The conditions under which the low-power adapter status bit is set are related to the input and output voltage of the charger, generally this is when VBUS approaches a value close to VBAT, and input power is low. There are other times when LOW_PWR_ADP_STAT is not set which could still be helpful to use API mode. In some applications it may be advantageous to control the input current limit from a weak source, for example the rectified voltage of a doorbell. If too much current is pulled from the door-bell it could ring. Therefore, API mode should be enabled all the time in the door-bell example, even if LOW_PWR_ADP_STAT is not active. When using known weak sources, the smaller steps sizes and lower allowable minimum input current limit in API mode can be utilized to prevent an overload of the input source.

API entry and exit sequence utilizing the LOW_PWR_ADP_STAT bit:

1. Read LOW_PWR_ADP_STAT bit
2. If LOW_PWR_ADP_STAT is 1
3. Then set EN_API to 1 and adjust API_ILIM as needed
4. If LOW_PWR_ADP_STAT is 0
5. Then no action is needed
6. If EN_API is 1, IINDPM_STAT is 1, and API_ILIM is 100mA (max)
7. Then exit API mode by setting EN_API to 0

API mode should be monitored by the host. If the input is dynamic, like a solar panel, the API_ILIM register can be set to the maximum of 100mA and Input Voltage Dynamic Power Management (VINDPM) can be used to extract maximum power. Once the IINDPM status is set, then it is best to exit API mode to extract the highest power.