Fairchild FAN7602C service manual

FAN7602C Green Current Mode PWM Controller

FAN7602C — Green Current Mode PWM Controller

April 2009

Features

 Green Current Mode PWM Controller

 Random Frequency Fluctuation for Low EMI

 Internal High-Voltage Startup Switch

 Burst Mode Operation

 Line Voltage Feedforward to Limit Maximum Power

 Line Under-Voltage Protection

 Latch Protection & Internal Soft-Start (10ms) Function

 Overload Protection

 Over-Voltage Protection

 Over-Temperature Protection

 Low Operation Current: 1mA Typical

 8-Pin DIP/SOP

Applications

 Adapter

 LCD Monitor Power

 Auxiliary Power Supply

Related Resources

 AN-6014- Green Current Mode PWM Controller

(Except for frequency fluctuation part in AN-6014)

Description

The FAN7602C is a green current-mode PWM controller. It is specially designed for off-line adapter applications; DVDP, VCR, LCD monitor applications; and auxiliary power supplies.

The internal high-voltage startup switch and the burst mode operation reduce the power loss in standby mode. As a result, the input power is lower than 1W when the input line voltage is 265V load condition, input power is under 0.15W.

The maximum power can be limited constantly, regardless of the line voltage change, using the power limit function.

The switching frequency is not fixed and it has random frequency fluctuation.

The FAN7602C includes various protections for the system reliability and the internal soft-start prevents the output voltage over-shoot at startup.

and the load is 0.5W. At no-

AC

Ordering Information

Part Number

FAN7602CN 8-DIP Rail FAN7602C

FAN7602CM Rail FAN7602C

FAN7602CMX

For Fairchild’s definition of Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html.

Operating Junction

Temperature

-40°C to +150°C RoHS

Eco Status

Package

8-SOP

Packing

Method

Tape and Reel FAN7602C

Top Mark

Typical Application Diagram

FAN7602C — Green Current Mode PWM Controller

Internal Block Diagram

LUVP

1

2V/1.5V

LUVP

Latch

LUVP

Latch/

Plimit

CS/FB

GND

FAN7602C

V

NC

V

Out

STR

CC

Figure 1. Typical Flyback Application

V

STR

8

OLP

TSD

OVP

Auto Restart

Protection

Latch

Protection

Reset Circuit

SS End

5V Ref

OVP

UVLO

19V

12V/8V

6

V

CC

Vcc

Soft

Start

Driver

Circuit

Power Limit

Plimit

Offset

Plimit

Offset

5

3

4

OUT

CS/FB

GND

Latch/

Plimit

10ms

SS End

Soft Start

PWM

OSC

Block

Delay

Random

Circuit

0.95V/0.88V

2

Latch

PWM+

OLP

4V

Plimit

Offset

Generator

Plimit

Offset

OLP

Soft

Start

Figure 2. Functional Block Diagram

Pin Configuration

FAN7602C — Green Current Mode PWM Controller

Figure 3. Pin Configuration (Top View)

Pin Definitions

Pin # Name Description

1 LUVP

2 Latch/Plimit

3 CS/FB

4 GND

5 OUT

6 VCC

7 NC

8 V

STR

Line Under-Voltage Protection Pin. This pin is used to protect the set when the input voltage is lower than the rated input voltage range.

Latch Protection and Power Limit Pin. When the pin voltage exceeds 4V, the latch protection works. The latch protection is reset when the VCC voltage is lower than 5V. For the power limit function, the OCP level decreases as the pin voltage increases.

Current Sense and Feedback Pin. This pin is used to sense the MOSFET current for the current mode PWM and OCP. The output voltage feedback information and the current sense information are added using an external RC filter.

Ground Pin. This pin is used for the ground potential of all the pins. For proper operation, the signal ground and the power ground should be separated.

Gate Drive Output Pin. This pin is an output pin to drive an external MOSFET. The peak sourcing current is 450mA and the peak sinking current is 600mA. For proper operation, the stray inductance in the gate driving path must be minimized.

Supply Voltage Pin. IC operating current and MOSFET driving current are supplied using this pin.

No Connection.

Startup Pin. This pin is used to supply IC operating current during IC startup. After

startup, the internal JFET is turned off to reduce power loss.

FAN7602C — Green Current Mode PWM Controller

Absolute Maximum Ratings

Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only.

Symbol Parameter Min. Max. Unit

VCC Supply Voltage 25 V

IO Output Current -600 +450 mA

V

CS/FB Input Voltage -0.3 20 V

CS/FB

V

LUVP Input Voltage -0.3 10 V

LUVP

V

Latch/Plimit Input Voltage -0.3 10 V

Latch

V

STR

TJ

T

Storage Temperature Range -55 +150 °C

STG

PD Power Dissipation 1.2 W

ESD Electrostatic Discharge Capability

Input Voltage 600 V

STR

Junction Temperature +150

Recommended Operating Junction Temperature -40 +150

Human Body Model, JESD22-A114 3.5

Charged Device Model, JESD22-C101 2.0

°C

kV

Thermal Impedance

Symbol Parameter Value Unit

θJA Thermal Resistance

Note:

1. Regarding the test environment and PCB type, please refer to JESD51-2 and JESD51-10.

(1)

, Junction-to-Ambient 8-DIP 100

°C/W

Electrical Characteristics

VCC = 14V, TA = -25°C~125°C, unless otherwise specified.

Symbol Parameter Condition Min. Typ. Max. Unit

Startup Section

I

V

STR

Under Voltage Lock Out Section

Vth(start) Start Threshold Voltage VCC Increasing 11 12 13 V

Vth(stop) Stop Threshold Voltage VCC Decreasing 7 8 9 V

HY(uvlo) UVLO Hysteresis 3.6 4.0 4.4 V

Supply Current Section

IST Startup Supply Current TA = 25°C 250 320 µA

ICC Operating Supply Current Output Not Switching 1.0 1.5 mA

Soft-Start Section

tSS Soft-Start Time

Startup Current V

STR

(2)

5 10 15 ms

= 30V, TA = 25°C 0.7 1.0 1.4 mA

STR

FAN7602C — Green Current Mode PWM Controller

PWM Section

f

Operating Frequency V

OSC

ᅀf

Frequency Fluctuation

OSC

V

CS/FB Threshold Voltage TA = 25°C 0.9 1.0 1.1 V

CS/FB1

tD Propagation Delay to Output

D

MAX

MIN

Maximum Duty Cycle 70 75 80 %

Minimum Duty Cycle 0 %

(2)

±3 kHz

(2)

100 150 ns

Burst Mode Section

V

Burst On Threshold Voltage TA = 25°C 0.84 0.95 1.06 V

CS/FB2

V

Burst Off Threshold Voltage TA = 25°C 0.77 0.88 0.99 V

CS/FB3

Power Limit Section

K

Offset Gain V

Plimit

Output Section

VOH Output Voltage High TA = 25°C, I

VOL Output Voltage Low TA = 25°C, I

tR Rising Time

tF Falling Time

(2)

T

(2)

T

= 0.2V, TA = 25°C 59 65 73 kHz

CS/FB

Latch/Plimit

A

= 2V, TA = 25°C 0.12 0.16 0.20

= 100mA 11.5 12.0 14.0 V

source

= 100mA 1.0 2.5 V

sink

= 25°C, CL = 1nF 45 150 ns

= 25°C, CL= 1nF 35 150 ns

Continued on the following page…

Electrical Characteristics (Continued)

VCC = 14V, TA = -25°C~125°C, unless otherwise specified.

Symbol Parameter Condition Min. Typ. Max. Unit

Protection Section

FAN7602C — Green Current Mode PWM Controller

V

LATCH

t

OLP

t

OLP_ST

V

OLP

V

LUVPoff

V

LUVPon

V

OVP

TSD 170 °C

HYS

Latch Voltage 3.6 4.0 4.4 V

Overload Protection Time

Overload Protection Time at Startup

(2)

20 22 24 ms

30 37 44 ms

Overload Protection Level 0 0.1 V

Line Under-Voltage Protection On to Off

Line Under-Voltage Protection Off to On

TA = 25°C 1.9 2.0 2.1 V

TA = 25°C 1.4 1.5 1.6 V

Over-Voltage Protection TA = 25°C 18 19 20 V

Shutdown Temperature

(2)

60 °C

Note:

2. These parameters, although guaranteed, are not 100% tested in production.

Fairchild FAN7602C service manual

Specifications and Main Features

Frequently Asked Questions

User Manual