TPS40054: interruption input force the output going to Zero Volt ...

Kamal Najmi

Part Number: TPS40054
Other Parts Discussed in Thread: TPS40055, TPS40057, LM25145

my customer HDH :in some situations we have problems with the TPS40055 when the input voltage has a short breakdown. Then the controller makes under-voltage lockout for a short period. When the output voltage is still charged at returning start up, then the TPS40055 makes a soft start with pulling the output voltage hard to zero volts at the first start moment. This is actually a short circuit of the output capacitor in that moment. The TPS40057 would prevent the effect, right?

If we would use the TPS40057 with prebias function instead, is it a real 1:1 replacement?

regards,

kamal

over 7 years ago

0 YangZhang over 7 years ago

TI__Genius 11085 points

Hi Kamal,

Yes, the TPS40057 and TPS40055 are pin to pin compatible. If this is a new design, we recommend using a newer part: LM25145.

Regards,

Yang

0 Kamal Najmi over 7 years ago in reply to YangZhang

TI__Expert 3435 points

hi Yang,
sorry but I am asking if the TPS40055 has a issue during a short interruption of the input voltage.
if yes can we solve the issue with the TPS40057?

Actually this is not a new design ....
regards,
kamal

0 YangZhang over 7 years ago in reply to Kamal Najmi

TI__Genius 11085 points

Yes, the difference between the TPS40055 and TPS40057 is that the 40057 allows prebiased startup. The TPS40057 should not pull the outupt low when it is prebiased at startup.

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TPS40054: interruption input force the output going to Zero Volt ...