Off-Line Quasi-Resonant Switching Regulators

STR-X6759N

9

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. Precau-

tions must be taken to prevent accidental contact with power-line potentials.

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 on 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.

•

Coat the back surface of the product and both surfaces of the

insulating plate to improve heat transfer between the product and

the heatsink.

•

Volatile-type silicone greases may permeate the product and

produce cracks after long periods of time, resulting in reduced

heat radiation effect, and possibly shortening the lifetime of the

product.

•

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

SC102

Dow Corning Toray Silicone Co., Ltd.

Heatsink Mounting Method

•

Torque When Tightening Mounting Screws. Thermal resistance

increases when tightening torque is low, and radiation effects are

decreased. When the torque is too high, the screw can strip, the heatsink

can be deformed, and distortion can arise in the product frame. To avoid

these problems, observe the recommended tightening torques for this

product package type, TO-3P: 0.588 to 0.785 N•m (6 to 8 kgf•cm).

the heatsink should be free from burrs and metal fragments, and the

heatsink should be flat and large enough to contact over the entire side

of the product, including mounting flange and exposed thermal pad,

and have a minimal mounting hole to prevent possible deflection and

cracking of the product case when fastened to the heatsink.

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.

Recommended operation temperature

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com