Abstract:
A new tunnel diode-transistor twisted ring counter is described. Each stage of the counter consists of a tunnel diode controlling a long tailed pair which switches current into the following stage. Rectangular input pulses are "differentiated" by a shorted delay cable and the tunnel diodes are progressively switched to high voltage states by the positive pulses and then progressively reverse switched to low voltage states by the negative pulses. The scaling capacity of the counter for rectangular input pulses is (2n-1) where n is the number of stages. A maximum scaling rate of 450 MHz was observed for a practical three stage quinary counter.