Hey all,
What's the best silicon device to use for high current amplification? My project is to design a 10-20 Watt Amplifier. My voltage has been amplified to about 10 Volts peak using a VD-biased single 2n3904... i figured it would be reasonable to find a device that will amplify current (hopefully applicable in a push-pull configuration, class A, B, or A/B) up to 1 to 2 Amps. Whats the verdict? I studied up on JFETs but they seem to have too low a maximum current rating.
If you have some good suggestions, can you suggest part numbers too please?? Thanks all!!! ;)
Just look at how discrete power amps are done: BJT's, MOSFETs, IGBTs.
It's likely you will need a power transistor, at least a TO-220 package - often used in an emitter follower configuration. Most of these have low gain. More often than not these are preceeded with another medium power transistor. You may or may not get away driving the power transistors with a TO-92 device, more often than not the job requires a TO-126 device. An alternative is to use darlingtons. Note the problem often isn't current in these designs but power dissipation.
You can of course use ICs power amps.
LM3886 from national semiconductor. It's one cool IC that delivers 50W output power into an 8ohm load @ +/-35v. You could easily drop the poewr supply voltage and make it output about 20W ;) You need a heatsink though, but the same goes for power transistors/FETs.