Hi, we will use TPS65261 as our main power supply unit. I read the datasheet but couldn't understand how to use VDIV pin. It seems that VDIV pin is supplied from VIN with a voltage divider. Inside the chip, these is a voltage comparator which compares VDIV pin to fixed 1.23 V.
So, whenever VDIV pin is below 1.23V, it should produce active-low reset. But here it what confuses me :
What are these threshold values ? Wasn't 1.23 V inside chip a fixed value ? My initial thought was that i can only adjust R1-R2 resistors to my specific input voltage. There are also formulas to calculate these threshold voltages :
Another question, what is VREF ? If it is VIN, then equations for threshold voltages result in unrealistic voltages. ( I user R1 = 146K R2 = 20 of EVM Kit for calculation ) . As you see i am quite confused, my questions overall :
1) What should be done with VDIV pin if not used ?
2)Does VDIV pin has any effect other than just pulling-down reset. Will my output voltages ok when i have a reset signal ?
3)How are resistors 146K and 20K chosen in EVM ? EVM has voltage range of 4.5V-18V but even 10V input would produce a voltage lower than 1.23 V thus creating a reset signal. My input voltage is 5.5V, how should i choose these resistors.
Thanks in advance for your help.
Regards,
Mehmet Akif Erol
