STMicroelectronics' latest Li-Ion battery charger chip, the L6924D, integrates all of the required power elements, plus other functions, into a 3- by 3-mm package. All key charging system parameters are programmable, enabling the IC to be used across a full range of applications. The fully monolithic battery charger is produced with ST's BCD6 smart power technology and integrates the power MOSFET, reverse blocking diode, sense resistor, and thermal protection into a 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 (CC/CV) 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 to 12 V. It's also USB compatible, allowing use in popular USB-powered computer peripherals. 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 and is priced at $0.90 in quantities of 10,000 units. Further information is available at www.st.com/powermanagement.