LM25148-Q1: VCC/VDDA behavior during shutdown

Matthew Trescott

Prodigy 20 points

Part Number: LM25148-Q1

Hello,

I have a couple questions I couldn't find answers to in the datasheet.

Is the VCC regulator always on when VIN is applied, or is VCC disabled when EN is below 0.5 V?

If VCC is disabled during shutdown, does this also apply to the VCCX switch?

Basically I was hoping to use VCC or VDDA to translate the 3.3 V enable signal from my MCU to a 5 V signal for a different part of the circuit. A separate switching regulator supplies VCCX with 5 V.

Thanks!

10 months ago

+1 Orlando Murray 10 months ago

TI__Mastermind 22299 points

Matthew,

VCC is enabled in standby, when EN>0.5V.

VCC LDO and switch should be disabled in shutdown, however there is a parasitic diode from VCCX to VCC, so {VCC = VCCX - Vdiode} if VCCX is present during shutdown.

Hope this helps,

-Orlando

0 Matthew Trescott 10 months ago in reply to Orlando Murray

Prodigy 20 points

Hi Orlando, thanks for your response. Is this also true for the VDDA regulator?

+1 Orlando Murray 10 months ago in reply to Matthew Trescott

TI__Mastermind 22299 points

Matthew,

I believe so, VDDA is derived from VCC.

-Orlando

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LM25148-Q1: VCC/VDDA behavior during shutdown