Vishay provides an extensive selection of Photovoltaic MOSFET drivers. These devices make it exceedingly easy for designers to customize economical, solid state, relay solutions. These simple components allow any designer to quickly synthesize a solid state equivalent of any mechanical relay.
The only design exercise is one of laying out a very simple board with a small number of parts, and specifying external MOSFETs capable of handling the required load voltages and currents. As in the case of a mechanical relay, the only external power requirement is the current to drive the input. A secondary side housekeeping power supply is not required to power the drivers themselves. All the power required to operate the relay comes from the LED current.
Vishay’s newest MOSFET drivers come in two varieties. The VOM1271T is available in a small footprint and includes an integrated active turn off circuit, to decrease MOSFET power dissipation. The VO1263 comes in a DIP 8 package and includes two isolated channels, which allow the designer greater flexibility to design various relay configurations, such as a SPDT, a break before make solution, or use the outputs in series for greater MOSFET gate drive voltage.