Datasheet SG6846B Datasheet (Fairchild)

SG6846B Highly Integrated Green-Mode PWM Controller

SG6846B — Highly Integrated Green-Mode PWM Controller

October 2008

Features

 Low Startup Current: 8µA  Low Operating Current: 3.7mA  Peak-Current Mode Operation with Cycle-by-cycle

Current Limiting

 PWM Frequency Continuously Decreasing with

Burst Mode at Light Loads

 V

Over Voltage Protection (OVP)

DD

 AC Input Brownout Protection with Hysteresis  Constant Output Power Limit (Full AC Input Range)  Internal Latch Circuit for OVP, OTP, and OCP

(BLSY, BLSZ)

 Two-level OCP Delay with 200ms  Programmable PWM Frequency with Frequency

Hopping

 OCP Threshold is 2/3 Peak Current Limit  Soft Startup Time: 5ms

Applications

General-purpose switch-mode power supplies and flyback power converters, including:

 Power Adapters  Open-frame SMPS  SMPS with Surge-current Output, such as for

Printers, Scanners, Motor Drivers

Description

The highly integrated PWM controller, SG6846B, provides several features to enhance the performance of fly-back converters. To minimize standby power consumption, a proprietary green-mode function provides off-time modulation to continuously decrease the switching frequency under light-load conditions. Under zero-load conditions, the power supply enters burst-mode. This completely shuts off PWM output. If V

is larger than around 1.6V, PWM pulses out. This

FB

green-mode function enables power supplies to meet international power conservation requirements.

The SG6846B is designed for SMPS with surge-current output. It is incorporated with a two-level OCP function. Besides, the cycle-by-cycle current limiting, if the switching current is higher than OCP threshold and lasts for 200ms, SG6846B stops gate immediately and latches itself (BLSY version) or restarts after V charges up to 16.5V (BCSY version). SG6846B also integrates frequency-hopping function internally. The frequency hopping function helps reduce EMI emission of a power supply with minimum line filters. It has builtin synchronized slope compensation, proprietary internal compensation for constant output power limit over universal AC input range. The gate output is clamped at 18V to protect the external MOSFET from over-voltage damage.

Protection include: AC input brownout protection with hysteresis and V temperature protection, an external NTC thermistor can be applied to sense the ambient temperature. When OCP, V circuit is used to latch-off the controller. The latch resets when V

SG6846B is available in 8-pin SOP package.

OVP, or OTP are activated, an internal latch

DD

supply is removed.

DD

over-voltage protection. For over-

DD

Ordering Information

Part

Number

SG6846BLSY -40 to +105°C Yes Green 8-Pin Small Outline Package (SOP) Tape & Reel

SG6846BLSZ -40 to +105°C Yes RoHS 8-Pin Small Outline Package (SOP) Tape & Reel

SG6846BCSY -40 to +105°C No Green 8-Pin Small Outline Package (SOP) Tape & Reel

SG6846BCSZ -40 to +105°C No RoHS 8-Pin Small Outline Package (SOP) Tape & Reel

For Fairchild’s definition of “green” Eco Status, please vis i t : http://www.fairchildsemi.com/company/green/rohs_green.html.

Operating

Temperature Range

OCP

Latch

Eco

Status

Package

Packing

Method

Typical Application

L

AC input

N

EMI

Filter

3

7

VINRIVDD GATE

SG6846B — Highly Integrated Green-Mode PWM Controller

+

8

+

VO+

VO-

Block Diagram

0.9V/0.7V

VIN

3

7

VDD

4

2

FB

V

DD

-TH-G

UVLO

16.5V/10.5V

6

SENSE

GND

RT

5

1

SG6846B

Figure 1. Typical Application

Over Power Compersation

0.895-0.065

Internal BIAS

Latch

XVIN

4

VDD

Soft Driver

Slope

1R

Green Mode

+

3R

1R

Blanking Circuit

S

Q

R

OSC

Compensation

6.2V

8

2

6

GATE

FB

SENSE

2R

1.15V

RT

23.6V

I

RT

5

1.05V

Debounce

OTP Delay

SCP Delay

OCP Delay

1

GND

Figure 2. Block Diagram

Marking Information

SG6846BFTP

XXXXXXXXYWWV

※ Marking for SG6846BLSZ (Pb-free)

SG6846BCSZ (Pb-free)

SG6846B — Highly Integrated Green-Mode PWM Controller

F: L = OCP Latch, C = OCP auto-recovery

T: S = SOP

P: Z = Lead Free + ROHS Compatible

Null = regular package

XXXXXXXX: Wafer Lot

Y: Year; WW: Week

V: Assembly Location

Figure 3. Top Mark 1

: Fairchild logo

Z: Plant Code

X: Year Code

Y: Week Code

TT: Die Run Code

F: L = OCP Latch, C = OCP auto-recovery

T: Package type, S = SOP

Green Package

P: Y =

M: Manufacturing flow code

※ Marking for SG6846BLSY (Green-compound) SG6846BCSY (Green-compound)

Figure 4. Top Mark 2

Pin Configuration

Figure 5. Pin Configuration

Pin Definitions

Pin # Name Function Description

1 GND Ground Ground.

The signal from the external compensation circuit is fed into this pin. The PWM

2 FB Feedback

3 VIN

4 RI

5 RT

6 SENSE Current Sense

7 VDD Power Supply

8 GATE Driver Output

Line-voltage

Detection

Reference

Setting

Temperature

Detection

duty cycle is determined in response to the signal from this pin and the currentsense signal from pin 6.

Line-voltage detection is used for brownout protection with hysteresis. Constant output power limit over universal AC input range is achieved using this pin. Add a low-pass filter to filter out line ripple on the bulk capacitor.

A resistor from the RI pin to ground generates a reference current source that determines the switching frequency. Increasing the resistance reduces the switching frequency. A 26k resistor results in a 65kHz switching frequency.

For over-temperature protection, an external NTC thermistor is connected from this pin to the GND pin. The impedance of the NTC decreases at high temperatures. Once the voltage of the RT pin drops below a threshold, PWM output is disabled.

The sensed voltage is used for peak-current-mode control and cycle-by-cycle current limiting. If the switching current is higher than OCP threshold and lasts for 200ms, SG6846B turns off immediately. This two-level OCP feature is especially suitable for SMPS with surge current output.

If an open-circuit failure occurs in the feedback loop, the internal protection circuit disables PWM output as long as V

The totem-pole output driver for the power MOSFET; internally clamped below 18V.

exceeds a threshold.

DD

SG6846B — Highly Integrated Green-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. All voltage values, except differential voltages, are given with respect to GND pin.

Symbol Parameter Min. Max. Unit

VDD Supply Voltage 30 V

VL Input Voltage to FB, SENSE, VIN, RT, RI Pins -0.3 7.0 V

PD Power Dissipation at TA<50°C SOP 400 mW

JC Thermal Resistance (Junction-to-Case) SOP 54.4 °C/W

TJ Operating Junction Temperature -40 +150 °C

T

Storage Temperature Range -65 +150 °C

STG

TL Lead Temperature, Wave Soldering, 10 Seconds +260 °C

ESD

Human Body Model, JESD22-A114 5.0

Charge Device Model, JESD22-C101 1.5

kV

Recommended Operating Conditions

The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not recommend exceeding them or designing to Absolute Maximum Ratings.

Symbol Parameter Min. Max. Unit

TA Operating Ambient Temperature -40 +105 °C

Electrical Characteristics

VDD = 15V and TA = 25°C unless otherwise noted.

Symbol Parameter Test Condition Min. Typ. Max. Unit

VDD Section

V

Continuously Operating Voltage 20 V

DD-OP

V

Turn-on Threshold Voltage 15.5 16.5 17.5 V

DD-ON

V

Turn-off Voltage 9.5 10.5 11.5 V

DD-OFF

V

DD-SCP

V

Threshold Voltage for Latch-off Release 3 4 5 V

DD-LH

I

Startup Current V

DD-ST

I

Operating Supply Current GATE Open 3.7 5.0 mA

DD-OP

V

VDD Over-Voltage Protection (Latch off) 23 24 25 V

DD-OVP

t

D-VDDOVP

VDD OVP Debounce Time RI = 26k 150 µs

I

VDD OVP Latch-off Holding Current VDD = 5V 30 50 70 µA

DD-OVP

VIN Section

Threshold Voltage on VDD for Short-Circuit Protection

– 0.16V 8 30 µA

DD-ON

V

DD-OFF

+0.5V

V

DD-OFF

+1.0V

V

DD-OFF

+1.5V

SG6846B — Highly Integrated Green-Mode PWM Controller

V

PWM Turn-off Threshold Voltage 0.65 0.70 0.75 V

IN-OFF

V

PWM Turn-on Threshold Voltage

IN-ON

V

IN-OFF

+0.18

V

IN-OFF

+0.20

V

IN-OFF

+0.22

Feedback Input Section

AV Input-Voltage to Current-Sense Attenuation 1/3.5 1/4.0 1/4.5 V/V

ZFB Input Impedance 4.0 5.5 7.0 k

V

FB Pin Open Voltage 5.2 6.2 6.6 V

FBO

Current Sense Section

Z

Input Impedance 12 k

SENSE

tPD Delay to Output 100 250 ns

t

Leading-edge Blanking Time 270 360 ns

LEB

V

SLOPE

V

STH1V

V

STH3V

V

STH1V-2/3

V

STH3V-2/3

t

D-OCP

t

D-Short

t

SS-65KHz

t

SS-130KHz

Slope Compensation Duty = DCY

Threshold Voltage for Current Limit VIN = 1V 0.80 0.83 0.86 V

Threshold Voltage for Current Limit VIN = 3V 0.67 0.70 0.73 V

OCP Threshold Voltage for Current Limit VIN = 1V 0.58 0.61 0.64 V

OCP Threshold Voltage for Current Limit VIN = 3V 0.48 0.51 0.54 V

Delay Time for Over-Current Protection RI = 26k 175 200 225 ms

V

> V

Output Short Circuit Protection delay time

R

Period During Soft Start Time

CS

V

< V

DD

= 26k 4.5 5.0 5.5 ms

I

RI = 13k 2.25 2.50 2.75 ms

0.30 0.33 0.36 V

MAX

, RI = 26k,

STH

DD-SCP

6 7 8 ms

Continued on following page…

V

SG6846B — Highly Integrated Green-Mode PWM Controller

( 1 ) no rm a l

ope r a t i on

N

O

I P > 2 / 3 I

T i m i ng = 8 m s

( 2 )

( 3 )

PK

?

(5 )

Timing= 200 ms

OCP

(4 )

V

< 12 V?

DD

NO

SCP

(7 ) Gate-off

YES

V

YES

DD

SCP

NO

(6 )

<= 12 V ?

Figure 6. SG6846B OCP/SCP Logic Flow Diagram

Electrical Characteristics (Continued)

VDD = 15V and TA = 25°C unless otherwise noted.

Symbol Parameter Test Condition Min. Typ. Max. Unit

Oscillator Section

Center

f

Normal PWM Frequency

OSC

Frequency

RI = 26k, VFB>VN

Jitter Range

Center

f

OSC,MAX

Maximum PWM Frequency

Frequency

R

= 13k, VFB>VN

I

Jitter Range

Center

f

Minimum PWM Frequency

OSC,MIN

Frequency

RI = 36k, VFB>VN

Jitter Range

t

hop-1

f

OSC-G

Jitter Period

RI = 26k, VFB ≥ VN

Green-Mode Minimum Frequency RI = 26k 18.0 22.5 25.0 kHz

62 65 68

±3.7 ±4.2 ±4.7

124 130 136

±7.4 ±8.4 ±9.4

44.8 47.0 49.2

±2.54 ±2.90 ±3.26

3.9 4.4 4.9 ms

SG Slope for Green-Mode Modulation RI = 26k 85 Hz/mV

V

FB-N

FB-G

FB Pin Frequency Reduction Threshold

FB Voltage at f

OSC-G

Pin, FB voltage 1.9 2.1 2.3 V

RI = 26k, VFB = VN

Jitter Range

3.7 4.2 4.7 KHz

Pin, FB voltage RI = 26k, VFB = VG 1.4 1.6 1.8 V

fDV Frequency Variation vs. VDD Deviation VDD = 11.5V to 20V 5 %

fDT

Frequency Variation vs. Temperature Deviation

TA = -30 to 85°C 1.5 5.0 %

Continued on following page…

kHz

SG6846B — Highly Integrated Green-Mode PWM Controller

Electrical Characteristics (Continued)

VDD = 15V and TA = 25°C unless otherwise noted.

Symbol Parameter Test Condition Min. Typ. Max. Unit

PWM Output Section

DCY

Maximum Duty Cycle 80 85 90 %

MAX

VOL Output Voltage Low VDD = 15V, IO = 50mA 1.5 V

VOH Output Voltage High VDD = 12V, IO = 50mA 8 V

tR Rising Time GATE = 1nF 350 ns

tF Falling Time GATE = 1nF 50 ns

V

Gate Output Clamping Voltage VDD = 20V 18 V

CLAMP

Over-Temperature Protection (OTP) Section

(1)

IRT Output Current of RT Pin RI = 26k 64 70 76 µA

V

RTTH

Threshold Voltage for OTP 1.00 1.05 1.10 V

SG6846BLSY or

t

DOTP-LATCH

R

RT-OFF

Over-Temperature Latch-off Debounce

Equivalent Impedance of RT for OTP

(1)

SG6846BCSY, R

= 26k, VFB>VN

I

SG6846BLSZ or SG6846BCSZ, R

= 26k, VFB>VN

I

R

= 26k 14 15 16 k

I

100 ms

100 µs

RI Section

RI

NOR

RI

MAX

RI

MIN

Note:

1. The relationship between R

RI Operating Range 13 36 k

Maximum RI Value for Protection 10 M

Minimum RI Value for Protection 6 k

RT-OFF

and RI is: ))(K R / 26 A (70 / V I / VR

μ

Ω×==

IRTRTOFF-LATCH-OTPOFF-RT

(1)

Typical Performance Characteristics

SG6846B — Highly Integrated Green-Mode PWM Controller

17.0

16.8

16.6

(V)

16.4

DD-ON

V

16.2

16.0

Turn-on Th r esho ld Voltage (V

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

Figure 7. Turn-on Threshold Voltage (V

vs. Temperature

) vs Temperature

DD-ON

)

Turn-off Voltage (V

11.5

11.0

10.5

(V)

10.0

DD-OFF

V

9.5

9.0

-40 -25 -10 5 20 35 50 65 80 95 1 10 125

Temperature (℃)

) vs Temperature

DD-OFF

Figure 8. Turn-off Threshold Voltage (V

vs. Temperature

DD-OFF

)

Operating Supply Current (IDD-op) vs Temperature

(µA)

DD- ST

I

26.0

22.0

18.0

14.0

10.0

Startup Current (I

) vs Temperature

DD-ST

6.0

5.5

5.0

IDD-o p ( mA)

4.5

6.0

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

Figure 9. Startup Current (I

) vs. Temperature Figure 10. Operating Supply Current (I

DD-ST

4.0

-40 -25 -10 5 20 35 50 65 8 0 95 110 125

Temperature (℃)

DD-op

) vs.

Temperature

OCP Thre s hold Voltage for C urrent Limit (V

0.66

0.64

0.62

(V)

0.60

STH1V-2/3

V

0.58

0.56

-40 -25 -10 5 20 35 50 65 80 95 110 1 25

Temperature

Temperature (℃)

Figure 11. OCP Threshold Voltage for Current Limit

(V

) vs. Temperature

STH1V-2/3

)vs

OC P ThresholdVoltagefor Cu rrent Lim it(V

0.60

0.58

0.56

(V)

0.54

STH3V-2/3

V

0.52

0.50

-40 -25 -10 5 20 3 5 50 65 80 95 110 125

Temperature

STH3V-2/3

Temperature (℃)

Figure 12. OCP Threshold Voltage for Current Limit

(V

) vs. Temperature

STH3V-2/3

)vs

Typical Performance Characteristics (Continued)

SG6846B — Highly Integrated Green-Mode PWM Controller

NormalPWM Frequency (f

64.0

63.5

63.0

(kHz)

OSC

f

62.5

62.0

-40 -25 -10 5 20 35 50 65 80 95 110 12 5

Temperature (℃)

)vs Temper ature

OSC

Figure 13. Normal PWM Frequency (f

vs. Temperature

OSC

87.2

87.0

86.8

86.6

DCYmax (%)

86.4

86.2

)

Maximum Duty C ycle (DCYmax) vs Temp er ature

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperatu r e (℃)

Figure 14. Maximum Duty Cycle (D

CYmax

)

vs. Temperature

(µA)

RT

I

70.8

70.6

70.4

70.2

70.0

Ou tp ut Current o fRTPin (IRT)vs Tempe rature

(V)

RTTH

V

1.10

1.08

1.06

1.04

1.02

Trigger Voltage of OTP (V

)vs Temper atur e

RTTH

69.8

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

Figure 15. Output Current of RT pin (IRT)

vs. Temperature

1.00

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

Figure 16. Trigger Voltage of OTP(V

RTTH

vs. Temperature

)

PWM Turn-on Threshold Voltage (V

0.925

0.920

(V)

0.915

IN-ON

V

0.910

0.905

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperatur e (℃)

) vs Temperature

IN-ON

Figure 17. PWM Turn-on Threshold Voltage (V

vs. Temperature

IN-ON

PWM Turn-off Threshold Voltage (V

0.715

0.710

0.705

(V)

0.700

IN-OFF

V

0.695

0.690

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

)

Figure 18. PWM Turn-off Threshold Voltage (V

vs. Temperature

) vs Temperature

IN-O FF

IN-OFF

)

Operation Description

SG6846B — Highly Integrated Green-Mode PWM Controller

Startup Operation

The turn-on/turn-off thresholds are fixed internally at

16.5V and 10.5V. To enable the SG6846B during startup, the hold-up capacitor must first be charged to

16.5V through the startup resistor.

If an open-circuit or short-circuit to ground occurs at the RI pin, the internal protection circuit immediately shuts down the controller.

The hold-up capacitor continues to supply V

before

DD

energy can be delivered from the auxiliary winding of the main transformer. The V

must not drop below

DD

10.5V during this startup process. This UVLO hysteresis window ensures that the hold-up capacitor can adequately supply V

during startup.

DD

The typical startup current is only 8µA, which allows a high-resistance, low-wattage startup resistor to be used. For constant output power limit over a universal inputvoltage range, the peak-current threshold is adjusted by the voltage of the VIN pin. Since the VIN pin is connected to the rectified AC input line voltage through the resistive divider, a higher line voltage generates a higher V the V

voltage. The threshold voltage decreases as

IN

increases, making the maximum output power at

IN

high line input voltage equal to that at low line input. The value of R-C network should not be so large it affects the power limit (shown in Figure 19). R and C should put on less than 300 and 1000pF, respectively, to minimize power loss. A 1.5M/0.25W startup resistor and a 10µF/25V V

hold-up capacitor are sufficient for

DD

a universal input range.

The required operating current has been reduced to

3.7mA, which enables higher efficiency and reduces the V

hold-up capacitance requirement.

DD

Green-Mode Operation

The proprietary green-mode function provides off-time modulation to continuously decrease the switching frequency under light-load conditions. Maximum on-time is limited to provide protection against abnormal conditions. To further reduce power consumption under zero-load condition, the PWM oscillator is completely turned off and the power supply enters burst-mode. Green mode dramatically reduces power consumption under light-load and zero-load conditions. Power supplies using SG6846B can meet restrictive international regulations regarding standby power consumption.

Oscillator Operation

A resistor connected from the RI pin to GND generates a internal reference current source used to determine the PWM frequency. Increasing the resistance decreases the amplitude of the current source and reduces the PWM frequency. Using a 26kΩ resistor results in a corresponding 65kHz switching frequency. The relationship between R frequency is:

and the switching

I

1690

f

(kHz)

PWM

=

)(kR

Ω

I

(2)

If an open-circuit or short-circuit to ground occurs at the RI pin, the internal protection circuit immediately shuts down the controller.

Two-level Over-current Protection (OCP)

The cycle-by-cycle current limiting shuts down the PWM immediately when the switching current is over the peak-current threshold. Additionally, when the switching current is higher than over-current threshold, the internal counter counts down. When the total accumulated counting time is more than ~200ms (R

= 26k), the

I

controller is latched off and the internal counter counts up. When the switching current is lower than overcurrent threshold, the internal counter counts down. When the total accumulated counting time is more than ~200ms (R

= 26k), the controller is latched off.

I

This two-level OCP protection and up/down counter are especially designed for SMPS with surge current output, such as those for printers, scanners, and motor drivers.

Constant Output Power Limit

For constant output power limit over universal inputvoltage range, the peak-current threshold is adjusted by the voltage of the VIN pin. Since the VIN pin is connected to the rectified AC input line voltage through the resistive divider, a higher line voltage generates a higher V V

IN

voltage. The threshold voltage decreases as

IN

increases, making the maximum output power at

high-line input voltage equal to that at low-line input.

Brownout Protection

Since the VIN pin is connected through a resistive divider to the rectified AC input line voltage, it can also be used for brownout protection. If the V less than 0.7V, the PWM output is shut off. If the V

voltage is

IN

is

IN

over 0.9V, the PWM output is turned on again. The hysteresis window for on/off is ~0.2V.

VDD Over-voltage Protection (OVP)

VDD over-voltage protection is built in to prevent damage. If V

is over 24V, SG6846B is latched off.

DD

Over-Temperature Protection (OTP)

An external NTC thermistor can be connected from the RT pin to GND. The impedance of the NTC decreases at high temperatures. When the voltage of the RT pin

drops below 1.05V, the SG6846B is turned off. For

protection-mode options, see Ordering Information.

Operation Description (Continued)

Noise Immunity

Noise from the current sense or the control signal may cause significant pulse-width jitter, particularly in continuous-conduction mode. Slope compensation helps alleviate this problem. Good placement and layout practices should be followed. Avoid long PCB traces and component leads. Compensation and filter components should be located near the SG6846B.

SG6846B — Highly Integrated Green-Mode PWM Controller

Figure 19. Current Sense R-C Filter

P1

Reference Circuit

RT1

F1

P2

P7

t

VZ1

1 2

LF1

CY2

3 4

CY1

CX1

34

LF2

SG6846B — Highly Integrated Green-Mode PWM Controller

2

12

CX2

R2

R1

R3 R4

BD1

4

1

21

+

R8

3

R9

21

+

C3

D1

C2

R12

21

1 2

21

+

C5

C4

D2

21

D3

L4

21

R11

TX1

5

6

7 9 1

3

13

10

11

R16

D4

2

R17

2

C16

C17

21

P32V

+

P16V

+

L1

21

C12

+

L2

21

C14

+

32V

21

C13

+

16V

21

C15

+

1

3

C11

1

3

D5

U1

1

FB

2

21

C1

3

+

R5

4

R7

8

GND

GATE

7

FB

VDD

6

VIN

SENSE

R10

5

RI

RT

R13

C6

NTC1

23

Q1

1

L3

R6

1 2

R14

P16V

R15

FB

C7

12

43

C9

U2

A K

P16V P32V

R19

R21

P32VP16V

R20

R18

R

U3

Figure 20. Application Circuit for 32V / 16V Output

BOM

Part No. Value Part No. Value Part No. Value

R1, R2, R3, R4 470K +/-5% C4 103P 630V D3 FR103 1.0A 200V

R8, R9 S1M +/-1% C10,C11 102P 1KV BD1 DBL406G

R5 16K2 +/-1% C6,C7 102P 50V D4 BYT28-300

R15 1K5 +/-5% C9 222P 50V D5 BYV32-150

R13 10 +/-5% C14,C17 470µ 25V F1 250V4A QUICK

R18 4K7 +/-5% C15 220µ 25V L1,L2 1.8µH

R21 15K +/-1% C13,C16 220µ 50V L4 10µH

R7 27K +/-5% C2 150µ 400V U3 TL431 +/-1%

R6 330 +/-1% C1 4.7µ 50V U1 SG6846

R19 102K +/-1% C3 10µ 50V U2 PC817

R14 022 +/-5% CX1 X1 0.47µ 275V Q1 7NB60

R16, R17 1W 20 +/-5% C8 Y2 222P 250V TX1 EI-33

R11 20K +/-5% C5 100µ 50V RT1 SCK053

R12 100K +/-5% CX2 X2 0.1µF 275V VZ1 14 470V R20 887K +/-1% D1 1N4148

R22 10K +/-1% D2 BYV95C

Physical Dimensions

8

5.00

4.80

3.81

SG6846B — Highly Integrated Green-Mode PWM Controller

A

0.65

5

B

6.20

5.80

PIN ONE

INDICATOR

(0.33)

1.75 MAX

R0.10

8° 0°

0.90

0.406

1

0.25

0.10

DETAIL A

SCALE: 2:1

4

1.27

0.51

0.33

0.50

0.25

SEATING PLANE

(1.04)

4.00

3.80

CMBA0.25

C

0.10 C

x 45°

GAGE PLANE

0.36

1.75

5.60

1.27

LAND PATTERN RECOMMENDATION

SEE DETAIL A

0.25

0.19

OPTION A - BEVEL EDGE

OPTION B - NO BEVEL EDGE

NOTES: UNLESS OTHERWISE SPECIFIED

A) THIS PACKAGE CONFORMS TO JEDEC MS-012, VARIATION AA, ISSUE C, B) ALL DIMENSIONS ARE IN MILLIMETERS. C) DIMENSIONS DO NOT INCLUDE MOLD FLASH OR BURRS. D) LANDPATTERN STANDARD: SOIC127P600X175-8M. E) DRAWING FILENAME: M08AREV13

Figure 21. 8-Pin Small Outline Package (SOP)

Package drawings are provided as a service to cust omers considering Fairchild components. Drawings may change in any manner without notice. Pl ease note the revision and/or date on t he drawing and contact a Fairchild S emic onductor representative to ver ify or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products.

Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings:

http://www.fairchildsem i.com/p ackagi ng/

.

SG6846B — Highly Integrated Green-Mode PWM Controller