● Recommended Foot Print (reference)

8

SMT Gullwing Lead-form

Wide SMT Gullwing Lead-form

10.2

2.2

8.2

2.2

(Unit : mm)

PC3ST21NSZ Series

■ Design Considerations

Sheet No.: D2-A07101EN

Please refrain from using these devices in a direct drive configuration. These Phototriac Coupler are

intended to be used as triggering device for main Triacs. Please ensure that the output rating of these

devices will be sufficient for triggering the main output Triac of your choice. Failure to do may result in

malfunctions.

For applications with inductive loads such as motors,please use caution in utilizing a zero crossing type

Phototraiac Coupler as this may cause undesired operations due to the phase difference between voltage

and current of load.

For designs that will experience excessive noise or sudden changes in load voltage, please include an

appropriate snubber circuit as shown in the below circuit. Please keep in mind the Sharp Phototriac Coupler

incorporate superrior dV/dt ratings which can eliminate the need for a snubber circuit.

For over voltage protection, a Varistor may be used.

● Degradation

In general, the emission of the IRED used in Phototriac Couplers will degrade over time.

In the case where long term operation and / or constant extreme temperature fluctuations will be applied to

the devices, please allow for a worst case scenario of 50% degradation over 5years.

Therefore in order to maintain proper operation, a design implementing these Phototriac Couplers should

provide at least twice the minimum required triggering current from initial operation.

● Design guide