LTC3770 Series

Fast No RSENSE™Step-Down Synchronous Controller with Margining, Tracking and PLL

Catalog

Fast No RSENSE™Step-Down Synchronous Controller with Margining, Tracking and PLL

Part	Duty Cycle (Max) [Max]	Mounting Type	Number of Outputs	Voltage - Supply (Vcc/Vdd) [Min]	Voltage - Supply (Vcc/Vdd) [Max]	Operating Temperature [Max]	Operating Temperature [Min]	Supplier Device Package	Control Features	Function	Output Configuration	Topology	Output Type	Output Phases	Package / Case [custom]	Package / Case	Package / Case [custom]
Analog Devices LTC3770EUH#PBF	90 %	Surface Mount	1	4 V	32 V	85 °C	-40 °C	32-QFN (5x5)	Current Limit Enable On Time Control Power Good Soft Start Tracking	Step-Down	Positive	Buck	Transistor Driver	1
Analog Devices LTC3770EG#PBF	90 %	Surface Mount	1	4 V	32 V	85 °C	-40 °C	28-SSOP	Current Limit Enable On Time Control Power Good Soft Start Tracking	Step-Down	Positive	Buck	Transistor Driver	1	0.209 in	28-SSOP	5.3 mm
Analog Devices LTC3770EUH#TRPBF	90 %	Surface Mount	1	4 V	32 V	85 °C	-40 °C	32-QFN (5x5)	Current Limit Enable On Time Control Power Good Soft Start Tracking	Step-Down	Positive	Buck	Transistor Driver	1

Catalog

Fast No RSENSE™Step-Down Synchronous Controller with Margining, Tracking and PLL

Key Features

• Wide VINRange: 4V to 32V

• ±0.67% 0.6V Reference Voltage

• Output Voltage Tracking Capability

• Programmable Margining

• Sense Resistor Optional

• True Current Mode Control

• 2% to 90% Duty Cycle at 200kHz

• tON(MIN)≤ 100ns

• Phase Lock Loop Frequency Synchronization

• Powerful Dual N-Channel MOSFET Driver

• Adjustable Cycle-by-Cycle Current Limit

• Adjustable Switching Frequency

• Programmable Soft-Start

• Current Foldback Protection (Disabled at Start-Up)

• Output Overvoltage Protection

• Micropower Shutdown: IQ< 30µA

• Power Good Output Voltage Monitor Tracks the Reference Input Pin

• Available in (5mm × 5mm) QFN and 28-Lead SSOP Packages

Description

The LTC3770 is a synchronous step-down switching regulator controller with output voltage up/down tracking capability and voltage margining. Its advanced functions and high accuracy reference are ideal for powering high performance server, ASIC and computer memory systems.The LTC3770 uses a constant on-time, valley current mode control architecture to deliver very low duty factors without requiring a sense resistor. The operating frequency is selected by an external resistor and is compensated for variations in input supply voltage. An internal phase-lock loop allows the IC to be synchronized to an external clock.Fault protection is provided by an overvoltage comparator and input undervoltage lockout. The regulator current limit is user programmable. A wide supply range allows voltages as high as 32V to be stepped down to as low as a 0.6V output. Power supply sequencing is accomplished using an external soft-start timing capacitor.ApplicationsDistributed Power SystemsServer Power Supply