The Micrel MIC2205 is a high efficiency 2MHz PWM synchronous buck (step-down) regulator that features a LOWQTM LDO standby mode that draws only 18A of quiescent current. The MIC2205 allows an ultra-low noise, small size, and high efficiency solution for portable power applications. In PWM mode, the MIC2205 operates with a constant frequency 2MHz PWM control. Under light load conditions, such as in system sleep or standby modes, the PWM switching operation can be disabled to reduce switching losses. In this light load LOWQTM mode, the LDO maintains the output voltage and draws only 18A of quiescent current. The LDO mode of operation saves battery life while not introducing spurious noise and high ripple as experienced with pulse skipping or bursting mode regulators.