LTC3772B Series

Micropower No RSENSEConstant Frequency Step-Down DC/DC Controller

Catalog

Micropower No RSENSEConstant Frequency Step-Down DC/DC Controller

Part	Duty Cycle (Max) [Max]	Function	Output Configuration	Package / Case	Control Features	Mounting Type	Output Phases	Operating Temperature [Max]	Operating Temperature [Min]	Number of Outputs	Topology	Voltage - Supply (Vcc/Vdd) [Min]	Voltage - Supply (Vcc/Vdd) [Max]	Supplier Device Package	Frequency - Switching	Output Type	Frequency - Switching [Max]	Frequency - Switching [Min]
Analog Devices LTC3772EDDB#TRMPBF	100 %	Step-Down	Positive	8-WFDFN Exposed Pad	Current Limit Enable	Surface Mount	1	85 °C	-40 °C	1	Buck	2.75 V	9.8 V	8-DFN (3x2)	550 kHz	Transistor Driver
Analog Devices LTC3772ETS8#TRPBF	100 %	Step-Down	Positive	SOT-23-8 Thin TSOT-23-8	Current Limit Enable	Surface Mount	1	85 °C	-40 °C	1	Buck	2.75 V	9.8 V	TSOT-23-8	550 kHz	Transistor Driver
Analog Devices LTC3772BEDDB#TRPBF	100 %	Step-Down	Positive	8-WFDFN Exposed Pad	Current Limit Enable	Surface Mount	1	85 °C	-40 °C	1	Buck	2.75 V	9.8 V	8-DFN (3x2)		Transistor Driver	550 kHz	200 kHz
Analog Devices LTC3772ETS8#TRMPBF	100 %	Step-Down	Positive	SOT-23-8 Thin TSOT-23-8	Current Limit Enable	Surface Mount	1	85 °C	-40 °C	1	Buck	2.75 V	9.8 V	TSOT-23-8	550 kHz	Transistor Driver

Catalog

Micropower No RSENSEConstant Frequency Step-Down DC/DC Controller

Key Features

• No Current Sense Resistor Required

• High Output Currents Easily Achieved

• Internal Soft-Start Ramps VOUT

• Wide VINRange: 2.75V to 9.8V

• Low Dropout: 100% Duty Cycle

• Constant Frequency 550kHz Operation

• Low Ripple Pulse Skipping Operation at Light Load

• Output Voltage as Low as 0.8V

• ±1.5% Voltage Reference Accuracy

• Current Mode Operation for Excellent Line and Load Transient Response

• Only 8μA Supply Current in Shutdown

• Low Profile 8-Lead SOT-23 (1mm) and (3mm × 2mm) DFN (0.75mm) Packages

Description

The LTC3772B is a constant frequency current mode step-down DC/DC controller in a low profile 8-lead SOT-23 (ThinSOT™) and a 3mm × 2mm DFN package. The No RSENSE™architecture eliminates the need for a current sense resistor, improving efficiency and saving board space.The LTC3772B automatically switches into pulse skipping operation at light loads. It consumes only 200μA of quiescent current under a no-load condition.The LTC3772B incorporates an undervoltage lockout feature that shuts down the device when the input voltage falls below 2V. To maximize the runtime from a battery source, the external P-channel MOSFET is turned on continuously in dropout (100% duty cycle). High switching frequency of 550kHz allows the use of a small inductor and capacitors. An internal soft-start smoothly ramps the output voltage from zero to its regulation point.Burst ModeLTC3772YesLTC3772BNoApplications1- or 2-Cell Li-Ion Battery-Powered ApplicationsWireless DevicesPortable ComputersDistributed Power Systems