Mosfets >50W

The Exicon range of lateral MOSFETS were specifically developed for high performance linear amplifier applications. They are capable of very high standards of amplification, with low distortion and very fast slew rates. Completely free from secondary breakdown and thermal runaway they are extremely reliable.

In addition they have a number of characteristics which make them ideal for audio amplifiers, such as an ultra lineair transfer characterisic, negative (self stabilising) temperature coefficient for sharing current without the need for source or drain resistors, and simple drive requirements resulting in fewer components in the audio path. Unlike most other power Mosfets they lack a Safe Operation Area (SOA), so for most applications (<250Wrms) you only need a single pair of them:

The Exicon MOSFETs are designed for audio amplifiers and unlike bi-polar transistors are well matched n-channel to p-channel resulting in high performance, low distortion audio.

The special selected MOSFETs offer better reliability when used in paralleled setups for high power applications. For single pair applications there is NO need for selected pairs, makes no sense either!

There is variation on parameters noteably threshold voltage, and although lateral MOSFET variation is an order of magnatude better than switching MOSFETs, the selected versions offer closer matching on this parameter.

Since there are (also in other brands) differences in P- and N-channel types behaviour, the matching is between MOSFETs of the same polarity and not between N to P channel. The benefit of closer matching on threshold voltage is that you can omit the current sharing source resistors even for high power amplifiers with many devices in parallel.

Notes

1. The test bands are different for N channel and P channel

2. There is no benefit from having the same colour dot as the test bands are not the same.

3. Matching N channel to P channel on threshold can be achieved in the amplifier by adding a dc offset to the gate drive.