FAN5640S7X Datasheet, PDF (1/11 Pages) Fairchild Semiconductor – FAN5640 Dual High-Side Constant Current Source for High-Voltage Keypad LED Illumination

March 2012
FAN5640 — Dual High-Side Constant Current Source
for High-Voltage Keypad LED Illumination
Features
 20V Maximum Driver Input Level
 Dual Output
 25mA Drive Capability per Channel
 Two Strings of 2-4 LEDs Each
 External Resistor Sets Maximum Current
 Fast Turn-On/Off Capability
 Low Bias Current
 SC70-6 Package
 Thermal Shutdown Protection
Applications
 Keypad Illumination
 Main Display and Sub-Display Illumination
 Cell Phones, Smart Phones
 Pocket PCs
 PDA, DSC, PMP, and MP3 Players
Description
The FAN5640 is designed to illuminate one or two strings
of keypad LEDs with constant high-side current sources.
The device can drive up to four white LEDs in series at a
maximum current of 25mA per channel. If the second
channel is not needed, the channels can be tied
together to boost output current up to 50mA.
An external resistor programs the maximum output
current. Dimming can be accomplished by pulse width
modulation of the enable pin or the input supply rail.
Figure 1. Typical Application
Ordering Information
Part Number
FAN5640S7X
Operating Temperature Range
-40°C to 85°C
Package
SC70-6 2x2.2mm
Packing Method
Tape and Reel
© 2006 Fairchild Semiconductor Corporation
FAN5640 • Rev. 1.0.2
www.fairchildsemi.com