DESCRIPTION
The LTC®3562 is a quad high efficiency monolithic synchronous step-down regulator with an I2C interface. Two regulators are externally adjustable and can have their feedback voltages programmed between 425mV and 800mV in 25mV steps (Type A). The other two regulators are fixed output regulators whose output voltages can be programmed between 600mV and 3.775V in 25mV steps (Type B). All four regulators operate independently and can be put into pulse skip, LDO, Burst Mode operation, or forced Burst Mode operation through I2C control. The Type-A regulators have separate RUN pins that can be enabled if I2C control is unavailable.

FEATURES
■ Four Independent I2C Controllable Step-Down
   Regulators (2 × 600mA, 2 × 400mA)
■ Two I2C Programmable Feedback Voltage
   Regulators (R600A, R400A): VFB 425mV to 800mV
■ Two I2C Programmable Output Voltage Regulators
   (R600B, R400B): VOUT 600mV to 3.775V
■ Programmable Modes: Pulse Skip, LDO, Burst Mode,®
   Forced Burst Mode Operation
■ Quiescent Current < 100μA (All Regulators Enabled
   in LDO Mode)
■ Fixed 2.25MHz Switching Frequency (Pulse Skip
   Mode)
■ Slew Limiting Reduces Switching Noise
■ Power-On Reset Output for Regulator R600A
■ Small, Thermally Enhanced, 20-Lead 3mm × 3mm
   QFN Package

APPLICATIONS
■ Miscellaneous Handheld Applications with Multiple Supply Rails
■ Personal Information Appliances
■ Wireless and DSL Modems
■ Digital Still Cameras
■ MP3 Players
■ Portable Instruments