In-Pixel temperature sensors with an accuracy of ±0.25 °C, a 3σ variation of ±0.7 °C in the spatial domain and a 3σ variation of ±1 °C in the temporal domain

In-Pixel temperature sensors with an accuracy of ±0.25 °C, a 3σ variation of ±0.7 °C in the spatial domain and a 3σ variation of ±1 °C in the temporal domain

Abarca Prouza, A.N. (TU Delft Electronic Instrumentation)
Theuwissen, A.J.P.A.M. (TU Delft Electronic Instrumentation; Harvest Imaging, Belgium)

2020-07

This article presents in-pixel (of a CMOS image sensor (CIS) temperature sensors with improved accuracy in the spatial and the temporal domain. The goal of the temperature sensors is to be used to compensate for dark (current) fixed pattern noise (FPN) during the exposure of the CIS. The temperature sensors are based on substrate parasitic bipolar junction transistor (BJT) and on the nMOS source follower of the pixel. The accuracy of these temperature sensors has been improved in the analog domain by using dynamic element matching (DEM), a temperature independent bias current based on a bandgap reference (BGR) with a temperature independent resistor, correlated double sampling (CDS), and a full BGR bias of the gain amplifier. The accuracy of the bipolar based temperature sensor has been improved to a level of ±0.25 °C, a 3σ variation of ±0.7 °C in the spatial domain, and a 3σ variation of ±1 °C in the temporal domain. In the case of the nMOS based temperature sensor, an accuracy of ±0.45 °C, 3σ variation of ±0.95 °C in the spatial domain, and ±1.4 °C in the temporal domain have been acquired. The temperature range is between-40 °C and 100 °C.

CMOS image sensor
Dark current
In-pixel temperature sensors
Tixel

http://resolver.tudelft.nl/uuid:0386f62d-dad1-4c07-b1af-05844711d220

https://doi.org/10.3390/mi11070665

2072-666X

Micromachines, 11 (7)

Institutional Repository

journal article

© 2020 A.N. Abarca Prouza, A.J.P.A.M. Theuwissen