Samsung BN44-00505A Schematic

VAC

C1

C6 R1

D1

D2 R2

C2

T1

D51

C51

R51

R52

U51

R54

R56

C52

D

P

S

PC1

PC1

C3

R

OCP

C

Y

BR1

R53

R55

L51

C53

C5

BR

GND

FB/OLP

S/OCP

VCC

D/ST

2

1

7

653 4

STR-W6000S

U1

R

C

C4

R

A

R

B

TC_STR-W6000S_1_R1

VOUT(+)

VOUT(-)

Products

V

DSS

(min.)

R

DS(ON)

(max.)

STR-W6051S

650 V

3.95 Ω

STR-W6052S

2.8 Ω

STR-W6053S

1.9 Ω

STR-W6072S

800 V

3.6 Ω

Products

P

OUT

(Open frame)

AC230V

AC85~265V

STR-W6051S

45 W

30 W

STR-W6052S

60 W

40 W

STR-W6053S

90 W

60 W

STR-W6072S

50 W

32 W

http://www.sanken-ele.co.jp/en/

Off-Line PWM Controllers with Integrated Power MOSFET

STR-W6000S Series

General Descriptions

The STR-W6000S series are power ICs for switching
power supplies, incorporating a MOSFET and a current
mode PWM controller IC.

The low standby power is accomplished by the
automatic switching between the PWM operation in
normal operation and the burst-oscillation under light
load conditions. The product achieves high
cost-performance power supply systems with few
external components.

Features

 Current Mode Type PWM Control
 Brown-In and Brown-Out function
 Auto Standby Function

No Load Power Consumption < 30 mW

 Operation Mode

Normal Operation ----------------------------- PWM Mode

Standby ---------------------------- Burst Oscillation Mode

 Random Switching Function
 Slope Compensation Function
 Leading Edge Blanking Function
 Bias Assist Function
 Audible Noise Suppression function during Standby

mode

 Protections

・Overcurrent Protection (OCP); Pulse-by-Pulse,

built-in compensation circuit to minimize OCP point

variation on AC input voltage

・Overload Protection (OLP); auto-restart
・Overvoltage Protection (OVP); auto-restart
・Thermal Shutdown Protection (TSD); auto-restart

Typical Application Circuit

Package

TO220F-6L

Not to Scale
Lineup

 Electrical Characteristics

f

 Output Power, P

* The output power is actual continues power that is measured at

= 67 kHz

OSC(AVG)

*

OUT

50 °C ambient. The peak output power can be 120 to 140 % of the
value stated here. Core size, ON Duty, and thermal design affect
the output power. It may be less than the value stated here.

Applications

 White goods
 Office automation equipment
 Industrial equipment

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 1
Aug. 07, 2014

STR-W6000S Series

CONTENTS

General Descriptions ----------------------------------------------------------------------- 1

1. Absolute Maximum Ratings --------------------------------------------------------- 3

2. Electrical Characteristics ------------------------------------------------------------ 4

3. Performance Curves ------------------------------------------------------------------ 5

3.1 Derating Curves --------------------------------------------------------------- 5

3.2 Ambient Temperature versus Power Dissipation Curves ------------ 6

3.3 MOSFET Safe Operating Area Curves ---------------------------------- 7

3.4 Transient Thermal Resistance Curves ----------------------------------- 8

4. Functional Block Diagram ----------------------------------------------------------- 9

5. Pin Configuration Definitions ------------------------------------------------------- 9

6. Typical Application Circuit -------------------------------------------------------- 10

7. Package Outline ----------------------------------------------------------------------- 11

8. Marking Diagram -------------------------------------------------------------------- 11

9. Operational Description ------------------------------------------------------------- 12

9.1 Startup Operation ----------------------------------------------------------- 12

9.2 Undervoltage Lockout (UVLO) ------------------------------------------- 13

9.3 Bias Assist Function --------------------------------------------------------- 13

9.4 Constant Output Voltage Control ---------------------------------------- 13

9.5 Leading Edge Blanking Function ---------------------------------------- 14

9.6 Random Switching Function ---------------------------------------------- 14

9.7 Automatic Standby Mode Function-------------------------------------- 14

9.8 Brown-In and Brown-Out Function ------------------------------------- 15

9.9 Overcurrent Protection Function (OCP) ------------------------------- 16

9.10 Overload Protection Function (OLP) ----------------------------------- 17

9.11 Overvoltage Protection (OVP) -------------------------------------------- 18

9.12 Thermal Shutdown Function (TSD) ------------------------------------- 18

10. Design Notes --------------------------------------------------------------------------- 18

10.1 External Components ------------------------------------------------------- 18

10.2 PCB Trace Layout and Component Placement ----------------------- 20

11. Pattern Layout Example ------------------------------------------------------------ 22

12. Reference Design of Power Supply ----------------------------------------------- 23
OPERATING PRECAUTIONS -------------------------------------------------------- 25
IMPORTANT NOTES ------------------------------------------------------------------- 26

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 2
Aug. 07, 2014

STR-W6000S Series

Parameter

Symbol

Test Conditions

Pins

Rating

Units

Notes

Drain Peak Current

(1)

I

DPEAK

Single pulse

1 – 3

5.0

A

STR-W6051S

7.0

STR-W6052S

7.5

STR-W6072S

9.5

STR-W6053S

Maximum Switching
Current

(2)

I

DMAX

Single pulse

Ta= ‒20 to 125°C

1 – 3

5.0

A

STR-W6051S

7.0

STR-W6052S

7.5

STR-W6072S

9.5

STR-W6053S

Avalanche Energy

(3)(4)

EAS

I

LPEAK

=2.0A

1 – 3

47

mJ

STR-W6051S

I

LPEAK

=2.3A

60

STR-W6072S

I

LPEAK

=2.3A

62

STR-W6052S

I

LPEAK

=2.7A

86

STR-W6053S

S/OCP Pin Voltage

V

OCP

3 – 5

− 2 to 6

V

VCC Pin Voltage

VCC

4 – 5

32

V

FB/OLP Pin Voltage

VFB

6 – 5

− 0.3 to 14

V

FB/OLP Pin Sink Current

IFB

6 – 5

1.0

mA

BR Pin Voltage

VBR

7 – 5

− 0.3 to 7

V

BR Pin Sink Current

IBR

7 – 5

1.0

mA

MOSFET Power
Dissipation

(5)

PD1

With infinite
heatsink

1 – 3

22.3

W

STR-W6051S

23.6

STR-W6052S

25.8

STR-W6072S

26.5

STR-W6053S

Without heatsink

1 – 3

1.3

W

Control Part Power
Dissipation

PD2

VCC×ICC

4 – 5

0.13

W

Internal Frame Temperature
in Operation

TF −

− 20 to 115

°C

Operating Ambient
Temperature

TOP

−

− 20 to 115

°C

Storage Temperature

T

stg

−

− 40 to 125

°C

Junction Temperature

Tch

− 150

°C

1. Absolute Maximum Ratings

 The polarity value for current specifies a sink as "+," and a source as "−," referencing the IC.
 Unless otherwise specified T

= 25 °C

A

(1)

Refer to 3.3 MOSFET Safe Operating Area Curves.

(2)

The maximum switching current is the drain current determined by the drive voltage of the IC and threshold voltage

(Vth) of the MOSFET.

(3)

Refer to Figure 3-2 Avalanche Energy Derating Coefficient Curve.

(4)

Single pulse, V

(5)

Refer to 3.2 Ta-PD1curves.

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 3
Aug. 07, 2014

= 99 V, L = 20 mH

DD

STR-W6000S Series

Parameter

Symbol

Test

Conditions

Pins

Min.

Typ.

Max.

Units

Notes

Power Supply Startup Operation

Operation Start Voltage

V

CC(ON)

4 – 5

13.8

15.3

16.8

V Operation Stop Voltage

(1)

V

CC(OFF)

4 – 5

7.3

8.1

8.9

V Circuit Current in Operation

I

CC(ON)

V

CC

= 12 V

4 – 5 − −

2.5

mA

Startup Circuit Operation
Voltage

V

ST(ON)

4 – 5 − 40 − V

Startup Current

I

STARTUP

V

CC

= 13.5 V

4 – 5

− 3.9

− 2.5

− 1.1

mA

Startup Current Biasing
Threshold Voltage

V

CC(BIAS)

I

CC

= − 100 µA

4 – 5

8.5

9.5

10.5

V

Normal Operation

Average Switching
Frequency

f

OSC(AVG)

1 – 5

60

67

74

kHz

Switching Frequency
Modulation Deviation

Δf

1 – 5 − 5 − kHz

Maximum ON Duty

D

MAX

1 – 5

63

71

79

%

Protection Function

Leading Edge Blanking Time

tBW − − 390 − ns

OCP Compensation
Coefficient

DPC

− − 18

−

mV/μs

OCP Compensation ON Duty

D

DPC

− − 36 − %

OCP Threshold Voltage at
Zero ON Duty

V

OCP(L)

3 – 5

0.70

0.78

0.86

V

OCP Threshold Voltage at
36% ON Duty

V

OCP(H)

V

CC

= 32 V

3 – 5

0.79

0.88

0.97

V

Maximum Feedback Current

I

FB(MAX)

V

CC

= 12 V

6 – 5

− 340

− 230

− 150

µA

Minimum Feedback Current

I

FB(MIN)

6 – 5

− 30

− 15

− 7

µA

FB/OLP pin Oscillation Stop
Threshold Voltage

V

FB(STB)

6 – 5

0.85

0.95

1.05

V

OLP Threshold Voltage

V

FB(OLP)

6 – 5

7.3

8.1

8.9

V

OLP Operation Current

I

CC(OLP)

V

CC

= 12 V

4 – 5 − 300 − µA

OLP Delay Time

t

OLP

6 – 5

54

68

82

ms

FB/OLP Pin Clamp Voltage

V

FB(CLAMP)

6 – 5

11

12.8

14

V

Brown-In Threshold Voltage

V

BR(IN)

V

CC

= 32 V

7 – 5

5.2

5.6 6 V

Brown-Out Threshold
Voltage

V

BR(OUT)

V

CC

= 32 V

7 – 5

4.45

4.8

5.15

V

BR Pin Clamp Voltage

V

BR(CLAMP)

V

CC

= 32 V

7 – 5 6 6.4 7 V

BR Function Disabling
Threshold

V

BR(DIS)

V

CC

= 32 V

7 – 5

0.3

0.48

0.7

V

OVP Threshold Voltage

V

CC(OVP)

4 – 5

26

29

32

V

Thermal Shutdown Operating
Temperature

T

j(TSD)

− 130 − −

°C

2. Electrical Characteristics

 The polarity value for current specifies a sink as "+," and a source as "−," referencing the IC.

 Unless otherwise specified, T

= 25 °C, VCC = 18 V

A

(1)

V

CC(BIAS)

> V

CC(OFF)

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 4
Aug. 07, 2014

always.

STR-W6000S Series

Parameter

Symbol

Test

Conditions

Pins

Min.

Typ.

Max.

Units

Notes

MOSFET

Drain-to-Source Breakdown
Voltage

V

DSS

8 – 1

650 − −

V

STR-W605×S

800 − −

STR-W6072S

Drain Leakage Current

I

DSS

8 – 1 − −

300

μA

On Resistance

R

DS(ON)

8 – 1

− − 3.95

Ω

STR-W6051S

− − 3.6

STR-W6072S

− − 2.8

STR-W6052S

− − 1.9

STR-W6053S

Switching Time

tf

8 – 1 − −

250

ns

Thermal Resistance

Channel to Frame Thermal
Resistance

(2)

θ

ch-F

−

− − 2.63

°C/W

STR-W6051S

− − 2.26

STR-W6052S

− − 2.03

STR-W6072S

− − 1.95

STR-W6053S

Figure 3-1 SOA Temperature Derating Coefficient Curve

Figure 3-2 Avalanche Energy Derating Coefficient Curve

0

20

40

60

80

100

0 25 50 75 100 125

Safe Operating Area

Temperature Derating Coefficient (%)

Channel Temperature, Tch (°C)

0

20

40

60

80

100

25 50 75 100 125 150

E

AS

Temperature Derating Coefficient (%)

Channel Temperature, Tch (°C)

(2)

The thermal resistance between the channels of the MOSFET and the internal frame.

3. Performance Curves

3.1 Derating Curves

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 5
Aug. 07, 2014

STR-W6000S Series

 STR-W6051S

 STR-W6052S

 STR-W6053S

 STR-W6072S

0

5

10

15

20

25

30

0 25 50 75 100 125 150

Power Dissipation, P

D1

(W)

Ambient Temperature, TA(°C )

With infinite heatsink

PD1=23.6W

PD1=1.3W

Without heatsink

PD1_STR-W6052S_R1

0

5

10

15

20

25

30

0 25 50 75 100 125 150

Power Dissipation, P

D1

(W)

Ambient Temperature, TA(°C )

With infinite heatsink

PD1=26.5W

PD1=1.3W

Without heatsink

PD1_STR-W6053S_R1

0

5

10

15

20

25

30

0 25 50 75 100 125 150

Power Dissipation, P

D1

(W)

Ambient Temperature, TA(°C )

With infinite heatsink

PD1=25.8W

PD1=1.3W

Without heatsink

PD1_STR-W6072S_R1

0

5

10

15

20

25

30

0 25 50 75 100 125 150

Power Dissipation, P

D1

(W)

Ambient Temperature, TA(°C )

With infinite heatsink

PD1=22.3W

PD1=1.3W

Without heatsink

PD1_STR-W6051S_R1

3.2 Ambient Temperature versus Power Dissipation Curves

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 6
Aug. 07, 2014

STR-W6000S Series

 STR-W6051S

 STR-W6052S

 STR-W6053S

 STR-W6072S

0.01

0.1

1

10

1 10 100 1000

Drain Current, I

D

(A)

Drain-to-Source Voltage (V)

SOA_STR-W6052S_R1

0.01

0.1

1

10

100

1 10 100 1000

Drain Current, I

D

(A)

Drain-to-Source Voltage (V)

SOA_STR-W6053S_R1

0.01

0.1

1

10

100

1 10 100 1000

Drain Current, I

D

(A)

Drain-to-Source Voltage (V)

SOA_STR-W6072S_R1

0.1ms

1ms

0.1ms

1ms

0.1ms

1ms

0.01

0.1

1

10

1 10 100 1000

Drain Current, I

D

(A)

Drain-to-Source Voltage (V)

0.1ms

1ms

3.3 MOSFET Safe Operating Area Curves

 When the IC is used, the safe operating area curve should be multiplied by the temperature derating coefficient

derived from Figure 3-1.

 The broken line in the safe operating area curve is the drain current curve limited by on-resistance.
 Unless otherwise specified, TA = 25 °C, Single pulse

SOA_STR-W6051S_R1

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 7
Aug. 07, 2014

STR-W6000S Series

 STR-W6051S

 STR-W6052S

 STR-W6053S

 STR-W6072S

0.01

0.1

1

10

Transient Thermal Resistance

θch-c (°C/W)

Time (s)

TR_STR-W6051S_R1

0.01

0.1

1

10

Transient Thermal Resistance

θch-c (°C/W)

Time (s)

TR_STR-W6052S_R1

0.001

0.01

0.1

1

10

Transient Thermal Resistance

θch-c (°C/W)

Time (s)

TR_STR-W6053S_R1

0.001

0.01

0.1

1

10

Transient Thermal Resistance

θch-c (°C/W)

Time (s)

TR_STR-W6072S_R1

1µ 10µ 100µ 1m 10m 100m

1µ 10µ 100µ 1m 10m 100m

1µ 10µ 100µ 1m 10m 100m

1µ 10µ 100µ 1m 10m 100m

3.4 Transient Thermal Resistance Curves

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 8
Aug. 07, 2014

STR-W6000S Series

UVLO OVP TSDREG

Brown-in

Brown-out

PWM OSC

OLP

Feedback

control

Slope

compensation

LEB

Drain peak current

compensation

OCP

Startup

DRV

VREG

6.4V

12.8V

7V VCC

VCC

BR

FB/OLP

D/ST

S/OCP

GND

1

3

5

6

7

4

SRQ

BD_STR-W6000S_R1

1

6

4

D/ST

S/OCP
VCC
GND

FB/OLP
BR

(LF2003)

3

5

7

Pin

Name

Descriptions

1

D/ST

MOSFET drain and startup current input

2

−

(Pin removed)

3

S/OCP

MOSFET source and overcurrent protection
(OCP) signal input

4

VCC

Power supply voltage input for control part and
overvoltage protection (OVP) signal input

5

GND

Ground

6

FB /OLP

Constant voltage control signal input and over
load protection (OLP) signal input

7

BR

Brown-In and Brown-Out detection voltage input

4. Functional Block Diagram

5. Pin Configuration Definitions

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 9
Aug. 07, 2014

STR-W6000S Series

BR

GND

FB/OLP

S/OCP

VCC

D/ST

2

1

7

653 4

STR-W6000S

VAC

C1

C6 R1

D1

BR1

R2

C2

T1

D

P

PC1

C3

R

OCP

C

Y

CRD clamp snubber

C5

C（CR）
damper snubber

D2

C4

R

C

R

B

R

A

D51

C51

R51

R52

U51

R54

R56

C52

S

PC1

R53

R55

L51

C53

VOUT

(+)

TC_STR-W6000S_2_R1

(-)

BR

GND

FB/OLP

S/OCP

VCC

D/ST

2

1

7

653 4

STR-W6000S

VAC

C1

C6 R1

D1

BR1

R2

C2

T1

D

P

PC1

C3

R

OCP

C

Y

CRD clamp snubber

C5

C（RC）
damper snubber

D2

D51

C51

R51

R52

U51

R54

R56

C52

S

PC1

R53

R55

L51

C53

VOUT

(+)

TC_STR-W6000S_3_R1

(-)

6. Typical Application Circuit

 The following drawings show circuits enabled and disabled the Brown-In/Brown-Out function.
 The PCB traces D/ST pins should be as wide as possible, in order to enhance thermal dissipation.
 In applications having a power supply specified such that D/ST pin has large transient surge voltages, a clamp

snubber circuit of a capacitor-resistor-diode (CRD) combination should be added on the primary winding P, or a
damper snubber circuit of a capacitor (C) or a resistor-capacitor (RC) combination should be added between the
D/ST pin and the S/OCP pin.

Figure 6-1 Typical application circuit (enabled Brown-In/Brown-Out function, DC line detection)

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 10
Aug. 07, 2014

Figure 6-2 Typical application circuit (disabled Brown-In/Brown-Out function)

STR-W6000S Series

1 2 3

4 567

10.0 ±0.2

0.5

7.9±0.2

4±0.2

16.9±0.3

2.8

6-0. 74±0.15

6-0. 65

-0.1

+0.2

6×P 1.27±0.1 5=7. 62±0.15

4.2± 0.2

2.8± 0.2

φ

3.2±0.2

2.6± 0.1

10.4±0.5

R-en d

(5.4)

5.0±0.5

0.45

-0.1

+0.2

5.08 ±0.6

(

2

­R

1

)

0.5

0.5

0.5 0.5

Gate burr

（Dimensions from root）

（Dimensions from root）

(Dimensions between tips)

Fron t view Side view

NOTES:

1) Dimension is in millimeters

2) Leadform: LF No.2003

3) Gate burr indicates protrusion of 0.3 mm (max).

4) Pb-free. Device composition compliant with the RoHS directive

2

1

7

Part Number

STR

W 6 0 × × S

Y M D D X

Lot Number

Y is the last digit of the year (0 to 9)
M is the month (1 to 9, O, N or D)
DD is a day (01 to 31)
X is the Sanken Control Symbol

3

7. Package Outline

 TO220F-6L
 The pin 2 is removed to provide greater creepage and clearance isolation between the high voltage pin (pin 1:

D/ST) and the low voltage pin (pin 3: S/OCP).

8. Marking Diagram

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 11
Aug. 07, 2014

STR-W6000S Series

.)(minVV.)(maxV

)OVP(CCCC)BIAS(CC



⇒10.5 (V)

CCV

26 (V)

(1)

STRATUP

)INT(CC)ON(CC

START

I

VV

×C2t

－



(2)

VAC

C1

D2 R2

C2

T1

D

P

BR1

VCC

GND

D/ST

1

5

4

U1

V

D

BR

7

V

CC(ON)

VCC pin

voltage

Drain current,

I

D

t

START

V

CC(ON)

VCC pin

voltage

Drain current,

I

D

t

START

BR pin

voltage

V

BR(IN)

V

CC(OFF)

9. Operational Description

 All of the parameter values used in these descriptions

are typical values, unless they are specified as
minimum or maximum.

 With regard to current direction, "+" indicates sink

current (toward the IC) and "–" indicates source
current (from the IC).

9.1 Startup Operation

Figure 9-1 shows the circuit around IC. Figure 9-2

shows the start up operation.

The IC incorporates the startup circuit. The circuit is
connected to D/ST pin. When D/ST pin voltage reaches
to Startup Circuit Operation Voltage V
startup circuit starts operation.

During the startup process, the constant current,
I
VCC pin voltage increases to V

= − 2.5 mA, charges C2 at VCC pin. When

STARTUP

CC(ON)

control circuit starts operation.

During the IC operation, the voltage rectified the
auxiliary winding voltage, VD, of Figure 9-1 becomes a
power source to the VCC pin. After switching operation
begins, the startup circuit turns off automatically so that
its current consumption becomes zero.

The approximate value of auxiliary winding voltage is
about 15 V to 20 V, taking account of the winding turns
of D winding so that VCC pin voltage becomes
Equation (1) within the specification of input and output
voltage variation of power supply.

= 40 V, the

ST(ON)

= 15.3 V, the

 With Brown-In / Brown-Out function

When BR pin voltage is more than V
and less than V

= 5.6 V, the Bias Assist Function

BR(IN)

BR(DIS)

= 0.48 V

(refer to Section 9.3) is disabled. Thus, VCC pin
voltage repeats increasing to V
V
becomes V

(shown in Figure 9-3). When BR pin voltage

CC(OFF)

or more, the IC starts switching

BR(IN)

and decreasing to

CC(ON)

operation.

Figure 9-1 VCC pin peripheral circuit

(Without Brown-In / Brown-Out)

The oscillation start timing of IC depends on
Brown-In / Brown-Out function (refer to Section 9.8).

Figure 9-2 Startup operation

(Without Brown-In / Brown-Out)

 Without Brown-In / Brown-Out function (BR pin

voltage is V

When VCC pin voltage increases to V

= 0.48 V or less)

BR(DIS)

CC(ON)

, the IC

starts switching operation, As shown in Figure 9-2.

The startup time of IC is determined by C2 capacitor

value. The approximate startup time t

START

(shown in

Figure 9-2) is calculated as follows:

where,

t

START

V

CC(INT)

: Startup time of IC (s)
: Initial voltage on VCC pin (V)

Figure 9-3 Startup operation

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 12
Aug. 07, 2014

(With Brown-In / Brown-Out)

STR-W6000S Series

Circuit current, I

CC

I

CC（ON

）

V

CC（OFF

）

V

CC（ON

）

VCC pin
voltage

StartStop

IC starts operation

VCC pin

voltage

V

CC(ON)

V

CC(BIAS)

V

CC(OFF)

Startup failure

Startup success

Target operating
voltage

Time

Bias assist period

Increase with rising of
output voltage

PC1

C3

R

OCP

3 5 6

S/OCP

FB/OLP

GND

U1

I

FB

V

ROCP

V

SC

FB Comparator

Drain current,

I

D

+

-

Voltage on both
sides of R

OCP

V

ROCP

Target voltage including
Slope Compensation

9.2 Undervoltage Lockout (UVLO)

Figure 9-4 shows the relationship of VCC pin voltage
and circuit current ICC. When VCC pin voltage decreases
to V

= 8.1 V, the control circuit stops operation by

CC(OFF)

UVLO (Undervoltage Lockout) circuit, and reverts to
the state before startup.

Figure 9-4 Relationship between

VCC pin voltage and ICC

9.3 Bias Assist Function

Figure 9-5 shows VCC pin voltage behavior during
the startup period.

After VCC pin voltage increases to V
at startup, the IC starts the operation. Then circuit
current increases and VCC pin voltage decreases. At the
same time, the auxiliary winding voltage VD increases in
proportion to output voltage. These are all balanced to
produce VCC pin voltage.

CC(ON)

= 15.3 V

biasing voltage, V

= 9.5 V. While the Bias Assist

CC(BIAS)

function is activated, any decrease of the VCC pin
voltage is counteracted by providing the startup current,
I

, from the startup circuit. Thus, the VCC pin

STARTUP

voltage is kept almost constant.

By the Bias Assist function, the value of C2 is
allowed to be small and the startup time becomes shorter.
Also, because the increase of VCC pin voltage becomes
faster when the output runs with excess voltage, the
response time of the OVP function becomes shorter.

It is necessary to check and adjust the startup process
based on actual operation in the application, so that poor
starting conditions may be avoided.

9.4 Constant Output Voltage Control

The IC achieves the constant voltage control of the
power supply output by using the current-mode control
method, which enhances the response speed and
provides the stable operation.

The FB/OLP pin voltage is internally added the slope
compensation at the feedback control (refer to Section 4
Functional Block Diagram), and the target voltage, VSC,
is generated. The IC compares the voltage, V
current detection resistor with the target voltage, VSC, by
the internal FB comparator, and controls the peak value
of V

so that it gets close to VSC, as shown in Figure

ROCP

9-6 and Figure 9-7.

ROCP

, of a

Figure 9-6 FB/OLP pin peripheral circuit

Figure 9-5 VCC pin voltage during startup period

The surge voltage is induced at output winding at
turning off a power MOSFET. When the output load is
light at startup, the surge voltage causes the unexpected
feedback control. This results the lowering of the output
power and VCC pin voltage. When the VCC pin voltage
decreases to V
operation and a startup failure occurs. In order to prevent
this, the Bias Assist function is activated when the VCC
pin voltage decreases to the startup current threshold

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 13
Aug. 07, 2014

= 8.1 V, the IC stops switching

CC(OFF)

Figure 9-7 Drain current, ID, and FB comparator

operation in steady operation

STR-W6000S Series

t

ON1

Target voltage
without Slope Compensation

t

ON2

T T T

Normal

operation

Standby

operation

Normal

operation

Burst oscillation

Output current,

I

OUT

Drain current,

I

D

Below several kHz

 Light load conditions

When load conditions become lighter, the output

voltage, V

, increases. Thus, the feedback current

OUT

from the error amplifier on the secondary-side also

increases. The feedback current is sunk at the FB/OLP

pin, transferred through a photo-coupler, PC1, and the

FB/OLP pin voltage decreases. Thus, VSC decreases,

and the peak value of V

is controlled to be low,

ROCP

and the peak drain current of ID decreases.

This control prevents the output voltage from

increasing.
 Heavy load conditions

When load conditions become greater, the IC

performs the inverse operation to that described above.

Thus, VSC increases and the peak drain current of ID

increases.

This control prevents the output voltage from

decreasing.

In the current mode control method, when the drain
current waveform becomes trapezoidal in continuous
operating mode, even if the peak current level set by the
target voltage is constant, the on-time fluctuates based
on the initial value of the drain current.

This results in the on-time fluctuating in multiples of
the fundamental operating frequency as shown in Figure
9-8. This is called the subharmonics phenomenon.

In order to avoid this, the IC incorporates the Slope
Compensation function. Because the target voltage is
added a down-slope compensation signal, which reduces
the peak drain current as the on-duty gets wider relative
to the FB/OLP pin signal to compensate VSC, the
subharmonics phenomenon is suppressed.

Even if subharmonic oscillations occur when the IC
has some excess supply being out of feedback control,
such as during startup and load shorted, this does not
affect performance of normal operation.

In peak-current-mode control method, there is a case
that the power MOSFET turns off due to unexpected
response of FB comparator or overcurrent protection
circuit (OCP) to the steep surge current in turning on a
power MOSFET.

In order to prevent this response to the surge voltage
in turning-on the power MOSFET, the Leading Edge
Blanking, t

= 390 ns is built-in. During tBW, the OCP

BW

threshold voltage becomes about 1.7 V which is higher
than the normal OCP threshold voltage (refer to Section

9.9).

9.6 Random Switching Function

The IC modulates its switching frequency randomly
by superposing the modulating frequency on f

OSC(AVG)

in
normal operation. This function reduces the conduction
noise compared to others without this function, and
simplifies noise filtering of the input lines of power
supply.

9.7 Automatic Standby Mode Function

Automatic standby mode is activated automatically
when the drain current, ID, reduces under light load
conditions, at which ID is less than 15 % to 20 % of the
maximum drain current (it is in the OCP state). The
operation mode becomes burst oscillation, as shown in
Figure 9-9. Burst oscillation mode reduces switching
losses and improves power supply efficiency because of
periodic non-switching intervals.

Figure 9-9 Auto Standby mode timing

Generally, to improve efficiency under light load
conditions, the frequency of the burst oscillation mode

Figure 9-8 Drain current, ID, waveform

in subharmonic oscillation

becomes just a few kilohertz. Because the IC suppresses
the peak drain current well during burst oscillation mode,
audible noises can be reduced.

If the VCC pin voltage decreases to V

CC(BIAS)

= 9.5 V

during the transition to the burst oscillation mode, the

9.5 Leading Edge Blanking Function

The IC uses the peak-current-mode control method

for the constant voltage control of output.

Bias Assist function is activated and stabilizes the
Standby mode operation, because I

STARTUP

is provided to
the VCC pin so that the VCC pin voltage does not
decrease to V

CC(OFF)

.

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Aug. 07, 2014

STR-W6000S Series

BR pin voltage

V

BR(IN)

V

BR(OUT)

t

OLP

Drain current,

I

D

V

DC

U1

BR

7

C4R

C

GND

5

R

B

R

A

V

AC

BR1

C1



















C

BA

)TH(BR)OP(DC

R

RR

1VV

(3)

However, if the Bias Assist function is always
activated during steady-state operation including
standby mode, the power loss increases. Therefore, the
VCC pin voltage should be more than V

CC(BIAS)

, for
example, by adjusting the turns ratio of the auxiliary
winding and secondary winding and/or reducing the
value of R2 in Figure 10-2 (refer to Section 10.1
Peripheral Components for a detail of R2).

9.8 Brown-In and Brown-Out Function

This function stops switching operation when it
detects low input line voltage, and thus prevents
excessive input current and overheating.

This function turns on and off switching operation
according to the BR pin voltage detecting the AC input
voltage. When BR pin voltage becomes more than
V

and the drain currnet.

pin voltage is V
voltage decreases from steady-state and the BR pin
voltage falls to V
Delay Time, t
operation.

voltage reaches V
state that the VCC pin voltage is V
starts switching operation.

unnecessary, connect the BR pin trace to the GND pin
trace so that the BR pin voltage is V

stop period in burst oscillation mode. When the BR pin
voltage falls to V
and the sum of switching operation period becomes
t

= 0.48 V, this function is activated.

BR(DIS)

Figure 9-10 shows waveforms of the BR pin voltage

Even if the IC is in the operating state that the VCC

or more, when the AC input

CC(OFF)

= 4.8 V or less for the OLP

BR(OUT)

= 68 ms, the IC stops switching

OLP

When the AC input voltage increases and the BR pin

= 5.6 V or more in the operating

BR(IN)

or more, the IC

CC(OFF)

In case the Brown-In and Brown-Out function is

or less.

BR(DIS)

This function is disabled during switching operation

or less in burst oscillation mode

BR(OUT)

= 68 ms or more, the IC stops switching operation.

OLP

There are two types of detection method as follows:

9.8.1 DC Line Detection

Figure 9-11 shows BR pin peripheral circuit of DC
line detection. There is a ripple voltage on C1
occurring at a half period of AC cycle. In order to
detect each peak of the ripple voltage, the time
constant of RC and C4 should be shorter than a half
period of AC cycle.

Since the cycle of the ripple voltage is shorter than
t

, the switching operation does not stop when only

OLP

the bottom part of the ripple voltage becomes lower
than V

Thus it minimizes the influence of load conditions
on the voltage detection.

The components around BR pin:
・ RA and RB are a few megohms. Because of high

voltage applied and high resistance, it is

recommended to select a resistor designed against

electromigration or use a combination of resistors

in series for that to reduce each applied voltage,

according to the requirement of the application.

・ RC is a few hundred kilohms
・ C4 is 470 pF to 2200 pF for high frequency noise

reduction

Neglecting the effect of both input resistance and
forward voltage of rectifier diode, the reference value
of C1 voltage when Brown-In and Brown-Out
function is activated is calculated as follows:

.

BR(OUT)

Figure 9-11 DC line detection

Figure 9-10 BR pin voltage and drain current waveforms

where,

V

: C1 voltage when Brown-In and

V

DC(OP)

BR(TH)

Brown-Out function is activated

: Any one of threshold voltage of BR pin

(see Table 9-1)

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 15
Aug. 07, 2014

STR-W6000S Series

Parameter

Symbol

Value

(Typ.)

Brown-In Threshold Voltage

V

BR(IN)

5.6 V

Brown-Out Threshold Voltage

V

BR(OUT)

4.8 V

)OP(DCRMS)OP(AC

V

2

1

V 

(4)

V

DC

U1

BR

7

C4R

C

GND

5

R

B

R

A

V

AC

BR1

C1

VCC

4

R

S























C

BA

)TH(BRRMS)OP(AC

R

RR

1V

2

V

(5)

Surge pulse voltage width at turning on

t

BW

V

OCP

’

Table 9-1 BR pin threshold voltage

V

can be expressed as the effective value of AC

DC(OP)

input voltage using Equation (4).

RA, RB, RC and C4 should be selected based on actual

operation in the application.

9.8.2 AC Line Detection

Figure 9-12 shows BR pin peripheral circuit of AC

line detection.

In order to detect the AC input voltage, the time
constant of RC and C4 should be longer than the
period of AC cycle. Thus the response of BR pin
detection becomes slow compared with the DC line
detection.

This method detects the AC input voltage, and thus
it minimizes the influence from load conditions.

Neglecting the effect of input resistance is zero, the
reference effective value of AC input voltage when
Brown-In and Brown-Out function is activated is
calculated as follows:

where,

V

AC(OP)RMS

:The effective value of AC input voltage

when Brown-In and Brown-Out function
is activated

V

:Any one of threshold voltage of BR pin

BR(TH)

(see Table 9-1)

RA, RB, RC and C4 should be selected based on
actual operation in the application.

9.9 Overcurrent Protection Function

(OCP)

Overcurrent Protection Function (OCP) detects each

drain peak current level of a power MOSFET on
pulse-by-pulse basis, and limits the output power when
the current level reaches to OCP threshold voltage.

During Leading Edge Blanking Time (tBW), OCP is

disabled. When power MOSFET turns on, the surge
voltage width of S/OCP pin should be less than tBW, as
shown in Figure 9-13. In order to prevent surge voltage,
pay extra attention to R

).

In addition, if a C (RC) damper snubber of Figure

9-14 is used, reduce the capacitor value of damper
snubber.

trace layout (refer to Section

OCP

Figure 9-12 AC line detection

The components around BR pin:
・ RA and RB are a few megohms. Because of high

voltage applied and high resistance, it is
recommended to select a resistor designed against
electromigration or use a combination of resistors
in series for that to reduce each applied voltage,
according to the requirement of the application.

・ RC is a few hundred kilohms
・ RS must be adjusted so that the BR pin voltage is

more than V
voltage is V

・ C4 is 0.22 μF to 1 μF for averaging AC input

voltage and high frequency noise reduction.

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 16
Aug. 07, 2014

BR(DIS)

CC(OFF)

= 0.48 V when the VCC pin

= 8.1 V

Figure 9-13 S/OCP pin voltage

STR-W6000S Series

C1

T1

D51

R

OCP

U1

C51

C（RC）
Damper snubber

1

D/ST

S/OCP

3

C（RC）
Damper snubber

OCP Threshold Voltage after

compensation, V

OCP

'

ON Duty (%)

D

DPC

V

OCP(L)

0

100

V

OCP(H)

0.5

1.0

50

D

MAX

ONTimeDPCV'V

)L(OCPOCP



)AVG(OSC

)L(OCP

f

ONDuty

DPCV 

(6)

PC1

C3

6

FB/OLP

U1

VCC

4

GND

3

D2

R2

C2

D

VCC pin voltage

FB/OLP pin voltage

Drain current,

I

D

V

CC(OFF)

V

FB(OLP)

t

OLP

V

CC(ON)

Non-switching interval

t

OLP

where,
V

: OCP Threshold Voltage at Zero ON Duty

OCP(L)

DPC: OCP Compensation Coefficient
ONTime: On-time of power MOSFET
ONDuty: On duty of power MOSFET
f

OSC(AVG)

: Average PWM Switching Frequency

Figure 9-14 Damper snubber

< Input Compensation Function >

ICs with PWM control usually have some propagation
delay time. The steeper the slope of the actual drain
current at a high AC input voltage is, the larger the
detection voltage of actual drain peak current is,
compared to V

. Thus, the peak current has some

OCP

variation depending on the AC input voltage in OCP
state.

In order to reduce the variation of peak current in
OCP state, the IC incorporates a built-in Input
Compensation function.

The Input Compensation Function is the function of
correction of OCP threshold voltage depending with AC
input voltage, as shown in Figure 9-15.

When AC input voltage is low (ON Duty is broad),
the OCP threshold voltage is controlled to become high.
The difference of peak drain current become small
compared with the case where the AC input voltage is
high (ON Duty is narrow).

The compensation signal depends on ON Duty. The
relation between the ON Duty and the OCP threshold
voltage after compensation V

' is expressed as

OCP

Equation (6). When ON Duty is broader than 36 %, the
V

' becomes a constant value V

OCP

OCP(H)

= 0.88 V

9.10 Overload Protection Function (OLP)

Figure 9-16 shows the FB/OLP pin peripheral circuit,
and Figure 9-17 shows each waveform for OLP
operation.

Figure 9-16 FB/OLP pin peripheral circuit

Figure 9-17 OLP operational waveforms

Figure 9-15 Relationship between ON Duty and Drain

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 17
Aug. 07, 2014

Current Limit after compensation

When the peak drain current of ID is limited by OCP
operation, the output voltage, V
feedback current from the secondary photo-coupler
becomes zero. Thus, the feedback current, IFB, charges

, decreases and the

OUT

C3 connected to the FB/OLP pin and the FB/OLP pin
voltage increases. When the FB/OLP pin voltage

STR-W6000S Series



)NORMAL(CC

)NORMAL(OUT

OUT(OVP)

V

V

V

29 (V)

(7)

VCC pin voltage

Drain current,

I

D

V

CC(OFF)

V

CC(ON)

V

CC(OVP)

VAC

C1

C6 R1

D1

D2 R2

C2

T1

D

P

PC1

C3

R

OCP

BR1

C5

BR

GND

FB/OLP

S/OCP

VCC

D/ST

2

1

7

653 4

U1

R

C

C4

R

A

R

B

CRD clamp snubber

C(RC)
damper
snubber

increases to V
time, t

= 68 ms or more, the OLP function is

OLP

= 8.1 V or more for the OLP delay

FB(OLP)

activated, the IC stops switching operation.

During OLP operation, Bias Assist Function is

disabled. Thus, VCC pin voltage decreases to V

CC(OFF)

the control circuit stops operation. After that, the IC
reverts to the initial state by UVLO circuit, and the IC
starts operation when VCC pin voltage increases to
V

by startup current. Thus the intermittent

CC(ON)

operation by UVLO is repeated in OLP state.

This intermittent operation reduces the stress of parts
such as power MOSFET and secondary side rectifier
diode. In addition, this operation reduces power
consumption because the switching period in this
intermittent operation is short compared with oscillation
stop period. When the abnormal condition is removed,
the IC returns to normal operation automatically.

9.11 Overvoltage Protection (OVP)

When a voltage between VCC pin and GND pin
increases to V
activated, the IC stops switching operation. During OVP
operation, the Bias Assist function is disabled, the
intermittent operation by UVLO is repeated (refer to
Section 9.10). When the fault condition is removed, the
IC returns to normal operation automatically (refer to
Figure 9-18).

In case the VCC pin voltage is provided by using
auxiliary winding of transformer, the overvoltage
conditions such as output voltage detection circuit open
can be detected because the VCC pin voltage is
proportional to output voltage. The approximate value of
output voltage V
by using Equation (7).

= 29 V or more, OVP function is

CC(OVP)

OUT(OVP)

in OVP condition is calculated

9.12 Thermal Shutdown Function (TSD)

When the temperature of control circuit increases to

T

= 130 °C or more, Thermal Shutdown function

j(TSD)

(TSD) is activated, the IC stops switching operation.

,

During TSD operation, the Bias Assist function is
disabled, the intermittent operation by UVLO is repeated
(refer to Section 9.10). When the fault condition is
removed and the temperature decreases to less than
T

, the IC returns to normal operation automatically.

j(TSD)

10. Design Notes

10.1 External Components

Take care to use properly rated, including derating as

necessary and proper type of components.

Figure 10-1 The IC peripheral circuit

 Input and Output Electrolytic Capacitor

Apply proper derating to ripple current, voltage, and
temperature rise. Use of high ripple current and low

where,
V

OUT(NORMAL)

V

CC(NORMAL)

: Output voltage in normal operation

: VCC pin voltage in normal operation

impedance types, designed for switch mode power
supplies, is recommended.

 S/OCP Pin Peripheral Circuit

In Figure 10-1, R

is the resistor for the current

OCP

detection. A high frequency switching current flows
to R

, and may cause poor operation if a high

OCP

inductance resistor is used. Choose a low inductance
and high surge-tolerant type.

 VCC Pin Peripheral Circuit

The value of C2 in Figure 10-1 is generally

Figure 9-18 OVP operational waveforms

recommended to be 10µ to 47μF (refer to Section 9.1
Startup Operation, because the startup time is
determined by the value of C2).
In actual power supply circuits, there are cases in
which the VCC pin voltage fluctuates in proportion to
the output current, I

(see Figure 10-2), and the

OUT

Overvoltage Protection function (OVP) on the VCC

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 18
Aug. 07, 2014

STR-W6000S Series

Without R2

With R2

VCC pin voltage

Output current, I

OUT

D51

C51

R51

R52

U51

R54

R56

C52

S

PC1

R53

R55

L51

C53

VOUT

(-)

T1

(+)

pin may be activated. This happens because C2 is

charged to a peak voltage on the auxiliary winding D,

which is caused by the transient surge voltage coupled

from the primary winding when the power MOSFET

turns off.

For alleviating C2 peak charging, it is effective to add

some value R2, of several tenths of ohms to several

ohms, in series with D2 (see Figure 10-1). The

optimal value of R2 should be determined using a

transformer matching what will be used in the actual

application, because the variation of the auxiliary

winding voltage is affected by the transformer

structural design.

Figure 10-2 Variation of VCC pin voltage and power

・ A damper snubber circuit of a capacitor (C) or a

resistor-capacitor (RC) combination should be
added between the D/ST pin and the S/OCP pin.
In case the damper snubber circuit is added, this
components should be connected near D/ST pin
and S/OCP pin.

 Peripheral circuit of secondary side shunt regulator

Figure 10-3 shows the secondary side detection circuit
with the standard shunt regulator IC (U51).
C52 and R53 are for phase compensation. The value
of C52 and R53 are recommended to be around

0.047μF to 0.47μF and 4.7 kΩ to 470 kΩ, respectively.
They should be selected based on actual operation in
the application.

 FB/OLP Pin Peripheral Circuit

 BR pin peripheral circuit

Because RA and RB (see Figure 10-1) are applied high
voltage and are high resistance, the following should be
considered according to the requirement of the
application:

See the section 9.8 about the AC input voltage
detection function and the components around BR pin.
When the detection resistor (RA, RB, RC) value is
decreased and the C4 value is increased to prevent
unstable operation resulting from noise at the BR pin,
pay attention to the low efficiency and the slow
response of BR pin.

 Snubber Circuit

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 19
Aug. 07, 2014

C3 is for high frequency noise reduction and phase

compensation, and should be connected close to these

pins. The value of C3 is recommended to be about

2200 pF to 0.01µF, and should be selected based on

actual operation in the application.

▫ Select a resistor designed against electromigration,

or

▫ Use a combination of resistors in series for that to

reduce each applied voltage

In case the surge voltage of VDS is large, the circuit

should be added as follows (see Figure 10-1);

・ A clamp snubber circuit of a capacitor-resistor-

diode (CRD) combination should be added on the
primary winding P.

Figure 10-3 Peripheral circuit of secondary side shunt

regulator (U51)

 Transformer

Apply proper design margin to core temperature rise
by core loss and copper loss.
Because the switching currents contain high
frequency currents, the skin effect may become a
consideration.
Choose a suitable wire gauge in consideration of the
RMS current and a current density of 4 to 6 A/mm2.
If measures to further reduce temperature are still
necessary, the following should be considered to
increase the total surface area of the wiring:

▫ Increase the number of wires in parallel.
▫ Use litz wires.
▫ Thicken the wire gauge.

In the following cases, the surge of VCC pin
voltage becomes high.
▫ The surge voltage of primary main winding, P, is

high (low output voltage and high output current
power supply designs)

▫ The winding structure of auxiliary winding, D, is

susceptible to the noise of winding P.

STR-W6000S Series

Margin tape

Margin tape

Margin tape

Margin tape

P1 S1 P2 S2 D

P1 S1 D S2 S1 P2

Winding structural example (a)

Winding structural example (b)

Bobbin Bobbin

When the surge voltage of winding D is high, the

VCC pin voltage increases and the Overvoltage

Protection function (OVP) may be activated. In

transformer design, the following should be

considered;

▫ The coupling of the winding P and the secondary

output winding S should be maximized to reduce the
leakage inductance.

▫ The coupling of the winding D and the winding S

should be maximized.

▫ The coupling of the winding D and the winding P

should be minimized.

In the case of multi-output power supply, the
coupling of the secondary-side stabilized output

winding, S1, and the others (S2, S3…) should be
maximized to improve the line-regulation of those
outputs.

Figure 10-4 shows the winding structural examples

of two outputs.

Winding structural example (a):

S1 is sandwiched between P1 and P2 to
maximize the coupling of them for surge
reduction of P1 and P2.
D is placed far from P1 and P2 to minimize the
coupling to the primary for the surge reduction of
D.

Winding structural example (b)

P1 and P2 are placed close to S1 to maximize the
coupling of S1 for surge reduction of P1 and P2.
D and S2 are sandwiched by S1 to maximize the
coupling of D and S1, and that of S1 and S2.
This structure reduces the surge of D, and
improves the line-regulation of outputs.

10.2 PCB Trace Layout and Component

Placement

Since the PCB circuit trace design and the component
layout significantly affects operation, EMI noise, and
power dissipation, the high frequency PCB trace should
be low impedance with small loop and wide trace.

In addition, the ground traces affect radiated EMI noise,
and wide, short traces should be taken into account.

Figure 10-5 shows the circuit design example.
(1) Main Circuit Trace Layout

This is the main trace containing switching currents,
and thus it should be as wide trace and small loop as
possible.
If C1 and the IC are distant from each other, placing
a capacitor such as film capacitor (about 0.1 μF and
with proper voltage rating) close to the transformer
or the IC is recommended to reduce impedance of
the high frequency current loop.

(2) Control Ground Trace Layout

Since the operation of IC may be affected from the
large current of the main trace that flows in control
ground trace, the control ground trace should be
separated from main trace and connected at a single
point grounding of point A in Figure 10-5 as close to
the R

(3) VCC Trace Layout

This is the trace for supplying power to the IC, and
thus it should be as small loop as possible. If C2 and
the IC are distant from each other, placing a
capacitor such as film capacitor Cf (about 0.1 μF to

1.0 μF) close to the VCC pin and the GND pin is
recommended.

(4) R

R
S/OCP pin. The connection between the power
ground of the main trace and the IC ground should
be at a single point ground (point A in Figure 10-5)
which is close to the base of R

pin as possible.

OCP

Trace Layout

OCP

should be placed as close as possible to the

OCP

.

OCP

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 20
Aug. 07, 2014

Figure 10-4 Winding structural examples

(5) Peripheral components of the IC

The components for control connected to the IC
should be placed as close as possible to the IC, and
should be connected as short as possible to the each
pin.

(6) Secondary Rectifier Smoothing Circuit Trace

Layout:
This is the trace of the rectifier smoothing loop,
carrying the switching current, and thus it should be
as wide trace and small loop as possible. If this trace
is thin and long, inductance resulting from the loop
may increase surge voltage at turning off the power
MOSFET. Proper rectifier smoothing trace layout
helps to increase margin against the power MOSFET

STR-W6000S Series

BR

GND

FB/OLP

S/OCP

VCC

D/ST

2

1

7

653 4

C1

C6 R1

D1

R2

C2

T1

D

P

PC1

C3

R

OCP

C

Y

C5

D2

C4

R

C

D51

C51

S

A

U1

R

A

R

B

(1)Main trace should be wide

trace and small loop

(6)Main trace of secondary side should

be wide trace and small loop

(7)Trace of D/ST pin should be

wide for heat release

(2) Control GND trace should be

connected at a single point as
close to the R

OCP

as possible

(4)R

OCP

should be as
close to S/OCP pin
as possible.

(5)The components connected to the IC should

be as close to the IC as possible, and should
be connected as short as possible

(3) Loop of the power

supply should be small

breakdown voltage, and reduces stress on the clamp
snubber circuit and losses in it.

(7) Thermal Considerations

Because the power MOSFET has a positive thermal
coefficient of R

, consider it in thermal design.

DS(ON)

Since the copper area under the IC and the D/ST pin
trace act as a heatsink, its traces should be as wide as
possible.

Figure 10-5 Peripheral circuit example around the IC

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Aug. 07, 2014

STR-W6000S Series

2

CN1

C5

T1

D51

R52

Z51

D

P1

S1

PC1

1

L51

C54

R53

F1

1

3

C1

TH1

L1

8

7

C6

C10

C11

C7

C13

C12

D1

D2

D3 R2

R5

R1

D52

C52

C55

C57

R51

R54

R55

R56

R59

R58

R57

R62

PC1

C51

C56

C4

OUT1(+)

OUT1(-)

L52

C59

C2

C3

JW1

JW51

TK1

JW3

BR

GND

FB/OLP

S/OCP

VCC

D/ST

2

1

7

653 4

STR-W6000S

Z1

C8

D4

S2

3

4

D56

C65

R66

C64

CN51

S3

C53

JW59

JW52

JW61

JW53

JW57
JW58

D53

Z52

R60

R61

5

6

D54

C61

R65

C60

L53

C63

JW54

D55

Z54

R63

R64

C58

C62

JW56

Z53

JW55

S4

OUT2(+)

OUT3(+)

OUT4(+)

OUT2(-)

OUT3(-)

OUT4(-)

TK2

11. Pattern Layout Example

The following show the PCB pattern layout example and the schematic of the four outputs circuit using

STR-W6000S series without Brown-In and Brown-Out function.

The above circuit symbols correspond to these of Figure 11-1. Only the parts in the schematic are used. Other parts

in PCB are leaved open. C11 and D4 are shorted.

Figure 11-1 PCB circuit trace layout example

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Aug. 07, 2014

Figure 11-2 Circuit schematic for PCB circuit trace layout

STR-W6000S Series

IC

STR-W6053S

Input voltage

AC85 V to AC265 V

Maximum output power

56 W (70.4 W

PEAK

)

Output 1

8 V / 2.5 A

Output 2

12 V / 3 A (4.2 A

PEAK

)

BR

GND

FB/OLP

S/OCP

VCC

D/ST

2

1

7

653 4

U1

VAC

C3

C4 R1

D1

BR1

R3

C6

T1

D

P1

PC1

C7

R2

C9

C5

D2

C8

R5

F1

C1 C2

L1

TH1

D51

R51

U51

R56

S3

PC1

L51

8V/2.5A

C52

R52

R53

C53

R55

R54

C51

S1

S2

C55

D52

C54

C56

12V/4.2A

C57

P2

R57

VDC

R6

R7

R4

TC_STR-W6000S_4_R1

OUT1(+)

OUT1(-)

OUT2(+)

OUT2(-)

Symbol

Part type

Ratings

(1)

Recommended

Sanken Parts

Symbol

Part type

Ratings

(1)

Recommended

Sanken Parts

F1 Fuse

AC 250 V, 6 A

PC1 Photo-coupler

PC123 or equiv

L1

(2)

CM inductor

2.2 mH

U1 IC － STR-W6053S

TH1

(2)

NTC thermistor

Short T1 Transformer

See
the specification

BR1 General

600 V, 6 A

L51 Inductor

5 μH D1 Fast recovery

1000 V, 0.5 A

EG01C

D51 Schottky

100 V, 10 A

FMEN-210A

D2 Fast recovery

200 V, 1 A

AL01Z

D52 Fast recovery

150 V, 10 A

FMEN-210B

C1

(2)

Film, X2

0.1 μF, 275 V

C51

(2)

Ceramic

470 pF, 1 kV

C2

(2)

Film, X2

0.1 μF, 275 V

C52 Electrolytic

1000 μF, 16 V

C3 Electrolytic

220 μF, 400 V

C53

(2)

Ceramic

0.15 μF, 50 V

C4 Ceramic

3300 pF, 2 kV

C54 Electrolytic

1000 µF, 16 V

C5

(2)

Ceramic

Open

C55

(2)

Ceramic

470 pF, 1 kV

C6 Electrolytic

22 μF, 50V

C56 Electrolytic

1500 μF, 25 V

C7

(2)

Ceramic

0.01 μF

C57 Electrolytic

1500 μF, 25 V

C8

(2)

Ceramic

1000 pF

R51 General

1.5 kΩ

C9 Ceramic, Y1

2200 pF, 250 V

R52 General

1 kΩ R1

(3)

Metal oxide

56 kΩ, 2 W

R53

(2)

General

33 kΩ

R2 General

0.27 Ω, 1 W

R54

(2)

General, 1%

3.9 kΩ

R3 General

5.6 Ω

R55 General, 1%

22 kΩ

R4

(3)

General

2.2MΩ

R56 General, 1%

6.8 kΩ

R5

(3)

General

2.2MΩ

R57 General

Open

R6

(3)

General

2.2MΩ

U51 Shunt regulator

V

REF

= 2.5 V

TL431or equiv

R7

(2)

General

470kΩ

12. Reference Design of Power Supply

As an example, the following show the power supply specification, the circuit schematic, the bill of materials, and

the transformer specification.

 Power supply specification

 Circuit schematic

 Bill of materials

(1)

Unless otherwise specified, the voltage rating of capacitor is 50 V or less and the power rating of resistor is 1/8 W or less.

(2)

It is necessary to be adjusted based on actual operation in the application.

(3)

Resistors applied high DC voltage and of high resistance are recommended to select resistors designed against electromigration or use

STR-W6000S - DS Rev.2.0 SANKEN ELECTRIC CO.,LTD. 23
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combinations of resistors in series for that to reduce each applied voltage, according to the requirement of the application.

STR-W6000S Series

Winding

Symbol

Number of

turns (T)

Wire diameter

(mm)

Construction

Primary winding 1

P1

26

TEX – φ 0.35 × 2

Two-layers,
solenoid winding

Primary winding 2

P2

18

TEX – φ 0.35 × 2

Single-layer,
solenoid winding

Auxiliary winding

D

10

TEX – φ 0.23 × 2

Single-layer,
space winding

Output winding 1

S1

7

φ 0.4 × 4

Single-layer,
space winding

Output winding 2

S2

7

φ 0.4 × 4

Single-layer,
space winding

Output winding 3

S3

5

φ 0.4 × 4

Single-layer,
space winding

●: Start at this pin

Cross-section view

Bobbin

D

S1

P1

VDC

D/ST
VCC

GND

12V

S2

S1
P2

S3

P2

S3

8V

S2

D

P1

OUT1(+)

OUT1(-)

OUT2(+)

OUT2(-)

 Transformer specification

▫ Primary inductance, LP ：LP：315 μH
▫ Core size ：EER28L
▫ Al-value ：163 nH/N2 (Center gap of about 0.8 mm)

▫ Winding specification

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Aug. 07, 2014

STR-W6000S Series

Type

Suppliers

G746

Shin-Etsu Chemical Co., Ltd.

YG6260

Momentive Performance Materials Japan LLC

SC102

Dow Corning Toray Co., Ltd.

OPERATING PRECAUTIONS

In the case that you use Sanken products or design your products by using Sanken products, the reliability largely
depends on the degree of derating to be made to the rated values. Derating may be interpreted as a case that an operation
range is set by derating the load from each rated value or surge voltage or noise is considered for derating in order to
assure or improve the reliability. In general, derating factors include electric stresses such as electric voltage, electric
current, electric power etc., environmental stresses such as ambient temperature, humidity etc. and thermal stress caused
due to self-heating of semiconductor products. For these stresses, instantaneous values, maximum values and minimum

values must be taken into consideration. In addition, it should be noted that since power devices or IC’s including power

devices have large self-heating value, the degree of derating of junction temperature affects the reliability significantly.

Because reliability can be affected adversely by improper storage environments and handling methods, please
observe the following cautions.

Cautions for Storage

 Ensure that storage conditions comply with the standard temperature (5 to 35°C) and the standard relative humidity

(around 40 to 75%); avoid storage locations that experience extreme changes in temperature or humidity.

 Avoid locations where dust or harmful gases are present and avoid direct sunlight.

 Reinspect for rust on leads and solderability of the products that have been stored for a long time.

Cautions for Testing and Handling

When tests are carried out during inspection testing and other standard test periods, protect the products from power

surges from the testing device, shorts between the product pins, and wrong connections. Ensure all test parameters are

within the ratings specified by Sanken for the products.

Remarks About Using Thermal Silicone Grease

 When thermal silicone grease is used, it shall be applied evenly and thinly. If more silicone grease than required is

applied, it may produce excess stress.

 The thermal silicone grease that has been stored for a long period of time may cause cracks of the greases, and it

cause low radiation performance. In addition, the old grease may cause cracks in the resin mold when screwing the
products to a heatsink.

 Fully consider preventing foreign materials from entering into the thermal silicone grease. When foreign material

is immixed, radiation performance may be degraded or an insulation failure may occur due to a damaged insulating
plate.

 The thermal silicone greases that are recommended for the resin molded semiconductor should be used.

Our recommended thermal silicone grease is the following, and equivalent of these.

Cautions for Mounting to a Heatsink

 When the flatness around the screw hole is insufficient, such as when mounting the products to a heatsink that has

an extruded (burred) screw hole, the products can be damaged, even with a lower than recommended screw torque.
For mounting the products, the mounting surface flatness should be 0.05mm or less.

 Please select suitable screws for the product shape. Do not use a flat-head machine screw because of the stress to

the products. Self-tapping screws are not recommended. When using self-tapping screws, the screw may enter the
hole diagonally, not vertically, depending on the conditions of hole before threading or the work situation. That
may stress the products and may cause failures.

 Recommended screw torque: 0.588 to 0.785 N･m (6 to 8 kgf･cm).

 For tightening screws, if a tightening tool (such as a driver) hits the products, the package may crack, and internal

stress fractures may occur, which shorten the lifetime of the electrical elements and can cause catastrophic failure.
Tightening with an air driver makes a substantial impact. In addition, a screw torque higher than the set torque can
be applied and the package may be damaged. Therefore, an electric driver is recommended.
When the package is tightened at two or more places, first pre-tighten with a lower torque at all places, then tighten
with the specified torque. When using a power driver, torque control is mandatory.

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STR-W6000S Series

Soldering

 When soldering the products, please be sure to minimize the working time, within the following limits:

• 260 ± 5 °C 10 ± 1 s (Flow, 2 times)

• 380 ± 10 °C 3.5 ± 0.5 s (Soldering iron, 1 time)

 Soldering should be at a distance of at least 1.5 mm from the body of the products.

Electrostatic Discharge

 When handling the products, the operator must be grounded. Grounded wrist straps worn should have at least 1MΩ

of resistance from the operator to ground to prevent shock hazard, and it should be placed near the operator.

 Workbenches where the products are handled should be grounded and be provided with conductive table and floor

mats.

 When using measuring equipment such as a curve tracer, the equipment should be grounded.

 When soldering the products, the head of soldering irons or the solder bath must be grounded in order to prevent

leak voltages generated by them from being applied to the products.

 The products should always be stored and transported in Sanken shipping containers or conductive containers, or

be wrapped in aluminum foil.

IMPORTANT NOTES

 The contents in this document are subject to changes, for improvement and other purposes, without notice. Make

sure that this is the latest revision of the document before use.

 Application examples, operation examples and recommended examples described in this document are quoted for

the sole purpose of reference for the use of the products herein and Sanken can assume no responsibility for any
infringement of industrial property rights, intellectual property rights, life, body, property or any other rights of
Sanken or any third party which may result from its use.

 Unless otherwise agreed in writing by Sanken, Sanken makes no warranties of any kind, whether express or

implied, as to the products, including product merchantability, and fitness for a particular purpose and special
environment, and the information, including its accuracy, usefulness, and reliability, included in this document.

 Although Sanken undertakes to enhance the quality and reliability of its products, the occurrence of failure and

defect of semiconductor products at a certain rate is inevitable. Users of Sanken products are requested to take, at
their own risk, preventative measures including safety design of the equipment or systems against any possible
injury, death, fires or damages to the society due to device failure or malfunction.

 Sanken products listed in this document are designed and intended for the use as components in general purpose

electronic equipment or apparatus (home appliances, office equipment, telecommunication equipment, measuring
equipment, etc.).
When considering the use of Sanken products in the applications where higher reliability is required (transportation
equipment and its control systems, traffic signal control systems or equipment, fire/crime alarm systems, various
safety devices, etc.), and whenever long life expectancy is required even in general purpose electronic equipment
or apparatus, please contact your nearest Sanken sales representative to discuss, prior to the use of the products
herein.
The use of Sanken products without the written consent of Sanken in the applications where extremely high
reliability is required (aerospace equipment, nuclear power control systems, life support systems, etc.) is strictly
prohibited.

 When using the products specified herein by either (i) combining other products or materials therewith or (ii)

physically, chemically or otherwise processing or treating the products, please duly consider all possible risks that
may result from all such uses in advance and proceed therewith at your own responsibility.

 Anti radioactive ray design is not considered for the products listed herein.

 Sanken assumes no responsibility for any troubles, such as dropping products caused during transportation out of

Sanken’s distribution network.

 The contents in this document must not be transcribed or copied without Sanken’s written consent.

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