Tool/software:
I have a question about the TPS48110-Q1 High Side Driver. I believe I have it tuned for an over-current protection threshold of ~8.4A with a sense resistor of 0.0025Ω (R222), R_SET (R198) = 100Ω, and R_IWRN (R199) = 58kΩ. I have also set the short circuit protection threshold to 24A with R_ISCP (R172) set to 3.48kΩ. I also have it set for latch-off as opposed to re-try, with C_TMR (C142) set to 470nF for an overcurrent time (t_OC) of 7ms. Unfortunately, I am unable to get the circuit to trip off due to exceeding the over-current threshold at all, even going up to 10A. My implementation is shown below.
Based on the datasheet Figure 8-10, I would expect that if the load current exceeds the overcurrent threshold of 8.4A, I would start to see the voltage at pin 9 (TMR) increase as that node begins to charge. However I did not see the voltage increase no matter the load current.
I also never saw the FLT_I pin go low at any point.
I have used the provided calculation spreadsheet (SLURB09, TPS4811-Q1 Design Calculator) from TI’s website to choose the values for my discrete parts, but I confirmed the math on my own based on the datasheet’s equations.
Please let me know if there is something I have implemented incorrectly given the goals I described above (over-current threshold 8.4A, short-circuit current threshold of 24A, 7ms t_OC).
