TPS1HC30-Q1: TPS1HC30-Q1 leakage current

Hello Viola, 

Pulling OUT to a known voltage value will reduce the leakage current that causes a voltage drop across the pin. TI implemented a switch in series with the pullup resistor controlled by the DIAG_EN pin.

Best, 

Alan

Hi Alan,

also want to check, when off state the open fault how to detect?

the equation shown VBB-VOU<VOL.off; how could I know the VOUT voltage? 

is that implement in TPS1HC30-Q1?

or i need to feedback the voltage to my MCU and do the judgement?

also want to check the leakage current on Rpu is constant? what's the value? 

Hi Viola, 

Yes, as you mentioned open-load detection in OFF state can be determined by routing feedback voltage to MCU and calculating VBB – VOUT < Vol,of.  In addition to this, the FLT pin goes low to indicate the fault to the MCU, and the SNS pin is pulled up to VSNSFH.

The Rpu leakage would be VBAT / 150k with a load connected. 

Best, 

Alan

Hi Alan,

Since our customer has determined Ropen= 6kohm, this means if the VOUT point impedance is greater than 6kohm, an open load will be detected, otherwise will consider normal.

According to customer's requirement I tried to calculate it but seems strange.

VOU=BVV*6kohm/(6kohm +Rpu)=0.692V @VBB=18V.

VBB-VOU=17.307>Vol.off

it seems can not detect open load, right?

How should i design for this requirement?

Hello,

It seems like there is an error in calculation.

VOUT = VBB * (150k / (6k +150k)) = 17.307

VBB -VOUT = 0.692 > VOLOFF