The LTC4011 provides a complete, cost-effective nickel battery fast charge solution in a small package using few external components. A 550kHz PWM current source controller and all necessary charge initiation, monitoring and termination control circuitry are included. The LTC4011 automatically senses the presence of a DC adapter and battery insertion or removal. Heavily discharged batteries are precharged with a trickle current. The LTC4011 can simultaneously use both V and T/t fast charge termination techniques and can detect various battery faults. If necessary, a top-off charge is automatically applied to NiMH batteries after fast charging is completed. The IC will also resume charging if the battery self-discharges after a full charge cycle. All LTC4011 charging operations are qualified by actual charge time and maximum average cell voltage. Charging may also be gated by minimum and maximum temperature limits. NiMH or NiCd fast charge termination parameters are pin-selectable. Integrated PowerPath control support ensures that the system remains powered at all times without allowing load transients to adversely affect charge termination.