Can I dynamically change the resistance on the ISET pin to get different charging rates? I am using a microcontroller and I want to set the charging rates based on the battery temperature, so I would like to have a transistor toggle in a different resistor or two on the ISET line for different charging rates.
Yes, dynamically changing the MP2602 ISET resistance is acceptable. This is a good way to implement JEITA spec compliance if the battery charger IC does not support JEITA directly and there is already an MCU in the system. An example usage is to have an 8.45K resistor to GND in parallel with a 2.05K resistor with series FET. For normal operation, the MCU keeps the FET turned ON and the ISET pin “sees” 8.45k||2.05k=1.65K for a 1A charge rate. When a lower charge current is desired, the MCU opens the FET and the ISET pin “sees” only the 8.45K resistor for a 200mA charge rate.