LNK623-626
The following minimum set of tests is strongly recommended:
3. Thermal check – At maximum output power, both minimum
and maximum input voltage and maximum ambient tempera-
ture; verify that temperature specifications are not exceeded
for LinkSwitch-CV, transformer, output diodes and output
capacitors. Enough thermal margin should be allowed for
the part-to-part variation of the RDS(ON) of LinkSwitch-CV, as
specified in the data sheet. It is recommended that the
maximum source pin temperature does not exceed ±±0 °C.
±. Maximum drain voltage – Verify that peak VDS does not exceed
680 V at highest input voltage and maximum output power.
2. Maximum drain current – At maximum ambient temperature,
maximum input voltage and maximum output load, verify
drain current waveforms at start-up for any signs of trans-
former saturation and excessive leading edge current spikes.
LinkSwitch-CV has a leading edge blanking time of 2±1 ns to
prevent premature termination of the ON-cycle. Verify that
the leading edge current spike is below the allowed current
limit envelope for the drain current waveform at the end of
the 2±1 ns blanking period.
Design Tools
Up-to-date information on design tools can be found at the
Power Integrations web site: www.powerint.com
10
Rev. E 09/09
www.powerint.com
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