LT1937 Series

White LED Step-Up Converter in SC70 and ThinSOT

Catalog

White LED Step-Up Converter in SC70 and ThinSOT

Part	Number of Outputs	Internal Switch(s)	Voltage - Supply (Min) [Min]	Topology	Voltage - Supply (Max) [Max]	Applications	Mounting Type	Voltage - Output	Dimming	Type	Current - Output / Channel	Package / Case	Operating Temperature [Max]	Operating Temperature [Min]	Frequency
Analog Devices LT1937ES5#TRPBF	1		2.5 V	Step-Up (Boost)	10 V	Backlight	Surface Mount	36 V	Analog PWM	DC DC Regulator	320 mA	SOT-23-5 Thin TSOT-23-5	85 °C	-40 °C	1.2 MHz
Analog Devices LT1937ES5#TRMPBF	1		2.5 V	Step-Up (Boost)	10 V	Backlight	Surface Mount	36 V	Analog PWM	DC DC Regulator	320 mA	SOT-23-5 Thin TSOT-23-5	85 °C	-40 °C	1.2 MHz

Catalog

White LED Step-Up Converter in SC70 and ThinSOT

Key Features

• Inherently Matched LED Current

• High Efficiency: 84% Typical

• Drives Up to Four LEDs from a 3.2V Supply

• Drives Up to Six LEDs from a 5V Supply

• 36V Rugged Bipolar Switch

• Fast 1.2MHz Switching Frequency

• Uses Tiny 1mm Tall Inductors

• Requires Only 0.22µF Output Capacitor

• Low Profile SC70 and ThinSOT™Packaging

Description

The LT1937 is a step-up DC/DC converter specifically designed to drive white LEDs with a constant current. The device can drive two, three or four LEDs in series from a Li-Ion cell. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors. The LT1937 switches at 1.2MHz, allowing the use of tiny external components. The output capacitor can be as small as 0.22µF, saving space and cost versus alternative solutions. A low 95mV feedback voltage minimizes power loss in the current setting resistor for better efficiency.The LT1937 is available in low profile SC70 and ThinSOT packages.ApplicationsCellular PhonesPDAs, Handheld ComputersDigital CamerasMP3 PlayersGPS Receivers