how to make 20 Watt Audio Power Amplifier

TDA2005 - 20 Watt Audio Power Amplifier

The TDA2005 is a class B dual audio power amplifier specifically designed for car radio applications. Its high current capability (up to 3.5 A) and the ability to drive very low impedance loads (down to 1.6 ohms) makes this circuit a good choice for cheap power booster amplifiers. The IC is sold in two variants: TDA2005M for bridge and TDA2005S for stereo applications.

ABSOLUTE MAXIMUM RATINGS
Symbol	Parameter	Value
Vs	Operating Supply Voltage	18 V
Vs	DC Supply Voltage	28 V
Vs	Peak Supply Voltage (for 50 ms)	40 V
Io	Output Peak Current (non repetitive t=0.1ms)	4.5 A
Io	Output Peak Current (repetitive f>10 Hz)	3.5 A
Ptot	Power Dissipation at Tcase = 60 °C	30 W
Tstg, Tj	Storage and Junction Temperature	-40 to 150°C

The Tda2005 IC has a high output power: PO=10W+10W @ RL=2ohm, d=10% (stereo) and PO=20W @ RL=4ohm, d=1% (bridge) for Vs=14.4V. The high reliability of the IC comes from the various protections against: output DC and AC short circuit to ground, overrating chip temperature, load dump voltage surge, fortuitous open ground and very inductive loads.

The IC can be used used in bridge (TDA2005M) or stereo (TDA2005S) amplifiers - with or without boostrap - with easily programmable gain and bandwidth. The Tda2005 needs a very low number of external components, and has a very simple mounting system with no electrical isolation between the package and heatsink.

Schematics with TDA2005

2 x 10W stereo Amplifier Schematic

Fig 1: 2 x 10W Stereo Amplifier Schematic circuit with TDA2005S

20W Bridge Amplifier Circuit (G_V=34dB)

Fig 2: 20W Bridge Amplifier Circuit with TDA2005M (Voltage Gain = 34dB)