Showing papers on "CMOS published in 1957"

Digital to analog converter

Abstract: An apparatus and method are disclosed for converting digital input signals of either polarity to representative analog output signals. An internal synchronous counter is clocked to generate internal digital signals of the same code as the input digital signal which are compared with the input digital signal which is stored in a bank of latches. Upon coincidence therebetween, an inhibiting pulse is produced from a coincidence circuit for disabling a buffer-integrator circuit. During the time interval between the enabling of the counter and the inhibiting pulse, the buffer-integrator integrates a single polarity reference voltage provided thereto to establish an analog voltage representative of the stored digital signal. Sample and hold circuits periodically sample the output of the integrator circuit to update and provide the analog output. Self compensation for operational amplifier offsets is provided during each conversion cycle. The converter is suitable to be fabricated using CMOS technology on a single chip and requires no ladder network.