The MC34673 from NXP Semiconductors is a Battery Charger IC that has been designed for single-cell Li-ion or Li-Polymer batteries. It requires an input voltage of 2.6-6.6 V and an input current of 1.4 mA. This battery charger primarily consists of an integrated supply, sensing, and control circuits, logic control devices, power MOSFETs, and resistors. It supports a high input voltage of up to 28 V, which eliminates the need for an over-voltage protection circuit in handheld devices such as cell phones. This charger IC operates over a complete charging cycle based on trickle, constant-current (CC), and constant-voltage (CV) modes. It uses an external resistor to adjust the CC-mode current up to 1.2 A and the voltage developed across the resistor can also be used to monitor the actual charge current with an accuracy of ±0.7%.

This battery charger IC presets the trickle-mode current to 20% of the CC-mode current when the battery voltage is lower than the trickle-mode threshold while the end-of-charge (EOC) current threshold is preset to 10% of the CC-mode current to save the board space and cost. It is equipped with protection features such as thermal foldback and IC internal die temperature sensor and can be interfaced with a microprocessor or LEDs for status indication. This RoHS-compliant charger is available in a thermally-enhanced surface-mount package that measures 2 x 3 x 0.65 mm.