Fairchild Semiconductor FAN4822 Datasheet

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FAN4822

ZVS Average Current PFC Controller

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

• A verage line v oltage compensation with bro wnout 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

Block Diagram

1

14

13

4

5

3

6

FB

2.5V

I

AC

V

RMS

I

SENSE

R

TCT

REF

VEAO

VEA

–

+

GAIN

MODULATOR

R+

R–

V

REF

CCZ

8

GND

+

–

IEA

2

IEAO

+

–

OSC

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) con­troller 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, over­voltage 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 recov­ery and MOSFET switching losses to reduce EMI and maxi­mize efficiency.

V

CC

12

PFC OUT

11

ZVS OUT

10

FB

2.7V

–1V

+

–

I LIMIT

+

–

OVP

SRQ

SRQ

V

CCZ

13.5V

Q

ZV SENSE

7

+

––

QS

R

Q

PWR GND

9

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FAN4822 PRODUCT SPECIFICATION

Pin Configuration

FAN4822

16-Pin SOIC (S16W)

1
2
3
4
5
6
7
8

TOP VIEW

14-Pin DIP (P14)

VEAO

IEAO

I

SENSE

I

AC

V

RMS

RTC

ZV SENSE

T

Pin Description

FAN4822

1
2
3
4
5
6
7

TOP VIEW

14
13
12
11
10

9
8

FB
REF
V

CC

PFC OUT
ZVS OUT
PWR GND
GND

VEAO

IEAO

I

SENSE

I

V

RMS

RTC

ZV SENSE

N/C

AC

T

(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

4 (4) I
5 (5) V
6 (6) R

AC

RMS

C

T

T

Current sense input to the PFC current limit comparator.
PFC gain modulator reference input.
Input for RMS line voltage compensation.
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.

16
15
14
13
12
11
10

9

FB
REF
V

CC

PFC OUT
ZVS OUT
PWR GND
GND
N/C

Absolute Maximum Ratings

Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum rat­ings are stress ratings only and functional device operation is not implied.

Parameter Min Max Unit

Shunt Regulator Current (I
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 ( θ

Plastic DIP
Plastic SOIC

2

)55mA

CC

)

JA

80

110

°C/W
°C/W

REV. 1.0.1 8/10/01

∆

∆

∆

∆

Ω

PRODUCT SPECIFICATION FAN4822

Operating Conditions

Temperature Range Min. Max. Units

FAN4822IX –40 85 °C

Electrical Characteristics

Unless otherwise specified, R

Parameter Conditions Min. Typ. Max. Units

Voltage Error Amplifier

Input Voltage Range 0 7 V
Transconductance V
Feedback Reference Voltage V
Open Loop Gain 60 75 dB
PSRR V
Output Low 0.65 1 V
Output High 6.0 6.7 V
Source Current
Sink Current

Current Error Amplifier

Input Voltage Range –1.5 2 V
Transconductance V
Input Offset Voltage ±3 ±15 mV
Open Loop Gain 60 75 dB
PSRR V
Output Low 0.65 1 V
Output High 6.0 6.7 V
Source Current
Sink Current

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

= 52.3k Ω , C

T

NON-INV
EAO

CCZ

V

IN

V

IN

NON-INV

CCZ

V

IN

V

IN

= 470pF, T

T

= V

INV

= V

FB

– 3V < V

= ±0.5V, V
= ±0.5V, V

= V

INV

– 3V < V

= ±0.5V, V
= ±0.5V, V

= Operating Temperature Range (Note 1)

A

, VEAO = 3.75V 50 70 120

2.4 2.5 2.6 V

CC

OUT
OUT

< V

– 0.5V 60 75 dB

CCZ

= 6V –40 –80 µA
= 1.5V 40 80 mA

, IEAO = 3.75V 130 195 310

CC

OUT
OUT

< V

– 0.5V 60 75 dB

CCZ

= 6V –30 –80 µ A
= 1.5V 40 80 µ A

µ

µ

Ω

REV. 1.0.1 8/10/01

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