Str-A6251M: Universal-Input/15 W 67 KHZ Flyback Switching Regulator
Str-A6251M: Universal-Input/15 W 67 KHZ Flyback Switching Regulator
Str-A6251M: Universal-Input/15 W 67 KHZ Flyback Switching Regulator
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STR-A6251M
Data Sheet
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28103.43b
Sw egu
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Universal-Input/15 W
67 kHz Flyback Switching Regulator
The STR-A6251M is a 67 kHz PWM topology (with ±5% fre-
quency jittering for minimum EMI) regulator specifically designed to
satisfy the requirements for increased integration and reliability in
flyback converters. It incorporates a primary control and drive circuit
with an avalanche-rated power MOSFET. This is a higher-frequency
version of the STR-A6251.
Covering the power range from below 21 watts for a 230 VAC
input, or to 15 watts for a universal (85 to 264 VAC) input, this device
can be used in a wide range of applications, from DVD players and
VCR player/recorders to ac adapters for cellular phones and digital
cameras. An auto-burst standby function reduces power consumption at
light load, while multiple protections, including the avalanche-energy
guaranteed MOSFET, provide high reliability of system design.
Cycle-by-cycle current limiting, undervoltage lockout with hyster-
esis, overvoltage protection, and thermal shutdown protect the power
supply during the normal overload and fault conditions. Overvoltage
ABSOLUTE MAXIMUM RATINGS protection and thermal shutdown are latched after a short delay. The
at TA = +25°C latch may be reset by cycling the input supply. Low start-up current and
Control Supply Voltage, VCC . . . . 36 V a low-power standby mode selected from the secondary circuit completes
Drain-Source Voltage, VDSS . . . . . . 650 V
a comprehensive suite of features. It is provided in an 8-pin mini-DIP
Drain Switching Current, ID . . . . 2.5 A*
Peak Drain Switching Current, plastic package with pin 6 removed.
IDM . . . . . . . . . . . . . . . . . . . . . . 2.5 A
FEATURES AND BENEFITS
Single-Pulse Avalanche Energy,
EAS . . . . . . . . . . . . . . . . . . . . 72 mJ ■ 67 kHz PWM with ±5% Frequency Jittering
S/OCP Voltage Range, Cost Reduction of EMI Noise Filtering
VOCP . . . . . . . . . . . . –0.3 V to +6 V ■ Rugged 650 V Avalanche-Rated MOSFET
FB/CC/OLP Voltage Range, Simplified Surge Absorption
VFB/OLP . . . . . . . . . . –0.3 V to +12 V No VDSS Derating Required
FM Voltage Range,
■ Low rDS(on) (3.95 Ω maximum)
VFM . . . . . . . . . . . . . –0.3 V to +6 V
Package Power Dissipation, PD ■ Auto-Burst Mode for Stand-By Operation or Light Loads
control (VCC × ICC(ON)) . . . . . 0.15 W Less Transformer Audible Noise
MOSFET (VDSS × ID) . . . . . . 1.35 W ■ Built-In Leading Edge Blanking
total . . . . . . . . . . . . . . . . . . . . 1.5 W ■ Soft Start and Low Start-Up Current
MOSFET Channel Temp., TJ . +150°C Start-Up Circuit Disabled in Operation
Internal Frame Temp., TF . . . . +125°C ■ Low Operating Current (4 mA max)
Storage Temperature Range, ■ Automatic Burst Stand-By (intermittent operation)
TS . . . . . . . . . . . . -40°C to +125°C
Input Power <0.1 W at No Load continued
* Drain switching current is limited by tem-
perature (page 2) and safe operating area
(page 4).
Always order by complete part number, e.g., STR-A6251M .
STR-A6251M ih ng rs
Universal-Input/15 W itc lato
67 kHz Flyback Switching Regulator Sw egu
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FUNCTIONAL BLOCK DIAGRAM
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.
STR-A6251M ih ng rs
Universal-Input/15 W itc lato
67 kHz Flyback Switching Regulator Sw egu
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APPLICATIONS INFORMATION
Typical Application
NOTE: The start-up performance of the IC can only be Complete product description and applications information
guaranteed for values of C2 greater than 22 µF. This value is provided in Application Note 28103.40, Series STR-
is required to keep the internal supply voltage within A6200 Flyback Switching Regulators.
regulation during IC initialization.
The products described herein are manufactured in Japan by Sanken Sanken products listed in this publication are designed and intended
Electric Co., Ltd. for sale by Allegro MicroSystems, Inc. for use as components in general-purpose electronic equipment or
Sanken and Allegro reserve the right to make, from time to time, such apparatus (home appliances, office equipment, telecommunication
departures from the detail specifications as may be required to permit equipment, measuring equipment, etc.). Their use in any application
improvements in the performance, reliability, or manufacturability of its requiring radiation hardness assurance (e.g., aerospace equipment) is
products. Therefore, the user is cautioned to verify that the information not supported.
in this publication is current before placing any order. When considering the use of Sanken products in applications where
When using the products described herein, the applicability and higher reliability is required (transportation equipment and its control
suitability of such products for the intended purpose shall be reviewed at systems or equipment, fire- or burglar-alarm systems, various safety
the users responsibility. devices, etc.), contact a company sales representative to discuss and
obtain written confirmation of your specifications.
Although Sanken undertakes to enhance the quality and reliability of
its products, the occurrence of failure and defect of semiconductor The use of Sanken products without the written consent of Sanken in
products at a certain rate is inevitable. applications where extremely high reliability is required (aerospace
equipment, nuclear power-control stations, life-support systems, etc.) is
Users of Sanken products are requested to take, at their own risk, strictly prohibited.
preventative measures including safety design of the equipment or
systems against any possible injury, death, fires or damages to society The information included herein is believed to be accurate and
due to device failure or malfunction. reliable. Application and operation examples described in this publica-
tion 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.
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Sw egu 67 kHz Flyback Switching Regulator
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PACKAGE DIMENSIONS
Dimensions in Inches
(for reference only)
Dimensions in Millimeters
(controlling dimensions)
EI 26EI