Fairchild FAN7602C service manual

April 2009

FAN7602C

Green Current Mode PWM Controller

Features

Description

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

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 265VAC and the load is 0.5W. At noload 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.

Related Resources

AN-6014- Green Current Mode PWM Controller (Except for frequency fluctuation part in AN-6014)

Ordering Information

	Part Number	Operating Junction	Eco Status	Package	Packing	Top Mark
		Temperature			Method
	FAN7602CN			8-DIP	Rail	FAN7602C
	FAN7602CM	-40°C to +150°C	RoHS	8-SOP	Rail	FAN7602C
	FAN7602CMX				Tape and Reel	FAN7602C

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

Controller PWM Mode Current Green — FAN7602C

© 2009 Fairchild Semiconductor Corporation	www.fairchildsemi.com
FAN7602C • Rev. 1.0.0

Typical Application Diagram

LUVP	VSTR
Latch/	NC
Plimit
CS/FB	FAN7602C VCC
GND	Out

Figure 1. Typical Flyback Application

Internal Block Diagram

VSTR

8

LUVP

6

VCC

LUVP

1

OVP

OLP

Auto Restart

SS End

19V

2V/1.5V

TSD

Protection

OVP

5V Ref

12V/8V

Latch

Reset

Latch

Protection

Circuit

UVLO

Vcc

SS End

Driver

10ms

OUT

5

Soft Start

Circuit

PWM

Plimit

OSC

Block

Offset

CS/FB

Random

Delay

3

Circuit

Latch/

0.95V/0.88V

Latch

2

Plimit

OLP

PWM+

Power Limit

4V

Soft

Plimit

Start

Plimit

Plimit

Offset

OLP

Offset

Offset

Soft

4

GND

Generator

Start

Figure 2. Functional Block Diagram

Controller PWM Mode Current Green — FAN7602C

© 2009 Fairchild Semiconductor Corporation	www.fairchildsemi.com
FAN7602C • Rev. 1.0.0	2

Pin Configuration

Figure 3. Pin Configuration (Top View)

Pin Definitions

Pin #

Name

Description

1

LUVP

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.

2

Latch/Plimit

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.

3

CS/FB

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.

4

GND

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.

5

OUT

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.

6

VCC

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

using this pin.

7

NC

No Connection.

8

VSTR

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.

Controller PWM Mode Current Green — FAN7602C

© 2009 Fairchild Semiconductor Corporation	www.fairchildsemi.com
FAN7602C • Rev. 1.0.0	3

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
	VCS/FB	CS/FB Input Voltage		-0.3	20	V
	VLUVP	LUVP Input Voltage		-0.3	10	V
	VLatch	Latch/Plimit Input Voltage		-0.3	10	V
	VSTR	VSTR Input Voltage			600	V
	TJ	Junction Temperature			+150	°C
		Recommended Operating Junction Temperature		-40	+150
	TSTG	Storage Temperature Range		-55	+150	°C
	PD	Power Dissipation			1.2	W
	ESD	Electrostatic Discharge Capability	Human Body Model, JESD22-A114		3.5	kV
			Charged Device Model, JESD22-C101		2.0

Thermal Impedance

Symbol	Parameter		Value	Unit
θJA	Thermal Resistance(1), Junction-to-Ambient	8-DIP	100	°C/W

Note:

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

Controller PWM Mode Current Green — FAN7602C

© 2009 Fairchild Semiconductor Corporation	www.fairchildsemi.com
FAN7602C • Rev. 1.0.0	4

Electrical Characteristics

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

Symbol	Parameter	Condition	Min.	Typ.	Max.	Unit
Startup Section
ISTR	VSTR Startup Current	VSTR = 30V, TA = 25°C	0.7	1.0	1.4	mA
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(2)		5	10	15	ms
PWM Section
fOSC	Operating Frequency	VCS/FB = 0.2V, TA = 25°C	59	65	73	kHz
fOSC	Frequency Fluctuation(2)			±3		kHz
VCS/FB1	CS/FB Threshold Voltage	TA = 25°C	0.9	1.0	1.1	V
tD	Propagation Delay to Output(2)			100	150	ns
DMAX	Maximum Duty Cycle		70	75	80	%
DMIN	Minimum Duty Cycle				0	%
Burst Mode Section
VCS/FB2	Burst On Threshold Voltage	TA = 25°C	0.84	0.95	1.06	V
VCS/FB3	Burst Off Threshold Voltage	TA = 25°C	0.77	0.88	0.99	V
Power Limit Section
KPlimit	Offset Gain	VLatch/Plimit = 2V, TA = 25°C	0.12	0.16	0.20
Output Section
VOH	Output Voltage High	TA = 25°C, Isource = 100mA	11.5	12.0	14.0	V
VOL	Output Voltage Low	TA = 25°C, Isink = 100mA		1.0	2.5	V
tR	Rising Time(2)	TA = 25°C, CL = 1nF		45	150	ns
tF	Falling Time(2)	TA = 25°C, CL= 1nF		35	150	ns

Continued on the following page…

Controller PWM Mode Current Green — FAN7602C

© 2009 Fairchild Semiconductor Corporation	www.fairchildsemi.com
FAN7602C • Rev. 1.0.0	5

Electrical Characteristics (Continued)

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

	Symbol	Parameter	Condition	Min.	Typ.	Max.	Unit
	Protection Section
	VLATCH	Latch Voltage		3.6	4.0	4.4	V
	tOLP	Overload Protection Time(2)		20	22	24	ms
	tOLP_ST	Overload Protection Time at		30	37	44	ms
		Startup
	VOLP	Overload Protection Level			0	0.1	V
	VLUVPoff	Line Under-Voltage Protection	TA = 25°C	1.9	2.0	2.1	V
		On to Off
	VLUVPon	Line Under-Voltage Protection	TA = 25°C	1.4	1.5	1.6	V
		Off to On
	VOVP	Over-Voltage Protection	TA = 25°C	18	19	20	V
	TSD	Shutdown Temperature(2)			170		°C
	HYS				60		°C

Note:

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

Controller PWM Mode Current Green — FAN7602C

© 2009 Fairchild Semiconductor Corporation	www.fairchildsemi.com
FAN7602C • Rev. 1.0.0	6