Digital-to-analog switching interface circuit

A digital-to-analog switching interface circuit for producing transient-free output signals in response to a pair of binary input switching signals having the same output states during the switching transition, said interface circuit comprising:

• first and second PNP transistors having intercoupled emitters coupled to a positive current source, the collectors of said first and second transistors being respectively coupled to the anodes of first and second diodes, the cathodes of which are coupled together and through a third diode to negative reference;
• first and second signal output terminals coupled respectively to the collectors of said first and second PNP transistors;
• and
• third and fourth PNP transistors, the emitters of which are coupled respectively to the base elements of said first and second PNP transistors, the base of said third transistor being coupled to the collector of said fourth transistor, the base of said fourth transistor being coupled to the collector of said third transistor, the bases of said third and fourth transistors being coupled respectively through fourth and fifth diodes to first and second input terminals of said interface circuitry.