LM74670-Q1: LM74670-Q1 Zero Iq

PAN-M

Part Number: LM74670-Q1

Please teach me a basic feature.
About the Zero Iq, what kind of this state?
What is the difference point with the diode?

Regards.
PAN-M

over 8 years ago

0 Brian Daugherty over 8 years ago

TI__Expert 5940 points

Pan-M,

There is no connection to GND so there is no Iq. Power to turn on the FET comes from the FET body diode's forward voltage, which is where power flows for ~ 2% of the time, with the FET turned fully on for ~98% of the time. See fig 9 in the data sheet to see this and the impact on Vout. When a reverse voltage is detected, the FET is pulled down (off) and the circuit is simply a reversed biased body diode, fucntioning just like a regular diode, and again with no Iq current.

Brian

0 PAN-M over 8 years ago in reply to Brian Daugherty

Mastermind 8375 points

Thank you for answer.
This feature isn't difference point with a diode, is it?
PAN-M

0 Brian Daugherty over 8 years ago in reply to PAN-M

TI__Expert 5940 points

Pan-M

It is much more efficient than using a diode since 98% of the time, current passes through the FET in an 'on' state vs a diode. Functionality, it performs the same thing as a diode, just better wrt system power loss.

Brian

0 PAN-M over 8 years ago in reply to Brian Daugherty

Mastermind 8375 points

I understood that.
Thanks,
PAN-M

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LM74670-Q1: LM74670-Q1 Zero Iq