PMP8803

Hello Madhuri,

In order to change the current limit, you would change the value of Rs which is R18 on the PMP8803 schematic that you can down load from the link.

This will change the current that is sensed on the Cs pin of the TPS23753A.  You may have to adjust the slope compensation to maintain stability though.

You can find the calculations on page 19 of the TPS23753A data sheet.  Page 20 show the configuration.  Your 1.1A is within the IEEE limit of 13W so there isn't a problem .

Thanks,

Thank you Greenja for chiming in.
Madhuri,

We reviewed the design.
1.1A is desired vs the 1A at 12V it was intended for.

There will always be headroom already built into any design such as this.
Input is 36-75V of the PMP, so it can already do 1.1A, its just how much headroom is there at the low VIN?

The xfmr will be ok at 1.1A load.  It looks like there is about a 10% margin on the the primary current limit at 1.1A load and 34V input.
So, it should be able to run at 1.1A load at 36V input.  If it does hit current limit at 36V input, change the current limit resistor from 0.39 Ohms to 0.36 Ohms or 0.33 Ohms.

Thank you for using TI.