenced while the output automati-cally biases to one-half the supply voltage. The quiescentpower drain is only 24 milliwatts when operating from a 6 voltsupply, making the LM386 ideal for battery operation.