MIC3385

MIC3385 8MHz Inductorless Buck Regulator with LDO Standby Mode General Description The Micrel MIC3385 is a high-efficiency inductorless buck regulator that features a LOWQ® LDO standby mode that draws only 18µA of quiescent current. The MIC3385 requires no external inductor enabling an ultra-low noise, small size, and high efficiency solution for portable power applications. In PWM mode, the MIC3385 operates with a constant frequency 8MHz 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 LOWQ® mode, the LDO maintains the output voltage and draws only 18µA 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. The MIC3385 operates from 2.7V to 5.5V input and features internal power MOSFETs that can supply up to 600mA output current in PWM mode. It can operate with a maximum duty cycle of 100% for use in low-dropout conditions. The MIC3385 is available in the 14-pin 3mm x 3.5mm MLF® package with a junction operating range from –40°C to +125°C. Data sheets and support documentation can be found on Micrel’s web site at: www.micrel.com. LOWQ® Features 2.7 to 5.5V supply voltage Light load LOWQ® LDO mode – 18µA quiescent current – Low noise, 75µVrms 8MHz PWM mode – Output current to 600mA – >90% efficiency – 100% maximum dut...