Phototriacs with low trigger current

Vishay Intertechnology Inc. has unveiled a new line of phototriacs that feature a low trigger current of 1.6mA, which the company said is lower than any other competitive device. The new devices also provide a static dV/dt greater than 5kV/5s.

Housed in a 6-pin DIP package, the new VO4157 and VO4158 series zero-crossing (ZC) and VO4257 and VO4258 series non-zero-crossing (NZC) phototriac optocouplers are designed for switching AC loads and driving larger SCRs or triacs in industrial applications. These new devices target applications such as solid-state relays, AC motor drives/triac drives, switching power supplies, programmable controllers, temperature controls and solenoid/valve controls in industrial products.

The new ZC VO4157 and VO4158 series phototriacs consist of a GaAs infrared LED that is optically coupled to a photosensitive ZC triac detector chip. This design type helps to reduce EMI noise harmonics while featuring lower peak operating currents, making it suitable for noise sensitive circuits, said the company.

Devices in the VO4257 and VO4258 series of NZC phototriacs have the advantage of being able to trigger any time during the ac phase cycle and turn off at the next zero crossing, making them suitable for phase modulation applications.

Both families feature very low trigger currents of 1.6mA, making it possible to directly interface with microcontrollers and digital circuits. Trigger currents of 2mA and 3mA are also available. All three versions are offered in 700V and 800V blocking voltages and can provide isolation for low-voltage logic for 120-, 240- and 380Vac lines to control resistive, inductive or capacitive loads. In addition, the new phototriacs feature reinforced insulation per IEC60950 2.10.5.1.

Samples of the VO4157/8 and VO4257/8 phototriacs are already available. Delivery for production quantities is six to eight weeks. Pricing for U.S. delivery starts at $1.50 each depending on the blocking voltage and input trigger current values in quantities of 10,000.

- Gina Roos
eeProductCenter