TLV809E: Power-on Reset

Hi Dongbao 

We cannot measure the transient VPOR exactly at 15 uA current (forced using external DC source) at RESET trip point.

So, we continuously forced 15 uA current at RESET pin even before the supply starts ramping.

The RESET voltage of 0.5V seen when VDD = 0V is due to the parasitic body diode turning ON between RESET and VDD carrying this 15 uA current,

Until the RESET trips, this parasitic body diode will continue to carry this current and hence the tracking of the delta voltage is observed at RESET with respect to supply voltage.

As you can see from the plot, the RESET trips at VDD of 0.75V carrying 15 uA current where the parasitic body diode stops taking current and gets diverted to NMOS between RESET & GND.

This is done to show the transient behavior with 15 uA load.

Actual RESET voltage before tripping is  = VRESET - 0.5V {where 0.5V is coming from body diode}

Regards

Trailokya