Other Parts Discussed in Thread: TPS40211, TPS40210EVM, LM25085
We are testing a TPS40211 evaluation board and have the current set at .55A by changing the resistor to .47 ohm. This works from 25C to 100C, constant current. However, from 25C to -30C it doesn't keep the current constant as well. Wondering if there are other tweaks to this circuit. We are driving an inductive coil for a load, 24VDC input to the board.
Also, we want to make the current soft start, ramp from zero current to .55A in 2 seconds. We tried changing the SS capacitor to .47uf and 4.7uf, the most we could get was 47ms and 470ms for a ramp. Do you only change the SS capacitor, or do we need to change something else to 'program this'?