Buck Converter Also Monitors Batteries

Designed for portable, battery-powered products capable of operating from a Li-Ion cell or two NiCd cells, the TK654xx IC provides the power switch, synchronous rectifier, and control circuit for a buck step-down converter. Only three external components are needed to complete the step-down conversion. The low-power buck converter boasts of ultra-fast transient response times and laser-trimmed output voltages ranging from 1.8V to 3.3V. The low resistance MOSFET switch and synchronous rectifier allow average currents of up to 200 mA while maintaining peak efficiencies of 95%. Operating and quiescent currents are 15 µA and 10 µA, respectively. The chip also has a programmable Low Battery Input pin. , The step-down dc-to-dc converter is housed in a SOT23L package.