Undervoltage Protection and Vout2 configration

[erifat]

Hello, we are looking for answers to a few questions.

Our questions:

1)Will it be enough to change the resistor value on the VSET2 pin to obtain 3.1V on the VOUT2 pin? Can we control the voltage on the VOUT2 pin from the register software? (3.1V needed for our temperature sensor)
If we want to set 3.1V output without software, will 180K work for us? There is no resistor value for 3.1V in the table. What is your suggestion?

2) We need to cut consumption below 3.0V, which is the battery bottom voltage, so that we can preserve battery life(Under voltage control). We were not sure about under voltage control. It works with both USB and Bat input. It should consume power at micro ampere levels below 3.0V. We wanted to turn it off under 3.0 with an external reset IC, but there is no Enable pin. VSET2 cuts off the output when it reaches 0Volt, but VSET1 needs to be checked separately. The SHPHLD pin does not provide exactly this. What is your suggestion?

[Kazi Afroza Sultana]

There is some details feedback from expert

Question 1 : The values of output voltage for the BUCKs that can be selected through the resistors on VSETx pins are in a limited range, so it is only the list of voltages listed in the table. There is no intermediate values that would not be listed in the table.

So, it's not possible. 

Question 2 : 

It seems you want to stop the BUCKs and the LDOs when the VBAT voltage is below 3.0V. 

I think the POF feature (Power Fail Comparator) is here to do so: the internal comparator for POF detection monitors the voltage on VSYS (~VBAT in normal operation) and default value is 2.8V (typ) falling but the level is programmable, so you can set it to 3.0V.

[Andy Sinclair]

Hi.

For question 2, I suggest entering ship or hibernate mode in this condition.
The host can send a TWI command to enter this state.

Andy