SANKEN STR3A150

STR3A151, STR3A152, STR3A153,
STR3A154, STR3A155
PWM Off-Line Switching Regulator ICs
Features and Benefits
Description
• Current mode PWM control
• Built-in Random Switching function: reduces
EMI noise, simplifies EMI filters, and cuts cost by
external part reduction
• Built-in Slope Compensation function: avoids
subharmonic oscillation
• Built-in Leading Edge Blanking (LEB) function
• Auto Standby function:
▫ Input power, PIN < 10 mW at no load with low power
consumption shunt regulator
▫ Normal load operation: PWM switching
▫ Light load operation: Standby mode (Burst oscillation)
STR3A100 series are power ICs for switching power supplies,
incorporating a power MOSFET and a current mode PWM
controller IC in one package.
Including a startup circuit and a standby function in the
controller, the product achieves low power consumption, low
standby power, and high cost-effectiveness in power supply
systems, while reducing external components.
The products are provided in an industry standard DIP8
package.
Applications
Switching power supplies for electronic devices such as:
• Stand-by power supply for LCD/PDP television,
desktop PC, multi-function printer, audio equipment,
and so forth
• Small switched-mode power supply (SMPS) for printer,
BD/DVD player, set-top box, and so forth
• Auxiliary power supply for air conditioner, refrigerator,
washer, dishwasher, and so forth
Continued on the next page…
Package: DIP8
Not to scale
Typical Application
C9
CRD Snubber Circuit
D1
VAC
C5
L2
D4
T1
R3
R9
PC1
P
C1
D3
7
6
R8
S
C8
C6
R6
5
D2
D/ST D/ST D/ST
NC D/ST
C4
R4
R5
C7
8
VOUT
U2
R2
R7
U1
STR3A100
C2
D
GND
S/OCP VCC GND FB/OLP
C, RC
Damper
Snubber
Circuit
1
ROCP
2
3
4
C3
PC1
STR3A150-DS
SANKEN ELECTRIC CO., LTD.
July 20, 2012
STR3A151, STR3A152, STR3A153,
STR3A154, STR3A155
PWM Off-Line Switching Regulator ICs
Features and Benefits (continued)
• Soft Start function: reduces stress on internal power MOSFET
and secondary output rectifier diode at startup
• Protection Functions:
▫ Overcurrent Protection function (OCP); pulse-by-pulse,
built-in compensation circuit to minimize OCP point variation
on AC input voltage
▫ Overload Protection function (OLP); auto restart, built-in
timer, reduces heat during overload condition, and no external
components required
▫ Overvoltage Protection function (OVP); latched shutdown
▫ Thermal Shutdown function (TSD); latched shutdown
Selection Guide
Part Number
STR3A151
STR3A152
STR3A153
STR3A154
STR3A155
fOSC
(kHz)
67
POUT*
(W)
MOSFET
OVP/TSD
VDSS(min)
(V)
RDS(on)(max)
(Ω)
230 VAC
85 to 265 VAC
650
4.0
3.0
1.9
1.4
1.1
24
30
36
40
43
16
23
30
32
35
Latched
*The listed output power is based on the thermal ratings, and the peak output power can be 120% to
140% of the value stated here. At low output voltage and short duty cycle, the output power may be less
than the value stated here.
STR3A150-DS
SANKEN ELECTRIC CO., LTD.
2
July 20, 2012
STR3A151, STR3A152, STR3A153,
STR3A154, STR3A155
PWM Off-Line Switching Regulator ICs
The polarity value for current specifies a sink as "+," and a source as “−,” referencing the IC.
Absolute Maximum Ratings Unless specifically noted, TA is 25°C
Characteristic
Drain Peak Current1
Symbol
IDPEAK
Notes
Pins
STR3A151
3.6
A
4
A
5.2
A
6.4
A
STR3A153
Single pulse
8−1
STR3A155
Avalanche
EAS
Unit
STR3A152
STR3A154
Energy2
Rating
7.2
A
STR3A151
Single pulse, ILPEAK = 2.13 A
53
mJ
STR3A152
Single pulse, ILPEAK = 2.19 A
56
mJ
STR3A153
Single pulse, ILPEAK = 2.46 A
72
mJ
STR3A154
Single pulse, ILPEAK = 2.66 A
83
mJ
STR3A155
Single pulse, ILPEAK = 3.05 A
8−1
110
mJ
−2 to 6
V
2−3
32
V
4−3
−0.3 to 14
V
4−3
1.0
mA
1.68
W
1.76
W
S/OCP Pin Voltage
VOCP
1−3
Control Part Input Voltage
VCC
FB/OLP Pin Voltage
VFB
FB/OLP Pin Sink Current
IFB
STR3A151
STR3A152
MOSFET Power Dissipation3
PD1
STR3A153
STR3A154
Control Part Power Dissipation
PD2
VCC × ICC
Operating Ambient Temperature
Storage Temperature
Channel Temperature
Mounted on 15 mm × 15 mm
printed circuit board
8−1
STR3A155
1.81
W
2−3
1.3
W
TOP
–
−40 to 125
°C
Tstg
–
−40 to 125
°C
Tch
–
150
°C
1Refer
to MOSFET Safe Operating Area Curve.
2Refer to MOSFET Avalanche Energy Derating Coefficient Curve.
3Refer to MOSFET Temperature versus Power Dissipation Curve.
STR3A150-DS
SANKEN ELECTRIC CO., LTD.
3
July 20, 2012
STR3A151, STR3A152, STR3A153,
STR3A154, STR3A155
PWM Off-Line Switching Regulator ICs
Electrical Characteristics of Control Part Unless specifically noted, TA is 25°C, VCC = 18 V
Characteristic
Symbol
Operation Start Voltage
VCC(ON)
Operation Stop Voltage*
VCC(OFF)
Circuit Current in Operation
ICC(ON)
Minimum Start Voltage
VST(ON)
Startup Current
ISTARTUP
Startup Current Threshold Biasing
Voltage*
Average Operation Frequency
Frequency Modulation Deviation
Maximum Duty Cycle
Leading Edge Blanking Time
Test Conditions
VCC = 12 V
Pins
Min.
Typ.
Max.
Unit
2–3
13.8
15.3
16.8
V
2–3
7.3
8.1
8.9
V
2–3
−
−
2.5
mA
8–3
−
40
−
V
2–3
−3.9
−2.5
−1.1
mA
VCC(BIAS)
2–3
8.5
9.5
10.5
V
fOSC(AVG)
8–3
60
67
74
kHz
VCC = 13.5 V
Δf
8–3
−
5
−
kHz
DMAX
8–3
65
74
83
%
tBW
–
−
350
−
ns
OCP Compensation Coefficient
DPC
–
−
17
−
mV/μs
OCP Compensation Duty Cycle Limit
DDPC
−
−
36
−
%
OCP Threshold Voltage at
Zero Duty Cycle
VOCP(L)
1–3
0.69
0.78
0.87
V
OCP Threshold Voltage at
36% Duty Cycle
VOCP(H)
1–3
0.79
0.88
0.97
V
Maximum Feedback Current
IFB(MAX)
4–3
−110
−70
−35
μA
Minimum Feedback Current
IFB(MIN)
4–3
−30
−15
−7
μA
FB/OLP Oscillation Stop Threshold
Voltage
VFB(OFF)
STR3A151
STR3A152
STR3A153
VCC = 32 V
4–3
1.09
1.21
1.33
V
STR3A154
STR3A155
VCC = 32 V
4–3
0.85
0.98
1.09
V
OLP Threshold Voltage
VFB(OLP)
VCC = 32 V
4–3
7.3
8.1
8.9
V
OLP Operation Current
ICC(OLP)
VCC = 12 V
2–3
−
230
−
μA
tOLP
–
54
70
86
ms
FB/OLP Clamp Voltage
OLP Delay Time
VFB(CLAMP)
4–3
11.0
12.8
14.0
V
OVP Threshold Voltage
VCC(OVP)
2–3
27.5
29.5
31.5
V
TJ(TSD)
−
135
−
−
°C
Thermal Shutdown Activating
Temperature
*VCC(BIAS) > VCC(OFF) always.
STR3A150-DS
SANKEN ELECTRIC CO., LTD.
4
July 20, 2012
STR3A151, STR3A152, STR3A153,
STR3A154, STR3A155
PWM Off-Line Switching Regulator ICs
Electrical Characteristics of MOSFET Unless specifically noted, TA is 25°C
Characteristic
Symbol
Drain-to-Source Breakdown Voltage
VDSS
Drain Leakage Current
IDSS
Test Conditions
Pins
Min.
Typ.
Max.
Unit
8–1
650
–
–
V
8–1
–
–
300
μA
–
–
4.0
Ω
–
–
3.0
Ω
–
–
1.9
Ω
STR3A154
–
–
1.4
Ω
STR3A155
–
–
1.1
Ω
8–1
–
–
250
ns
–
–
–
18
°C/W
–
–
–
17
°C/W
STR3A151
STR3A152
On-Resistance
Switching Time
RDS(ON)
STR3A153
tf
STR3A151
STR3A152
STR3A153
Thermal Resistance
Rθch-C
STR3A154
STR3A155
STR3A150-DS
8–1
The thermal
resistance
between channel
and case. Case
temperature (TC)
is measured at
the center of the
branded side.
SANKEN ELECTRIC CO., LTD.
5
July 20, 2012
STR3A151, STR3A152, STR3A153,
STR3A154, STR3A155
PWM Off-Line Switching Regulator ICs
Characteristic Performance
STR3A151
MOSFET Safe Operating Area Curve
100
10
Single pulse, TA = 25°C
0.1 ms
80
Drain Current, ID (A)
Safe Operating Area
Temperature Derating Coefficient (%)
S. O. A. Temperature Derating Coefficient Curve
60
40
20
0
0
25
50
75
100
125
1
1 ms
Drain current limited
by on-resistance
0.1
To use this graph, apply the S.O.A.
temperature derating coefficient
taken from the graph at the left
150
Channel Temperature, Tch (°C)
0.01
1
10
100
1000
Drain-to-Source Voltage, VDS (V)
MOSFET Temperature versus Power Dissipation Curve
100
Allowable Power Dissipation, PD1 (W)
EAS
Temperature Derating Coefficient (%)
MOSFET Avalanche Energy Derating Coefficient Curve
80
60
40
20
0
25
50
75
100
125
150
2.0
PD1 = 1.68 W
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
Transient Thermal Resistance, Rθch-c (°C/W)
Channel Temperature, Tch (°C)
10
25
50
75
100
125
150
Ambient Temperature, TA (°C)
Transient Thermal Resistance Curve
1
0.1
0.01
10–6
10–5
10–4
10–3
10–2
10–1
Time (s)
STR3A150-DS
SANKEN ELECTRIC CO., LTD.
6
July 20, 2012
STR3A151, STR3A152, STR3A153,
STR3A154, STR3A155
PWM Off-Line Switching Regulator ICs
Characteristic Performance
STR3A152
MOSFET Safe Operating Area Curve
100
10
Single pulse, TA = 25°C
0.1 ms
80
Drain Current, ID (A)
Safe Operating Area
Temperature Derating Coefficient (%)
S. O. A. Temperature Derating Coefficient Curve
60
40
20
0
0
25
50
75
100
125
1
1 ms
Drain current limited
by on-resistance
0.1
To use this graph, apply the S.O.A.
temperature derating coefficient
taken from the graph at the left
150
Channel Temperature, Tch (°C)
0.01
1
10
100
1000
Drain-to-Source Voltage, VDS (V)
MOSFET Temperature versus Power Dissipation Curve
100
Allowable Power Dissipation, PD1 (W)
EAS
Temperature Derating Coefficient (%)
MOSFET Avalanche Energy Derating Coefficient Curve
80
60
40
20
0
25
50
75
100
125
150
2.0
PD1 = 1.68 W
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
Channel Temperature, Tch (°C)
25
50
75
100
125
150
Ambient Temperature, TA (°C)
Transient Thermal Resistance, Rθch-c (°C/W)
Transient Thermal Resistance Curve
100
10
1
0.1
0.01
10–6
10–5
10–4
10–3
10–2
10–1
Time (s)
STR3A150-DS
SANKEN ELECTRIC CO., LTD.
7
July 20, 2012
STR3A151, STR3A152, STR3A153,
STR3A154, STR3A155
PWM Off-Line Switching Regulator ICs
Characteristic Performance
STR3A153
MOSFET Safe Operating Area Curve
100
10
Single pulse, TA = 25°C
0.1 ms
80
Drain Current, ID (A)
Safe Operating Area
Temperature Derating Coefficient (%)
S. O. A. Temperature Derating Coefficient Curve
60
40
20
0
0
25
50
75
100
125
1 ms
1
Drain current limited
by on-resistance
0.1
To use this graph, apply the S.O.A
temperature derating coefficient
taken from the graph at the left
150
Channel Temperature, Tch (°C)
0.01
1
10
100
1000
Drain-to-Source Voltage, VDS (V)
MOSFET Temperature versus Power Dissipation Curve
100
Allowable Power Dissipation, PD1 (W)
EAS
Temperature Derating Coefficient (%)
MOSFET Avalanche Energy Derating Coefficient Curve
80
60
40
20
0
25
50
75
100
125
150
2.0
PD1 = 1.76 W
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
Transient Thermal Resistance, Rθch-c (°C/W)
Channel Temperature, Tch (°C)
10
25
50
75
100
125
150
Ambient Temperature, TA (°C)
Transient Thermal Resistance Curve
1
0.1
0.01
10–6
10–5
10–4
10–3
10–2
10–1
Time (s)
STR3A150-DS
SANKEN ELECTRIC CO., LTD.
8
July 20, 2012
STR3A151, STR3A152, STR3A153,
STR3A154, STR3A155
PWM Off-Line Switching Regulator ICs
Characteristic Performance
STR3A154
MOSFET Safe Operating Area Curve
100
10
Single pulse, TA = 25°C
0.1 ms
80
Drain Current, ID (A)
Safe Operating Area
Temperature Derating Coefficient (%)
S. O. A. Temperature Derating Coefficient Curve
60
40
20
0
0
25
50
75
100
125
1 ms
1
Drain current limited
by on-resistance
0.1
To use this graph, apply the S.O.A
temperature derating coefficient
taken from the graph at the left
150
Channel Temperature, Tch (°C)
0.01
1
10
100
1000
Drain-to-Source Voltage, VDS (V)
MOSFET Temperature versus Power Dissipation Curve
100
Allowable Power Dissipation, PD1 (W)
EAS
Temperature Derating Coefficient (%)
MOSFET Avalanche Energy Derating Coefficient Curve
80
60
40
20
0
25
50
75
100
125
150
2.0
PD1 = 1.76 W
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
Transient Thermal Resistance, Rθch-c (°C/W)
Channel Temperature, Tch (°C)
10
25
50
75
100
125
150
Ambient Temperature, TA (°C)
Transient Thermal Resistance Curve
1
0.1
0.01
0.001
10–6
10–5
10–4
10–3
10–2
10–1
Time (s)
STR3A150-DS
SANKEN ELECTRIC CO., LTD.
9
July 20, 2012
STR3A151, STR3A152, STR3A153,
STR3A154, STR3A155
PWM Off-Line Switching Regulator ICs
Characteristic Performance
STR3A155
MOSFET Safe Operating Area Curve
100
10
0.1 ms
80
1 ms
Drain Current, ID (A)
Safe Operating Area
Temperature Derating Coefficient (%)
S. O. A. Temperature Derating Coefficient Curve
60
40
20
0
0
25
50
75
100
125
Drain current limited
by on-resistance
1
Single pulse, TA = 25°C
0.1
To use this graph, apply the S.O.A
temperature derating coefficient
taken from the graph at the left
150
Channel Temperature, Tch (°C)
0.01
1
10
100
1000
Drain-to-Source Voltage, VDS (V)
MOSFET Temperature versus Power Dissipation Curve
100
Allowable Power Dissipation, PD1 (W)
EAS
Temperature Derating Coefficient (%)
MOSFET Avalanche Energy Derating Coefficient Curve
80
60
40
20
0
25
50
75
100
125
150
2.0
PD1 = 1.81 W
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
Transient Thermal Resistance, Rθch-c (°C/W)
Channel Temperature, Tch (°C)
10
25
50
75
100
125
150
Ambient Temperature, TA (°C)
Transient Thermal Resistance Curve
1
0.1
0.01
10–6
10–5
10–4
10–3
10–2
10–1
Time (s)
STR3A150-DS
SANKEN ELECTRIC CO., LTD.
10
July 20, 2012
STR3A151, STR3A152, STR3A153,
STR3A154, STR3A155
PWM Off-Line Switching Regulator ICs
Functional Block Diagram
2
Control Part
VCC
D/ST
Startup
UVLO
Reg
PWM
Oscillator
VREG
OVP
5, 6,
7, 8
TSD
DRV
SQ
R
OCP
VCC
4
OLP
Drain Peak Current
compensation
Feedback
control
FB/OLP
LEB
Slope
compensation
S/OCP
GND
1
3
Pin List Table
Pin-out Diagram
S/GND 1
8 D/ST
VCC 2
7 D/ST
GND 3
6 D/ST
FB/OLP 4
5 D/ST
STR3A150-DS
Number
Name
1
S/OCP
Function
2
VCC
Power supply voltage input for Control Part and input of Overvoltage
Protection (OVP) signal
3
GND
Ground
4
FB/OLP
5, 6,7, 8
D/ST
MOSFET source and input of Overcurrent Protection (OCP) signal
Feedback signal input for constant voltage control signal and input of
Overload Protection (OLP) signal
MOSFET drain pin and input of the startup current
SANKEN ELECTRIC CO., LTD.
11
July 20, 2012
STR3A151, STR3A152, STR3A153,
STR3A154, STR3A155
PWM Off-Line Switching Regulator ICs
Package Diagram
DIP8 package
9.4 ±0.3
5
1
4
6.5 ±0.2
8
1.0 +0.3
-0.05
+0.3
1.52
-0.05
3.3 ±0.2
7.5 ±0.5
4.2 ±0.3
3.4 ±0.1
(7.6 TYP)
0.2 5 + 0.
- 0.01
5
０～１５° ０～１５°
2.54 TYP
0.89 TYP
0.5 ±0.1
Unit： mm
3A15x
SK YMD
Pb-free.
Device composition compliant
with the RoHS directive.
STR3A150-DS
SANKEN ELECTRIC CO., LTD.
Part Number
Lot Number
Y is the last digit of the year (0 to 9)
M is the month (1 to 9, O, N, or D)
D is a period of days:
1 – 1st to 10th
2 – 11th to 20th
3 – 21st to 31st
Sanken Control Number
12
July 20, 2012
STR3A151, STR3A152, STR3A153,
STR3A154, STR3A155
PWM Off-Line Switching Regulator ICs
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°C 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 Silicone Grease with a Heatsink
• When silicone grease is used in mounting the products on a
heatsink, it shall be applied evenly and thinly. If more silicone
grease than required is applied, it may produce excess stress.
• Volatile-type silicone greases may crack after long periods of
time, resulting in reduced heat radiation effect. Silicone greases
with low consistency (hard grease) may cause cracks in the mold
resin when screwing the products to a heatsink.
Our recommended silicone greases for heat radiation purposes,
which will not cause any adverse effect on the product life, are
indicated below:
Type
Suppliers
G746
Shin-Etsu Chemical Co., Ltd.
YG6260
Momentive Performance Materials Inc.
SC102
Dow Corning Toray Co., Ltd.
STR3A150-DS
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 1 MΩ 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.
SANKEN ELECTRIC CO., LTD.
13
July 20, 2012
STR3A151, STR3A152, STR3A153,
STR3A154, STR3A155
PWM Off-Line Switching Regulator ICs
• 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 and operation 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 or
any other rights of Sanken or any third party which may result from its use.
• 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.
• 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.
• 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.
STR3A150-DS
SANKEN ELECTRIC CO., LTD.
14
July 20, 2012
STR3A151D, STR3A152D, STR3A153D,
STR3A154D, STR3A155D
PWM Off-Line Switching Regulator ICs
Features and Benefits
Description
• Current mode PWM control
• Built-in Random Switching function: reduces
EMI noise, simplifies EMI filters, and cuts cost by
external part reduction
• Built-in Slope Compensation function: avoids
subharmonic oscillation
• Built-in Leading Edge Blanking (LEB) function
• Auto Standby function:
▫ Input power, PIN < 10 mW at no load with low power
consumption shunt regulator
▫ Normal load operation: PWM switching
▫ Light load operation: Standby mode (Burst oscillation)
STR3A100 series are power ICs for switching power supplies,
incorporating a power MOSFET and a current mode PWM
controller IC in one package.
Including a startup circuit and a standby function in the
controller, the product achieves low power consumption, low
standby power, and high cost-effectiveness in power supply
systems, while reducing external components.
The products are provided in an industry standard DIP8
package.
Applications
Switching power supplies for electronic devices such as:
• Stand-by power supply for LCD/PDP television,
desktop PC, multi-function printer, audio equipment,
and so forth
• Small switched-mode power supply (SMPS) for printer,
BD/DVD player, set-top box, and so forth
• Auxiliary power supply for air conditioner, refrigerator,
washer, dishwasher, and so forth
Continued on the next page…
Package: DIP8
Not to scale
Typical Application
C9
CRD Snubber Circuit
D1
VAC
C5
L2
D4
T1
R3
R9
PC1
P
C1
D3
7
6
R8
S
C8
C6
R6
5
D2
D/ST D/ST D/ST
NC D/ST
C4
R4
R5
C7
8
VOUT
U2
R2
R7
U1
STR3A100
C2
D
GND
S/OCP VCC GND FB/OLP
C, RC
Damper
Snubber
Circuit
1
ROCP
2
3
4
C3
PC1
STR3A150D-DS
SANKEN ELECTRIC CO., LTD.
July 20, 2012
STR3A151D, STR3A152D,
STR3A153D, STR3A154D,
STR3A155D
PWM Off-Line Switching Regulator ICs
Features and Benefits (continued)
• Soft Start function: reduces stress on internal power MOSFET
and secondary output rectifier diode at startup
• Protection Functions:
▫ Overcurrent Protection function (OCP); pulse-by-pulse,
built-in compensation circuit to minimize OCP point variation
on AC input voltage
▫ Overload Protection function (OLP); auto restart, built-in
timer, reduces heat during overload condition, and no external
components required
▫ Overvoltage Protection function (OVP); auto restart
▫ Thermal Shutdown function (TSD); auto restart
Selection Guide
Part Number
STR3A151D
STR3A152D
STR3A153D
STR3A154D
STR3A155D
fOSC
(kHz)
67
POUT*
(W)
MOSFET
OVP/TSD
VDSS(min)
(V)
RDS(on)(max)
(Ω)
230 VAC
85 to 265 VAC
650
4.0
3.0
1.9
1.4
1.1
24
30
36
40
43
16
23
30
32
35
Auto restart
*The listed output power is based on the thermal ratings, and the peak output power can be 120% to
140% of the value stated here. At low output voltage and short duty cycle, the output power may be less
than the value stated here.
STR3A150D-DS
SANKEN ELECTRIC CO., LTD.
2
July 20, 2012
STR3A151D, STR3A152D,
STR3A153D, STR3A154D,
STR3A155D
PWM Off-Line Switching Regulator ICs
The polarity value for current specifies a sink as "+," and a source as “−,” referencing the IC.
Absolute Maximum Ratings Unless specifically noted, TA is 25°C
Characteristic
Symbol
Notes
Pins
STR3A151D
STR3A152D
Drain Peak Current1
Avalanche Energy2
IDPEAK
EAS
Rating
Unit
3.6
A
4
A
5.2
A
STR3A154D
6.4
A
STR3A155D
7.2
A
STR3A153D
Single pulse
8−1
STR3A151D
Single pulse, ILPEAK = 2.13 A
53
mJ
STR3A152D
Single pulse, ILPEAK = 2.19 A
56
mJ
STR3A153D
Single pulse, ILPEAK = 2.46 A
72
mJ
STR3A154D
Single pulse, ILPEAK = 2.66 A
83
mJ
STR3A155D
Single pulse, ILPEAK = 3.05 A
110
mJ
8−1
S/OCP Pin Voltage
VOCP
1−3
−2 to 6
V
Control Part Input Voltage
VCC
2−3
32
V
FB/OLP Pin Voltage
VFB
4−3
−0.3 to 14
V
FB/OLP Pin Sink Current
IFB
4−3
1.0
mA
1.68
W
1.76
W
1.81
W
STR3A151D
STR3A152D
MOSFET Power Dissipation3
PD1
STR3A153D
STR3A154D
Mounted on 15 mm × 15 mm
printed circuit board
8−1
STR3A155D
Control Part Power Dissipation
PD2
2−3
1.3
W
Operating Ambient Temperature
TOP
VCC × ICC
–
−40 to 125
°C
Storage Temperature
Tstg
–
−40 to 125
°C
Channel Temperature
Tch
–
150
°C
1Refer
to MOSFET Safe Operating Area Curve.
to MOSFET Avalanche Energy Derating Coefficient Curve.
3Refer to MOSFET Temperature versus Power Dissipation Curve.
2Refer
STR3A150D-DS
SANKEN ELECTRIC CO., LTD.
3
July 20, 2012
STR3A151D, STR3A152D,
STR3A153D, STR3A154D,
STR3A155D
PWM Off-Line Switching Regulator ICs
Electrical Characteristics of Control Part Unless specifically noted, TA is 25°C, VCC = 18 V
Characteristic
Symbol
Operation Start Voltage
VCC(ON)
Operation Stop Voltage*
VCC(OFF)
Circuit Current in Operation
ICC(ON)
Minimum Start Voltage
VST(ON)
Startup Current
ISTARTUP
Startup Current Threshold Biasing
Voltage*
Average Operation Frequency
Frequency Modulation Deviation
Maximum Duty Cycle
Leading Edge Blanking Time
Test Conditions
VCC = 12 V
Pins
Min.
Typ.
Max.
Unit
2–3
13.8
15.3
16.8
V
2–3
7.3
8.1
8.9
V
2–3
−
−
2.5
mA
8–3
−
40
−
V
2–3
−3.9
−2.5
−1.1
mA
VCC(BIAS)
2–3
8.5
9.5
10.5
V
fOSC(AVG)
8–3
60
67
74
kHz
VCC = 13.5 V
Δf
8–3
−
5
−
kHz
DMAX
8–3
65
74
83
%
tBW
–
−
350
−
ns
OCP Compensation Coefficient
DPC
–
−
17
−
mV/μs
OCP Compensation Duty Cycle Limit
DDPC
−
−
36
−
%
OCP Threshold Voltage at
Zero Duty Cycle
VOCP(L)
1–3
0.69
0.78
0.87
V
OCP Threshold Voltage at
36% Duty Cycle
VOCP(H)
1–3
0.79
0.88
0.97
V
Maximum Feedback Current
IFB(MAX)
4–3
−110
−70
−35
μA
Minimum Feedback Current
IFB(MIN)
4–3
−30
−15
−7
μA
FB/OLP Oscillation Stop Threshold
Voltage
VFB(OFF)
STR3A151D
STR3A152D
STR3A153D
VCC = 32 V
4–3
1.09
1.21
1.33
V
STR3A154D
STR3A155D
VCC = 32 V
4–3
0.85
0.98
1.09
V
OLP Threshold Voltage
VFB(OLP)
VCC = 32 V
4–3
7.3
8.1
8.9
V
OLP Operation Current
ICC(OLP)
VCC = 12 V
2–3
−
230
−
μA
tOLP
–
54
70
86
ms
FB/OLP Clamp Voltage
OLP Delay Time
VFB(CLAMP)
4–3
11.0
12.8
14.0
V
OVP Threshold Voltage
VCC(OVP)
2–3
27.5
29.5
31.5
V
TJ(TSD)
−
135
−
−
°C
Thermal Shutdown Activating
Temperature
*VCC(BIAS) > VCC(OFF) always.
STR3A150D-DS
SANKEN ELECTRIC CO., LTD.
4
July 20, 2012
STR3A151D, STR3A152D,
STR3A153D, STR3A154D,
STR3A155D
PWM Off-Line Switching Regulator ICs
Electrical Characteristics of MOSFET Unless specifically noted, TA is 25°C
Characteristic
Symbol
Drain-to-Source Breakdown Voltage
VDSS
Drain Leakage Current
IDSS
Test Conditions
Pins
Min.
Typ.
Max.
Unit
8–1
650
–
–
V
8–1
–
–
300
μA
–
–
4.0
Ω
–
–
3.0
Ω
–
–
1.9
Ω
STR3A154D
–
–
1.4
Ω
STR3A155D
–
–
1.1
Ω
8–1
–
–
250
ns
–
–
–
18
°C/W
–
–
–
17
°C/W
STR3A151D
STR3A152D
On-Resistance
Switching Time
RDS(ON)
STR3A153D
tf
STR3A151D
STR3A152D
STR3A153D
Thermal Resistance
Rθch-C
STR3A154D
STR3A155D
STR3A150D-DS
8–1
The thermal
resistance
between channel
and case. Case
temperature (TC)
is measured at
the center of the
branded side.
SANKEN ELECTRIC CO., LTD.
5
July 20, 2012
STR3A151D, STR3A152D,
STR3A153D, STR3A154D,
STR3A155D
PWM Off-Line Switching Regulator ICs
Characteristic Performance
STR3A151D
MOSFET Safe Operating Area Curve
100
10
Single pulse, TA = 25°C
0.1 ms
80
Drain Current, ID (A)
Safe Operating Area
Temperature Derating Coefficient (%)
S. O. A. Temperature Derating Coefficient Curve
60
40
20
0
0
25
50
75
100
125
1
1 ms
Drain current limited
by on-resistance
0.1
To use this graph, apply the S.O.A
temperature derating coefficient
taken from the graph at the left
150
Channel Temperature, Tch (°C)
0.01
1
10
100
1000
Drain-to-Source Voltage, VDS (V)
MOSFET Temperature versus Power Dissipation Curve
100
Allowable Power Dissipation, PD1 (W)
EAS
Temperature Derating Coefficient (%)
MOSFET Avalanche Energy Derating Coefficient Curve
80
60
40
20
0
25
50
75
100
125
150
2.0
PD1 = 1.68 W
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
Transient Thermal Resistance, Rθch-c (°C/W)
Channel Temperature, Tch (°C)
10
25
50
75
100
125
150
Ambient Temperature, TA (°C)
Transient Thermal Resistance Curve
1
0.1
0.01
10–6
10–5
10–4
10–3
10–2
10–1
Time (s)
STR3A150D-DS
SANKEN ELECTRIC CO., LTD.
6
July 20, 2012
STR3A151D, STR3A152D,
STR3A153D, STR3A154D,
STR3A155D
PWM Off-Line Switching Regulator ICs
Characteristic Performance
STR3A152D
MOSFET Safe Operating Area Curve
100
10
Single pulse, TA = 25°C
0.1 ms
80
Drain Current, ID (A)
Safe Operating Area
Temperature Derating Coefficient (%)
S. O. A. Temperature Derating Coefficient Curve
60
40
20
0
0
25
50
75
100
125
1 ms
1
Drain current limited
by on-resistance
0.1
To use this graph, apply the S.O.A
temperature derating coefficient
taken from the graph at the left
150
Channel Temperature, Tch (°C)
0.01
1
10
100
1000
Drain-to-Source Voltage, VDS (V)
MOSFET Temperature versus Power Dissipation Curve
100
Allowable Power Dissipation, PD1 (W)
EAS
Temperature Derating Coefficient (%)
MOSFET Avalanche Energy Derating Coefficient Curve
80
60
40
20
0
25
50
75
100
125
150
2.0
PD1 = 1.68 W
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
Channel Temperature, Tch (°C)
25
50
75
100
125
150
Ambient Temperature, TA (°C)
Transient Thermal Resistance, Rθch-c (°C/W)
Transient Thermal Resistance Curve
100
10
1
0.1
0.01
10–6
10–5
10–4
10–3
10–2
10–1
Time (s)
STR3A150D-DS
SANKEN ELECTRIC CO., LTD.
7
July 20, 2012
STR3A151D, STR3A152D,
STR3A153D, STR3A154D,
STR3A155D
PWM Off-Line Switching Regulator ICs
Characteristic Performance
STR3A153D
MOSFET Safe Operating Area Curve
100
10
Single pulse, TA = 25°C
0.1 ms
80
Drain Current, ID (A)
Safe Operating Area
Temperature Derating Coefficient (%)
S. O. A. Temperature Derating Coefficient Curve
60
40
20
0
0
25
50
75
100
125
1 ms
1
Drain current limited
by on-resistance
0.1
To use this graph, apply the S.O.A
temperature derating coefficient
taken from the graph at the left
150
Channel Temperature, Tch (°C)
0.01
1
10
100
1000
Drain-to-Source Voltage, VDS (V)
MOSFET Temperature versus Power Dissipation Curve
100
Allowable Power Dissipation, PD1 (W)
EAS
Temperature Derating Coefficient (%)
MOSFET Avalanche Energy Derating Coefficient Curve
80
60
40
20
0
25
50
75
100
125
150
2.0
PD1 = 1.76 W
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
Transient Thermal Resistance, Rθch-c (°C/W)
Channel Temperature, Tch (°C)
10
25
50
75
100
125
150
Ambient Temperature, TA (°C)
Transient Thermal Resistance Curve
1
0.1
0.01
10–6
10–5
10–4
10–3
10–2
10–1
Time (s)
STR3A150D-DS
SANKEN ELECTRIC CO., LTD.
8
July 20, 2012
STR3A151D, STR3A152D,
STR3A153D, STR3A154D,
STR3A155D
PWM Off-Line Switching Regulator ICs
Characteristic Performance
STR3A154D
MOSFET Safe Operating Area Curve
100
10
Single pulse, TA = 25°C
0.1 ms
80
Drain Current, ID (A)
Safe Operating Area
Temperature Derating Coefficient (%)
S. O. A. Temperature Derating Coefficient Curve
60
40
20
0
0
25
50
75
100
125
1 ms
1
Drain current limited
by on-resistance
0.1
To use this graph, apply the S.O.A
temperature derating coefficient
taken from the graph at the left
150
Channel Temperature, Tch (°C)
0.01
1
10
100
1000
Drain-to-Source Voltage, VDS (V)
MOSFET Temperature versus Power Dissipation Curve
100
Allowable Power Dissipation, PD1 (W)
EAS
Temperature Derating Coefficient (%)
MOSFET Avalanche Energy Derating Coefficient Curve
80
60
40
20
0
25
50
75
100
125
150
2.0
PD1 = 1.76 W
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
Transient Thermal Resistance, Rθch-c (°C/W)
Channel Temperature, Tch (°C)
10
25
50
75
100
125
150
Ambient Temperature, TA (°C)
Transient Thermal Resistance Curve
1
0.1
0.01
0.001
10–6
10–5
10–4
10–3
10–2
10–1
Time (s)
STR3A150D-DS
SANKEN ELECTRIC CO., LTD.
9
July 20, 2012
STR3A151D, STR3A152D,
STR3A153D, STR3A154D,
STR3A155D
PWM Off-Line Switching Regulator ICs
Characteristic Performance
STR3A155D
MOSFET Safe Operating Area Curve
100
10
0.1 ms
80
Drain Current, ID (A)
Safe Operating Area
Temperature Derating Coefficient (%)
S. O. A. Temperature Derating Coefficient Curve
60
40
20
0
0
25
50
75
100
125
1 ms
1
Drain current limited
by on-resistance
Single pulse, TA = 25°C
0.1
To use this graph, apply the S.O.A
temperature derating coefficient
taken from the graph at the left
150
Channel Temperature, Tch (°C)
0.01
1
10
100
1000
Drain-to-Source Voltage, VDS (V)
MOSFET Temperature versus Power Dissipation Curve
100
Allowable Power Dissipation, PD1 (W)
EAS
Temperature Derating Coefficient (%)
MOSFET Avalanche Energy Derating Coefficient Curve
80
60
40
20
0
25
50
75
100
125
150
2.0
PD1 = 1.81 W
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
Transient Thermal Resistance, Rθch-c (°C/W)
Channel Temperature, Tch (°C)
10
25
50
75
100
125
150
Ambient Temperature, TA (°C)
Transient Thermal Resistance Curve
1
0.1
0.01
10–6
10–5
10–4
10–3
10–2
10–1
Time (s)
STR3A150D-DS
SANKEN ELECTRIC CO., LTD.
10
July 20, 2012
STR3A151D, STR3A152D,
STR3A153D, STR3A154D,
STR3A155D
PWM Off-Line Switching Regulator ICs
Functional Block Diagram
2
Control Part
VCC
D/ST
Startup
UVLO
Reg
PWM
Oscillator
VREG
OVP
5, 6,
7, 8
TSD
DRV
SQ
R
OCP
VCC
4
OLP
Drain Peak Current
compensation
Feedback
control
FB/OLP
LEB
Slope
compensation
S/OCP
GND
1
3
Pin List Table
Pin-out Diagram
S/GND 1
8 D/ST
VCC 2
7 D/ST
GND 3
6 D/ST
FB/OLP 4
5 D/ST
STR3A150D-DS
Number
Name
1
S/OCP
Function
2
VCC
Power supply voltage input for Control Part and input of Overvoltage
Protection (OVP) signal
3
GND
Ground
4
FB/OLP
5, 6,7, 8
D/ST
MOSFET source and input of Overcurrent Protection (OCP) signal
Feedback signal input for constant voltage control signal and input of
Overload Protection (OLP) signal
MOSFET drain pin and input of the startup current
SANKEN ELECTRIC CO., LTD.
11
July 20, 2012
STR3A151D, STR3A152D,
STR3A153D, STR3A154D,
STR3A155D
PWM Off-Line Switching Regulator ICs
Package Diagram
DIP8 package
9.4 ±0.3
5
1
4
6.5 ±0.2
8
1.0 +0.3
-0.05
+0.3
1.52
-0.05
3.3 ±0.2
7.5 ±0.5
4.2 ±0.3
3.4 ±0.1
(7.6 TYP)
0.2 5 + 0.
- 0.01
5
０～１５° ０～１５°
2.54 TYP
0.89 TYP
0.5 ±0.1
Unit： mm
3A15xD
SK YMD
Pb-free.
Device composition compliant
with the RoHS directive.
STR3A150D-DS
SANKEN ELECTRIC CO., LTD.
Part Number
Lot Number
Y is the last digit of the year (0 to 9)
M is the month (1 to 9, O, N, or D)
D is a period of days:
1 – 1st to 10th
2 – 11th to 20th
3 – 21st to 31st
Sanken Control Number
12
July 20, 2012
STR3A151D, STR3A152D,
STR3A153D, STR3A154D,
STR3A155D
PWM Off-Line Switching Regulator ICs
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°C 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 Silicone Grease with a Heatsink
• When silicone grease is used in mounting the products on a
heatsink, it shall be applied evenly and thinly. If more silicone
grease than required is applied, it may produce excess stress.
• Volatile-type silicone greases may crack after long periods of
time, resulting in reduced heat radiation effect. Silicone greases
with low consistency (hard grease) may cause cracks in the mold
resin when screwing the products to a heatsink.
Our recommended silicone greases for heat radiation purposes,
which will not cause any adverse effect on the product life, are
indicated below:
Type
Suppliers
G746
Shin-Etsu Chemical Co., Ltd.
YG6260
Momentive Performance Materials Inc.
SC102
Dow Corning Toray Co., Ltd.
STR3A150D-DS
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 1 MΩ 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.
SANKEN ELECTRIC CO., LTD.
13
July 20, 2012
STR3A151D, STR3A152D,
STR3A153D, STR3A154D,
STR3A155D
PWM Off-Line Switching Regulator ICs
• 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 and operation 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 or
any other rights of Sanken or any third party which may result from its use.
• 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.
• 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.
• 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.
STR3A150D-DS
SANKEN ELECTRIC CO., LTD.
14
July 20, 2012
STR3A161HD, STR3A162HD, STR3A163HD
PWM Off-Line Switching Regulator ICs
Features and Benefits
Description
• Current mode PWM control
• Built-in Random Switching function: reduces
EMI noise, simplifies EMI filters, and cuts cost by
external part reduction
• Built-in Slope Compensation function: avoids
subharmonic oscillation
• Built-in Leading Edge Blanking (LEB) function
• Auto Standby function:
▫ Input power, PIN < 10 mW at no load with low power
consumption shunt regulator
▫ Normal load operation: PWM switching
▫ Light load operation: Standby mode (Burst oscillation)
STR3A100 series are power ICs for switching power supplies,
incorporating a power MOSFET and a current mode PWM
controller IC in one package.
Including a startup circuit and a standby function in the
controller, the product achieves low power consumption, low
standby power, and high cost-effectiveness in power supply
systems, while reducing external components.
The products are provided in an industry standard DIP8
package.
Applications
Switching power supplies for electronic devices such as:
• Stand-by power supply for LCD/PDP television,
desktop PC, multi-function printer, audio equipment,
and so forth
• Small switched-mode power supply (SMPS) for printer,
BD/DVD player, set-top box, and so forth
• Auxiliary power supply for air conditioner, refrigerator,
washer, dishwasher, and so forth
Continued on the next page…
Package: DIP8
Not to scale
Typical Application
C9
CRD Snubber Circuit
D1
VAC
C5
L2
D4
T1
R3
R9
PC1
P
C1
D3
7
6
R8
S
C8
C6
R6
5
D2
D/ST D/ST D/ST
NC D/ST
C4
R4
R5
C7
8
VOUT
U2
R2
R7
U1
STR3A100
C2
D
GND
S/OCP VCC GND FB/OLP
C, RC
Damper
Snubber
Circuit
1
ROCP
2
3
4
C3
PC1
STR3A160HD-DS
SANKEN ELECTRIC CO., LTD.
July 20, 2012
STR3A161HD, STR3A162HD,
STR3A163HD
PWM Off-Line Switching Regulator ICs
Features and Benefits (continued)
• Soft Start function: reduces stress on internal power MOSFET
and secondary output rectifier diode at startup
• Protection Functions:
▫ Overcurrent Protection function (OCP); pulse-by-pulse,
built-in compensation circuit to minimize OCP point variation
on AC input voltage
▫ Overload Protection function (OLP); auto restart, built-in
timer, reduces heat during overload condition, and no external
components required
▫ Overvoltage Protection function (OVP); auto restart
▫ Thermal Shutdown function (TSD); auto restart
Selection Guide
Part Number
STR3A161HD
STR3A162HD
STR3A163HD
fOSC
(kHz)
100
POUT*
(W)
MOSFET
OVP/TSD
VDSS(min)
(V)
RDS(on)(max)
(Ω)
230 VAC
85 to 265 VAC
700
4.2
3.2
2.2
26
29
35
17
20
29
Auto restart
*The listed output power is based on the thermal ratings, and the peak output power can be 120% to
140% of the value stated here. At low output voltage and short duty cycle, the output power may be less
than the value stated here.
STR3A160HD-DS
SANKEN ELECTRIC CO., LTD.
2
July 20, 2012
STR3A161HD, STR3A162HD,
STR3A163HD
PWM Off-Line Switching Regulator ICs
The polarity value for current specifies a sink as "+," and a source as “−,” referencing the IC.
Absolute Maximum Ratings Unless specifically noted, TA is 25°C
Characteristic
Symbol
Notes
Pins
STR3A161HD
Drain Peak
Current1
IDPEAK
STR3A162HD
Single pulse
8−1
STR3A163HD
Single pulse, ILPEAK = 1.58 A
STR3A163HD
Single pulse, ILPEAK = 1.88 A
4
A
4.8
A
mJ
29
mJ
41
mJ
VOCP
1−3
−2 to 6
V
Control Part Input Voltage
VCC
2−3
32
V
FB/OLP Pin Voltage
VFB
4−3
−0.3 to 14
V
FB/OLP Pin Sink Current
IFB
4−3
1.0
mA
MOSFET Power Dissipation3
PD1
STR3A161HD
STR3A162HD
1.68
W
Control Part Power Dissipation
PD2
VCC × ICC
Operating Ambient Temperature
Storage Temperature
Channel Temperature
S/OCP Pin Voltage
Single pulse, ILPEAK = 1.43 A
A
23.8
EAS
STR3A162HD
Unit
3.6
8−1
Avalanche Energy2
STR3A161HD
Rating
STR3A163HD
Mounted on 15 mm × 15 mm
printed circuit board
8−1
1.76
W
2−3
1.3
W
TOP
–
−40 to 125
°C
Tstg
–
−40 to 125
°C
Tch
–
150
°C
1Refer
to MOSFET Safe Operating Area Curve.
to MOSFET Avalanche Energy Derating Coefficient Curve.
3Refer to MOSFET Temperature versus Power Dissipation Curve.
2Refer
STR3A160HD-DS
SANKEN ELECTRIC CO., LTD.
3
July 20, 2012
STR3A161HD, STR3A162HD,
STR3A163HD
PWM Off-Line Switching Regulator ICs
Electrical Characteristics of Control Part Unless specifically noted, TA is 25°C, VCC = 18 V
Characteristic
Symbol
Operation Start Voltage
VCC(ON)
Operation Stop Voltage*
VCC(OFF)
Circuit Current in Operation
ICC(ON)
Minimum Start Voltage
VST(ON)
Startup Current
ISTARTUP
Startup Current Threshold Biasing
Voltage*
Average Operation Frequency
Frequency Modulation Deviation
Maximum Duty Cycle
Leading Edge Blanking Time
Test Conditions
VCC = 12 V
Pins
Min.
Typ.
Max.
Unit
2–3
13.8
15.3
16.8
V
2–3
7.3
8.1
8.9
V
2–3
−
−
2.5
mA
8–3
−
40
−
V
2–3
−3.9
−2.5
−1.1
mA
VCC(BIAS)
2–3
8.5
9.5
10.5
V
fOSC(AVG)
8–3
90
100
110
kHz
VCC = 13.5 V
Δf
8–3
−
8
−
kHz
DMAX
8–3
77
83
89
%
tBW
–
−
280
−
ns
OCP Compensation Coefficient
DPC
–
−
27
−
mV/μs
OCP Compensation Duty Cycle Limit
DDPC
−
−
36
−
%
OCP Threshold Voltage at
Zero Duty Cycle
VOCP(L)
1–3
0.69
0.78
0.87
V
OCP Threshold Voltage at
36% Duty Cycle
VOCP(H)
1–3
0.79
0.88
0.97
V
Maximum Feedback Current
IFB(MAX)
4–3
−110
−70
−35
μA
Minimum Feedback Current
IFB(MIN)
4–3
−30
−15
−7
μA
FB/OLP Oscillation Stop Threshold
Voltage
VFB(OFF)
VCC = 32 V
4–3
1.09
1.21
1.33
V
OLP Threshold Voltage
VFB(OLP)
VCC = 32 V
4–3
7.3
8.1
8.9
V
OLP Operation Current
ICC(OLP)
VCC = 12 V
2–3
−
230
−
μA
tOLP
–
54
70
86
ms
FB/OLP Clamp Voltage
VFB(CLAMP)
4–3
11.0
12.8
14.0
V
OVP Threshold Voltage
VCC(OVP)
2–3
27.5
29.5
31.5
V
TJ(TSD)
−
135
−
−
°C
OLP Delay Time
Thermal Shutdown Activating
Temperature
*VCC(BIAS) > VCC(OFF) always.
STR3A160HD-DS
SANKEN ELECTRIC CO., LTD.
4
July 20, 2012
STR3A161HD, STR3A162HD,
STR3A163HD
PWM Off-Line Switching Regulator ICs
Electrical Characteristics of MOSFET Unless specifically noted, TA is 25°C
Characteristic
Symbol
Drain-to-Source Breakdown Voltage
VDSS
Drain Leakage Current
IDSS
Test Conditions
Pins
Min.
Typ.
Max.
Unit
8–1
700
–
–
V
8–1
–
–
300
μA
–
–
4.2
Ω
–
–
3.2
Ω
–
–
2.2
Ω
8–1
–
–
250
ns
–
–
–
18
°C/W
STR3A161HD
On-Resistance
RDS(ON)
STR3A162HD
8–1
STR3A163HD
Switching Time
Thermal Resistance
STR3A160HD-DS
tf
Rθch-C
The thermal resistance between
channel and case. Case
temperature (TC) is measured at the
center of the branded side.
SANKEN ELECTRIC CO., LTD.
5
July 20, 2012
STR3A161HD, STR3A162HD,
STR3A163HD
PWM Off-Line Switching Regulator ICs
Characteristic Performance
STR3A161HD
MOSFET Safe Operating Area Curve
100
10
Single pulse, TA = 25°C
0.1 ms
80
Drain Current, ID (A)
Safe Operating Area
Temperature Derating Coefficient (%)
S. O. A. Temperature Derating Coefficient Curve
60
40
20
0
0
25
50
75
100
125
1
1 ms
Drain current limited
by on-resistance
0.1
To use this graph, apply the S.O.A.
temperature derating coefficient
taken from the graph at the left
150
Channel Temperature, Tch (°C)
0.01
1
10
100
1000
Drain-to-Source Voltage, VDS (V)
MOSFET Temperature versus Power Dissipation Curve
100
Allowable Power Dissipation, PD1 (W)
EAS
Temperature Derating Coefficient (%)
MOSFET Avalanche Energy Derating Coefficient Curve
80
60
40
20
0
25
50
75
100
125
150
2.0
PD1 = 1.68 W
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
Transient Thermal Resistance, Rθch-c (°C/W)
Channel Temperature, Tch (°C)
10
25
50
75
100
125
150
Ambient Temperature, TA (°C)
Transient Thermal Resistance Curve
1
0.1
0.01
10–6
10–5
10–4
10–3
10–2
10–1
Time (s)
STR3A160HD-DS
SANKEN ELECTRIC CO., LTD.
6
July 20, 2012
STR3A161HD, STR3A162HD,
STR3A163HD
PWM Off-Line Switching Regulator ICs
Characteristic Performance
STR3A162HD
MOSFET Safe Operating Area Curve
100
10
Single pulse, TA = 25°C
0.1 ms
80
Drain Current, ID (A)
Safe Operating Area
Temperature Derating Coefficient (%)
S. O. A. Temperature Derating Coefficient Curve
60
40
20
0
0
25
50
75
100
125
1 ms
1
Drain current limited
by on-resistance
0.1
To use this graph, apply the S.O.A.
temperature derating coefficient
taken from the graph at the left
150
Channel Temperature, Tch (°C)
0.01
1
10
100
1000
Drain-to-Source Voltage, VDS (V)
MOSFET Temperature versus Power Dissipation Curve
100
Allowable Power Dissipation, PD1 (W)
EAS
Temperature Derating Coefficient (%)
MOSFET Avalanche Energy Derating Coefficient Curve
80
60
40
20
0
25
50
75
100
125
150
2.0
PD1 = 1.68 W
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
Channel Temperature, Tch (°C)
25
50
75
100
125
150
Ambient Temperature, TA (°C)
Transient Thermal Resistance, Rθch-c (°C/W)
Transient Thermal Resistance Curve
100
10
1
0.1
0.01
10–6
10–5
10–4
10–3
10–2
10–1
Time (s)
STR3A160HD-DS
SANKEN ELECTRIC CO., LTD.
7
July 20, 2012
STR3A161HD, STR3A162HD,
STR3A163HD
PWM Off-Line Switching Regulator ICs
Characteristic Performance
STR3A163HD
MOSFET Safe Operating Area Curve
100
10
Single pulse, TA = 25°C
0.1 ms
80
Drain Current, ID (A)
Safe Operating Area
Temperature Derating Coefficient (%)
S. O. A. Temperature Derating Coefficient Curve
60
40
20
0
0
25
50
75
100
125
1 ms
1
Drain current limited
by on-resistance
0.1
To use this graph, apply the S.O.A
temperature derating coefficient
taken from the graph at the left
150
Channel Temperature, Tch (°C)
0.01
1
10
100
1000
Drain-to-Source Voltage, VDS (V)
MOSFET Temperature versus Power Dissipation Curve
100
Allowable Power Dissipation, PD1 (W)
EAS
Temperature Derating Coefficient (%)
MOSFET Avalanche Energy Derating Coefficient Curve
80
60
40
20
0
25
50
75
100
125
150
2.0
PD1 = 1.76 W
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
Transient Thermal Resistance, Rθch-c (°C/W)
Channel Temperature, Tch (°C)
10
25
50
75
100
125
150
Ambient Temperature, TA (°C)
Transient Thermal Resistance Curve
1
0.1
0.01
10–6
10–5
10–4
10–3
10–2
10–1
Time (s)
STR3A160HD-DS
SANKEN ELECTRIC CO., LTD.
8
July 20, 2012
STR3A161HD, STR3A162HD,
STR3A163HD
PWM Off-Line Switching Regulator ICs
Functional Block Diagram
2
Control Part
VCC
D/ST
Startup
UVLO
Reg
PWM
Oscillator
VREG
OVP
5, 6,
7, 8
TSD
DRV
SQ
R
OCP
VCC
4
OLP
Drain Peak Current
compensation
Feedback
control
FB/OLP
LEB
Slope
compensation
S/OCP
GND
1
3
Pin List Table
Pin-out Diagram
S/GND 1
8 D/ST
VCC 2
7 D/ST
GND 3
6 D/ST
FB/OLP 4
5 D/ST
STR3A160HD-DS
Number
Name
1
S/OCP
Function
2
VCC
Power supply voltage input for Control Part and input of Overvoltage
Protection (OVP) signal
3
GND
Ground
4
FB/OLP
5, 6,7, 8
D/ST
MOSFET source and input of Overcurrent Protection (OCP) signal
Feedback signal input for constant voltage control signal and input of
Overload Protection (OLP) signal
MOSFET drain pin and input of the startup current
SANKEN ELECTRIC CO., LTD.
9
July 20, 2012
STR3A161HD, STR3A162HD,
STR3A163HD
PWM Off-Line Switching Regulator ICs
Package Diagram
DIP8 package
9.4 ±0.3
5
1
4
6.5 ±0.2
8
1.0 +0.3
-0.05
+0.3
1.52
-0.05
3.3 ±0.2
7.5 ±0.5
4.2 ±0.3
3.4 ±0.1
(7.6 TYP)
0.2 5 + 0.
- 0.01
5
０～１５° ０～１５°
2.54 TYP
0.89 TYP
0.5 ±0.1
Unit： mm
3A16xH
SK YMD
Pb-free.
Device composition compliant
with the RoHS directive.
STR3A160HD-DS
SANKEN ELECTRIC CO., LTD.
Part Number
Lot Number
Y is the last digit of the year (0 to 9)
M is the month (1 to 9, O, N, or D)
D is a period of days:
1 – 1st to 10th
2 – 11th to 20th
3 – 21st to 31st
Sanken Control Number
10
July 20, 2012
STR3A161HD, STR3A162HD,
STR3A163HD
PWM Off-Line Switching Regulator ICs
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°C 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 Silicone Grease with a Heatsink
• When silicone grease is used in mounting the products on a
heatsink, it shall be applied evenly and thinly. If more silicone
grease than required is applied, it may produce excess stress.
• Volatile-type silicone greases may crack after long periods of
time, resulting in reduced heat radiation effect. Silicone greases
with low consistency (hard grease) may cause cracks in the mold
resin when screwing the products to a heatsink.
Our recommended silicone greases for heat radiation purposes,
which will not cause any adverse effect on the product life, are
indicated below:
Type
Suppliers
G746
Shin-Etsu Chemical Co., Ltd.
YG6260
Momentive Performance Materials Inc.
SC102
Dow Corning Toray Co., Ltd.
STR3A160HD-DS
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 1 MΩ 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.
SANKEN ELECTRIC CO., LTD.
11
July 20, 2012
STR3A161HD, STR3A162HD,
STR3A163HD
PWM Off-Line Switching Regulator ICs
• 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 and operation 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 or
any other rights of Sanken or any third party which may result from its use.
• 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.
• 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.
• 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.
STR3A160HD-DS
SANKEN ELECTRIC CO., LTD.
12
July 20, 2012
Application Information
STR3A100 Series PWM Off-Line Switching Regulator ICs
General Description
STR3A100 series are power ICs for switching power supplies, incorporating a power MOSFET and a current mode
PWM controller IC in one package.
Including a startup circuit and a standby function in the controller, the product achieves low power consumption, low
standby power, and high cost-effectiveness in power supply
systems, while reducing external components.
Features and Benefits
• Current mode PWM control
• Built-in Random Switching function: reduces
EMI noise, simplifies EMI filters, and cuts cost by
external part reduction
• Built-in Slope Compensation function: avoids
subharmonic oscillation
• Built-in Leading Edge Blanking (LEB) function
• Auto Standby function:
▫ Input power, PIN < 10 mW at no load with low power
consumption shunt regulator
▫ Normal load operation: PWM switching
▫ Light load operation: Standby mode (Burst oscillation)
• Soft Start function: reduces stress on internal power
MOSFET and secondary output rectifier diode at startup
• Protection Functions:
▫ Overcurrent Protection function (OCP); pulse-by-pulse,
built-in compensation circuit to minimize OCP point
variation on AC input voltage
Figure 1. The STR3A100 series package is a fully molded, industrystandard DIP8.
▫ Overload Protection function (OLP); auto restart,
built-in timer, reduces heat during overload condition,
and no external components required
▫ Overvoltage Protection function (OVP); latched
shutdown, or auto restart for D and HD types
▫ Thermal Shutdown function (TSD); latched shutdown,
or auto restart for D and HD types
Applications
Switching power supplies for electronic devices such as:
• Stand-by power supply for LCD/PDP television,
desktop PC, multi-function printer, audio equipment,
and so forth
• Small switched-mode power supply (SMPS) for printer,
BD/DVD player, set-top box, and so forth
• Auxiliary power supply for air conditioner, refrigerator,
washer, dishwasher, and so forth
The product lineup for the STR3A100 series provides the following options:
Part Number
STR3A151
STR3A152
STR3A153
STR3A154
STR3A155
fOSC
(kHz)
67
POUT*
(W)
MOSFET
OVP/TSD
VDSS(min)
(V)
RDS(on)(max)
(Ω)
230 VAC
85 to 265 VAC
650
4.0
3.0
1.9
1.4
1.1
24
30
36
40
43
16
23
30
32
35
Latched
24
30
36
40
43
16
23
30
32
35
Auto restart
26
29
35
17
20
29
Auto restart
STR3A151D
STR3A152D
STR3A153D
STR3A154D
STR3A155D
67
650
4.0
3.0
1.9
1.4
1.1
STR3A161HD
STR3A162HD
STR3A163HD
100
700
4.2
3.2
2.2
Part Number Assignment:
*The listed output power is based on the thermal ratings, and the peak output power can be 120% to
140% of the value stated here. At low output voltage and short duty cycle, the output power may be less
than the value stated here.
STR3A100-AN Rev.1.1
SANKEN ELECTRIC CO., LTD.
STR3A1 nn a a
1
2 34
1. Product series name
2. ID number for VDSS and RDS(ON)
of the incorporated power MOSFET
3. fOSC: 67 kHz, or 100 kHz for H type
4. OVP, TSD protection: latched, or
auto restart for D type
Functional Block Diagram
Control Part
VCC
2
D/ST
Startup
UVLO
Reg
PWM
Oscillator
VREG
OVP
5, 6,
7, 8
TSD
DRV
SQ
R
OCP
VCC
OLP
Feedback
control
FB/OLP
4
Drain Peak Current
compensation
LEB
Slope
compensation
S/OCP
GND
1
3
Pin List Table
Pin-out Diagram
S/GND 1
8 D/ST
VCC 2
7 D/ST
GND 3
6 D/ST
FB/OLP 4
5 D/ST
Number
Name
1
S/OCP
Function
MOSFET source and input of Overcurrent Protection (OCP) signal
2
VCC
Power supply voltage input for Control Part and input of Overvoltage
Protection (OVP) signal
3
GND
Ground
4
FB/OLP
5, 6,7, 8
D/ST
Feedback signal input for constant voltage control signal and input of
Overload Protection (OLP) signal
MOSFET drain pin and input of the startup current
Table of Contents
Specifications
3
Package Outline Drawing
Package Diagram
Absolute Maximum Ratings
Electrical Characteristics
Typical Application
3
3
4
5
7
Functional Description
8
Startup Operation
8
Startup Period
Undervoltage Lockout (UVLO) Circuit
Bias Assist Function
Auxiliary Winding
STR3A100-AN Rev.1.1
8
8
9
9
Soft-Start Function
Constant Output Voltage Control
Automatic Standby Mode Function
Random Switching Function
Overcurrent Protection Function (OCP)
Overvoltage Protection Function (OVP)
Overload Protection Function (OLP)
Thermal Shutdown Function (TSD)
Design Notes
10
11
12
12
12
13
14
14
15
Peripheral Components
15
Phase Compensation
15
PCB Trace Layout and Component Placement 15
SANKEN ELECTRIC CO., LTD.
2
Package Diagram
DIP8 package
9.4 ±0.3
5
1
4
6.5 ±0.2
8
1.0 +0.3
-0.05
+0.3
1.52
-0.05
3.3 ±0.2
7.5 ±0.5
4.2 ±0.3
3.4 ±0.1
(7.6 TYP)
0.2 5 + 0.
- 0.01
5
０～１５° ０～１５°
2.54 TYP
0.89 TYP
0.5 ±0.1
Unit： mm
STR3A15x markings
3A15x
SK YMD
Pb-free.
Device composition compliant
with the RoHS directive.
XXXX
STR3A15xD markings
3A15xD
SK YMD
XXXX
STR3A100-AN Rev.1.1
Part Number
Lot Number
Y is the last digit of the year (0 to 9)
M is the month (1 to 9, O, N, or D)
D is a period of days:
1 – 1st to 10th
2 – 11th to 20th
3 – 21st to 31st
Sanken Control Number
STR3A16xHD markings
3A16xH
SK YMD
Part Number
Lot Number
Y is the last digit of the year (0 to 9)
M is the month (1 to 9, O, N, or D)
D is a period of days:
1 – 1st to 10th
2 – 11th to 20th
3 – 21st to 31st
Sanken Control Number
XXXX
SANKEN ELECTRIC CO., LTD.
Part Number
Lot Number
Y is the last digit of the year (0 to 9)
M is the month (1 to 9, O, N, or D)
D is a period of days:
1 – 1st to 10th
2 – 11th to 20th
3 – 21st to 31st
Sanken Control Number
3
Electrical Characteristics
• Refer to the datasheet of each product for these details.
• The polarity value for current specifies a sink as "+ ," and a source as “−,” referencing the IC.
Absolute Maximum Ratings Unless specifically noted, TA is 25°C
Characteristic
Drain Peak Current
Avalanche Energy
Symbol
IDPEAK
EAS
Rating
Unit
STR3A151
STR3A151D
STR3A161HD
Notes
3.6
A
STR3A152
STR3A152D
STR3A162HD
4
A
STR3A163HD
Pins
4.8
A
STR3A153
STR3A153D
5.2
A
STR3A154
STR3A154D
6.4
A
STR3A155
STR3A155D
7.2
A
Single pulse
8−1
STR3A151
STR3A151D
Single pulse, ILPEAK = 2.13 A
53
mJ
STR3A152
STR3A152D
Single pulse, ILPEAK = 2.19 A
56
mJ
STR3A153
STR3A153D
Single pulse, ILPEAK = 2.46 A
72
mJ
STR3A154
STR3A154D
Single pulse, ILPEAK = 2.66 A
83
mJ
STR3A155
STR3A155D
Single pulse, ILPEAK = 3.05 A
110
mJ
STR3A161HD
Single pulse, ILPEAK = 1.43 A
23.8
mJ
STR3A162HD
Single pulse, ILPEAK = 1.58 A
29
mJ
STR3A163HD
Single pulse, ILPEAK = 1.88 A
8−1
41
mJ
−2 to 6
V
2−3
32
V
4−3
−0.3 to 14
V
4−3
1.0
mA
1.68
W
1.76
W
1.81
W
S/OCP Pin Voltage
VOCP
1−3
Control Part Input Voltage
VCC
FB/OLP Pin Voltage
VFB
FB/OLP Pin Sink Current
IFB
STR3A151
STR3A151D
STR3A152
STR3A152D
STR3A161HD
STR3A162HD
MOSFET Power Dissipation
PD1
STR3A153
STR3A153D
STR3A154
STR3A154D
STR3A163HD
Mounted on 15 mm × 15 mm
printed circuit board
8−1
STR3A155
STR3A155D
Control Part Power Dissipation
PD2
2−3
1.3
W
Operating Ambient Temperature
TOP
–
−40 to 125
°C
Storage Temperature
Tstg
–
−40 to 125
°C
Channel Temperature
Tch
–
150
°C
STR3A100-AN Rev.1.1
VCC × ICC
SANKEN ELECTRIC CO., LTD.
4
Electrical Characteristics of Control Part Unless specifically noted, TA is 25°C, VCC = 18 V
Characteristic
Symbol
Operation Start Voltage
VCC(ON)
Operation Stop Voltage*
VCC(OFF)
Circuit Current in Operation
ICC(ON)
Minimum Start Voltage
VST(ON)
Startup Current
ISTARTUP
Startup Current Threshold Biasing
Voltage*
VCC(BIAS)
Average Operation Frequency
fOSC(AVG)
Frequency Modulation Deviation
Maximum Duty Cycle
Leading Edge Blanking Time
OCP Compensation Coefficient
OCP Compensation Duty Cycle Limit
Test Conditions
VCC = 12 V
Pins
Min.
Typ.
Max.
Unit
2–3
13.8
15.3
16.8
V
2–3
7.3
8.1
8.9
V
2–3
−
−
2.5
mA
8–3
−
40
−
V
2–3
−3.9
−2.5
−1.1
mA
2–3
8.5
9.5
10.5
V
STR3A15x
STR3A15xD
8–3
60
67
74
kHz
STR3A16xHD
8–3
90
100
110
kHz
Δf
STR3A15x
STR3A15xD
8–3
−
5
−
kHz
STR3A16xHD
8–3
−
8
−
kHz
DMAX
STR3A15x
STR3A15xD
8–3
65
74
83
%
STR3A16xHD
tBW
DPC
VCC = 13.5 V
8–3
77
83
89
%
STR3A15x
STR3A15xD
–
−
350
−
ns
STR3A16xHD
–
−
280
−
ns
STR3A15x
STR3A15xD
–
−
17
−
mV/μs
STR3A16xHD
–
−
27
−
mV/μs
DDPC
−
−
36
−
%
OCP Threshold Voltage at
Zero Duty Cycle
VOCP(L)
1–3
0.69
0.78
0.87
V
OCP Threshold Voltage at
36% Duty Cycle
VOCP(H)
1–3
0.79
0.88
0.97
V
Maximum Feedback Current
IFB(MAX)
4–3
−110
−70
−35
μA
Minimum Feedback Current
IFB(MIN)
4–3
−30
−15
−7
μA
FB/OLP Oscillation Stop Threshold
Voltage
VFB(OFF)
STR3A151
STR3A151D
STR3A152
STR3A152D
STR3A153
STR3A153D
STR3A16xHD
VCC = 32 V
4–3
1.09
1.21
1.33
V
STR3A154
STR3A154D
STR3A155
STR3A155D
VCC = 32 V
4–3
0.85
0.98
1.09
V
OLP Threshold Voltage
VFB(OLP)
VCC = 32 V
4–3
7.3
8.1
8.9
V
OLP Operation Current
ICC(OLP)
VCC = 12 V
2–3
−
230
−
μA
tOLP
–
54
70
86
ms
FB/OLP Clamp Voltage
VFB(CLAMP)
4–3
11
12.8
14.0
V
OVP Threshold Voltage
VCC(OVP)
2–3
27.5
29.5
31.5
V
TJ(TSD)
−
135
−
−
°C
OLP Delay Time
Thermal Shutdown Activating
Temperature
*VCC(BIAS) > VCC(OFF) always.
STR3A100-AN Rev.1.1
SANKEN ELECTRIC CO., LTD.
5
Electrical Characteristics of MOSFET Unless specifically noted, TA is 25°C
Characteristic
Drain-to-Source Breakdown Voltage
Symbol
VDSS
Test Conditions
STR3A15x
STR3A15xD
Pins
8–1
STR3A16xHD
Drain Leakage Current
On-Resistance
Switching Time
Thermal Resistance
IDSS
RDS(ON)
8–1
Max.
Unit
650
–
–
V
700
–
–
V
–
–
300
μA
–
–
4.0
Ω
STR3A152
STR3A152D
–
–
3.0
Ω
STR3A153
STR3A153D
–
–
1.9
Ω
–
–
1.4
Ω
STR3A155
STR3A155D
–
–
1.1
Ω
STR3A161HD
–
–
4.2
Ω
STR3A162HD
–
–
3.2
Ω
STR3A163HD
–
–
2.2
Ω
8–1
–
–
250
ns
–
–
–
18
°C/W
–
–
–
17
°C/W
STR3A154
STR3A154D
STR3A151
STR3A151D
STR3A152
STR3A152D
STR3A153
STR3A153D
STR3A16xHD
STR3A154
STR3A154D
STR3A155
STR3A155D
STR3A100-AN Rev.1.1
Typ.
STR3A151
STR3A151D
8–1
tf
Rθch-C
Min.
The thermal
resistance
between channel
and case. Case
temperature (TC)
is measured at
the center of the
branded side.
SANKEN ELECTRIC CO., LTD.
6
Typical Application Circuit
C9
CRD Snubber Circuit
D1
VAC
C5
L2
D4
T1
R3
R9
PC1
P
C1
D3
7
6
R8
S
C8
C6
R6
5
D2
D/ST D/ST D/ST
NC D/ST
C4
R4
R5
C7
8
VOUT
U2
R2
R7
U1
STR3A100
C2
D
GND
S/OCP VCC GND FB/OLP
C, RC
Damper
Snubber
Circuit
1
ROCP
2
3
4
C3
PC1
The following design features should be observed:
• The PCB traces from the D/ST pins (pins 5, 6, 7, and 8) should be as wide as possible, in order to
enhance thermal dissipation.
• In applications having a power supply specified such that VDS 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 (CR) combination should be
added between the D/ST pins and the S/OCP pin.
STR3A100-AN Rev.1.1
SANKEN ELECTRIC CO., LTD.
7
Functional Description
All of the parameter values used in these descriptions are typical
values, according to the STR3A153 specification, 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).
D1
T1
VAC
C1
Startup Operation
Startup Period
Figure 2 shows the VCC pin peripheral circuit. The built-in
startup circuit is connected to the D/ST pins, and it generates a
constant current, ISTARTUP = –2.5 mA to charge capacitor C2 connected to the VCC pin. During this process, when the VCC pin
voltage reaches VCC(ON) = 15.3V, the control circuit starts operation. After that, the startup circuit stops automatically, in order to
eliminate its own power consumption.
The startup time is determined by the C2 capacitance, and a value
of 10 to 47 μF is generally recommended. The approximate startup
time, tSTART , is calculated as follows:
z
where:
C2 ×
VCC(ON) – VCC(INT)
|I(STARTUP)|
VCC
2
STR3A100
GND
D2
R2
C2
VD
3
D
Figure 2. VCC pin peripheral circuit
(1)
tSTART is the startup time in s, and
ICC
ICC(ON) (max)
= 2.5 mA
VCC(INT) is the initial voltage of the VCC pin in V.
In operation, when the VCC pin voltage decreases to VCC(OFF) =
8.1 V, the control circuit stops operation, by the UVLO (Undervoltage Lockout) circuit, and reverts to the state before startup.
The rectified voltage from the auxiliary winding, VD (figure 2)
becomes a power source to the control circuit after the operation
start.
Stop
Undervoltage Lockout (UVLO) Circuit
Figure 3 shows the relationship of VCC and ICC . When the VCC
pin voltage increases to VCC(ON) = 15.3 V, the control circuit starts
operation and the circuit current, ICC, increases.
Start
tSTART
5,6,7,8
D/ST
P
8.1 V
VCC(OFF)
15.3 V VCC pin voltage
VCC(ON)
Figure 3. VCC versus ICC
The VCC pin voltage should become as follows within the specification of input voltage range and the output load range of power
supply, taking account of the winding turns of the D winding; the
target voltage of the VCC pin voltage is about 15 to 20 V:
VCC(BIAS)(max) < VCC < VCC(OVP)(min)
(2)
10.5 (V) < VCC < 27.5 (V)
STR3A100-AN Rev.1.1
SANKEN ELECTRIC CO., LTD.
8
Bias Assist Function
Figure 4 shows the VCC pin voltage behavior during the startup
period. When the VCC pin voltage reaches VCC(ON) = 15.3 V, the
control circuit starts operation, the circuit current, ICC, increases,
and thus the VCC pin voltage begins dropping. At the same time,
the auxiliary winding voltage, VD , increases in proportion to the
output voltage rise. Thus, the VCC pin voltage is set by the balance between dropping by the increase of ICC and rising by the
increase of the auxiliary winding voltage, VD.
Just at the turning-off of the power MOSFET, a surge voltage
occurs at the output winding. If the feedback control is activated
by the surge voltage on light load condition at startup, and the
VCC pin voltage decreases to VCC(OFF) = 8.1 V, a startup failure
can occur, because the output power is restricted and the output
voltage decreases.
In order to prevent this, during a state of operating feedback
control, when the VCC pin voltage falls to the Startup Current
Threshold Biasing Voltage, VCC(BIAS) = 9.5 V, the Bias Assist function is activated. While the Bias Assist function is operating, the
decrease of the VCC pin voltage is suppressed by providing the
startup current, ISTARTUP , from the startup circuit.
VCC
pin voltage
IC startup
VCC(ON) =
15.3 V
VCC(BIAS) =
9.5 V
VCC(OFF) =
8.1 V
Startup failure
Time
Figure 4. VCC during startup period
Without R2
VCC
pin voltage
By the Bias Assist function, the use of a small value C2 capacitor
is allowed, resulting in shortened startup time. Also, because the
increase of VCC pin voltage becomes faster when the output runs
with excess voltage, the response time of the OVP function can
also be shortened. It is necessary to check and adjust the process
so that poor starting conditions may be avoided.
Auxiliary Winding
In actual power supply circuits, there are cases in which the VCC
pin voltage fluctuates in proportion to the output of the SMPS
(see figure 5), and the Overvoltage Protection (OVP) on the VCC
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 6). 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.
STR3A100-AN Rev.1.1
Startup success
Target
Operating
Voltage
Increasing by output
voltage rising
Bias Assist period
With R2
IOUT
Figure 5. VCC versus IOUT with and without resistor R2
D2
2
VCC
STR3A100
Added
R2
D
C2
GND
3
Figure 6. VCC pin peripheral circuit with R2
SANKEN ELECTRIC CO., LTD.
9
Bobbin
Barrier
The variation of VCC pin voltage becomes worse if:
P1 S1 P2 S2 D
• The coupling between the primary and secondary windings of
the transformer gets worse and the surge voltage increases (low
output voltage, large current load specification, for example).
Barrier
• The coupling of the auxiliary winding, D, and the secondary
side stabilization output winding (winding of the output line
which is controlling constant voltage) gets worse and it is subject to surge voltage.
In order to reduce the influence of surge voltages on the VCC pin,
alternative structures of the auxiliary winding, D, can be used; as
examples of transformer structural designs see figure 7.
• Winding structural example (a): Separating the auxiliary winding D from the primary side windings P1 and P2.
The primary side winding is divided into two windings, P1
and P2.
• Winding structural example (b): Placing the auxiliary winding D within the secondary winding S1 in order to improve the
coupling of those windings.
Winding structural example (a)
P1, P2 Primary side winding
S1 Secondary side winding, with controlled
constant output voltage
S2 Secondary side output winding
D Auxiliary winding for VCC
Bobbin
Barrier
P1 S1 D S2 S1 P2
The output winding S1 is a stabilized output winding, controlled
to constant voltage.
Barrier
Soft-Start Function
Figure 8 shows the behavior of VCC pin voltage and the drain
current during the startup period.
The IC activates the soft start function during the startup period.
The soft start operation period is internally fixed to approximately
7 ms, and the Overcurrent Protection (OCP) threshold voltage
steps up in five steps during this period. This reduces the voltage and current stress on the internal power MOSFET and on
the secondary-side rectifier. Because the Leading Edge Blanking
function (refer to the Constant Output Voltage Control section) is
disabled during the soft start period, the on-time may be the LEB
time, tBW = 350 ns (280 ns for STR3A16×HD series) or less. It is
necessary to check and adjust the OLP delay time and the VCC
pin voltage during startup in actual operation.
Winding structural example (b)
Figure 7. Winding structural examples
VCC pin
voltage
Start up
Steady operation
VCC(ON)
VCC(OFF)
Time
This ID is limited by
OCP operation
Drain
Current,
ID
Time
Soft-start period with
7 ms fixed internally
Figure 8. Soft-start operation waveforms at startup
STR3A100-AN Rev.1.1
SANKEN ELECTRIC CO., LTD.
10
Constant Output Voltage Control
The constant output voltage control function uses current mode
control (peak current mode), which enhances response speed and
provides stable operation. This IC compares the voltage, VROCP ,
of the current detection resistor with the target voltage, VSC,
by the internal FB comparator, and controls the peak value of
VROCP so that it gets close to VSC. VSC is internally generated by
inputting the FB/OLP pin voltage to the feedback control (see the
Functional Block diagram) and adding the slope compensation
value (refer to figures 9 and 10).
• Light load conditions When load conditions become lighter,
the output voltage, VOUT , rises, and the feedback current from the
error amplifier on the secondary side also increases. The feedback
current is sunk at the FB/OLP pin, transferred through a photocoupler, PC1, and the FB/OLP pin voltage decreases. Thus, VSC
decreases, the peak value of VROCP is controlled to be low, and
1
VROCP
3
FB/OLP
GND
S/OCP
STR3A100
4
ROCP
PC1
the peak drain current of ID increases. This control prevents the
output voltage from increasing.
• Heavy load conditions When load conditions become
greater, the control circuit 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 11. 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 that 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 during normal
operation.
IFB
C3
Figure 9. FB/OLP peripheral circuit
VSC
–
+
Target voltage without Slope Compensation
Target voltage including
Slope Compensation
VROCP
S/OCP signal
voltage across ROCP
FB Comparator
ton1
Drain
Current,
ID
T
Figure 10. Drain current, ID, and FB comparator operation in
steady operation
STR3A100-AN Rev.1.1
ton2
T
T
Figure 11. Drain current, ID, waveform in subharmonic oscillation
SANKEN ELECTRIC CO., LTD.
11
In the current-mode control method, the FB comparator and/or
the OCP comparator may respond to the surge voltage resulting
from the drain surge current in turning-on the power MOSFET,
and may turn off the power MOSFET irregularly. Leading Edge
Blanking, tBW = 350 ns (280 ns for STR3A16×HD series), is
built-in to prevent malfunctions caused by surge voltage in
turning-on the power MOSFET.
However, if the Bias Assist function is always activated during
Standby mode, the power loss increases. Therefore, the VCC pin
voltage should be more than VCC(BIAS) , for example, by adjusting the turns ratio between the auxiliary winding and secondary
winding and/or reducing the value of R2 in figure 6.
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 20% to 25% (15% to 20% for STR3A154/54D
and STR3A155/55D) of the maximum drain current (it is in the
Overcurrent Protection state).
The IC modulates its switching frequency randomly within Δf
(±4%) superposed on the Average Operation Frequency. The
conduction noise with this function is smaller than that without
this function, and this function can simplify noise filtering of the
input lines of power supply.
The operation mode becomes burst oscillation, as shown in figure 12. Burst oscillation reduces switching losses and improves
power supply efficiency because of periodic non-switching
intervals. Generally, to improve efficiency under light load conditions, the frequency of the burst oscillation becomes just a few
kilohertz.
Overcurrent Protection Function (OCP)
During the transition to burst-oscillation, if the VCC pin voltage decreases to VCC(BIAS) = 9.5 V , the Bias Assist function is
activated and stabilizes the Standby mode operation, because
ISTARTUP is provided to the VCC pin so that the VCC pin voltage
does not decrease to VCC(OFF).
Random Switching Function
Overcurrent Protection Function (OCP) detects each peak drain
current level of the power MOSFET on pulse-by-pulse basis,
and limits the output power. This function incorporates the Input
Compensation function to reduce OCP point variation for the
AC input voltage, without any additional external components.
This OCP function detects the drain current by the current
detection resistor, ROCP , which is connected between the S/OCP
pin and the GND pin. When the voltage drops on both sides of
ROCP increase to an internal OCP threshold voltage, the power
MOSFET is turned off.
Burst Oscillation mode
Output Current, IOUT
Less than a few kilohertz
Drain Current, ID
Normal Load
Standby Load
Normal Load
Figure 12. Automatic standby mode operation
STR3A100-AN Rev.1.1
SANKEN ELECTRIC CO., LTD.
12
ICs with PWM control usually have some detection delay time
on OCP detection. The steeper the slope of the actual drain current at a high AC input voltage is, the later the actual detection
point is, compared to the internal OCP threshold voltage, VOCP.
Thus, the actual OCP point limiting the output current usually has
some variation depending on the AC input voltage, as shown in
figure 13.
Overvoltage Protection Function (OVP)
When the voltage between the VCC pin and the GND pin
increases to VCC(OVP) , 29.5 V or more, the OVP function is activated and stops switching operation. The IC has two operation
types of OVP function. One is the latched shutdown, the other is
auto restart.
The IC incorporates a built-in Input Compensation function that
superposes a signal with a defined slope onto the detection signal
on the S/OCP pin as shown in figure 14. When AC input voltage
is lower and the duty cycle is longer, the OCP compensation level
increases. Thus the OCP point in low AC input voltage increases
to minimize the difference of OCP points between low AC input
voltage and high AC input voltage.
• Latched Shutdown type: STR3A100 series. When the OVP
function is activated, the IC stops switching operation. The VCC
pin voltage decreases to VCC(BIAS) = 9.5 V, and then the Bias
Assist function is activated. Because the Bias Assit function prevents the VCC pin voltage from decreasing to VCC(OFF) = 8.1 V,
by applying the startup current, the IC remains in latched state.
Releasing the latched state is done by turning off the input voltage and by dropping the VCC pin voltage below VCC(OFF) .
Because the compensation signal level is designed to depend
upon the on-time of the duty cycle, the OCP threshold voltage
after compensation, VOCP(ontime) , is calculated as below. When
the duty cycle becomes 36% or more, the OCP threshold voltage
after compensation remains at VOCP(H) = 0.88 V, constantly.
VOCP(ontime) (V) = VOCP(L)(V) + DPC (mV/μs)
× On Time (μs).
where:
VOCP(L) is the OCP threshold voltage at zero duty cycle (V),
DPC is the OCP compensation coefficient (mV/μs), and
On Time is the on-time of the duty cycle (μs):
On Time = (D / fOSC(AVG))
(3)
• Auto Restart type: STR3A100D and STR3A100HD series.
While the OVP function is active, because the Bias Assist function is disabled, the VCC pin voltage falls below VCC(OFF) . At that
time, the UVLO (Undervoltage Lockout) circuit becomes active,
stopping the control circuit and then the IC reverts to the state
before startup. Then, when the VCC pin voltage rises due to the
startup current and reaches VCC(ON) = 15.3 V, the control circuit
will return to normal operation again. In this manner, the intermittent oscillation mode is operated by the UVLO circuit repeatedly while there is an excess voltage condition. By this intermittent oscillation operation, stress on the internal and external
circuits, such as the power MOSFET and the secondary rectifier
diode, is reduced. Furthermore, because the switching period is
shorter than an oscillation stop period, power consumption under
intermittent operation can be minimized. When the fault condition is removed, the IC returns to normal operation automatically.
265 VAC (as an example)
85 VAC (as an example)
0.88 V
0.9
Variance resulting from
propagation delay
t
npu
Ci
A
ut
Low
inp
AC
h
Hig
Output Current,
IOUT
Figure 13. Output current at OCP without input compensation
STR3A100-AN Rev.1.1
About 0.82
VOCP(ontime) Typical (V)
Output Voltage,
VOUT
0.5
0
0
15
36
80
100
Duty Cycle, D (%)
Figure 14. Relationship of duty cycle and VOCP after compensation
SANKEN ELECTRIC CO., LTD.
13
When the auxiliary winding supplies the VCC pin voltage, the
OVP function is able to detect an excessive output voltage, such
as when the detection circuit for output control is open on the
secondary side, because the VCC pin voltage is proportional to
the output voltage.
mode operation by the UVLO circuit is performed repeatedly.
When the fault condition is removed, the IC returns to normal
operation automatically.
The output voltage of the secondary side at OVP operation,
VOUT(OVP) , is calculated approximately as follows:
If the temperature of the Control Part of the IC reaches more
than the Thermal Shutdown Activating Temperature TJ(TSD) =
135°C (min), the Thermal Shutdown function (TSD) is activated.
VOUT(OVP) =
VOUT(normal operation)
× 29.5 (V)
VCC(normal operation)
(4)
Overload Protection Function (OLP)
When the peak drain current of ID is limited by OCP operation,
the output voltage, VOUT , decreases and the feedback current
from the secondary photo-coupler, IFB (see figure 15), becomes
zero. As a result, the FB/OLP pin voltage increases. When the
FB/OLP pin voltage increases to VFB(OLP) = 8.1 V, or more, and
remains at that level for the OLP Delay Time, tOLP = 70 ms, or
more, the OLP function is activated. It stops switching operation
and reduces stress on the power MOSFET, secondary rectifier,
and so on.
When the OLP function is activated, the Bias Assist function is
disabled, as mentioned in the auto restart type description of the
Overvoltage Protection Function (OVP) section, and intermittent
Thermal Shutdown Function (TSD)
The IC has two operation types of TSD function. One is the
latched shutdown, the other is auto restart. These types perform
by the same operations as mentioned in the Overvoltage Protection Function (OVP) section.
• Latched Shutdown type: STR3A100 series. When the TSD
function is active, the IC stops switching operation in latched
state. Releasing the latched state is done by turning off the input
voltage and by dropping the VCC pin voltage below VCC(OFF).
• Auto Restart type: STR3A100D, STR3A100HD series.
Intermittent mode operation by the UVLO circuit is performed
repeatedly. When the factor causing the overheating condition
is removed, and the temperature of the Control Part falls below
TJ(TSD) , the IC returns to normal operation automatically.
Switching turns off
VCC Pin
Voltage
VCC(OFF)= 8.1V
VFB(OLP)= 8.1V
FB/OLP Pin
Voltage
Drain Current,
GND FB/OLP
Switching stopped
interval
3
4
PC1
OLP Delay Time, tOLP
ID
C3
IFB
Figure 15. OLP operation waveforms (left), and FB/OLP pin peripheral circuit (right)
STR3A100-AN Rev.1.1
SANKEN ELECTRIC CO., LTD.
14
Design Notes
Peripheral Components
Take care to use the proper rating and proper type of components.
• Input and output electrolytic capacitors
▫ Apply proper design margin to accommodate ripple current,
voltage, and temperature rise.
▫ Use of high ripple current and low impedance types, designed
for switch-mode power supplies, is recommended, depending
on their purposes.
• Transformer
▫ Apply proper design margin to core temperature rise by core
loss and copper loss.
▫ Because the switching circuits contain high frequency
currents, the skin effect may become a consideration.
▫ In consideration of the skin effect, choose a suitable wire
gauge in consideration of the rms current and a current density
of about 3 to 4 A/mm2.
▫ If measures to further reduce temperature are still necessary,
use paralleled wires or litz wires to increase the total surface
area of the wiring.
• Current detection resistor, ROCP
▫ A high frequency switching current flows to ROCP , and may
cause poor operation if a high inductance resistor is used.
▫ Choose a low inductance and high surge-tolerant type.
Phase Compensation
A typical phase compensation circuit with a secondary shunt
regulator (U2) is shown in figure 16. The values for C7and R6
are recommended to be about 0.047 to 0.47 μF, and about 4.7 to
470 kΩ, respectively, and should be selected based on actual
operation in the application.
Place C3 between the FB/OLP pin and the GND pin, as shown in
figure 17, to perform high frequency noise reduction and phase
compensation. The value for C3 is recommended to be about
2200 pF to 0.01 μF, and should be selected based on actual
operation in the application.
PCB Trace Layout and Component Placement
PCB circuit trace design and component layout significantly
affect operation, EMI noise, and power dissipation. Therefore,
pay extra attention to these designs. In general, where high frequency current traces form a loop, as shown in figure 18, wide,
short traces, and small circuit loops are important to reduce line
impedance. In addition, earth ground traces affect radiated EMI
noise, and the same measures should be taken into account.
Switch-mode power supplies consist of current traces with high
frequency and high voltage, and thus trace design and component layouts should be done to comply with all safety guidelines.
Furthermore, because the incorporated power MOSFET has a
positive thermal coefficient of RDS(ON) , consider it when preparing a thermal design.
8
7
D2
STR3A100
C2
R2
T1
D
S/OCP VCC GND FB/OLP
2
ROCP
T1
5
D/ST D/ST D/ST
NC D/ST
1
3
4
C3
PC1
L2
D4
6
VOUT
Figure 17. FB/OLP peripheral circuit
R9
R4
PC1
R8
C6
S
R5
C8
C7
U2
R6
R7
GND
Figure 16. Peripheral circuit around secondary shunt regulator (U2)
STR3A100-AN Rev.1.1
Figure 18. High-frequency current loops (hatched areas)
SANKEN ELECTRIC CO., LTD.
15
Figure 19 shows a circuit layout design example.
• ROCP Trace Layout
• S/OCP Trace Layout: S/OCP pin to ROCP to C1 to T1 (winding P) to D/ST pin
ROCP should be placed as close as possible to the S/OCP pin. The
connection between the power ground of the main trace and the
control circuit ground should be at a single point ground (A in
figure 19) to remove common impedance, and to avoid interference from switching currents to the control circuit. Figure 19 also
shows a circuit layout design example for the secondary side.
This is the main trace containing switching currents, and thus
it should be as wide and short as possible. If C1 and the IC are
distant from each other, an electrolytic capacitor or film capacitor (about 0.1 μF and with proper voltage rating) near the IC or
the transformer is recommended to reduce impedance of the high
frequency current loop.
• Secondary Smoothing Circuit Trace Layout: T1 (winding S) to
D4 to C6
• GND Trace Layout: GND pin to C2 (negative pin) to T1 (winding D) to R2 to D2 to C2 (positive pin) to VCC pin
This trace should be as wide as possible. If the loop distance is
lengthy, leakage inductance resulting from the long loop may
increase surge voltage at turning off the incorporated power
MOSFET. Proper secondary trace layout helps to increase margin
against the power MOSFET breakdown voltage, and reduces
stress on the clamp snubber circuit and losses in it.
This trace also must be as wide and short as possible. If C2 and
the IC are distant from each other, placing a capacitor (approximately 0.1 to 1.0 μF film capacitor) close to the VCC pin and the
GND pin is recommended.
C9
D4
T1
R3
C5
C1
P
D3
8
7
6
S
5
D2
D/ST D/ST D/ST
NC D/ST
C4
C6
R2
U1
STR3A100
C2
D
Main power circuit trace
S/OCP VCC GND FB/OLP
1
2
ROCP
3
4
GND trace for the IC
C3
PC1
A
Figure 19. Peripheral circuit example around the IC
STR3A100-AN Rev.1.1
SANKEN ELECTRIC CO., LTD.
16
• 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 and operation 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 or
any other rights of Sanken or any third party which may result from its use.
• 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.
• 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.
• 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.
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• The contents in this document must not be transcribed or copied without Sanken's written consent.
STR3A100-AN Rev.1.1
SANKEN ELECTRIC CO., LTD.
17