TPS2660: TPS26600 - OVP maximum current and voltage

Sunset

Genius 13405 points

Part Number: TPS2660

Hello Team,

the TPS26600 OVP pin could withstand a maximum voltage of 5V .

In the typical application with the voltage divider (voltage below), we can calculate the right value to be in spec.

In case the R3 would be damaged and would get open, the OVP voltage scenario would change.

What is the maximum current that can flow within the OVP pin?
Can R1 and R2 be used to limit the current to a safety level?

I would assume that in case R3 will get open, the OVP alarm would be set, but it would be important to understand if the OVP pin can withstand the new voltage stress. In case R3 get damaged, the alarm may not be necessary an OVP error, but if the device can withstand it, the system can still react on the anomaly.

Thanks,

SunSet

over 6 years ago

0 Karikalan Selvaraj over 6 years ago

TI__Genius 16305 points

Hi,

OVP pin leaks 100nA at 4V and can go upto 200nA at 5V.

When R3 is open due to damage, R1 and R2 will limit curent to few uA for current as R1+R2 will be of the order ~1Mohm.
For example, in a 24V rail application with R1+R2 = 1Mohm, OVP voltage and current will be around 6V to 7V and 17-18uA respectively.
This can be okay for a short period of time as the internal ESD structure can withstand for a short time as long as current is limited to few 10s of uAs.
Device is already operating beyond abs max spec and not guaranteed to operate correctly for long period of time.

Can you please tell how long can the OVP see this voltage before the system cuts of supply rail or take corrective action?

Regards,
Kari.