This application is for a low power
system that has varying loads from less than 10 mA up to 300 mA. It must work with a
valid adaptor or USB power input. Below are some of the key components that are
needed in normal operation. For this example, the fast charge current is 50 mA,
input current limit is 400 mA and the pre-charge and termination current is 10% of
the fast charge current.
- Supply voltage = 3.4 V to 20
V
- Fast charge current is default to
10 mA with ISET pin shorted to ground. To program the fast charge current,
connect an external resistor from ISET to ground.
- Input current limit is default to
100 mA with ILIM pin shorted to ground. To program the input current limit,
connect an external resistor from ILIM to ground.
- Termination current threshold is
default to 2 mA with IPRETERM pin
shorted to ground. To program the input current limit, connect an external
resistor from IPRETERM to ground.
- A 2.2-µH inductor is needed
between SW pin and SYS pin for PWM output.
- TS- Battery temperature sense
needs a NTC connected on TS pin.