TPS2596: Overvoltage clamp

Eric Bogomolny

Part Number: TPS2596

Hello,

I plan to use TPS259620DDA in my design. The data sheet states that in order to select 5.7V overvoltage clamp I need to connect OVCSEL pin of the device to GND via 400K resistor. However, 400K is not a standard value. The standard value is 399K. How will using the standard resistor value affect the clamp voltage? Also, how will the resistor tolerance affect the clamp voltage?

Thank you,

Eric Bogomolny.

7 months ago

0 Arush Gupta 7 months ago

TI__Genius 9545 points

Hi Eric,

You can use 399KOhms instead of 400KOhms for OVCSEL pin of device. Assuming 1% tolerance of resistor, your clamp voltage will remain within the min-max range given in the datasheet which shows approximately ±3% variation.

Best Regards,

Arush

0 Arush Gupta 7 months ago

TI__Genius 9545 points

Hi Eric,

Kindly close this thread by clicking on resolved if you don't have any other questions or you can reply here if you have more related questions.

Best Regards,

Arush

0 Eric Bogomolny 7 months ago in reply to Arush Gupta

Prodigy 60 points

So, what is the relationship between the resistor value and the clamping voltage? For example, what would be the clamping voltage, if the resistor is 200K?

0 Arush Gupta 7 months ago in reply to Eric Bogomolny

TI__Genius 9545 points

I will come back to you by Tuesday EOD

Best Regards,

Arush

0 Arush Gupta 7 months ago in reply to Eric Bogomolny

TI__Genius 9545 points

Hi Eric,

So this is a OVCSEL pin. You cannot program the OVC for values other than provided in the datasheet i.e. 3.8, 5.7 and 13.7V. The pin allows some margins so using 402k or 399k resistors won't cause any issue. As you asked what will happen for 200k, you will have to test it yourself for exact behavior. It should 3.8V OVC or 5.7V.

If you want to use some other value of OVC, you can try using a resistor divider at output and take that as feedback to input side.

Best Regards,

Arush

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TPS2596: Overvoltage clamp