LTC3822 - No RSENSE, 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

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)
Internal Soft-Start Circuitry
Selectable Maximum Peak Current Sense Threshold
Digital RUN Control Pin
Output Overvoltage Protection
Micropower Shutdown: IQ = 7.5µA
Tiny Thermally Enhanced Leadless (3mm x 3mm) DFN or 10-Lead MSOP Package

Typical Application

Applications

3.3VIN Systems
Li-Ion Battery Systems

Packaging

Order Information

Part Number	Package	Temp	Price(1-99)	Price (1k)*
LTC3822EDD#PBF	3x3 DFN-10	E	$2.35	$1.55
LTC3822EDD#TRPBF	3x3 DFN-10	E		$1.57
LTC3822EMSE#PBF	MS-10E	E	$2.35	$1.55
LTC3822EMSE#TRPBF	MS-10E	E		$1.61

Demo Boards

Part Number	Description	Price
DC1014A	LTC3822EMSE (MSOP) Demo Board \| 2.75V ≤ VIN ≤ 4.5V, Vout = 1.8V @ 10A	Contact Factory
DC972A	LTC3822EDD Demo Board (DFN) \| 2.75V ≤ VIN ≤ 4.5V, Vout = 1.8V @ 8A	Contact Factory