Hello,
last week I burned TPS5420 regulator on ADS5400 evaluation board. The manual states that "the input power supply voltage
range for the EVM can be 6 V to 36 V only if the onboard TI power solution is used." I tried to power the board from 19 V source, setting power related jumpers as described in the manual. Everything was fine for a time, then the chip burned out with a smoke.
Package was damaged near pin 5, which is ENABLE input. It turned out that pin 5 was shorted with pin 7, VIN (see Figure 14. EVM schematics, Sheet 4 in slau293.pdf document). While the input voltage is rated as high as 40 V, the ENABLE pin can tolerate 7 V only according to the datasheet, so the chip burnout is not surprising. I looked through a couple of similar TI EVM datasheets, they share the same design and would burn as well if someone try to power them from 36 V supply.
By the way, TPS5420 datasheet suggests to float the ENABLE pin if there is no need to control the regulator operation, so the simple workaround could be to cut the pin off.
Actually, it is not a big problem for me, as I can live with a default power option (at the time of accident I just hadn't an adequate 5 V regulated supply at hand). I write here merely to point out the issue.
Regards,
Michael
