Step-Down Converter Delivers High Current In Small Package

Offering higher current output in a space-saving SOP package, the TC120 300-kHz PFM/PWM step-down dc/dc regulator/controller combination is suitable for use in systems operating from two or more cells, or in line-powered applications. Unlike conventional PWM step-up converters, the device automatically shifts to PFM at low loads, resulting in reduced supply current and improved efficiency. The combination of PWM and PFM is suited for applications were low noise and long battery life is of the utmost importance. The chip consumes only 55µA of supply current when operating and 2.5µA in shutdown mode. While in shutdown mode, the regulator is disabled, and output voltage is internally pulled to ground, discharging the output capacitor. Other features include a built-in under-voltage lockout, an externally programmable soft start time, and output short-circuit protection.