**Part Number:** TPS7A49

Hi there,

we use TPS7A4901: Vin=14.4V~19V, Vout=12V, Iout<100mA. Css=CFF=10nF. SCH as below. Now we are at pre-production phase, there are 3 pcs damaged boards among 50 pcs during normal working.

All 3 pcs are Cout capacitor C10 or C11 shooted through (two ternimals shorted), which means TPS7A4901 output pin were short to GND, and 2 pcs of TPS7A4901 is damaged., 1 pcs TPS7A4901 remains good because we found it was in over temp situation with IR camera and shut down the whole power in time.

The suspect should be Cout design. and I read the page 17 of datasheet again but I have some confusion here ,hope some TI expert could help analysis.

On page 17 of datasheet, it says Cout has to be larger than 2.2uF for stability, and Cout(max) should also be limited by equation(7) and (8). However, **Why tss(CL) is 140us (1/100 of 14ms ) and why Vout =2V in equation(8)**? I thought Vout should be 1.2V as page 16 wrote.

For equation 8. , in order to limit current not reach 500mA max during the whole soft-start process time (14ms), the Cout shoud be less than 14ms *500mA / 1.2V .

For our applicaiton, Cout-max = 0.5A*14ms/12V = 583uF. Seems our design is ok with this limitation. Seems our design is ok

Any suggestion is appreciated! Thanks! @ Ryan Eslinger