CAT32EKT Datasheet, PDF (1/11 Pages) ON Semiconductor – CMOS White LED Driver

CAT32
CMOS White LED Driver
Description
The CAT32 is a DC/DC step up converter that delivers a regulated
output current. Operation at a constant switching frequency of
1.2 MHz allows the device to be used with very small value external
inductor and ceramic capacitors.
The CAT32 is targeted to drive multiple white light−emitting diodes
(LEDs) connected in series and provides the necessary regulated current
to control the brightness and the color purity. An external resistor R_SET
controls the output current level. LED currents of up to 40 mA can be
supported over a wide range of input supply voltages from 2 V to 7 V,
making the device ideal for battery−powered applications.
A high voltage output stage allows up to 4 White LEDs to be driven
in series. Series drive provides inherent current matching.
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 “near zero”
quiescent current.
In addition to overcurrent limiting protection, the device also
includes detection circuitry to ensure protection against open−circuit
load fault conditions.
The device is available in a low profile (1 mm max height) 6−lead
TSOT−23 package.
Features
• Low Quiescent Ground Current (0.5 mA Typical)
• Power Efficiency Over 80%
• Compatible Pinout with LT1932
• Adjustable Output Current (up to 40 mA)
• High Frequency 1.2 MHz Operation
• Input Voltage Operation down to 2.0 V
• Low Resistance (0.5 W) High Voltage Power Switch
• Drives up to 4 White LEDs in Series
• Shutdown Current Less than 1 mA
• Load Fault Protection Against Open−circuits
• Low Value External Components
• Low Profile (1 mm) TSOT−23 6−lead Package
• These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
Applications
• Color LCD and Keypad Backlighting
• Cellular Phones
• Handheld Terminals
• Digital Cameras
• PDAs/Games
• Portable MP3 Players
http://onsemi.com
1
TSOT−23
TD SUFFIX
CASE 419AF
PIN CONNECTIONS
1
SW
VIN
GND
SHDN
LED
RSET
TSOT−23
1 mm Maximum Height
q_JA = 250°C/W (free air)
(Top View)
MARKING DIAGRAMS
LLYM
VFYM
LL = CAT32TDI−T3
VF = CAT32TDI−GT3
Y = Production Year (Last Digit)
M = Production Month (1−9, A, B, C)
ORDERING INFORMATION
Device
CAT32TDI−T3
Package
TSOT−23
(Pb−Free)
Shipping
3,000/
Tape & Reel
CAT32TDI−GT3
TSOT−23
3,000/
(Pb−Free) Tape & Reel
© Semiconductor Components Industries, LLC, 2010
1
March, 2010 − Rev. 4
Publication Order Number:
CAT32/D