Other Parts Discussed in Thread: BQ24073
Dear Support,
I have designed a PM circuit to charge a battery using the BQ24073RGTR. Here is what it is doing:
- I connect USB... 5V go in, and 4.4V come out at Pins 11, and 10.
- Both EN1, and EN2 are low to indicate 100mA draw from the USB. Please not that USB bus is not yet enumerated to draw 500mA so I am assuming 100mA max
-TD Pin15 is made low (enabled) via 10K external pull-down resistor so charge disabled is not constantly charging the battery
- CE_N is low via 10K pull-down resistor to enable charging with low current max 100mA (system load requires 3mA, 97mA for battery)
-EN1 and EN2 are pull-down externally via 100K resistors pull-downs
- TS PIN 1 was changed from 49.9K to 10k pull-down since there is no thermistor.
- ILIM is set to 1.18K external resistor
-ISET is set to 5.90K assumes 750mAH battery with 0.2C charging (150mA)
-TMR is set to 47K resistor.
I see the voltage come out, I see PGOOD_N going low and enabling a green LED... I see CHG_N (pin9) going low indicating it is charging, but it is not... when I put an DMM in current mode to measure the charging current into the battery, it reads 0A. No current is being delivered into the battery. I don't understand what could be wrong if all parameters appear to be in order.
Any idea as to why the charger would not charge the battery?
