Hi, we decided to use the TPS61178RNWR since it had a high output current, relatively high startup voltage of 2.7V (so doesn't draw massive current when Vin < 1V). We purchased a EVM kit and did some tests which showed it should have no problem with driving 4A output. Chip only warmed up to 30C or so after half an hour.
We designed using the Altium design files which saved heaps of time. Anyway, when the board arrived, hard to find stock of this chip so we purchase some from Utmel in China. Code on chip shows 15RI. The first 3 boards we had issues with - the output was supposed to be 14.0V (R1 = 1M // 5M1 otherwise same parts as EVM) . The first 3 boards gave outputs of 20V, 13.6V and 12V. Measuring the feedback resistor, we could see the first board had a Vref of 1.78V instead of 1.198V. Is there any reason for this - we are thinking maybe the chip was too hot during assembly or else chips are counterfeit. Any help would be much appreciated. Thanks
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