To reach low channel ON resistance (<30 Ohm) and low OFF current leakage, 4-channel commutator uses the 2N4091. The DM7800 voltage translator is a monolithic device. This device give us +10V to -20V gate drive to the JFETs while at the same time giving DTL-TTL logic compatibility.

Here’s the circuit diagram:
4 Channel Commutator circuit schematic

[Source: National Semiconductor Application Note]