FAN73402 Datasheet, PDF (3/16 Pages) Fairchild Semiconductor – LED Backlight Driving Boost Switch

Pin Assignments
Figure 2. Package Diagram
Pin Definitions
Pin #
Name
Description
1
VCC This pin is the supply voltage of the IC.
2
DRV This pin is the gate drive signal of the boost switch.
3
GND This pin is the ground of the IC.
This pin is for sensing the current flowing through an external MOSFET. It includes a built-in
4
CS
300ns blanking time. The peak of the current flowing through the MOSFET is limited to this
pin voltage. Slope compensation of the boost controller can be programmed through the
series resistor of this pin.
5
REF
This pin is the 5V reference voltage pin. Maximum current capability is 3mA.
6
FAULT
This pin is for indicating the fault signal. This pin is connected to the open drain. When OLP
protection is occurred, the FAULT pin is pulled HIGH.
7
RT
Oscillator frequency set of the boost switch (50kHz ~ 300kHz).
This pin is for sensing the current flowing through the LEDs. A sensing resistor is connected
8
SENSE from this pin to ground. This pin is connected to the negative input of the internal error
amplifier.
9, 10
DRAIN Drain pin of PWM dimming power MOSFET.
12
ENA
Enable input pin. If voltage of this pin is higher than 1.22V, the IC starts to operate. If the
voltage of this pin is lower than 1.15V, the IC stops operating.
13
OVP
Over-voltage protection input pin. Output voltage of the boost circuit is connected to this pin
through a resistor divider circuit. If this pin voltage is higher than 3V, OVP is triggered.
14
CMP
This pin is the error amplifier output. Typically, a compensation capacitor and resistor are
connected to this pin from the ground.
15
ADIM
This pin is for setting the current flowing through the LEDs. This pin is connected to the
positive inputs of the internal error amplifier. Linear voltage range of ADIM is 0.3V~3.0V.
16
BDIM
This pin is for the burst dimming signal. If this pin voltage is HIGH, the internal dimming
MOSFET is turned on. If this pin voltage is LOW, the dimming MOSFET is turned off.
Note:
1. Pin 11 is a “No Connect” pin (not shown in Figure 2).
© 2012 Fairchild Semiconductor Corporation
FAN73402 • 1.0.0
3
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