STR-W6765
Description
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 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.
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 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
Quasi-Resonant Topology
Primary Switching Regulators
Typical Application
Package: 6-pin TO-220
Continued on the next page…
28103.30-6
Features and Benefits
▪ 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 system-
level reliability and does not require VDSS derating
▪ 800 V / 1.8 Ω, 52 to 110 W (Universal/230 Vac input)
Continued on the next page…
+B
GND
S1
P
D
D
S/GND
V
CC
S2
LowB
GND
For ErrAmp, Sanken SE series device recommended
For SI, Sanken linear regulator IC recommended
11
33 77
Cont
STR-W6735
66
OCP
/BD
44
FB
ROCP
ErrAmp
SS
/OLP
55
Standby
ON/OFF
Standby
Out
CX
RX
SI
A
B
B
A
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
2
Features and Benefits (continued)
Selection Guide
Part Number Package Packing
STR-W6765 TO-220 Bulk, 100 pieces
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 oth er wise stated.
▪ 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 system-
level reliability.
Applications include the following:
▪ Set Top Box
▪ LCD PC monitor, LCD TV
▪ Printer, Scanner
▪ SMPS power supplies
Description (continued)
Absolute Maximum Ratings at TA = 25°C
Parameter Symbol Terminal Conditions Rating Unit
Drain Current1IDpeak 1 - 3 Single pulse 11.2 A
Maximum Switching Current2IDmax 1 - 3 TA = –20°C to 125°C 11.2 A
Single Pulse Avalanche Energy3EAS 1 - 3 Single pulse, VDD = 99 V, L = 20 mH,
ILpeak = 5.8 A 300 mJ
Input Voltage for Controller (MIC) VCC 4 - 3 35 V
SS/OLP Terminal Voltage VSSOLP 5 - 3 –0.5 to 6.0 V
FB Terminal Inflow Current IFB 6 - 3 10 mA
FB Terminal Voltage VFB 6 - 3 IFB within the limits of IFB –0.5 to 9.0 V
OCP/BD Terminal Voltage VOCPBD 7 - 3 –1.5 to 5.0 V
MOSFET Power Dissipation4PD1 1 - 3 With infinite heatsink 28.7 W
Without heatsink 1.3 W
Controller (MIC) Power Dissipation PD2 4 - 3 VCC × ICC 0.8 W
Operating Internal Leadframe Temperature TF– Refer to TOP –20 to 115 °C
Operating Ambient Temperature TOP – –20 to 115 °C
Storage Temperature Tstg – –40 to 125 °C
Junction Temperature TJ– 150 °C
1Refer to figure 2
2IDMAX 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
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
3
Temperature, T
F
(°C)
Safe Operating Area
Temperature Derating Coefficient (%)
0
20
40
60
80
100
0 25 50 75 100 125 150
Drain-to-Source Voltage, VDS (V)
Drain Current, ID (A)
11.2
1.0
10.0
0.1
100.0
10 100 10001
1 ms
0.1 ms
Current limit
due to R
DS(on)
Refer to figure 1 for MOSFET SOA
temperature derating coefficient
Figure 1 – MOSFET Safe Operating Area
Derating Curve Figure 2 – MOSFET Safe Operating Area
Drain Current versus Voltage
at TA = 25°C, Single Pulse
D
S/GND
OCP/BD
V
CC
FB
Start
Stop
Burst
R
S
Q
Reg&
Iconst
OVP
DRIVE
Reg
Protection
latch
S
RQ
FB
OCP
BSD
BD
Bottom Selector
Counter
SS/OLP
OLP
Delay
S
R
Q
OSC
MaxON
Soft Start
Burst
Control
Burst
Control
4
+
-
+
-
+
-
+
-
+
-
+
-
1
3
6
7
5
Number Name Description Functions
1 D Drain 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
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
4
Channel Junction Temperature, T
J
(°C)
E
AS
Temperature Derating Coefficient (%)
0
20
40
60
80
100
25 50 75 100 125 150
Time, t (s)
Transient Thermal Resistance, RQJC (°C/W)
0.001
0.010
0.100
1.000
10.000
100μ10μ 10m1m 100m1μ
Ambient Temperature, TA (°C)
Power Dissipation, PD1 (W)
0
5
10
15
20
25
30
0 20 40 60 80 100 120 140 160
P
D1
= 1.3 W at T
A
&
Without heatsink
With infinite heatsink
P
D1
= 28.7 W at T
A
&
Figure 3 – MOSFET Avalanche Energy Derating Curve Figure 4 – Transient Thermal Resistance
Figure 5 – MOSFET Power Dissipation versus Temperature
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
5
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
Normal Operation
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
OCP/BDOCP/BD Terminal Outflow Current 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
FB Terminal Threshold Voltage VFB(OFF) 6 - 3 1.32 1.45 1.58 V
FB Terminal Inflow Current (Normal Operation) IFB(ON) 6 - 3 600 1000 1400 μA
Standby Operation
Standby Operation Start Voltage VCC(S) 4 - 3 10.3 11.1 12.1 V
Standby Operation Start Voltage Interval VCC(SK) 4 - 3 1.10 1.35 1.65 V
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 0.40 0.82 1.25 μs
Maximum On Time tON(MAX) 1 - 3 27.5 32.5 39.0 μs
Protection Operation
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
Overvoltage Protection Operation Voltage VCC(OVP) 4 - 3 25.5 27.7 29.9 V
Latch Circuit Holding Current2ICC(H) 4 - 3 – 45 140 μA
Latch Circuit Release Voltage2VCC(La.OFF) 4 - 3 6.0 7.2 8.5 V
ELECTRICAL CHARACTERISTICS for MOSFET, valid at TA = 25°C, unless otherwise specified
Drain-to-Source Breakdown Voltage VDSS 1 - 3 800 – – V
Drain Leakage Current IDSS 1 - 3 – – 300 μA
On Resistance RDS(on) 1 - 3 – – 1.8 Ω
Switching Time tf1 - 3 – – 400 ns
Thermal Resistance RθJA
Junction to Internal
Frame – – 1.55 °C/W
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
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
6
ELECTRICAL CHARACTERISTICS Test Conditions*
Parameter Test Conditions VCC
(V)
Measure-
ment
Circuit
Operation Start Voltage VCC voltage at which oscillation starts. 0→20
1
Operation Stop Voltage VCC voltage at which oscillation stops. 20→8.8
Circuit Current In Operation Inflow current flowing into power supply terminal in oscillation. 20
Circuit Current In Non-operation Inflow current flowing into power supply terminal prior to oscillation. 15
Oscillation Frequency Oscillating frequency ( fosc= 1 / T ). 20
Soft Start Operation Stop Voltage SS/OLP terminal voltage at which ISS/OLP reach ≥–100 μA by raising the SS/OLP terminal
voltage from 0 V gradually. 20 5
Soft Start Operation Charging
Current SS/OLP terminal charging current (SS/OLP terminal voltage = 0 V).
Bottom-Skip Operation Threshold
Voltage 1
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 two-
pulses-after to one-pulse-after. 20 3
Bottom-Skip Operation Threshold
Voltage 2
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.
Overcurrent Detection Threshold
Voltage
OCP/BD terminal voltage at which oscillation stops by lowering the OCP/BD terminal voltage
from 0 V gradually.
20 2
OCP/BDOCP/BD Terminal Outflow
Current OCP/BD terminal outflow current (OCP/BD terminal voltage = –0.95 V).
Quasi-Resonant Operation
Threshold Voltage 1
OCP/BD terminal voltage at which oscillation starts with setting the OCP/BD terminal voltage
at 1 V, and then lowering the voltage gradually.
Quasi-Resonant Operation
Threshold Voltage 2
OCP/BD terminal voltage at which oscillation stops by raising the OCP/BD terminal voltage
from 0 V gradually.
FB Terminal Threshold Voltage FB terminal voltage at which oscillation stops by raising the FB terminal voltage from 0 V
gradually. 20
4
FB Terminal Inflow Current (Normal
Operation) FB terminal inflow current (FB terminal voltage = 1.6 V). 20
Standby Operation Start Voltage VCC voltage at which ICC reaches ≥1 mA (FB terminal voltage = 1.6 V). 0→15
Standby Operation Start Voltage
Interval Specified by VCC(SK) = VCC(S) – VCC(OFF).–
Standby Non-Operation Circuit
Current
Inflow current flowing into power supply terminals prior to oscillation (FB terminal voltage =
1.6 V). 10.2
FB Terminal Inflow Current, Standby
Operation FB terminal inflow current (FB terminal voltage = 1.6 V). 10.2
FB Terminal Threshold Voltage
Standby Operation
FB terminal voltage at which oscillation starts by raising the FB terminal voltage from 0 V
gradually. 15
Minimum On Time Waveform between terminals 1 and 3 at low. 20 6
Maximum On Time Waveform between terminals 1 and 3 at low. 20 1
Continued on the next page…
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
7
ELECTRICAL CHARACTERISTICS Test Conditions*, continued
Parameter Test Conditions VCC
(V)
Measure-
ment
Circuit
Overload Protection Operation
Threshold Voltage SS/OLP terminal voltage at which oscillation stops. 20
5
Overload Protection Operation
Charging Current SS/OLP terminal charging current (SS/OLP terminal voltage = 2.5 V). –
Overvoltage Protection Operation
Voltage VCC voltage at which oscillation stops. 0→30
1
Latch Circuit Holding Current Inflow current at VCC(OFF) – 0.3; after OVP operation. VCC(OFF)
– 0.3
Latch Circuit Release Voltage VCC voltage at which ICC reaches 20 μA or lower by decreasing VCC after OVP operation. 30→6
Drain-to-Source Breakdown Voltage IDSS = 300 μA – 7
Drain Leakage Current VDSS = 800 V –
Single Pulse Avalanche Energy – 30 8
On-Resistance IDS = 1.4 A 20 9
Switching Time – 20 1
*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
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
8
㧝 㧟 㧠㧡㧢㧣
AA
10V
100ǡ
ޓT
4.7kǡ
VCC
ICC
TON
VV
10㧑
90㧑
tf
DS/GNDVCC
SS/OLP FB OCP/BD
50㧑
0.1ǴF
㧝 㧟 㧠㧡㧢㧣
10V
100ǡ
4.7kǡ
V
CC
20V
DS/GNDVCC
SS/OLP FB OCP/BD
0.1ǴF
㧝 㧟 㧠㧡㧢㧣
10V
100ǡ
4.7kǡ
V
CC
20V
DS/GNDVCC
SS/OLP FB OCP/BD
0.1ǴF
Measurement Circuit 1
Measurement Circuit 2
Measurement Circuit 3
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
9
Measurement Circuit 4
Measurement Circuit 6
Measurement Circuit 5
㧝 㧟 㧠㧡㧢㧣
AA
10V
100ǡ
4.7kǡ
V
CC
VV
D S/GND VCC SS/OLP FB OCP/BD
0.1ǴF
AA
VV
㧝 㧟 㧠㧡㧢㧣
10V
100ǡ
V
CC
20V
DS/GNDVCC
SS/OLP FB OCP/BD
AA
VV
㧝 㧟 㧠㧡㧢㧣
10V
100ǡ
4.7kǡ
V
CC
20V
D S/GND VCC SS/OLP FB OCP/BD
0.1ǴF
T
ON㧔MIN㧕
9V OSC1
V1-3
5V
OSC1
200㨪500nS
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
10
㧝㧟㧠㧡㧢㧣
MOSFET
MOSFET measuring equipment
V
DSS
I
DSS
D S/GND VCC SS/OLP FB OCP/BD
Avalanche
energy tester
I
L
V
DS
㧝 㧟 㧠㧡㧢㧣
V
CC
DS/GNDVCC
SS / OLP F B OC P/ BD
T1
V
DSPeak
V
DD
I
L
0
30V
V
CC
0
V
DS
ޓ
I
DS
㧝 㧟 㧠㧡㧢㧣
0.1ǴF
DS/GNDVCC
SS/OLP FB OCP/BD
4.7kǡ
R
DS(ON)=
V
DS(ON)/
I
DS
20V
V
DS(ON)
Measurement Circuit 7
Measurement Circuit 9
Measurement Circuit 8

DDDS
DS
AS VPeakV
PeakV
I
L
PeakLE
2
2
1
Equation for calculation of
avalanche engery, EAS; to be
adjusted for ILPeak = 5.8 A
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
11
V
DS
V
OCP/BD
GND
V
OCPBD(BS1)
V
OCPBD(BS2)
GND
V
DS
V
OCP/BD
Waveform 2
Waveform 1
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
12
PACKAGE DIMENSIONS, TO-220
10.0 ±0.2 4.2 ±0.2
2.8 ±0.2
Ø3.2 ±0.2
2.6 ±0.1
(2×R1)
Terminal dimension at case surface
5.08 ±0.6
1.74 +0.2
–0.1
1.34 +0.2
–0.1
0.45 +0.2
–0.1
16.9 ±0.3
10.4 ±0.5
5.0 ±0.5
7.9 ±0.2
4 ±0.2
2.8 MAX
(5.4)
Gate Burr
Branding
XXXXXXXX
XXXXXXXX
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: 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
1234567
Terminal dimensions at case surface
6×P1.27 ±0.15 = 7.62 ±0.15
Terminal dimension at lead tips
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
13
PACKING SPECIFICATIONS
Minimum packing option: Tube FM-205 E
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
All dimensions: mm
Side marked
“ANTISTATIC”
(3.6)
(15.4)
9 × R0.6
5.1
2.85
14.3
8.9
35.0
1.4
9.5+0.3
–0.1
4.8 +0.4
0
1.3 +0.3
–0.2
Shipping Carton Dimensions:
Capacity: 1800 pieces maximum per carton
36 tubes per carton
3 rows, 12 tubes per row
Spacer
Carton
(side
view)
Spacer
Tube
620
125
185
Tube
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
14
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)
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. Pre cau tions must be
taken to prevent accidental contact with power-line potentials. Do not connect ground ed test equipment.
The use of an isolation transformer is recommended during circuit development and breadboarding.
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6765
15
The products described herein are manufactured in Ja pan by Sanken Electric Co., Ltd. for sale by Allegro MicroSystems, Inc.
Sanken and Allegro reserve the right to make, from time to time, such de par tures from the detail spec i fi ca tions as may be re quired to per mit im-
prove ments in the per for mance, reliability, or manufacturability of its prod ucts. Therefore, the user is cau tioned to verify that the in for ma tion in this
publication is current before placing any order.
When using the products described herein, the ap pli ca bil i ty and suit abil i ty 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 prod ucts, the occurrence of failure and defect of semi con duc tor products
at a certain rate is in ev i ta ble.
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 equip ment or apparatus
(home ap pli anc es, office equipment, tele com mu ni ca tion equipment, measuring equipment, etc.). Their use in any application requiring radiation
hardness assurance (e.g., aero space equipment) is not supported.
When considering the use of Sanken products in ap pli ca tions where higher reliability is re quired (transportation equipment and its control systems
or equip ment, fire- or burglar-alarm systems, various safety devices, etc.), contact a company sales representative to discuss and obtain written
confirmation of your spec i fi ca tions.
The use of Sanken products without the written consent of Sanken in applications where ex treme ly high reliability is required (aerospace equip-
ment, nuclear power-control stations, life-support systems, etc.) is strictly prohibited.
The information in clud ed herein is believed to be accurate and reliable. Ap pli ca tion and operation examples described in this pub li ca tion are
given for reference only and Sanken and Allegro assume no re spon si bil i ty for any in fringe ment of in dus tri al 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 SSE-22774
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com