MC33063A: The transistor stops switching - cont'ed

domenyko

Part Number: MC33063A

Dear Jasper,

I'm referring to the tread (RE: MC33063A: The transistor stops switching).

The customer has implemented your suggestion with a manal rework on the board (see the picture), but the results were the same.

at around 300mA there is a short between pin1 an pin2.

Could the manual rework the root source ? Can the part be so sensitive on the presence/absence of the capacitnce ?

regards,

Domenico

over 6 years ago

0 Youhao Xi over 6 years ago

TI__Guru* 78270 points

Hi Demenko,

Jasper might be unavailable yesterday. Let me send him a reminder. You may also email him directly about this rather than using the e2e forum.

Thanks,
Youhao Xi, BCS Applications Engineering

0 Jasper Li over 6 years ago

TI__Mastermind 46905 points

Hi Domenyko,

Could you change the ceramic capacitor to between pin 6 and pin 4? also change the schottky diode to a 1A level components and connect the schottky diode 's GND pin to pin 4 in the same layout.

after the modification, measure the voltage waveform of the pin 2, input and output at IOUT=200mA.

0 Jasper Li over 6 years ago in reply to Jasper Li

TI__Mastermind 46905 points

Hi Domenyko,

The question is answered through email. so i close the post

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MC33063A: The transistor stops switching - cont'ed