Customized Bipolar Differential Cascode Shifter
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18
Shown in Fig. 1 is a single-ended cascode shifter in which the wiring scheme is improved in order to save space on the silicon. The differential outputs are generated from the shifter outputs by means of a differential converter. A shift control circuit generates control signals SL4, NS4 and SR4; SL2, NS2 and SR2, indicating the direction of the shifting operations: shift left (SL), no shift (NS) and shift right (SR), and the shift amount - 2 or 4. These control signals are generated from A and B signals indicating the shift amount and a left/right (L/R) signal which is at an UP level for performing a right shift and at a DOWN level for performing a left shift. This shift control circuit comprises differential cascode current switches, as shown in Fig 2.