STR-W6000S power IC

** The data sheet gives a typical value of 0.27 ohms @ 1 watt - in the table under fig 22. If it burns out, the IC is history.

..... Phil

esistor to pin 3 of the ic is burnt beyond recognition. l tried to find out from the manufacturers data sheet but all the application circuits there h ave no value marked on the resistors. can anyone give a typical value or ho w to figure out this value?

Thanks l have changed the ic and try that value too

The reference design for that chip shows a 0.27 ohm/1W resistor. Select a low inductance type such as a carbon composition resistor here... definitely not a wirewound type.

Cheers, Dave M

snipped-for-privacy@yahoo.com wrote:

You definitely should spec a low inductance type for the source resistor at these freq, but even certain carbon comps are supposedly trimmed in a spiral pattern making them inductive..

There are non inductive types available but they're tough to find. Still, I'd try any resistor before a wirewound in this app.

** Good advice, but where do you get carbon composition resistors in that value? The IC will operate fine with readily available metal film types.

And beware, there are some wire wound types that look *exactly* like metal film ones.

I was fooled by this once and the PSU would not start up normally.

.... Phil