Best Replacement for a 45n20 MOSFET Recommendations

[kds9591]

This N channel MOSFET has been discontinued by Fairchild. TO-220 case


Some of the specs are:

Drain-Source Breakdown Voltage: 200 V

Continuous Drain Current: 35 A

Power Dissipation: 176 W

Resistance Drain-Source RDS (on): 0.065 Ohms

Gate-Source Breakdown Voltage: +/- 30 V

Forward Transconductance gFS (Max / Min): 36 S

2 that I crossed ref. that should work are:


Fairchild

FDP52N20

FDP61N20

Perry, what substitute do you use?

[Perry Babin]

What's the application?

What's the full part number of the original FET?

[kds9591]

Output for a Lightning Audio Amp S2.1000.1D MOSFET Fairchild # SSP 45N20B location Q108 I saw in another thread you recommended a IRF3215

[Perry Babin]

An IRF3415 possibly? It's been a long time since I've seen one of these. What is the rail voltage in the amp?

[kds9591]

Don't know, just opened it up late tonight, powered it on but with the with the bottom cover on, went into protect mode. Powered down, took cover off and just took some quick resistance measurements and found a shorted 45n20b. I have another one (same model) with a different problem that I can look at tommorow and get back to you with the rail voltage.

[Perry Babin]

Remove the shorted FET so that it will power up.

[kds9591]

I'm going to bed but will take out the shorted MOSFET tommorrow and get back to you. That was a typo in my previous post, I meant a IRF3415, sorry. Thanks for your help so far, have a good night Perry and I'll post the info tommorrow.

[kds9591]

Perry I measured 60 volts for the rail voltage. I hope the IRF3415's will work because I have some on hand.

[Perry Babin]

If the voltage is ±60v, the 3415 could be a good choice.

[kds9591]

Thanks Perry for the recommendation, the IRF3415's worked out excellent.

The one output was shorted , there were 3 to a channel so I replaced all 3 for that channel so as not to have 2 different MOSFET's on the same channel. Ran the amp for a while, no problems, thanks again.