Question:

When I pull the ISET2 high and limit the current on ISET pin, what current limit should I get? Is it going to be 500mA (set by ISET2) or the current limit set by the ISET pin?

Answer:

ISET2 has a 3-state input and programs the Input Current limit/Regulation Threshold:

  •  A low will program a regulated fast charge current via the ISET resistor. External resistor from ISET to VSS defines fast charge current value. Range is 10.8k (50mA) to 675 Ω (800mA).
  •  Float will program a 100mA Current limit. Overrides ISET current limit setting. The voltage on ISET2 pin should be nominal to 0.9V.  
  •  High will program a 500mA max current limit, but if ISET is set to lower that 500mA, it will be limited to that value. Example: if ISET is limiting the current to 300mA, thus 300mA will be the limit. If ISET is 700mA, thus 500mA will be the limit.