A diode-OR circuit is used in electronics to isolate two or more voltage sources. There are two typical implementations:

When a DC supply voltage needs to be generated from one of a number of different sources, for example when terminating a parallel SCSI

Parallel SCSI

Parallel SCSI is one of the interface implementations in the SCSI family. In addition to being a data bus, SPI is a parallel electrical bus: There is one set of electrical connections stretching from one end of the SCSI bus to the other. A SCSI device attaches to the bus but does not interrupt it...

 bus, a very simple circuit like this can be used:



In digital electronics

Digital circuit

Digital electronics represent signals by discrete bands of analog levels, rather than by a continuous range. All levels within a band represent the same signal state...

 a diode-OR circuit is used to derive a simple Boolean logic function. This kind of circuit was once very common in Diode-transistor logic

Diode-transistor logic

Diode–transistor logic is a class of digital circuits that is the direct ancestor of transistor–transistor logic. It is called so because the logic gating function is performed by a diode network and the amplifying function is performed by a transistor .- Implementations :The DTL circuit shown in...

 but has been largely replaced by CMOS

CMOS

Complementary metal–oxide–semiconductor is a technology for constructing integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits...

in modern electronics: