STR-W6765
Quasi-Resonant Topology
Primary Switching Regulators
Description
▪ Quasi-resonant topology IC Low EMI noise and soft
switching
▪ Bottom-skip operation Improved system efficiency
over the entire output load by avoiding increase of
switching frequency
▪ Standby burst mode operation Lowers input power at
very light output load condition
▪ Avalanche-guaranteed MOSFET Improves systemlevel reliability and does not require VDSS derating
▪ 800 V / 1.8 Ω, 52 to 110 W (Universal/230 VAC input)
The STR-W6765 is a quasi-resonant topology IC designed for
SMPS applications. It shows lower EMI noise characteristics
than conventional PWM solutions, especially at greater than
2 MHz. It also provides a soft-switching mode to turn on the
internal MOSFET at close to zero voltage (VDS bottom point)
by use of the resonant characteristic of primary inductance
and a resonant capacitor.
es
ig
ns
Features and Benefits
ew
D
The package is a fully molded TO-220, which contains the
controller chip (MIC) and MOSFET, enabling output power up
to 52 W with universal input or 110 W with a 230 VAC input.
The bottom-skip mode skips the first bottom of VDS and turns
on the MOSFET at the second bottom point, to minimize an
increase of operating frequency at light output load, improving
system-level efficiency over the entire load range.
Continued on the next page…
There are two standby modes available to reduce the input
power under very light load conditions. The first is auto-burst
mode operation that is internally triggered by periodic sensing,
and the other is a manual standby mode, which is executed
by clamping the secondary output. In general applications,
the manual standby mode reduces the input power further
compared to auto-burst mode.
en
de
d
fo
rN
Package: 6-pin TO-220
Continued on the next page…
m
m
The soft-start mode minimizes surge voltage and reduces
power stress to the MOSFET and to the secondary rectifying
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o
Typical Application
+B
A
R
ErrAmp
P
N
ot
S1
GND
D
D
VCC
1
Standby
ON/OFF
LowB
4
STR-W6765
B
S2
SI
Standby
Out
GND
Cont
6
FB
S/GND
3
7
OCP
/BD
5
SS
/OLP
RX
A
B
For ErrAmp, Sanken SE series device recommended
For SI, Sanken linear regulator IC recommended
CX
ROCP
28103.30-6, Rev. 1
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp/en/
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
Description (continued)
Features and Benefits (continued)
▪ Various protections Improved system-level reliability
▫ Pulse-by-pulse drain overcurrent limiting
▫ Overvoltage protection (bias winding voltage sensing),
with latch
▫ Overload protection with latch
▫ Maximum on-time limit
diodes during the start-up sequence. Various protections such as
overvoltage, overload, overcurrent, maximum on-time protections
and avalanche-energy-guaranteed MOSFET secure good systemlevel reliability.
Applications include the following:
ns
Set Top Box
LCD PC monitor, LCD TV
Printer, Scanner
SMPS power supplies
es
ig
▪
▪
▪
▪
Selection Guide
Package
Packing
STR-W6765
TO-220
Bulk, 100 pieces
rN
ew
D
Part Number
Absolute Maximum Ratings at TA = 25°C
Input Voltage for Controller (MIC)
SS/OLP Terminal Voltage
FB Terminal Inflow Current
FB Terminal Voltage
OCP/BD Terminal Voltage
VCC
VSSOLP
IFB
VFB
VOCPBD
MOSFET Power Dissipation4
m
PD1
Rating
11.2
11.2
Unit
A
A
300
mJ
35
–0.5 to 6.0
10
–0.5 to 9.0
–1.5 to 5.0
28.7
1.3
0.8
–20 to 115
–20 to 115
–40 to 125
150
V
V
mA
V
V
W
W
W
°C
°C
°C
°C
fo
EAS
en
Single Pulse Avalanche Energy3
Terminal
Conditions
1 - 3 Single pulse
1 - 3 TA = –20°C to 125°C
Single pulse, VDD = 99 V, L = 20 mH,
1-3
ILpeak = 5.8 A
4-3
5-3
6-3
6 - 3 IFB within the limits of IFB
7-3
With infinite heatsink
1-3
Without heatsink
4 - 3 VCC × ICC
–
Refer to TOP
–
–
–
d
Symbol
IDpeak
IDmax
de
Parameter
Drain Current1
Maximum Switching Current2
N
ot
R
ec
o
m
Controller (MIC) Power Dissipation
PD2
Operating Internal Leadframe Temperature
TF
Operating Ambient Temperature
TOP
Storage Temperature
Tstg
Channel Temperature
Tch
1Refer to figure 2
2I
DMAX is the drain current determined by the drive voltage of the IC and the threshold voltage, Vth, of the MOSFET
3Refer to figure 3
4Refer to figure 5
All performance characteristics given are typical values for circuit or
system baseline design only and are at the nominal operating voltage and
an ambient temperature of +25°C, unless otherwise stated.
28103.30-6, Rev. 1
SANKEN ELECTRIC CO., LTD.
2
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
4
VCC
+
-
Reg and
Iconst
Start
Stop
Burst
R
S
OVP
S/GND
S
Q
S
+
-
OCP
R
OSC
Max On
BSD
+
BD
OLP
Soft Start
fo
Name
Description
D
2
NC
Drain
3
S/GND
Source/ground terminal
4
VCC
Power supply terminal
5
SS/OLP
6
FB
7
OCP/BD
ns
SS/OLP
7
5
Functions
MOSFET drain
No connection
de
Clipped
en
MOSFET source and ground
Input of power supply for control circuit
Input to set delay for Overload protection and Soft Start operation
Feedback terminal
Input for Constant Voltage Control and Burst (intermittent) Mode
oscillation control signals
m
Soft Start/Overload Protection terminal
m
Overcurrent Protection/Bottom Detection
Input for overcurrent detection and bottom detection signals
Figure 2 – MOSFET Safe Operating Area
ec
o
Figure 1 – MOSFET Safe Operating Area
Derating Curve
Drain Current versus Voltage
at TA = 25°C, Single Pulse
N
60
40
11.2
10.0
0.
1
it
lim (on)
nt S
rr e o R D
Cu ue t
d
1.0
m
s
s
m
Drain Current, ID (A)
ot
R
100.0
1
Safe Operating Area
Temperature Derating Coefficient (%)
6
d
1
80
OCP/BD
rN
Counter
Terminal List Table
100
+
-
ew
Bottom Select
FB
es
ig
+
FB +
3
D
R Q
Number
1
Delay
Q
Burst
Control
D
Control IC
Drive
Reg
Protection
Latch
20
Refer to figure 1 for MOSFET SOA
temperature derating coefficient
0.1
0
0
25
50
75
100
125
150
1
28103.30-6, Rev. 1
10
100
1000
Drain-to-Source Voltage, VDS (V)
Temperature, TF (°C)
SANKEN ELECTRIC CO., LTD.
3
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
Figure 3 – MOSFET Avalanche Energy Derating Curve
Figure 4 – Transient Thermal Resistance
20
0.010
0.001
0
50
75
100
125
150
1μ
10μ
100μ
10m
100m
de
d
Channel Junction Temperature, TJ (°C)
1m
Time, t (s)
fo
25
es
ig
D
40
0.100
ew
Transient Thermal Resistance, RQJC (°C/W)
60
1.000
rN
EAS Temperature Derating Coefficient (%)
80
ns
10.000
100
m
30
en
Figure 5 – MOSFET Power Dissipation versus Temperature
25
20
15
10
5
Without heatsink
PD1 = 1.3 W at TA ≤ 25°C
N
ot
R
ec
o
Power Dissipation, PD1 (W)
m
With infinite heatsink
PD1 = 28.7 W at TA ≤ 25°C
0
0
20
40
60
80
100
120
140
160
Ambient Temperature, TA (°C)
28103.30-6, Rev. 1
SANKEN ELECTRIC CO., LTD.
4
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
ELECTRICAL CHARACTERISTICS
Characteristic
Symbol
Terminals
Min.
Typ.
Max.
Units
ELECTRICAL CHARACTERISTICS for Controller (MIC)1, valid at TA = 25°C, VCC = 20 V, unless otherwise specified
Power Supply Start-up Operation
VCC(ON)
4-3
16.3
18.2
19.9
V
Operation Stop Voltage
VCC(OFF)
4-3
8.8
9.7
10.6
V
Circuit Current In Operation
ICC(ON)
4-3
–
–
6
mA
Circuit Current In Non-Operation
ICC(OFF)
4-3
–
–
100
μA
1-3
VSSOLP(SS)
5-3
22
25
kHz
1.1
1.2
1.4
V
Soft Start Operation Charging Current
ISSOLP(SS)
5-3
–710
–550
–390
μA
Bottom-Skip Operation Threshold Voltage 1
VOCPBD(BS1)
7-3
Bottom-Skip Operation Threshold Voltage 2
VOCPBD(BS2)
7-3
–0.720
–0.665
–0.605
V
–0.485
–0.435
–0.385
Overcurrent Detection Threshold Voltage
VOCPBD(LIM)
V
7-3
–0.995
–0.940
–0.895
V
IOCPBD
7-3
–250
–100
–40
μA
7-3
0.28
0.40
0.52
V
7-3
VOCPBD(TH1)
Quasi-Resonant Operation Threshold Voltage 2
VOCPBD(TH2)
FB Terminal Threshold Voltage
VFB(OFF)
IFB(ON)
0.80
0.93
V
1.32
1.45
1.58
V
6-3
600
1000
1400
μA
d
FB Terminal Inflow Current (Normal Operation)
0.67
6-3
fo
Quasi-Resonant Operation Threshold Voltage 1
rN
OCP/BDOCP/BD Terminal Outflow Current
ew
Normal Operation
19
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ig
Oscillation Frequency
D
fosc
Soft Start Operation Stop Voltage
ns
Operation Start Voltage
Standby Operation Start Voltage Interval
Standby Non-Operation Circuit Current
4-3
10.3
11.1
12.1
V
4-3
1.10
1.35
1.65
V
ICC(S)
4-3
–
20
56
μA
IFB(S)
6-3
–
4
14
μA
VFB(S)
6-3
0.55
1.10
1.50
V
m
FB Terminal Inflow Current, Standby Operation
VCC(S)
VCC(SK)
en
Standby Operation Start Voltage
de
Standby Operation
FB Terminal Threshold Voltage, Standby Operation
tON(MIN)
1-3
0.40
0.82
1.25
μs
tON(MAX)
1-3
27.5
32.5
39.0
μs
Overload Protection Operation Threshold Voltage
VSSOLP(OLP)
5-3
4.0
4.9
5.8
V
Overload Protection Operation Charging Current
5-3
–16
–11
–6
μA
VCC(OVP)
4-3
25.5
27.7
29.9
V
ICC(H)
4-3
–
45
140
μA
VCC(La.OFF)
4-3
6.0
7.2
8.5
V
R
ISSOLP(OLP)
Overvoltage Protection Operation Voltage
ot
Protection Operation
ec
o
m
Minimum On Time
Maximum On Time
Latch Circuit Holding
Current2
N
Latch Circuit Release Voltage2
ELECTRICAL CHARACTERISTICS for MOSFET, valid at TA = 25°C, unless otherwise specified
Drain-to-Source Breakdown Voltage
Drain Leakage Current
VDSS
1-3
800
–
–
V
μA
IDSS
1-3
–
–
300
On Resistance
RDS(on)
1-3
–
–
1.8
Ω
Switching Time
tf
1-3
–
–
400
ns
–
–
1.55
°C/W
Thermal Resistance
RθJA
Junction to Internal
Frame
1Current
polarity with respect to the IC: positive current indicates current sink at the terminal named, negative current indicates source at the
terminal named.
2Latch circuit refers to operation during Overload Protection or Overvoltage Protection.
28103.30-6, Rev. 1
SANKEN ELECTRIC CO., LTD.
5
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
ELECTRICAL CHARACTERISTICS Test Conditions*
Parameter
Measurement
Circuit
0→20
20→8.8
20
15
20
1
20
5
20
3
20
2
ns
D
Soft Start Operation Stop Voltage
VCC voltage at which oscillation starts.
VCC voltage at which oscillation stops.
Inflow current flowing into power supply terminal in oscillation.
Inflow current flowing into power supply terminal prior to oscillation.
Oscillating frequency ( fosc= 1 / T ).
SS/OLP terminal voltage at which ISS/OLP reach ≥–100 μA by raising the SS/OLP terminal
voltage from 0 V gradually.
es
ig
Operation Start Voltage
Operation Stop Voltage
Circuit Current In Operation
Circuit Current In Non-operation
Oscillation Frequency
Soft Start Operation Charging
Current
SS/OLP terminal charging current (SS/OLP terminal voltage = 0 V).
FB Terminal Threshold Voltage
ew
rN
fo
d
de
OCP/BD terminal voltage at which oscillation starts with setting the OCP/BD terminal voltage
at 1 V, and then lowering the voltage gradually.
OCP/BD terminal voltage at which oscillation stops by raising the OCP/BD terminal voltage
from 0 V gradually.
FB terminal voltage at which oscillation stops by raising the FB terminal voltage from 0 V
gradually.
FB terminal inflow current (FB terminal voltage = 1.6 V).
VCC voltage at which ICC reaches ≥1 mA (FB terminal voltage = 1.6 V).
ec
o
FB Terminal Inflow Current (Normal
Operation)
Standby Operation Start Voltage
Standby Operation Start Voltage
Interval
Standby Non-Operation Circuit
Current
FB Terminal Inflow Current, Standby
Operation
FB Terminal Threshold Voltage
Standby Operation
Minimum On Time
Maximum On Time
OCP/BD terminal outflow current (OCP/BD terminal voltage = –0.95 V).
en
Overcurrent Detection Threshold
Voltage
OCP/BDOCP/BD Terminal Outflow
Current
Quasi-Resonant Operation
Threshold Voltage 1
Quasi-Resonant Operation
Threshold Voltage 2
m
Bottom-Skip Operation Threshold
Voltage 2
Input 1 μs pulse width, as shown in waveform 1, to OCP/BD terminal twice after V1-3 rises.
After that, offset the input waveform gradually from 0 V in the minus direction. Measurment
of the offset voltage VOCPBD(BS1) is taken when the V1-3 start-to-fall point switches from twopulses-after to one-pulse-after.
After measuring VOCPBD(BS1), as shown in waveform 2, offset the input waveform gradually.
Measurment of the offset voltage VOCPBD(BS2) is taken when the V1-3 start-to-fall point
switches from two-pulses-after to one-pulse-after.
OCP/BD terminal voltage at which oscillation stops by lowering the OCP/BD terminal voltage
from 0 V gradually.
m
Bottom-Skip Operation Threshold
Voltage 1
Specified by VCC(SK) = VCC(S) – VCC(OFF).
20
20
0→15
–
Inflow current flowing into power supply terminals prior to oscillation (FB terminal voltage =
1.6 V).
10.2
FB terminal inflow current (FB terminal voltage = 1.6 V).
10.2
R
ot
N
VCC
(V)
Test Conditions
FB terminal voltage at which oscillation starts by raising the FB terminal voltage from 0 V
gradually.
Waveform between terminals 1 and 3 at low.
Waveform between terminals 1 and 3 at low.
4
15
20
20
6
1
Continued on the next page…
28103.30-6, Rev. 1
SANKEN ELECTRIC CO., LTD.
6
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
ELECTRICAL CHARACTERISTICS Test Conditions*, continued
Parameter
VCC
(V)
Test Conditions
Overload Protection Operation
Threshold Voltage
Overload Protection Operation
Charging Current
Overvoltage Protection Operation
Voltage
SS/OLP terminal voltage at which oscillation stops.
20
SS/OLP terminal charging current (SS/OLP terminal voltage = 2.5 V).
–
Latch Circuit Holding Current
Inflow current at VCC(OFF) – 0.3; after OVP operation.
Measurement
Circuit
es
ig
VCC voltage at which oscillation stops.
ns
5
VCC(OFF)
– 0.3
30→6
–
–
30
20
20
1
7
8
9
1
N
ot
R
ec
o
m
m
en
de
d
fo
rN
ew
D
Latch Circuit Release Voltage
VCC voltage at which ICC reaches 20 μA or lower by decreasing VCC after OVP operation.
Drain-to-Source Breakdown Voltage IDSS = 300 μA
Drain Leakage Current
VDSS = 800 V
Single Pulse Avalanche Energy
–
On-Resistance
IDS = 1.4 A
Switching Time
–
*Oscillating operation is specified with a rectangular waveform between terminals 1 and 3.
0→30
28103.30-6, Rev. 1
SANKEN ELECTRIC CO., LTD.
7
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
Measurement Circuit 1
㧝
VCC
㧠
㧟
SS/OLP
㧡
㧢
ޓT
V
100ǡ
90㧑
50㧑
10㧑
4.7kǡ
A
ICC
tf
OCP/BD
㧣
0.1ǴF
D
TON
FB
ns
S/GND
es
ig
D
VCC
ew
10V
rN
Measurement Circuit 2
S/GND
VCC
fo
D
㧟
㧠
FB
㧡
㧢
OCP/BD
㧣
en
100ǡ
de
d
㧝
SS/OLP
m
4.7kǡ
0.1ǴF
VCC
20V
ec
o
m
10V
N
ot
R
Measurement Circuit 3
D
㧝
S/GND
㧟
VCC
㧠
SS/OLP
FB
㧡
㧢
OCP/BD
㧣
100ǡ
4.7kǡ
0.1ǴF
VCC
10V
28103.30-6, Rev. 1
20V
SANKEN ELECTRIC CO., LTD.
8
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
Measurement Circuit 4
S/GND
㧝
SS/OLP
VCC
㧠
㧟
FB
㧡
OCP/BD
㧢
㧣
ns
D
0.1ǴF
V
4.7kǡ
A
D
A
VCC
rN
ew
10V
es
ig
V
100ǡ
Measurement Circuit 5
㧟
㧠
㧡
OCP/BD
FB
㧢
㧣
de
㧝
SS/OLP
VCC
fo
S/GND
d
D
en
100ǡ
m
V
A
VCC
m
20V
Measurement Circuit 6
N
ot
R
ec
o
10V
D
㧝
S/GND
㧟
VCC
㧠
SS/OLP
FB
㧡
OCP/BD
㧢
㧣
5V
OSC1
100ǡ
200㨪500nS
4.7kǡ
0.1ǴF
9V
OSC1
VCC
V1-3
10V
20V
TON㧔MIN㧕
28103.30-6, Rev. 1
SANKEN ELECTRIC CO., LTD.
9
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
Measurement Circuit 7
D
S/GND
㧟
㧠
FB
㧡
OCP/BD
㧢
㧣
ns
㧝
SS/OLP
VCC
IDSS
rN
ew
D
es
ig
VDSS
MOSFET
MOSFET measuring equipment
d
fo
Measurement Circuit 8
S/ GND
㧟
30V
VCC
㧠
FB
㧡
㧢
OCP/BD
VDS
Equation for calculation of
avalanche engery, EAS; to be
adjusted for ILPeak = 5.8 A
m
0
IL
VD S Peak
VDS
VDD
Avalanche
energy tester
ec
o
0
m
IL
N
ot
R
T1
ޓ
㧣
en
㧝
SS/OLP
VCC
de
D
E AS =
VDS Peak
1
2
⋅ L ⋅ (ILPeak ) ⋅
2
VDS Peak − VDD
VCC
Measurement Circuit 9
D
S/ GND
㧝
㧟
VCC
㧠
SS/OLP
㧡
FB
㧢
OCP/BD
㧣
4.7kǡ
VDS(ON)
IDS
0.1ǴF
RDS(ON)=VDS(ON)/IDS
20V
28103.30-6, Rev. 1
SANKEN ELECTRIC CO., LTD.
10
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
Waveform 1
ns
VDS
VOCP/BD
es
ig
GND
rN
ew
D
VOCPBD(BS1)
fo
Waveform 2
de
en
VOCP/BD
d
VDS
VOCPBD(BS2)
N
ot
R
ec
o
m
m
GND
28103.30-6, Rev. 1
SANKEN ELECTRIC CO., LTD.
11
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
PACKAGE DIMENSIONS, TO-220
ns
es
ig
16.9 ±0.3
Branding
D
2.8 MAX
2.6 ±0.1
+0.2
5.0 ±0.5
1.34 –0.1
rN
+0.2
1)
×R
(2
ew
Terminal dimension at case surface
fo
(5.4)
1.74 –0.1
10.4 ±0.5
XXXXXXXX
XXXXXXXX
Ø3.2 ±0.2
2.8 ±0.2
7.9 ±0.2
Gate Burr
4.2 ±0.2
4 ±0.2
10.0 ±0.2
+0.2
0.45 –0.1
5.08 ±0.6
Terminal dimension at lead tips
ec
o
m
m
en
de
d
6×P1.27 ±0.15 = 7.62 ±0.15
Terminal dimensions at case surface
ot
R
1 2 3 4 5 6 7
N
Gate burr: 0.3 mm (max.)
Terminal core material: Cu
Terminal treatment: Ni plating and solder dip
Heat sink material: Cu
Heat sink treatment: Ni plating
Leadform: 2003
Weight (approximate): 2.3 g
Drawing for reference only
Branding codes (exact appearance at manufacturer discretion):
1st line, type: W6765
2nd line, lot:
YMDD R
Where: Y is the last digit of the year of manufacture
M is the month (1 to 9, O, N, D)
DD is the 2-digit date
R is the manufacturer registration symbol
Dimensions in millimeters
28103.30-6, Rev. 1
SANKEN ELECTRIC CO., LTD.
12
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
Please select suitable screws for the product shape. Do not
use a flat-head machine screw because of the stress to the
products. Self-tapping screws are not recommended. When
using self-tapping screws, the screw may enter the hole
diagonally, not vertically, depending on the conditions of hole
before threading or the work situation. That may stress the
products and may cause failures.
• Recommended screw torque: 0.588 to 0.785 N●m (6 to 8
kgf●cm).
• For tightening screws, if a tightening tool (such as a driver)
hits the products, the package may crack, and internal
stress fractures may occur, which shorten the lifetime of
the electrical elements and can cause catastrophic failure.
Tightening with an air driver makes a substantial impact.
In addition, a screw torque higher than the set torque can
be applied and the package may be damaged. Therefore, an
electric driver is recommended.
When the package is tightened at two or more places, first
pre-tighten with a lower torque at all places, then tighten
with the specified torque. When using a power driver, torque
control is mandatory.
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 2.0 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.
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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:
Suppliers
G746
Shin-Etsu Chemical Co., Ltd.
YG6260
Momentive Performance Materials Inc.
SC102
Dow Corning Toray Co., Ltd.
Cautions for Mounting to a Heatsink
• When the flatness around the screw hole is insufficient, such
as when mounting the products to a heatsink that has an
extruded (burred) screw hole, the products can be damaged,
even with a lower than recommended screw torque. For
mounting the products, the mounting surface flatness should
be 0.05 mm or less.
28103.30-6, Rev. 1
SANKEN ELECTRIC CO., LTD.
13
Quasi-Resonant Topology
Primary Switching Regulators
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• 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.
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• 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.
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• 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.
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• 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.).
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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.
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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.
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• 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.
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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.
28103.30-6, Rev. 1
SANKEN ELECTRIC CO., LTD.
14