Improved Cascode Current Switch
Original Publication Date: 1988-Jan-01
Included in the Prior Art Database: 2005-Feb-14
The circuit improvement described in this article removes the need for two separate and distinct signal levels in a cascode current switch (CCS), with attendant simplification in logic design and wiring rules. The disclosed circuit is more compatible with other single input signal voltage technologies and the reduced number of level shifting stages required between cascode trees affords savings in chip real estate. Fig. 1 illustrates a CCS circuit of conventional design, and Fig. 2 depicts the improved CCS circuit described in this article. Emitter follower circuits have been added for 'E' and 'F' inputs, as shown in Fig. 2, and all inputs are now at the same voltage level.