CAT4237: White LED Driver, CMOS Boost Converter, High Voltage

The CAT4237 is a DC-DC step-up converter that delivers an accurate constant current ideal for driving LEDs. Operation at a constant switching frequency of 1 MHz allows the device to be used with small value external ceramic capacitors and inductor. LEDs connected in series are driven with a regulated current set by the external resistor R1. LED currents up to 40 mA can be supported over a wide range of input supply voltages from 2.8 V to 5.5 V, making the device ideal for battery-powered applications. The CAT4237 high-voltage output stage is perfect for driving six, seven or eight white LEDs in series with inherent current matching in LCD backlight applications.LED dimming can be done by using a DC voltage, a logic signal, or a pulse width modulation (PWM) signal. The shutdown input pin allows the device to be placed in power-down mode with 'zero' quiescent current.In addition to thermal protection and overload current limiting, the device also enters a very low power operating mode during 'Open LED' fault conditions.

Features

Drives 6 to 8 White LEDs in series from 3 V
Up to 87% efficiency
Low Quiescent Ground Current 0.6 mA
Adjustable Output Current (up to 40 mA)
High Frequency 1 MHz Operation
High Voltage Power Switch
Shutdown current less than 1 µA
Open LED low power mode
Automatic Shutdown at 1.9 V (UVLO)
Thermal shutdown protection
Digital Still Cameras

Applications

Color LCD and Keypad Backlighting
Digital Cameras

End Products

Mobile Phones
Portable Gaming Systems

Data Sheets (1)

Document Title	Document ID/Size	Revision	Revision Date
White LED Driver, CMOS Boost Converter, High Voltage	CAT4237/D (264.0kB)	3

Evaluation Board Documents (5)

Document Title	Document ID/Size	Revision
CAT4237 High Voltage White LED Driver Evaluation Board User's Manual	EVBUM2017/D (178.0kB)	5
CAT4237BGEVB Bill of Materials ROHS Compliant	CAT4237BGEVB_BOM_ROHS.PDF (81.0kB)	1
CAT4237BGEVB Gerber Layout Files (Zip Format)	CAT4237BGEVB_GERBER.ZIP (39.0kB)	0
CAT4237BGEVB Schematic	CAT4237BGEVB_SCHEMATIC.PDF (162.0kB)	1
CAT4237BGEVB Test Procedure	CAT4237BGEVB_TEST_PROCEDURE.PDF (84.0kB)	1