Overview
The LM389 is an array of three NPN transistors on the same substrate with an audio power amplifier similar to the LM386 The amplifier inputs are ground referenced while the output is automatically biased to one half the supply voltage The gain is internally set at 20 to minimize external parts but the addition of an external resistor and capacitor between pins 4 and 12 will increase the gain to any value up to 200 The three transistors have high gain and excellent matching characteristics They are well suited to a wide variety of applications in DC through VHF systems Low quiescent current drain Voltage gains from 20 to 200 Y Ground referenced input Y Self-centering output quiescent voltage Y Low distortion Transistors Y Operation from 1 mA to 25 mA Y Frequency range from DC to 100 MHz Y Excellent matching Y Y.