TelCom Intros TC120 Buck Controller

The TC120 from TelCom Semiconductor Inc. (Mountain View, CA) is a new 300kHz PFM/PWM step-down (Buck) dc/dc regulator/controller combination for use in systems operating from two or more cells, or in line-powered applications. Offering high current output in a space-saving SOP package, the TC120 automatically shifts to pulse frequency modulation at low loads, resulting in reduced supply current and improved efficiency. The device consumes 55uA (at 3.3V of supply current when operating, and 2.5uA (max) in shutdown. While in shutdown, the regulator is disabled, and output voltage is internally pulled to ground, discharging the output capacitor. Other features include a built-in undervoltage lockout (UVLO), an externally programmable soft start time, and output short circuit protection."The TC120 provides a highly efficient (95 percent typical), cost effective solution to the designer who needs to step-down voltages utilizing a small amount of board space while providing in excess of 2A of output current," stated Field Applications Engineer John Newman.The TC120 requires only an external inductor, Schottky diode, and two capacitors to implement a step-down converter having a maximum output current of 600mA (Vin=5V, Vout=3.3V). An external switching transistor (p-channel MOSFET) can be added to increase output current capability to support output loads of 2A or more. The device operates from a maximum input voltage of 10V and is available in a low-profile 8-pin SOP package. Typical applications include local logic supplies, notebook computers, palmtops, portable test equipment, portable audio systems, and other battery powered applications. Pricing starts at $1.39 in quantities of 1,000.