TelCom Intros TC105 and TC110 Switching ControllersMarch 28, 1999 by Jeff Shepard
TelCom Semiconductor Inc. (Mountain View, CA) introduced the TC105 and TC110 switching controllers intended for battery-operated applications. The TC105 is a step-down (buck) switching controller that provides output currents of up to 1A (max) at a typical efficiency of 92 percent, and the TC110 is a step-up (boost) switching controller that provides output currents as high as 300mA at a typical efficiency of 84 percent. The TC105 normally operates in PWM mode, but automatically switches to pulse frequency modulation (PFM) at low output loads for greater efficiency. Supply current draw is 102uA (max) and is reduced to less than 0.5uA when the device is in shutdown. The device accepts a maximum input voltage of 10V. Housed in an SOT23-5 package, the TC105 is targeted for a range of applications including palmtops, hand-held scanners, and 12V to 5V and 5V to 3V down-converters. Pricing starts at $1.49 in quantities of 3,000.Like the TC105, the TC110 also normally operates in PWM mode, and switches automatically to PFM mode at low output loads. Supply current draw for the 100kHz version is typically only 70uA, and is reduced to less than 0.5uA when in shutdown. The device accepts input voltages from 2.0V to 10.0V, with a guaranteed start-up voltage of 0.9V. Typical applications include portable instruments, palmtops, notebook computers and other battery-operated applications. Housed in the SOT23-5 package, the TC110 is priced from $1.38 in quantities of 3,000.