Document Type
Thesis
Date of Award
12-31-1990
Degree Name
Master of Science in Electrical Engineering - (M.S.)
Department
Electrical and Computer Engineering
First Advisor
William N. Carr
Second Advisor
Walter F. Kosonocky
Third Advisor
Durgamadhab Misra
Abstract
A novel X-ray sensor IC has beeli designed which counts individual photons at rates up to 5,000,000 counts per second. A two-dimensional X-ray flip-flop sensor array, consisting of an 30 x 30 matrix of CMOS flip-flop sensors integrated in one chip together with an internal clock generator and access selection circuitry is described. A flip-flop sensing cell contains cross-coupled CMOS devices, one of which is connected to a large-area reverse-biased diode. A large area diode exposed to X-ray flux triggers the flip-flop. By reading out the final stable state of the flip-flop, the absence or presence of an X-ray photon absorption event in the diode can be determined.
An incident X-ray photon absorption event partially discharges the large photodiode to an offset voltage level which triggers the flip-flop. The sensitivity of the flip-flop sensing cell is increased by 44 dB using a synchronous pulsed power bus for level detection. A digital-level serial output is obtained from the chip. The chip design measures 5.2 x 5.2 mm2 based on MOSIS 3-,um, single-level metal, single-level polysilicon process technology.
Recommended Citation
Lee, Huan-Chung, "An integrated circuit x-ray sensing array based on a CMOS flip-flop cell" (1990). Theses. 2811.
https://digitalcommons.njit.edu/theses/2811
