The TC105 is a step-down (Buck) switching controller that furnishes output currents of up to 1A (max) while delivering a typical efficiency of 92%. The TC105 normally operates in pulse width modulation mode (PWM), but automatically switches to pulse frequency modulation (PFM) at low output loads for greater efficiency. Oscillator frequency is 300 KHz, allowing use of small (22 µH) inductors. Supply current draw is only 102 µA (max), and is reduced to less than 0.5 µA when the SHDN input is brought low. Regulator operation is suspended during shutdown. The TC105 accepts a maximum input voltage of 10V. The TC105 is housed in a tiny 5-pin SOT-23A package, occupies minimum board space, and is ideal for a wide range of applications.