FAN7544 Datasheet, PDF (1/14 Pages) Fairchild Semiconductor – Simple Ballast Controller

FAN7544
Simple Ballast Controller
www.fairchildsemi.com
Features
• Low Start-up and Operating Current : 140µA, 6.5mA
• Under Voltage Lock Out With 1.9V of Hysteresis
• 600mA of Totem Pole Output with High State Clamp
• Trimmed 1.5% Internal Bandgap Reference
• Programmable Preheat Time & Frequency
• Programmable Run Frequency
• High Accuracy Oscillator
Descriptions
The FAN7544 provides simple and high performance elec-
tronic ballast control functions. The FAN7544 is optimized
for electronic ballast requiring a minimum board area, by
reducing component counts and lowering power dissipation.
The features include programmable preheating time and fre-
quency and programmable run frequency. The initial pre-
heating time and frequency can be adjusted according to the
types of lamps using the CPH, CT and RPH. Output gate
driver circuit clamps power MOSFET gate voltage to the
supply voltage.
8-DIP
8-SOP
Internal Block Diagram
1
1
CPH 4
Vz
2.9V
5V
1
2.9V
2.1
Iph - Irt
5V
CT 2
6.25Ict
5.2V
1.5V
RT 3
RPH 1
Current
Source
Current
Source
−
+
+
2V
− ^VCPH
5V
Ict
Irt
RQ
Oscillator
S
Latch
Irt=Vref/Rt
Iph=Vref/Rph
Shutdown signal
TSD
9V Vsup
Bias
Current
SQ
RQ
Frequency
Divider
©2004 Fairchild Semiconductor Corporation
UVLO
1.9V
8 _Vcc
11.6V
Vcc
7 OUT1
Vcc
6 OUT2
5 GND
Rev. 1.0.0