FAN5331_05 Datasheet, PDF (1/10 Pages) Fairchild Semiconductor – High Efficiency Serial LED Driver and OLED Supply with 20V Integrated Switch

August 2005
FAN5331
High Efficiency Serial LED Driver and OLED Supply with
20V Integrated Switch
Features
■ 1.6MHz Switching Frequency
■ Low Noise
■ Low R_DS(ON): 0.5Ω
■ Adjustable Output Voltage
■ 1A Peak Switch Current
■ 1W Output Power Capability
■ Low Shutdown Current: <1µA
■ Cycle-by-Cycle Current Limit
■ Over-Voltage Protection
■ Fixed-Frequency PWM Operation
■ Internal Compensation
■ 5-lead SOT-23 Package
Applications
■ Cell Phones
■ PDAs
■ Handheld Equipment
■ Display Bias
■ LED Bias
Typical Application
V_IN
2.7V to 5.5V
C_IN
4.7µF
5
V_IN
Description
The FAN5331 is a general purpose, fixed-frequency boost con-
verter designed to operate at high switching frequencies in
order to minimize switching noise measured at the battery ter-
minal of hand-held communications equipment. Quiescent cur-
rent in normal mode of operation as well as in shutdown mode
is designed to be minimal in order to extend battery life. Normal
mode of operation or shutdown mode can be selected by a logic
level shutdown circuitry.
The low ON-resistance of the internal N-channel switch ensures
high efficiency and low power dissipation. A cycle-by-cycle cur-
rent limit circuit keeps the peak current of the switch below a
typical value of 1A. The FAN5331 is available in a 5-lead SOT-
23 package.
L
10µH
BAT54
SW ¹
R1
V_OUT
C_OUT
4.7µF
C_F
120pF
3
FB
R2
ON
4
SHDN
2
GND
OFF
©2004 Fairchild Semiconductor Corporation
FAN5331 Rev. 1.0.1
Figure 1. Typical Application Diagram
1
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