MOS BUCKET-BRIGADE DEVICE FOR LOW VOLTAGE OPERATION.

The low voltage operation of MOS bucket-brigade circuits is described with respect to DC transfer characteristics and frequency response. In low voltage operation, the amplitude of the transfer signal is limited by the threshold voltage of the MOS transistor in the B-B array. The incomplete charge transfer which affects the signal band-width is caused by the switching time constant of the MOS transistor above the clock frequency of 2 MHz and is caused by channel length modulation of the MOS transistor below that frequency. An N-channel, 512-stage, MOS bucket-brigade device was prepared on 1. 0 OMEGA -cm p-type substrate with a (100) orientation through the standard MOS processing to attain low threshold voltage and less channel length modulation for low voltage operation. Experimental results for the device having V//t approximately equals 0. 5 v in the operation at a clock height of 6 v and a clock frequency of 50 kHz were as follows: transfer efficiency, 99. 95%; signal bandwidth, dc to about f// phi /2. 5; signal to noise ratio, 60 db; and signal distortion less than 1%. References to English-language sources are in English.