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FAN4810 Datasheet, PDF (1/14 Pages) Fairchild Semiconductor – Power Factor Correction Controller | |||
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FAN4810
Power Factor Correction Controller
www.fairchildsemi.com
Features
⢠TriFault Detect⢠for UL1950 compliance and enhanced
safety
⢠Slew rate enhanced transconductance error ampliï¬er for
ultra-fast PFC response
⢠Low power: 200µA startup current, 5.5mA operating
current
⢠Low total harmonic distortion, high PF
⢠Average current, continuous boost leading edge PFC
⢠Current fed gain modulator for improved noise immunity
⢠Overvoltage and brown-out protection, UVLO, and soft
start
⢠Synchronized clock output
General Description
The FAN4810 is a controller for power factor corrected,
switched mode power supplies. The FAN4810 includes
circuits for the implementation of leading edge, average
current, âboostâ type power factor correction and results in a
power supply that fully complies with IEC1000-3-2 speciï¬-
cation. It also includes a TriFault Detect⢠function to help
ensure that no unsafe conditions will result from single
component failure in the PFC. Gate-driver with 1A
capability minimizes the need for external driver circuit.
Low power requirements improve efï¬ciency and reduce
component costs. The PFC also includes peak current
limiting, input voltage brownout protection and a over-
voltage comparator shuts down the PFC section in the event
of a sudden decrease in load. The clock-out signal can be
used to synchronize down-stream PWM stages in order to
reduce system noise.
Block Diagram
16
VEAO
1
IEAO
VFB
15
2.5V
IAC
2
VRMS
4
ISENSE
3
VEA
â
+
3.6k⦠IEA
+
-
GAIN
MODULATOR
3.6kâ¦
POWER FACTOR CORRECTOR
0.5V
+
TRI-FAULT
+
â
2.75V
OVP
+
â
â
-1V +
â
PFC ILIMIT
RAMP 1
7
OSCILLATOR
DUTY CYCLE
8
LIMIT
VCC
17V
13
VCC
7.5V
REFERENCE
VREF
14
SQ
RQ
SQ
PFC OUT
12
RQ
6
VCC
25µA
5
CLKSD
9
VREF
1.25V
+
â
VFB
2.45V
VIN OK
â
+
VCC
SQ
RQ
UVLO
CLKOUT
11
10
REV. 1.0.12 9/24/03
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