Fairchild Offers Snubberless Triac Drive Optocouplers For Solid State Relay, AC Motor Control & Lighting Ballast Designs

Fairchild Semiconductor is claiming that it is providing designers with an easier way to design their motor control, power switch and lighting control applications with random-phase, snubberless triac drive optocouplers. These products, the FOD420 and FOD4208, feature a built-in active dv/dt clamp, which are said to provide best-in-class noise immunity (dv/dt) of 10,000V/µs, and be superior to the average dv/dt rating (1,500V/µs) of monolithic triacs.

This performance is said to eliminate the RC snubber network required for lower dv/dt rated monolithic opto triac drivers and to save valuable design time and bill of material (BOMs) costs. Their high noise immunity makes these products suitable for noisy industrial environments because they offer a more robust solution for isolating solid-state relays, ac motor controls and lighting ballasts.

Fairchild’s triac drive optocouplers provide 5,000V of isolation while controlling the power triacs that switch the load. Therefore, these optocouplers can be used in conjunction with Fairchild’s discrete power triacs such as the FKN08PN60S and the FKPF8N80.

The FOD420 and FOD4208 products utilize lead-free (Pb-free) terminals and have been characterized for moisture sensitivity in accordance with the Pb-free reflow requirements of the joint IPC/JEDEC standard J-STD-020.

The units are priced (each, 1000 pcs.) as follows: US $1.71 for the FOD420; $1.89 for the FOD4208. They have a delivery time of 6 weeks ARO.