www.fairchildsemi.com
REV. 1.0.1 8/10/01
Features
Average current sensing, continuous boost, leading edge
PFC for low total harmonic distortion and near unity
power factor
Built-in ZVS switch control with fast response for high
efficiency at high power levels
Average line voltage compensation with brownout control
Current fed gain modulator improves noise immunity and
provides universal input operation
Overvoltage comparator eliminates output "runaway" due
to load removal
UVLO, current limit, and soft-start
Precision 1.3% reference
General Description
The FAN4822 is a PFC controller designed specifically for
high power applications. The controller contains all of the
functions necessary to implement an average current boost
PFC converter, along with a Zero Voltage Switch (ZVS) con-
troller to reduce diode recovery and MOSFET turn-on
losses.
The average current boost PFC circuit provides high power
factor (>98%) and low Total Harmonic Distortion (THD).
Built-in safety features include undervoltage lockout, over-
voltage protection, peak current limiting, and input voltage
brownout protection.
The ZVS control section drives an external ZVS MOSFET
which, combined with a diode and inductor, soft switches the
boost regulator. This technique reduces diode reverse recov-
ery and MOSFET switching losses to reduce EMI and maxi-
mize efficiency.
Block Diagram
Q
S
R
+
1
14
VEAO
VEA
2.5V
FB
4
I
AC
5
V
RMS
+
3
I
SENSE
8
GND
2
IEAO
+
IEA
R+
R
+
6
R
T
C
T
OSC
GAIN
MODULATOR
S
R
Q
+
2.7V
FB
1V
12
V
CC
V
CCZ
13.5V
ZVS OUT
11
Q
S
R
Q
PFC OUT
9
PWR GND
10
OVP
I LIMIT
REF
13
ZV SENSE
7
+
V
CCZ
REF
Q
FAN4822
ZVS Average Current PFC Controller
FAN4822
PRODUCT SPECIFICATION
2
REV. 1.0.1 8/10/01
Pin Configuration
Pin Description
(Pin numbers is parentheses are for 16-pin package)
Pin
Name
Function
1 (1)
VEAO
Transconductance voltage error amplifier output.
2 (2)
IEAO
Transconductance current error amplifier output.
3 (3)
I
SENSE
Current sense input to the PFC current limit comparator.
4 (4)
I
AC
PFC gain modulator reference input.
5 (5)
V
RMS
Input for RMS line voltage compensation.
6 (6)
R
T
C
T
Connection for oscillator frequency setting components.
7 (7)
ZV SENSE
Input to the high speed zero voltage crossing comparator.
8 (10)
GND
Analog signal ground.
9 (11)
PWR GND
Return for the PFC and ZVS driver outputs.
10 (12)
ZVS OUT
ZVS MOSFET driver output.
11 (13)
PFC OUT
PFC MOSFET driver output.
12 (14)
V
CC
Shunt-regulated supply voltage.
13 (15)
REF
Buffered output for the internal 7.5V reference.
14 (16)
FB
Transconductance voltage error amplifier input.
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VEAO
IEAO
I
SENSE
I
AC
V
RMS
R
T
C
T
ZV SENSE
N/C
FAN4822
16-Pin SOIC (S16W)
FAN4822
14-Pin DIP (P14)
FB
REF
V
CC
PFC OUT
ZVS OUT
PWR GND
GND
N/C
TOP VIEW
1
2
3
4
5
6
7
14
13
12
11
10
9
8
VEAO
IEAO
I
SENSE
I
AC
V
RMS
R
T
C
T
ZV SENSE
FB
REF
V
CC
PFC OUT
ZVS OUT
PWR GND
GND
TOP VIEW
Absolute Maximum Ratings
Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum rat-
ings are stress ratings only and functional device operation is not implied.
Parameter
Min
Max
Unit
Shunt Regulator Current (I
CC
)
55
mA
Peak Driver Output Current
500
mA
Analog Inputs
0.3
7
V
Junction Temperature
150
C
Storage Temperature Range
65
150
C
Lead Temperature (Soldering, 10 sec)
150
C
Thermal Resistance (
JA
)
Plastic DIP
Plastic SOIC
80
110
C/W
C/W
PRODUCT SPECIFICATION
FAN4822
REV. 1.0.1 8/10/01
3
Operating Conditions
Electrical Characteristics
Unless otherwise specified, R
T
= 52.3k
, C
T
= 470pF, T
A
= Operating Temperature Range (Note 1)
Temperature Range
Min.
Max.
Units
FAN4822IX
40
85
C
Parameter
Conditions
Min.
Typ.
Max.
Units
Voltage Error Amplifier
Input Voltage Range
0
7
V
Transconductance
V
NON-INV
= V
INV
, VEAO = 3.75V
50
70
120
Feedback Reference Voltage V
EAO
= V
FB
2.4
2.5
2.6
V
Open Loop Gain
60
75
dB
PSRR
V
CCZ
3V < V
CC
< V
CCZ
0.5V
60
75
dB
Output Low
0.65
1
V
Output High
6.0
6.7
V
Source Current
V
IN
= 0.5V, V
OUT
= 6V
40
80
A
Sink Current
V
IN
= 0.5V, V
OUT
= 1.5V
40
80
mA
Current Error Amplifier
Input Voltage Range
1.5
2
V
Transconductance
V
NON-INV
= V
INV
, IEAO = 3.75V
130
195
310
Input Offset Voltage
3
15
mV
Open Loop Gain
60
75
dB
PSRR
V
CCZ
3V < V
CC
< V
CCZ
0.5V
60
75
dB
Output Low
0.65
1
V
Output High
6.0
6.7
V
Source Current
V
IN
= 0.5V, V
OUT
= 6V
30
80
A
Sink Current
V
IN
= 0.5V, V
OUT
= 1.5V
40
80
A
OVP Comparator
Threshold Voltage
2.6
2.7
2.8
V
Hysteresis
80
120
150
mV
I
SENSE
Comparator
Threshold Voltage
0.8
1.0
1.15
V
Delay to Output
150
300
ns
ZV Sense Comparator
Propagation Delay
100mV Overdrive
50
ns
Threshold Voltage
7.35
7.5
7.65
V
Input Capacitance
6
pF
FAN4822
PRODUCT SPECIFICATION
4
REV. 1.0.1 8/10/01
Gain Modulator
Gain (Note 2)
I
IAC
= 100mA, V
VRMS
= 0V,
V
FB
= 0V
0.36
0.51
0.66
I
IAC
= 50mA, V
VRMS
= 1.2V,
V
FB
= 0V
1.20
1.72
2.24
I
IAC
= 100
A, V
VRMS
= 1.8V,
V
FB
= 0V
0.55
0.78
1.01
I
IAC
= 100
A, V
VRMS
= 3.3V,
V
FB
= 0V
0.14
0.20
0.26
Bandwidth
I
IAC
= 250
A
10
MHz
Output Voltage
V
FB
= 0V, V
VRMS
= 1.15V, I
IAC
=
250
A
0.72
0.8
0.9
V
Oscillator
Initial Accuracy
T
A
= 25C
74
80
87
kHz
Voltage Stability
V
CCZ
3V < V
CC
< V
CCZ
0.5V
1
%
Temperature Stability
2
%
Total Variation
Line, temperature
72
89
kHz
Ramp Valley to Peak Voltage
2.5
V
Dead Time
100
300
450
ns
C
T
Discharge Current
4.5
7.5
9.5
mA
Reference
Output Voltage
T
A
= 25C, I
REF
= 1mA
7.4
7.5
7.6
V
Line Regulation
V
CCZ
3V < V
CC
< V
CCZ
0.5V
2
10
mV
Load Regulation
1mA < I
REF
, < 20mA
2
15
mV
Temperature Stability
0.4
%
Total Variation
Line, load, and temperature
7.35
7.65
V
Long Term Stability
T
j
= 125C, 1000 hours
5
25
mV
Short Circuit Current
V
CC
< V
CCZ
0.5V, V
REF
= 0V
15
40
100
mA
PFC Comparator
Minimum Duty Cycle
V
IEAO
> 6.7V
0
%
Maximum Duty Cycle
V
IEAO
< 1.2V
90
95
%
MOSFET Driver Outputs
Output Low Voltage
I
OUT
= 20mA
0.4
1.0
V
I
OUT
= 100mA
1.5
3.5
V
I
OUT
= 10mA, V
CC
= 8V
0.8
1.5
V
Output High Voltage
I
OUT
= 20mA
9.5
10.3
V
I
OUT
= 100mA
9
10.3
V
Output Rise/Fall Time
C
L
= 1000pF
40
ns
Undervoltage Lockout
Threshold Voltage
V
CCZ
0.9
V
CCZ
0.6
V
CCZ
0.2
V
Hysteresis
2.4
2.9
3.45
V
Parameter
Conditions
Min.
Typ.
Max.
Units
Electrical Characteristics
(Continued)
Unless otherwise specified, R
T
= 52.3k
, C
T
= 470pF, T
A
= Operating Temperature Range (Note 1)
PRODUCT SPECIFICATION
FAN4822
REV. 1.0.1 8/10/01
5
Notes
1. Limits are guaranteed by 100% testing, sampling, or correlation with worst-case test conditions.
2. Gain = K x 5.3 V; K = (I
GAINMOD
I
OFFSET
) x I
AC
x (V
EAO
1.5)
1
.
Supply
Shunt Voltage (V
CCZ
)
I
CC
=25mA
12.8
13.5
14.2
V
Load Regulation
25mA < I
CC
< 55mA
150
300
mV
Total Variation
Load and temperature
12.4
14.6
V
Start-up Current
V
CC
< 12.3V
0.7
1.1
mA
Operating Current
V
CC
= V
CCZ
0.5V
22
28
mA
Parameter
Conditions
Min.
Typ.
Max.
Units
Electrical Characteristics
(Continued)
Unless otherwise specified, R
T
= 52.3k
, C
T
= 470pF, T
A
= Operating Temperature Range (Note 1)
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