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TPS54824: TPS54824 EN PIN Logic Spec

Part Number: TPS54824
Other Parts Discussed in Thread: LM5117, LM5576, TPS543C20A, LM5069, LM34927, TPS62125

Team,

Currently my customer is using TPS54824 on their board, we have some questions about the EN pin spec. Could you please help with it?

About the EN pin of TPS54824, they are using it to control the device by interfacing with an open drain output logic.

There is a new application which is interfaced with an push-pull type output, and the VDD is an independent supply 3.3V.

I think it should be OK when TPS54824 VIN is powered (VIN = 12V).

How about the conditions listed below, is it OK?

VIN = 0V (12V power down)

&

push-pull is H, output 3.3V


You know, inside some kind of chip, it might have ESD protection circuit or paracitic PN junction which could make the pin voltage be clamped to some level, VIN or VCC.

If a low output impedance source, like push-pull type, is connected to this type of pin, it will cause some problems: large current, pulling down VDD, loss of functions, Latch-up of IC...etc.

So please help us to check the internal circuit of the EN pin of TPS54824, and reply whether it can interface with a push-pull type output logic or not, especially when VIN is powered down and push-pull is high logic output.


And for more devices, are these PIN listed as below support the logic type as mentioned?

LM5117 (UVLO pin)

LM5576 (SD pin)

TPS543C20A (EN pin)

LM5069 (UVLO pin)

LM34927 (UVLO pin)

TPS62125 (EN pin)

Regards,

Qiang

  • Hi Qiang,

    For TPS54824, it can use 3.3V push-pull circuit to power EN pin. The voltage of EN pin cannot exceed 6.5V.

    For TPS62125, it cannot use this way, because the max voltage of EN pin is Vin+0.3V.

    The remaining other products do not belong to our product line, so you may need to submit another thread for these products. Thanks.

    Aurora