The 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 package with a junction operating range from -40°C to +125°C.

• 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 duty cycle
• Adjustable output voltage option down to 1V
• Ultra-fast transient response
• No external inductor required
• Enables sub 1mm profile solution
• Fully integrated MOSFET switches
• Micropower shutdown
• Thermal shutdown and current limit protection
• Pb-free 14-pin 3mm x 3.5mm package
• -40°C to +125°C junction temperature range