bbrotherone
Newbie level 3
Hi.
I am using the MCP73831 Battery charger for my design. I decided to add 2.7k ohm resistor at the PROG pin. So, I_reg is set to 370mA.
LTST-C195KG, dual color chip led is connected between the VDD and STAT pins for status indicator. The labeled "21" is the symbol for the battery.
View attachment MCP738312.pdf
Pin2 and 4 - RED
Pin1 and 3 - Green
When testing the circuit, I got three different cases..
1. The red LED lights when charging and green when finished.
2. The red LED is on when charging and the red light wont turn green.
3. Red while charging, both Red and green when charged.
Case #1 is the normal result when charging is succeful
Case #2 would indicate that charging has not completed. While charging, LDO(MIC5504) drains the current which supposed to charge the battery. So the charge never ends.. As you can see the attached file, the input current of LDO is sum of I_load and I_GND.
The amount of current drained from LDO cannot be ignored....This is what I am guessing..
If I am right, the solution would be adding PMOS between J2 and C3 and schottky diode.
For case #3, LED would be faulty or it is high z state...
Any thoughts?
Modify message
I am using the MCP73831 Battery charger for my design. I decided to add 2.7k ohm resistor at the PROG pin. So, I_reg is set to 370mA.
LTST-C195KG, dual color chip led is connected between the VDD and STAT pins for status indicator. The labeled "21" is the symbol for the battery.
View attachment MCP738312.pdfPin2 and 4 - RED
Pin1 and 3 - Green
When testing the circuit, I got three different cases..
1. The red LED lights when charging and green when finished.
2. The red LED is on when charging and the red light wont turn green.
3. Red while charging, both Red and green when charged.
Case #1 is the normal result when charging is succeful
Case #2 would indicate that charging has not completed. While charging, LDO(MIC5504) drains the current which supposed to charge the battery. So the charge never ends.. As you can see the attached file, the input current of LDO is sum of I_load and I_GND.
The amount of current drained from LDO cannot be ignored....This is what I am guessing..
If I am right, the solution would be adding PMOS between J2 and C3 and schottky diode.
For case #3, LED would be faulty or it is high z state...
Any thoughts?
Modify message