No R, Low Input Voltage, Synchronous Step-Down DC/DC Controller

The LTC3822 is a synchronous step-down switching regulator controller that drives external N-channel power MOSFETs using few external components. The constant frequency current mode architecture with MOSFET VDS sensing eliminates the need for sense resistors and improves efficiency.

A maximum duty cycle of 99% provides low dropout operation. The switching frequency can be programmed up to 750kHz, allowing the use of small surface mount inductors and capacitors.

The LTC3822 is available in thermally enhanced DFN and 10-lead MSOP packages.

Features

LTC3822

Internal soft-start, 340μA in sleep mode

LTC3822-1

External soft start, selectable pulse skip/Burst Mode operation, tracking, phase lockable, power good (SSOP-16 package only), 105μA in sleep mode

Applications

* 3.3VIN Systems

* Li-Ion Battery Systems

* No Current Sense Resistor Required

* All N-Channel MOSFET Synchronous Drive

* High Current Outputs Possible

* Constant Frequency Current Mode Operation for Excellent Line and Load Transient Response

* VIN: 2.75V to 4.5V

* ±1% 0.6V Reference

* Low Dropout Operation: 99% Duty Cycle* Selectable Frequency (300kHz/550kHz/750kHz)