Snubber-Less Optocouplers Ease Design Chores

Promising to simplify solid-state relay, ac-motor control, and lighting ballast designs, the FOD420 and FOD4208 random-phase, snubber-less triac drive optocouplers integrate active dv/dt clamps to achieve what the company calls best-in-class noise immunity at 10,000 V/µs. This performance level eliminates the RC snubber network required for lower dv/dt rated monolithic opto triac drivers. Both optocouplers provide 5 kV of isolation while controlling the power triacs that switch the load and employ lead-free terminals characterized for moisture sensitivity in accordance with the reflow requirements of the joint IPC/JEDEC standard J-STD-020. Prices for the FOD420 and FOD4208 are $1.71 and $1.89 each/1,000, respectively. FAIRCHILD SEMICONDUCTOR, San Jose, CA. (800) 341-0392.