Title :
Maximum operating frequency in Si bipolar master-slave toggle flip-flop circuit
Author :
Ishii, Kiyoshi ; Ichino, Haruhiko ; Yamaguchi, Chikara
Author_Institution :
NTT LSI Labs., Kanagawa, Japan
fDate :
7/1/1994 12:00:00 AM
Abstract :
This paper presents a propagation-delay equation which is expressed as the influence of the individual device and circuit parameters on the maximum operating frequency of Si bipolar master-slave toggle flip-flop (MS-TFF) circuit with double feedback emitter followers. This equation shows that optimizing the size of individual transistors can enhance the operating speed. Test results show a 10% increase in operating frequency by adopting this design technique. It is also shown that the time constants RBCjC, RB CD, TF, RLCjC, and R CCjC of the upper-level current switch and TF of the second feedback emitter follower greatly affect the operating speed of circuits using recently developed Si bipolar transistors. The results predicted by the equation are in good agreement with both the experimental ones and SPICE simulations
Keywords :
bipolar integrated circuits; delays; elemental semiconductors; emitter-coupled logic; feedback; flip-flops; integrated logic circuits; logic design; sensitivity analysis; sequential circuits; silicon; Si; Si bipolar IC; bipolar transistors; circuit parameters; design technique; device parameters; double feedback emitter followers; master-slave toggle flip-flop circuit; maximum operating frequency; propagation-delay equation; time constants; Bipolar transistors; Circuit testing; Equations; Feedback circuits; Flip-flops; Frequency; Master-slave; SPICE; Switches; Switching circuits;
Journal_Title :
Solid-State Circuits, IEEE Journal of
