High-Efficiency Charger for Li-Ion Batteries

The ZSPM4551 is a DC/DC synchronous switching lithium-ion (Li-Ion) battery charger with fully integrated power switches, internal compensation, and full fault protection. Its switching frequency of 1MHz enables the use of small filter components, resulting in smaller board space and reduced BOM cost. In Full-Charge Constant-Current Mode, the regulation is for constant current (CC). Once termination voltage is reached, the regulator operates in voltage mode. When the regulator is disabled (the EN pin is low), the device draws 10µA (typical) quiescent current. The ZSPM4551 includes supervisory reporting through the NFLT (inverted fault) open-drain output to interface other components in the system. Device programming is achieved by an I²C interface through the SCL and SDA pins.