Phototriac Optocouplers provide dV/dt greater than 5 kV/µs.

Press Release Summary:

Encased in 6-pin DIP package, zero-crossing Series VO4157 and VO4158 consist of GaAs infrared LED that is optically coupled to photosensitive ZC TRIAC detector chip, minimizing EMI noise harmonics. Non-zero-crossing Series VO4257 and VO4258 can trigger any time during ac phase cycle and turn off at next zero crossing. Both families have trigger currents of 1.6 mA and are suited for switching ac loads and driving larger SCRs or TRIACs in industrial applications.

Original Press Release:

Vishays New Phototriacs Provide dV/dt Greater Than 5 kV/µs

SANTA CLARA, CALIFORNIA - November 18, 2005 - Vishay Intertechnology, Inc. (NYSE: VSH) today announced a new line of phototriacs that feature a trigger of 1.6 mA, lower than any other supplier, and a static dV/dt greater than 5 kV/µs. Encased in a 6-pin DIP package, the new zero-crossing (ZC) and non-zero-crossing (NZC) phototriac optocouplers are designed for switching AC loads and driving larger SCRs or TRIACs in industrial applications.

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 well suited for noise sensitive circuits. Devices in the VO4257 and VO4258 series of NZC phototriacs, on the other hand, have the advantage of being able to trigger any time during the ac phase cycle and turn off at the next zero crossing. This makes the NZC devices an ideal choice for many phase modulation applications.

Both families have very low trigger currents of 1.6 mA, making it possible to directly interface with microcontrollers and digital circuits. Trigger currents of 2.0 mA and 3.0 mA are also available. All three versions are offered in 700-V and 800-V blocking voltages and can provide isolation for low-voltage logic for 120-V, 240-V, and 380-V AC lines to control resistive, inductive, or capacitive loads.

The following table summarizes the characteristics of all 12 versions of the VO415x and VO425x phototriac optocouplers:
Zero Crossing           Non-Zero-Crossing       Blocking Voltage       Trigger Input
Part Number Part Number VDRM IFT
VO4157D VO4257D 700 V 1.6 mA
VO4157H VO4257H 700 V 2.0 mA
VO4157M VO4257M 700 V 3.0 mA
VO4158D VO4258D 800 V 1.6 mA
VO4158H VO4258H 800 V 2.0 mA
VO4158M VO4258M 800 V 3.0 mA

The new phototriacs feature reinforced insulation per IEC60950 Their target applications include solid-state relays, AC motor drives/triac drives, switching power supplies, programmable controllers, temperature controls, and solenoid/valve controls in industrial products.

Samples of the new VO4157/8 and VO4257/8 phototriacs are available now. Production quantities have a lead-time of six to eight weeks. Pricing for U.S. delivery in 10,000-piece quantities starts at $1.50 each depending on the blocking voltage and input trigger current values.

Vishay Intertechnology, Inc., a Fortune 1,000 Company listed on the NYSE (VSH), is one of the world's largest manufacturers of discrete semiconductors (diodes, rectifiers, transistors, and optoelectronics) and selected ICs, and passive electronic components (resistors, capacitors, inductors, and transducers). Vishay's components can be found in products manufactured in a very broad range of industries worldwide. Vishay is headquartered in Malvern, Pennsylvania, and has operations in 17 countries employing over 25,000 people. Vishay can be found on the Internet at

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