MP2731 VNTC pin

Battery Management
1

Hi,

My question is regarding the VNTC PIN.

From the datasheet:
The VNTC voltage (1.7V) is regulated by an LDO that is powered from VREF. The VNTC pin is available in both charge mode and OTG mode.

Will this pin also supply 1.7V (be on) when the battery is in discharge mode (i.e. when the input power source is not connected)? Or will the PIN be 0V when the input power source is disconnected?

The reason for asking is that I will like to use this output pin as a control signal for an LDO regulator (connecting it to the LDO enable pin). Then the LDO would be ON whenever the input power source is connected - hence forcing the whole system to be ON.

Thanks.

2

Hello hcglitte,

Yes, VNTC should still be on during discharge mode. Vref is powered by both the input or the battery.
image

Thank you,
Vinh Tran
Field Applications Engineer

3

This was my initial impression as well.
However, when doing measurement on the dev board, VNTC is 0V when Vin is disconnected and the battery is discharged.