Fairchild FAN5332A service manual
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FAN5332A High Efficiency, High Current Serial LED Driver and OLED Supply with 30V Integrated Switch
August 2005
FAN5332A
High Efficiency, High Current Serial LED Driver and OLED
Supply with 30V Integrated Switch
Features
1.5MHz Switching Frequency
Low Noise
Adjustable Output Voltage
Up to 1.5A Peak Switch Current
1.5W Output Power Capability
Low Shutdown Current: <1µA
Cycle-by-Cycle Current Limit
Over-Voltage Protection
Fixed -Frequency PWM Operation
Soft Start
Internal Compensation
Thermal Shutdown
5-lead SOT-23 Package
Applications
Cell Phones
PDAs
Handheld Equipment
Display Bias
LED Bias
Flash LED
Description
The FAN5332A is an LED driver that features fixed frequency
mode operation and an integrated FET switch. The device’s
high output power makes it suitable to drive flash LEDs in serial
connections. This device is designed to operate at high switching frequencies in order to minimize switching noise measured
at the battery terminal of hand-held communications equipment.
Quiescent current in both normal and shutdown mode is
designed to be minimal in order to extend battery life. Normal 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 current limit circuit keeps the peak current of the switch below a
typical value of 1.5A. The FAN5332A is available in a 5-lead
SOT23 package.
Typical Application
VIN
©2004 Fairchild Semiconductor Corporation
FAN5332A Rev. 1.0.1
C
10µF
ON
IN
2.7V to 5.5V
L
6.8µH
5
V
IN
SW
FB
BAT54
R1
1
3
FAN5332A
R2
OFF
4
SHDN
GND
2
Figure 1. Typical Application Diagram
1
C
82pF
V
OUT
C
OUT
2.2µF
F
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Pin Assignment
FAN5332A High Efficiency, High Current Serial LED Driver and OLED Supply with 30V Integrated Switch
Top View
SW
V
IN
GND
FB
SHDN
5-Lead SOT-23
Figure 2. Pin Assignment
Pin Description
Pin No. Pin Name Pin Description
1SW Switching Node.
2 GND
3FB Feedback Pin. Feedback node that connects to an external voltage divider.
4 SHDN
5V
IN
Analog and Power Ground.
Shutdown Control Pin. Logic HIGH enables, logic LOW disables the device.
Input Voltage Pin.
FAN5332A Rev. 1.0.1
2
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FAN5332A High Efficiency, High Current Serial LED Driver and OLED Supply with 30V Integrated Switch
Absolute Maximum Ratings (
Note1)
Parameter Min Max Unit
V
to GND 6.0 V
IN
FB, SHDN
SW to GND -0.3 35 V
Lead Soldering Temperature (10 seconds) 300 °C
Junction Temperature 150 °C
Storage Temperature -55 150 °C
Thermal Resistance ( Θ
Electrostatic Discharge Protection (ESD) Level (Note 3) HBM 2 kV
to GND -0.3 V
) (Note 2) 200 °C/W
JA
CDM 1
+ 0.3 V
IN
Recommended Operating Conditions
Parameter Min Typ Max Unit
Input Voltage 2.7 5.5 V
Output Voltage 12 30 V
Operating Ambient Temperature -40 25 85 °C
Output Capacitance (Note 4) 1.6 µF
Notes:
1. Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This
is a stress rating only and functional operation of the device at these or any other conditions above those indicated
in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for
extended periods may affect device reliability. Absolute maximum ratings apply individually only, not in combination.
2. Junction to ambient thermal resistance,
number of copper planes, number of via used, diameter of via used, available copper surface, and attached heat
sink characteristics.
3. Using EIA/JESD22A114B (Human Body Model) and EIA/JESD22C101-A (Charge Device Model).
4. This load capacitance value is required for the loop stability. Tolerance, temperature variation, and voltage
dependency of the capacitance must be considered. Typically a 2.2µF ceramic capacitor is required to achieve
specified value at V
OUT
= 30V.
,
θ
is a strong function of PCB material, board thickness, thickness and
JA
FAN5332A Rev. 1.0.1
3
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