FAN5340 Datasheet, PDF (1/12 Pages) Fairchild Semiconductor – Synchronous Constant-Current Series Boost LED Driver with PWM Brightness Control and Integrated Load Disconnect

April 2010
FAN5340
Synchronous Constant-Current Series Boost LED Driver
with PWM Brightness Control and Integrated Load
Disconnect
Features
ƒ Synchronous Current-Mode Boost Converter
ƒ Up to 500mW Output Power
ƒ Supports 2, 3, or 4 LEDs in Series
ƒ 2.7V to 4.8V Input Voltage Range
ƒ 1.2MHz Fixed Switching Frequency
ƒ 1mA Maximum Quiescent Current
ƒ Soft-Start Capability
ƒ Input Under-Voltage Lockout (UVLO)
ƒ Output Over-Voltage Protection (OVP)
ƒ Short-Circuit Detection
ƒ Thermal Shutdown (TSD) Protection
ƒ 8-Lead 3.00 x 3.00mm MLP
ƒ 8-Bump 1.57 x 1.57mm WLCSP
Applications
ƒ Cellular Phones, Smart Phones
ƒ Pocket PCs
ƒ WLAN DC-DC Converter Modules
ƒ PDA, DSC, PMP, and MP3 Players
Description
The FAN5340 is a synchronous constant-current LED driver
capable of efficiently delivering up to 500mW to a string of up
to four LEDs in series. Optimized for small form-factor
applications, the 1.2MHz fixed switching frequency allows
the use of chip inductors and capacitors.
For safety, the device features integrated short-circuit
detection plus over-voltage and thermal shutdown
protections. In addition, input under-voltage lockout
protection is triggered if the battery voltage is low.
Brightness (dimming) control is implemented by applying a
PWM signal of 300Hz to 1kHz on the EN pin. During
shutdown, the FAN5340 disconnects the LED anodes from
the output of the boost regulator, which holds the boost
regulator’s voltage on COUT, reducing audible noise from the
PWM dimming and removing power from the LED string.
GND
VIN
2–4
LEDs
1
EN ₂
VLED ₃
P1
GND
8
7 ^VOUT
6 ^SW
C_OUT
C_IN
FB ₄
5 ^PGND
RSET
Figure 1. Typical Application
Ordering Information
Part Number
FAN5340UCX
FAN5340MPX
(Prelminary)
Operating
Temperature Range
Package
-40 to 85°C
8-Bump, 1.57 x 1.57mm Wafer Level Chip-Scale
Package (WLCSP)
-40 to 85°C
8-Lead, 3.00 x 3.00mm Molded Leadless
Package (MLP)
Packing
Tape and Reel
Tape and Reel
© 2010 Fairchild Semiconductor Corporation
FAN5340 • Rev. 1.0.1
www.fairchildsemi.com