Standard Linear Controller Shrinks Battery Charger Size March 2002 Issue Published Date: March 01, 2002
Requiring few external components and housed in a small SOT-23-5L or SO-8 package, the TSM105 controller promises to reduce the size of battery chargers and power adapters used in the latest generation of mobile products. A resistor bridge, sense resistor, and an optional resistor and capacitor for compensation are all that is required to make the controller chip functionalÑthe resistor bridge connects to the battery charger or power adapter output to set the voltage regulation. The chip combines a voltage reference of 1.21V typical, two op amps with common collector ORÕed outputs, and a current sensing circuit. Operation is from a 2.8V to 12V supply, with total output supply current over the entire temperature range pegged at a mere 2 mA maximum and 1.05 mA typical. And the voltage reference output is 1.21V typical. The TSM105 also features constant voltage and current control, a current-sink output stage, and easy compensation. Price is $0.25 each/1,000. STMICROELECTRONICS INC., Lexington, MA. (781) 861-2650.
