TPS23754-1: can replace TPS23754-1 from TPS23756

Tommy Tzeng

Genius 4915 points

Part Number: TPS23754-1
Other Parts Discussed in Thread: TPS23756, PMP11254

Hi Sir,

we directly change TPS23754-1 from TPS23756, but found that +12v output has jitter problem.

hope learn from you, what parts of the schematic need to be modified?

as attached file.

tps23756 +12v output waveform:

direct change TPS23754-1 12v output waveform:

over 2 years ago

+1 Michael Pahl over 2 years ago

TI__Mastermind 21320 points

Hello,

The TPS23754-1 has a higher VC turn on threshold than the TPS23756.

Replacing the TPS23754-1 with the TPS23756 has no issues. Replacing the TPS23756 with the TPS23754-1 may have issues because of this. It will depend on the design. It looks like there is a lot of output capacitance for a 12V/25W diode flyback. The issue is probably due to the fact that the TPS23754-1 turns on later because it requires a higher VC voltage, which is changing the startup behavior. For reference, we have 44uF of output cap on our equivalent reference design (PMP11254), and you have 940uF.

Can you try reducing the amount of output capacitance?

Can you share the transformer spec?

If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

Regards,

Michael P.

Applications Engineer

Texas Instruments

+1 Michael Pahl over 2 years ago in reply to Michael Pahl

TI__Mastermind 21320 points

Any updates here?

0 Tommy Tzeng over 2 years ago in reply to Michael Pahl

Genius 4915 points

Hi Michael,

sorry~ customer not reply yet. i will push again.

Power management

Power management forum

TPS23754-1: can replace TPS23754-1 from TPS23756