Title :
Hybrid incremental-ΣΔ-ADC for ambient light sensing applications
Author :
Uhlig, J. ; Haenzsche, Stefan ; Gorner, Johannes ; Schuffny, Rene ; Reichel, Thomas ; Gopfert, Lars
Author_Institution :
Tech. Univ. Dresden, Dresden, Germany
Abstract :
Incremental delta-sigma ADCs are well suited for ambient light sensing applications due to their multiplex capability. Conventional ambient light sensor circuits consists of a current-to-voltage converter followed by an ADC. The proposed hybrid delta-sigma architecture integrates the current-to-voltage converter into the modulator loop. Circuit non-idealities of the current-to-voltage converter are thereby suppressed by noise shaping which greatly enhances the achievable resolution. Photodiode biasing as well as leakage current correction is realized by the fully differential current-to-voltage converter. The achievable resolution can be adapted by varying the conversion length.
Keywords :
photodetectors; photodiodes; sigma-delta modulation; ambient light sensing applications; ambient light sensor circuits; differential current-to-voltage converter; hybrid delta-sigma architecture; hybrid incremental-ΣΔ-ADC; leakage current correction; modulator loop; noise shaping; photodiode biasing; Capacitors; Clocks; Generators; Modulation; Photodiodes; Sensitivity;
Conference_Titel :
Circuits and Systems (ISCAS), 2013 IEEE International Symposium on
Conference_Location :
Beijing
Print_ISBN :
978-1-4673-5760-9
DOI :
10.1109/ISCAS.2013.6572081