LM1770 Series

Low-Voltage SOT23 Synchronous Buck Controller With No External Compensation

Catalog

Low-Voltage SOT23 Synchronous Buck Controller With No External Compensation

Part	Voltage - Input [Min]	Voltage - Input [Max]	Regulator Topology	Main Purpose	Voltage - Output	Frequency - Switching	Supplied Contents	Current - Output	Outputs and Type	Outputs and Type	Board Type	Utilized IC / Part	Frequency - Switching [Max]	Frequency - Switching [Min]	Function	Operating Temperature [Min]	Operating Temperature [Max]	Topology	Output Configuration	Output Type	Voltage - Supply (Vcc/Vdd) [Max]	Voltage - Supply (Vcc/Vdd) [Min]	Output Phases	Package / Case	Number of Outputs	Supplier Device Package	Mounting Type
Texas Instruments LM1770EVAL	2.8 V	5.5 V	Buck	DC/DC Step Down	2.5 V	378 kHz	Board(s)	2 A	Non-Isolated	1	Fully Populated	LM1770
Texas Instruments LM1770UMF/NOPB													1 MHz	100 kHz	Step-Down	-40 °C	125 ¯C	Buck	Positive	Transistor Driver	5.5 V	2.8 V	1	SC-74A SOT-753	1	SOT-23-5	Surface Mount
Texas Instruments LM1770SMF/NOPB													1 MHz	100 kHz	Step-Down	-40 °C	125 ¯C	Buck	Positive	Transistor Driver	5.5 V	2.8 V	1	SC-74A SOT-753	1	SOT-23-5	Surface Mount
Texas Instruments LM1770SMFX/NOPB													1 MHz	100 kHz	Step-Down	-40 °C	125 ¯C	Buck	Positive	Transistor Driver	5.5 V	2.8 V	1	SC-74A SOT-753	1	SOT-23-5	Surface Mount
Texas Instruments LM1770TMF/NOPB													1 MHz	100 kHz	Step-Down	-40 °C	125 ¯C	Buck	Positive	Transistor Driver	5.5 V	2.8 V	1	SC-74A SOT-753	1	SOT-23-5	Surface Mount

Catalog

Low-Voltage SOT23 Synchronous Buck Controller With No External Compensation

Key Features

• Input Voltage Range of 2.8V to 5.5V0.8V Reference VoltageNo Compensation RequiredConstant Frequency Across Input RangeLow Quiescent Current of 400µAInternal Soft-startShort Circuit Protection5-Pin SOT-23 PackageAll trademarks are the property of their respective owners.Input Voltage Range of 2.8V to 5.5V0.8V Reference VoltageNo Compensation RequiredConstant Frequency Across Input RangeLow Quiescent Current of 400µAInternal Soft-startShort Circuit Protection5-Pin SOT-23 PackageAll trademarks are the property of their respective owners.

Description

The LM1770 is an efficient synchronous buck switching controller in a tiny SOT-23 package. The constant on-time control scheme provides a simple design free of compensation components, allowing minimal component count and board space. It also incorporates a unique input feed-forward to maintain a constant frequency independent of the input voltage. The LM1770 is optimized for a low voltage input range of 2.8V to 5.5V and can provide an adjustable output as low as 0.8V. Driving an external high side PFET and low side NFET it can provide efficiencies as high as 95%. Three versions of the LM1770 are available depending on the switching frequency desired for the application. Nominal switching frequencies are in the range of 100kHz to 1000kHz. The LM1770 is an efficient synchronous buck switching controller in a tiny SOT-23 package. The constant on-time control scheme provides a simple design free of compensation components, allowing minimal component count and board space. It also incorporates a unique input feed-forward to maintain a constant frequency independent of the input voltage. The LM1770 is optimized for a low voltage input range of 2.8V to 5.5V and can provide an adjustable output as low as 0.8V. Driving an external high side PFET and low side NFET it can provide efficiencies as high as 95%. Three versions of the LM1770 are available depending on the switching frequency desired for the application. Nominal switching frequencies are in the range of 100kHz to 1000kHz.