应用功能: 1W音频功率放大器 The LM390 Power Audio Amplifier is optimized for 6V, 7.5V,9V operation into low impedance loads. The gain is internally set at 20 to keep the external part count low, but the addition of an external resistor and capacitor between pins 2 and 6 wil increase the gain to any value up to 200.