We are currently using the BQ27421 Eval board to evaluate the device and are beginning to wonder of we have a bad board. In the standard configuration once the external battery is applied, we only see ~0.003V (3mV) on the LDO output on VDD. We have checked to make sure there is no external shorts on VDD and measured resistance to ground is >300 Kohms so it does not appears shorted. We have attempted to toggle BIN with no change and we have used an external VCC on J4 with all signals tied to EXT and, again, we only see 3mV on VDD. One additional clue is that when we put a heavy load (1.6A) across the battery we are are seeing a 26mV drop across BAT and SRX which would indicate about a 16mOhm sense resistor instead of the typical 7mOhm. Are we missing something in the configuration of the board? It appears that the only time the LDO is switched off is in Shutdown mode and our understanding is that once a battery is applied we should b e in active mode. Also, Can the internal sense resistor vary that much off of typical?
Thanks for your help.
