Programmable Li-Ion Charger Fits In Tiny Package

Designed for single-cell applications, the L6924D Li-Ion battery charger chip from STMicroelectronics integrates all of the required power elements, plus other functions, into a 3-mm x 3-mm VFQFPN16 package. All key charging system parameters are programmable, enabling the L6924D to be used across a full range of low cost as well as more sophisticated applications. The chip integrates the power MOSFET, reverse blocking diode, sense resistor and thermal protection into a compact VFQFPN16 package.

Designers can choose between Linear and Quasi-Pulse charging modes, depending on the application’s requirements. Linear Mode suits applications with low-cost power adapters, such as an external voltage regulated adapter, when the L6924D can charge the battery in a constant-current/constant-voltage profile. Operation in Quasi-Pulse Mode can be used when a current-limited adapter is available, reducing the power dissipation. Closed loop thermal control protects the device against overheating in either mode.

The L6924D has an operating input voltage range of 2.5 V to 12 V and is also USB-compatible. All the key parameters are programmable, including pre-charge current, pre-charge voltage threshold, fast-charge current, the end-of-charge current threshold and the charging time. The L6924D battery charger is in volume production now. Pricing is $0.90 in quantities of 10,000 units.