Even though the IINDPM and VINDPM features are
useful to keep the system load running when reaching the adapter limit. However, the adapter
will overheat when keeping it running at its current and voltage limit for a long period of
time. Thus it is preferred to operate the adapter under its current rating is preferred.
The charger includes innovative automatic Input
Current Optimizer (ICO) to maximize the power of input source with input current limit higher
than 500 mA. Below is the steps to execute ICO function:
- Make sure system can power up by the adapter and battery can be charged in CC phase
- Set VINDPM() register value to slightly below the
adapter voltage with full load specification
- Set IIN_HOST() register value to the maximum
amount of input current limit the user would like to sink on VBUS
- Disable external ILIM_HIZ by setting EN_EXTILIM=0b. When ICO is disabled, IIN_DPM register
value should be the same as IIN_HOST.
- Set charge current in CHARGE_CURRENT register to
design specification which should be high enough to support ICO evaluation
- Enable ICO test by setting EN_ICO_MODE=1b, and wait for approximately 2sec, and check the
ICO_DONE status bit. If this bit goes to 1, ICO is completed
- After ICO_DONE=1b, read back ICO result in IIN_DPM register for current adapter. Value in
IIN_HOST register is not changed by ICO. If the host sets EN_ICO_MODE bit back to zero, the
IIN_DPM returns to the setting in IIN_HOST. To continue use the optimal input current limit
identified by ICO, it is recommended to read IIN_DPM register after ICO is done and write
this value back to IIN_HOST.