The LM 380 is a power audio amplifier for consumer applications. The internal gain is fixed at 34dB.
The output automatically self-centers to one-half the supply voltage.
The output is short-circuit proof with internal thermal limiting.
The package outline is standard dual-in-line.
The LM380N uses the center three pins on either side to act as a heatsink. This means the copper on the PC board must be large enough to dissipate the heat.

Features

• Wide supply voltage range: 10v-22v
• Power @ 8ohms 1%THD 4-watt
• Low quiescent power drain: 0.13W (VS\= 18V)
• Voltage gain fixed at 50
• High peak current capability: 1.3A
• Input referenced to GND
• High input impedance: 150k
• Low distortion
• Quiescent output voltage is ½ the supply voltage
• Standard dual-in-line package
• Quiescent current 7mA typical

Circuits using an LM 380:

The LM 380 naturally produces half-rail voltage on pin 8 during quiescent conditions and this feature will produce a half-rail voltage for op-amps etc.
In the circuit below, if the input voltage is 20v, the output voltage will be +10v and -10v.