Datasheet FAN7318A (Fairchild) - 4

FA N 7318A Pin Definitions Pin # Name Description — LC
1 TIMER This pin is for protection delay time setting. Error amplifier output. Typically, a compensation capacitor is connected to this pin from the 2 CMP ground.
D B
3 ADIM This pin is the input for negative analog dimming.
a
This pin is for programming the switching frequency. Typically, a capacitor is connected to
cklight
4 CT this pin from ground and a resistor is connected to this pin from the REF pin. This pin is 5V reference output. Typically, resistors are connected to this pin from the CT pin 5 REF and the BCT pin.
Invert
This pin is for programming the frequency of the burst dimming. Typically, a capacitor is 6 BCT connected to this pin from ground and a resistor is connected to this pin from the REF pin. This pin is the input for negative burst dimming. The voltage range of 0.5 to 2V at this pin
e
7 BDIM
r D
controls burst mode duty cycle from 0% to 100%.
r
8 ENA This pin is for turning on/off the IC.
ive IC
9 GND This pin is the ground. 10 OUTB This pin is NMOS gate-drive output. 11 OUTA This pin is PMOS gate-drive output. 12 VIN This pin is the supply voltage of the IC. 13 OLR2 This pin is for open-lamp regulation. Its functions are the same as the OLR1 pin. This pin is for open-lamp protection and feedback control of lamp currents. Its functions are 14 OLP2 the same as the OLP1 pin. This pin is for open-lamp regulation and short-lamp protection. It is connected to the full- wave rectifier internally. When the maximum of rectified OLR inputs is between 1.34V and 2V, the error amplifier output current is limited to 3.0µA. When the maximum of rectified OLR inputs reaches 2V, the error amplifier output current is 0A and its output voltage maintains constant. The maximum of rectified OLR inputs is inputted to the negative of 15 OLR1 another error amplifier for feedback control of lamp voltage. When the maximum of rectified OLR inputs is more than 2.2V, another error amplifier for OLR is operating and lamp voltage is regulated. In normal mode, if the maximum of rectified OLR inputs is higher than 1.34V or if the minimum of rectified OLR inputs is lower than 0.3V for a predetermined time by the TIMER pin capacitor and an internal current source 50µA, the IC shuts down to protect the system in over-voltage condition or short-lamp condition, respectively. This pin is for open-lamp protection and feedback control of lamp currents. It is connected to the half-wave rectifier and the full-wave rectifier internally. In striking mode, if the minimum of rectified OLP inputs is less than 0.7V for a predetermined time by the TIMER pin capacitor and an internal current source or; in normal mode, if the minimum of rectified OLP 16 OLP1 inputs is less than 0.5V for another predetermined time by the TIMER pin capacitor and another internal current source; the IC shuts down to protect the system in open-lamp condition. The maximum of rectified OLP inputs is inputted to the negative of the error amplifier for feedback control of lamp current. © 2009 Fairchild Semiconductor Corporation www.fairchildsemi.com FAN7318A • 1.0.0 4