The APL3201 needs no external MOSFET or diodes, and accepts input voltage up to 6.0V. The small packages and low external component count make the APL3201 ideally suited for portable applications. On-chip thermal limiting simplifies PC board layout and allows optimum charging rate without the thermal limits imposed by worst-case battery and input voltage. When the APL3201 thermal limit is reached, the charger does not shut down but simply reduces charging current. Ambient or battery temperature can be monitored with an external thermistor. When the temperature is out of range, charging pauses.