MC34063A: MC34063 input output short issue

Pallav Gandhi

Part Number: MC34063A

Dear All,

We are facing a issue in which MC34063 pin2 is showing short with pin1. We are using it to convert 24V DC to 4V DC. Load connected to it is consuming 200ma normally with 1.5A burst.

Can any one guide me for the same?

Regards.

over 7 years ago

0 Youhao Xi over 7 years ago

TI__Guru 74230 points

It sounds like the internal transistor is damaged. Would you please provide your schematic for a review?

0 Pallav Gandhi over 7 years ago in reply to Youhao Xi

Intellectual 900 points

Please find the attachment.

Regards.

0 Pallav Gandhi over 7 years ago in reply to Pallav Gandhi

Intellectual 900 points

Hi all,

Can anyone please guide me for the same.

Regards.

0 Youhao Xi over 7 years ago in reply to Pallav Gandhi

TI__Guru 74230 points

The schematic looks fine. However, your burst mode current goes to 1.5A that may over stress the internal switch and cause damage. Recommend to use an external switch as shown in Fig 6.

0 Pallav Gandhi over 7 years ago in reply to Youhao Xi

Intellectual 900 points

Thanks Youhao Xi. I will try the same.

Regards.

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MC34063A: MC34063 input output short issue