Hi.
Please help me about below issue.
Please refer schematic.
(Condition)
Vin : 5V_IN
R1 : 1K (540mA Charging Current)
TS : 10K to VSS, NTC is not using.
CHG : 10K Pull up and connected to MCU
VBAT : Main battery voltage or Charger Output(VOUT) voltage. VBAT is also using as 5V boost converter(FP6715)'s input source.
Boost Converter (5V_OUT) : 5V_OUT is using as charging source of another small battery device.
Case1)
1. When Boost converter is disabled (Only main battery charging)
2. Main battery charging and termination operation is good.
Case2)
1. When Boost converter is enabled and charging another small battery device.
2. Main battery charging is OK.
3. Another small battery device is full charged and main battery charging current is under 20mA(Full Charged). Total VOUT current is under 30mA.
4. As I know termination current is 54mA, 10% of fast charging current. But CHG state is still LOW. Charging Termination is not occurred.
-. Vin = 5V
-. Vout = 4.18V
-. TP1 current is under 30mA
-. TP2 current is under 20mA
-. TP3 current is under 10mA
5. At this situation, when boost converter is disable, CHG is changed to 3V High.
6. And then if boost converter is enable, CHG is still 3V High.
7. When 5V_IN is removed and inserted, Termination is not working again.
Obviously, VOUT current (TP1) is below 30mA, which is less than the termination current of 54mA.
Why termination is not working?
Please let me know how can I fix this.
Thank you.