N+1 BIT RESOLUTION FROM AN N BIT A/D CONVERTER

摘要

ABSTRACTN+1 BIT RESOLUTIONFROM AN N BIT A/D CONVERTERIn microprocessor based control systems whereinseveral analog sensors are used to generate controlsignals of N bits, the system herein generates adigital signal having an N+1 bit resolution of theinformation. The N+1 bit resolution is generatedfrom an N bit A/D converter by means of a networkchanging the reference voltage input to the A/Dconverter by an offset voltage which is a function ofthe least significant bit position. The network, inthe absence of a control signal, generates a firstrange of reference voltages and in the presence ofthe control signal generates a second range whereinthe limit voltages are change by the offset voltage.The microprocessor reads and stores each N bitdigital word from the same sensor and under thecommand of the control signal, sums the two digitalwords and the result is an N+1 bit digital word.