ALLEGRO STR

STR-W6735
Quasi-Resonant Topology
Primary Switching Regulators
Features and Benefits
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
▪ 500 V / 0.57 Ω, 160 W (120 Vac input)
The STR-W6735 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 operation 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.
Continued on the next page…
Package: 6-pin TO-220
The package is a fully molded TO-220, which contains the
controller chip (MIC) and MOSFET, enabling output power up
to 160 W with a 120 Vac input. The bottom-skip function skips
the first bottom of VDS and turns on the MOSFET at the second
bottom point, to minimize an increase of operational frequency
at light output load, improving system-level efficiency over
the entire load range.
There are two standby functions available to reduce the input
power under very light load conditions. The first is an 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 the auto-burst mode.
The soft-start function minimizes surge voltage and reduces
power stress to the MOSFET and to the secondary rectifying
Continued on the next page…
Typical Application
+B
A
ErrAmp
P
S1
GND
D
VCC
1
Standby
ON/OFF
D
LowB
4
STR-W6735
S2
B
SI
Standby
Out
GND
Cont
6
FB
3
S/GND
ROCP
28103.30-5
7
OCP
/BD
5
RX
SS
/OLP
CX
A
B
For ErrAmp, Sanken SE series device recommended
For SI, Sanken linear regulator IC recommended
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6735
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
Description (continued)
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:
▪
▪
▪
▪
Set Top Box
LCD PC monitor, LCD TV
Printer, Scanner
SMPS power supplies
Selection Guide
Part Number
Package
Packing
STR-W6735
TO-220
Bulk, 100 pieces
Absolute Maximum Ratings at TA = 25°C
Parameter
Drain Current1
Maximum Switching Current2
Symbol
IDpeak
IDmax
Single Pulse Avalanche Energy3
EAS
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
PD1
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
–
–
–
Rating
20
20
Unit
A
A
380
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
Controller (MIC) Power Dissipation
PD2
Operating Internal Leadframe Temperature
TF
Operating Ambient Temperature
TOP
Storage Temperature
Tstg
Junction Temperature
TJ
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.
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
2
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6735
4
VCC
+
-
Reg&
Iconst
Start
Stop
Burst
OVP
R
Burst
Control
Delay
Q
S/GND
OSC
MaxON
+
Soft Start
D
BD
+
-
OCP/BD
SS/OLP
Counter
Description
Drain
3
6
OCP
+
Bottom Selector
OLP
Name
BSD
R
FB
+
FB +
S
Q
S
1
1
S
R Q
Number
D
DRIVE
Reg
Protection
latch
7
5
Functions
MOSFET drain
2
NC
Clipped
No connection
3
S/GND
Source/ground terminal
MOSFET source and ground
4
VCC
Power supply terminal
Input of power supply for control circuit
5
SS/OLP
Soft Start/Overload Protection terminal
Input to set delay for Overload Protection and Soft Start operation
6
FB
Feedback terminal
Input for Constant Voltage Control and Burst (intermittant)Mode
oscillation cotnrol signals
7
OCP/BD
Overcurrent Protection/Bottom Detection
Input for overcurrent detection and bottom detection signals
Figure 1 – MOSFET Safe Operating Area
Derating Curve
Figure 2 – MOSFET Safe Operating Area
Drain Current versus Voltage
at TA = 25°C, Single Pulse
100.00
20.00
80
Drain Current, ID (A)
m
s
s
40
1
m
60
0.
it
t lim on)
(
rren
Cu to R DS
due
10.00
1
Safe Operating Area
Temperature Derating Coefficient (%)
100
1.00
0.10
20
Refer to figure 1 for MOSFET SOA
temperature derating coefficient
0
0
25
50
75
100
125
150
0.01
1
10
100
1000
Drain-to-Source Voltage, VDS (V)
Temperature, TF (°C)
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
3
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6735
Figure 3 – MOSFET Avalanche Energy Derating Curve
Figure 4 – Transient Thermal Resistance
10.000
Transient Thermal Resistance, RQJC (°C/W)
80
60
40
20
0
1.000
0.100
0.010
0.001
25
50
75
100
125
150
1μ
10μ
100μ
1m
10m
100m
Time, t (s)
Channel Junction Temperature, TJ (°C)
Figure 5 – MOSFET Power Dissipation versus Temperature
30
25
Power Dissipation, PD1 (W)
EAS Temperature Derating Coefficient (%)
100
With infinite heatsink
PD1 = 28.7 W at TA ”ƒ&
20
15
10
5
0
Without heatsink
PD1 = 1.3 W at TA ”ƒ&
0
20
40
60
80
100
120
140
160
Ambient Temperature, TA (°C)
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
4
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6735
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
Operation Start Voltage
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
Oscillation Frequency
fosc
1-3
19
22
25
kHz
Soft Start Operation Stop Voltage
VSSOLP(SS)
5-3
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
–0.720
–0.665
–0.605
V
Bottom-Skip Operation Threshold Voltage 2
VOCPBD(BS2)
7-3
–0.485
–0.435
–0.385
V
Overcurrent Detection Threshold Voltage
VOCPBD(LIM)
7-3
–0.995
–0.940
–0.895
V
Normal Operation
IOCPBD
7-3
–250
–100
–40
μA
Quasi-Resonant Operation Threshold Voltage 1
VOCPBD(TH1)
7-3
0.28
0.40
0.52
V
Quasi-Resonant Operation Threshold Voltage 2
VOCPBD(TH2)
7-3
0.67
0.80
0.93
V
VFB(OFF)
6-3
1.32
1.45
1.58
V
IFB(ON)
6-3
600
1000
1400
μA
Standby Operation Start Voltage
VCC(S)
4-3
10.3
11.1
12.7
V
Standby Operation Start Voltage Interval
VCC(SK)
4-3
1.10
1.35
1.75
V
OCP/BDOCP/BD Terminal Outflow Current
FB Terminal Threshold Voltage
FB Terminal Inflow Current (Normal Operation)
Standby Operation
Standby Non-Operation Circuit Current
ICC(S)
4-3
–
20
56
μA
FB Terminal Inflow Current, Standby Operation
IFB(S)
6-3
–
4
14
μA
FB Terminal Threshold Voltage, Standby Operation
VFB(S)
6-3
0.55
1.10
1.50
V
Minimum On Time
tON(MIN)
1-3
–
0.75
1.20
μs
Maximum On Time
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
ISSOLP(OLP)
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
–
V
μA
Protection Operation
Overvoltage Protection Operation Voltage
Latch Circuit Holding
Current2
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
500
–
IDSS
1-3
–
–
300
On Resistance
RDS(on)
1-3
–
–
0.57
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.
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
5
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6735
ELECTRICAL CHARACTERISTICS Test Conditions*
Parameter
Operation Start Voltage
Operation Stop Voltage
Circuit Current In Operation
Circuit Current In Non-operation
Oscillation Frequency
Soft Start Operation Stop Voltage
Soft Start Operation Charging
Current
Bottom-Skip Operation Threshold
Voltage 1
Bottom-Skip Operation Threshold
Voltage 2
Overcurrent Detection Threshold
Voltage
OCP/BDOCP/BD Terminal Outflow
Current
Quasi-Resonant Operation
Threshold Voltage 1
Quasi-Resonant Operation
Threshold Voltage 2
FB Terminal Threshold Voltage
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
Overload Protection Operation
Threshold Voltage
Overload Protection Operation
Charging Current
Overvoltage Protection Operation
Voltage
Latch Circuit Holding Current
Test Conditions
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.
VCC
(V)
Measurement
Circuit
0→20
20→8.8
20
15
20
1
20
5
20
3
20
2
SS/OLP terminal charging current (SS/OLP terminal voltage = 0 V).
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.
OCP/BD terminal outflow current (OCP/BD terminal voltage = –0.95 V).
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).
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
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.
20
20
SS/OLP terminal voltage at which oscillation stops.
20
SS/OLP terminal charging current (SS/OLP terminal voltage = 2.5 V).
–
4
15
6
1
5
VCC voltage at which oscillation stops.
Inflow current at VCC(OFF) – 0.3; after OVP operation.
Latch Circuit Release Voltage
VCC voltage at which ICC reaches 20 μA or lower by decreasing VCC after OVP operation.
*Oscillating operation is specified with a rectangular waveform between terminals 1 and 3.
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
0→30
VCC(OFF)
– 0.3
30→6
1
6
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6735
Measurement Circuit 1
D
㧝
S/GND
VCC
SS/OLP
㧠
㧟
FB
㧡
㧢
OCP/BD
㧣
‫ޓ‬T
90㧑
50㧑
TON
V
100ǡ
10㧑
4.7kǡ
0.1ǴF
A
ICC
tf
VCC
10V
Measurement Circuit 2
D
㧝
S/GND
㧟
SS/OLP
VCC
㧠
FB
㧡
㧢
OCP/BD
㧣
100ǡ
4.7kǡ
0.1ǴF
VCC
20V
10V
Measurement Circuit 3
D
㧝
S/GND
㧟
VCC
SS/OLP
㧠
FB
㧡
㧢
OCP/BD
㧣
100ǡ
4.7kǡ
0.1ǴF
VCC
10V
20V
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
7
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6735
Measurement Circuit 4
D
S/GND
㧝
SS/OLP
VCC
㧠
㧟
FB
㧡
OCP/BD
㧢
㧣
0.1ǴF
V
100ǡ
V
4.7kǡ
A
A
VCC
10V
Measurement Circuit 5
D
S/GND
㧝
SS/OLP
VCC
㧠
㧟
OCP/BD
FB
㧡
㧢
㧣
100ǡ
V
A
VCC
20V
10V
Measurement Circuit 6
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
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
8
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6735
Measurement Circuit 7
D
S/GND
㧝
SS/OLP
VCC
㧟
㧠
FB
㧡
OCP/BD
㧢
㧣
IDSS
VDSS
MOSFET
MOSFET measuring equipment
Measurement Circuit 8
D
S/ GND
㧝
㧟
30V
VCC
SS/OLP
VCC
㧠
FB
㧡
㧢
OCP/BD
㧣
VDS
0
Equation for calculation of
avalanche engery, EAS; to be
adjusted for ILPeak = 5.8 A
IL
IL
‫ޓ‬
VD SPeak
VDS
VDD
0
Avalanche
energy tester
E AS
T1
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
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
9
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6735
Waveform 1
VDS
VOCP/BD
GND
VOCPBD(BS1)
Waveform 2
VDS
VOCP/BD
GND
VOCPBD(BS2)
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
10
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6735
PACKAGE DIMENSIONS, TO-220
Ø3.2 ±0.2
2.6 ±0.1
Terminal dimension at case surface
(5.4)
1)
5.0 ±0.5
×R
+0.2
1.74 –0.1
(2
+0.2
1.34 –0.1
6×P1.27 ±0.15 = 7.62 ±0.15
Terminal dimensions at case surface
10.4 ±0.5
XXXXXXXX
XXXXXXXX
2.8 MAX
Branding
16.9 ±0.3
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
1 2 3 4 5 6 7
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
Dimensions in millimeters
Drawing for reference only
Branding codes (exact appearance at manufacturer discretion):
1st line, type: W6735
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
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
11
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6735
PACKING SPECIFICATIONS
Minimum packing option: Tube FM-205 E
4.8
+0.4
0
1.4
5.1
9 × R0.6
35.0
(15.4)
9.5–0.1
+0.3
8.9
Shipping Tube Dimensions:
Wall thickness: 0.6±0.3 mm
Wall warp: <2 mm
Material: Hardened polyvinyl
Coating: antistatic
Tolerance ±0.4 mm,
unless otherwise specified
Side marked
“ANTISTATIC”
2.85
+0.3
(3.6)
1.3 –0.2
14.3
Spacer
Carton
(side
view)
Tube
Shipping Carton Dimensions:
Capacity: 1800 pieces maximum per carton
36 tubes per carton
3 rows, 12 tubes per row
Spacer
620
125
Tube
All dimensions: mm
185
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
12
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6735
WARNING — These devices are designed to be operated at lethal voltages and energy levels. Circuit designs
that embody these components must conform with applicable safety requirements. Precautions must be
taken to prevent accidental contact with power-line potentials. Do not connect grounded test equipment.
The use of an isolation transformer is recommended during circuit development and breadboarding.
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 in leads and solderability of 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 adjacent products, and shorts to the heatsink.
Remarks About Using Silicone Grease with a Heatsink
• When silicone grease is used in mounting this product on a heatsink, it shall be applied evenly and thinly. If more silicone grease than required is
applied, it may produce stress.
• Volatile-type silicone greases may produce cracks after long periods of time, resulting in reduced heat radiation effect. Silicone grease with low
consistency (hard grease) may cause cracks in the mold resin when screwing the product 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
GE Toshiba Silicone Co., Ltd.
SC102
Dow Corning Toray Silicone Co., Ltd.
Soldering
•
When soldering the products, please be sure to minimize the working time, within the following limits:
260±5°C 10 s
350±5°C 3 s
• Soldering iron should be at a distance of at least 1.5 mm from the body of the products
Electrostatic Discharge
•
When handling the products, operator must be grounded. Grounded wrist straps worn should have at least 1 MΩ of resistance to ground to prevent
shock hazard.
•
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 other to prevent leak voltages generated by them
from being applied to the products.
•
The products should always be stored and transported in our shipping containers or conductive containers, or be wrapped in aluminum foil.
Assembly
•
During soldering or other operations, the interior frame temperature of the device should never exceed 105°C.
•
Recommended screw torque through the mounting tab is 0,588 to 0.785 N • m (6 to 8 kgf • cm)
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
13
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6735
The products described herein are manufactured in Japan by Sanken Electric Co., Ltd. for sale by Allegro MicroSystems, Inc.
Sanken and Allegro reserve the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the performance, reliability, or manufacturability of its products. Therefore, the user is cautioned to verify that the information in this
publication is current before placing any order.
When using the products described herein, the applicability and suitability of such products for the intended purpose shall be reviewed at the users
responsibility.
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 society due to device failure or malfunction.
Sanken products listed in this publication are designed and intended for use as components in general-purpose electronic equipment or apparatus
(home appliances, office equipment, telecommunication equipment, measuring equipment, etc.). Their use in any application requiring radiation
hardness assurance (e.g., aerospace equipment) is not supported.
When considering the use of Sanken products in applications where higher reliability is required (transportation equipment and its control systems
or equipment, fire- or burglar-alarm systems, various safety devices, etc.), contact a company sales representative to discuss and obtain written
confirmation of your specifications.
The use of Sanken products without the written consent of Sanken in applications where extremely high reliability is required (aerospace equipment, nuclear power-control stations, life-support systems, etc.) is strictly prohibited.
The information included herein is believed to be accurate and reliable. Application and operation examples described in this publication are
given for reference only and Sanken and Allegro assume no responsibility for any infringement of industrial property rights, intellectual property
rights, or any other rights of Sanken or Allegro or any third party that may result from its use.
Copyright © 2006 Allegro MicroSystems, Inc.
This datasheet is based on Sanken datasheet SSE22935
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
14