Title :
A 32×32 50ps resolution 10 bit time to digital converter array in 130nm CMOS for time correlated imaging
Author :
Richardson, Justin ; Walker, Richard ; Grant, Lindsay ; Stoppa, David ; Borghetti, Fausto ; Charbon, Edoardo ; Gersbach, Marek ; Henderson, Robert K.
Author_Institution :
Univ. of Edinburgh, Edinburgh, UK
Abstract :
We report the design and characterisation of a 32times32 time to digital (TDC) converter plus single photon avalanche diode (SPAD) pixel array implemented in a 130 nm imaging process. Based on a gated ring oscillator approach, the 10 bit, 50 mum pitch TDC array exhibits a minimum time resolution of 50 ps, with accuracy of plusmn0.5 LSB DNL and 2.4 LSB INL. Process, voltage and temperature compensation (PVT) is achieved by locking the array to a stable external clock. The resulting time correlated pixel array is a viable candidate for single photon counting (TCSPC) applications such as fluorescent lifetime imaging microscopy (FLIM), nuclear or 3D imaging and permits scaling to larger array formats.
Keywords :
CMOS image sensors; avalanche diodes; convertors; oscillators; CMOS; SPAD pixel array; TDC array; digital converter array; fluorescent lifetime imaging microscopy; imaging process; ring oscillator; single photon avalanche diode; single photon counting; temperature compensation; time correlated imaging; time correlated pixel array; time to digital converter; Clocks; Diodes; Fluorescence; Image resolution; Microscopy; Pixel; Ring oscillators; Temperature; Voltage;
Conference_Titel :
Custom Integrated Circuits Conference, 2009. CICC '09. IEEE
Conference_Location :
San Jose, CA
Print_ISBN :
978-1-4244-4071-9
Electronic_ISBN :
978-1-4244-4073-3
DOI :
10.1109/CICC.2009.5280890
