This is the 4W bridge amplifier circuit design based on power IC LM388 as the main component. Currently there are 2 chips of LM388 used since a LM388 only have one channel amplification. A single LM388 will deliver about 1.5W power audio output, while 2 pieces of it used with bridge connection, ten it will deliver up to 4W power audio output.

Notes:
For 6V supply and 4? loudspeaker, the circuit will deliver 1W audio output.
For 12V supply and 8? loudspeaker, the circuit will deliver 4W audio output.

Download LM388 datasheet for your 4W bridge amplifier reference:
? Download link

Wide supply voltage range can be used for this circuit from 10VDC to 40VDC. Recommended supply voltage is 18V. You may use 0.5A – 1A transformer for the power supply circuit.

About TDA1020B:
The TDA1013B is an integrated 4W audio power amplifier with DC volume control , encapsulated in a 9-lead single in-line (SIL) plastic package. The wide supply voltage range makes this circuit ideal for applications in mains and battery-fed apparatus such as television receivers and record players.

The DC volume control stage has a logarithmic control characteristic with a range of more than 80 dB; control is by means of a DC voltage variable between 2 and 6.5 V. The audio amplifier has a well defined open loop gain and a fixed integrated closed loop. This device requires only a few external components and offers stability and performance.

TDA1013B Features:

• Few external components
• Wide supply voltage range
• Wide control range
• Pin compatible with TDA1013A
• Fixed gain
• High signal-to-noise ratio
• Thermal protection

Download the document of TDA1013B datasheet for 4W audio amplifier circuit reference:

TDA1013B Datasheet

1 file(s) 109.77 KB

Download Datasheet