Title :
A dual channel 20 bit current-input A/D converter for photo-sensor applications
Author :
Wang, Chris Binan ; Todsen, J. ; Kalthoff, T.
Author_Institution :
Burr Brown Corp., Tucson, AZ, USA
Abstract :
A dual channel 20 bit current-input A/D converter is implemented in a 0.6 μm CMOS process with a single 5 V supply for use in direct photo-sensor digitization. Continuous charge integration is achieved through the use of a double switched capacitor integrator at each channel input. The front end provides a programmable full-scale input charge range from 50 pC to 1000 pC while also converting the input current to a voltage output. The voltage output of the switched integrator is then digitized by a high dynamic range delta-sigma converter that multiplexes between the two input channels. This current-input A/D converter achieves 3 ppm RMS noise and 1 ppm linearity with low level inputs
Keywords :
CMOS integrated circuits; analogue-digital conversion; delta-sigma modulation; integrating circuits; photodetectors; switched capacitor networks; 0.6 micron; 20 bit; 5 V; A/D converter; CMOS process; continuous charge integration; current-input ADC; double SC integrator; dual channel configuration; high dynamic range delta-sigma converter; photo-sensor applications; programmable full-scale input charge range; switched capacitor integrator; voltage output; CMOS process; Capacitors; Computed tomography; Diodes; Dynamic range; Image converters; Linearity; Photodiodes; Switching converters; Voltage;
Conference_Titel :
Mixed-Signal Design, 2000. SSMSD. 2000 Southwest Symposium on
Conference_Location :
San Diego, CA
Print_ISBN :
0-7803-5975-5
DOI :
10.1109/SSMSD.2000.836446
