This post explains for the Audio Amplifier.
The Part Number is LM356.
The function of this IC is Low Voltage Audio Power Amplifier.
The packkage is DIP 8, SOP 8 Pin Type
Manufacturer: FCI Semiconductor
Preview images :
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Description
The 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 pins 1 and 8 will increase the gain to any value up to 200.
The inputs are ground referenced while the output is automatically biased to one half the supply voltage. […]
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Features
1. Battery operation
2. Minimum external parts
3. Wide supply voltage range : 4 – 12 Volt
4. Low quiescent current drain : 4mA
5. Ground referenced input
Applications:
1. AM-FM radio amplifiers
2. TV sound systems
3. Ultrasonic drivers
4. Power converters