For compact hand held device, constructing Audio amplifier with low voltage consumption is a difficult job. Here 1 watt audio amplifier circuit designed with IC LM4876 from texas instruments. It is a 1.1 watt audio power amplifier IC with logic low shutdown.
This amplifier IC most suitable for portable electronic device and low voltage Audio systems. This IC will provide 1 Watt continuous average output power into 8Ω speaker. It can operate with 2.0V to 5.5V with low current consumption.
Construction and Working
Here we have used 8 pin SOIC pakage IC LM4876, it requires few passive components hence the whole amplifier circuit design occupy minimum area, connect audio input to the -IN pin through input capacitor C1 and Input Resistor R1. Connect feedback resistor R2 between -IN pin and V01 pin.
The shutdown pin is a active low pin and connected with pullup resistor R3 and switch. Output speaker (8Ω) is connected between V01 and V02 pins.
The LM4876 has two internal operation amplifier circuit, these are connected in closed loop with the help of external feedback resistors, these two internal operational amplifiers will give 180º phase difference and hence the load connected in bridge mode.
- Does not require output coupling capacitor.
- Unity gain stable
- External gain set
- Shutdown Current 0.01µA
- Supply Voltage Range 2.0V to 5.5 V