Other Parts Discussed in Thread: TPS40304
Hi,
Good Day. I have a customer who is working with TPS40304A. Please see below the query of our customer for your reference. Thank you very much.
We have multiple output power supply consisting of many DC/DC converters each one based on your PWM controller TPS40304. All the outputs are working on separate, (almost purely resistive loads) and have different fixed values from 3V to 5.5V DC, however each DC/DC converter is in fact separate circuit feed by the same DC input. Everything works good at room temperature and on high temperatures however, all of them experience strange behavior working at temperatures below 0C down to -37C. On nominal load the output begin turning off and back on erratically, not synchronized, looking like OCP hick-up mode. Sometimes, the hick-up mode repetition can be reduced or even avoided by easing load conditions (meaning reducing output current, increasing output resistance) and sometimes the issue does not exist, meaning the issue is not 100% repeatable on every output at certain temperature
There is a link to interactive WEBENCH Power Designer in the TPS4030x datasheet. When I took close look onto the design changing working temperature the web tool shows that OCP setup resistor (from pin 9- LDRV/OC to ground) value is changing depending on temperature. Should that resistor be termoresistor?
Best Regards,
Ray Vincent