A Caltech Library Service

CCD speed-noise optimization at 1 MHz

Smith, Roger and Kaye, Stephen (2018) CCD speed-noise optimization at 1 MHz. In: High Energy, Optical, and Infrared Detectors for Astronomy VIII. Proceedings of SPIE. No.10709. Society of Photo-optical Instrumentation Engineers (SPIE) , Bellingham, WA, Art. No. 1070910 . ISBN 9781510619715.

[img] PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


The Zwicky Transient Facility (ZTF)[1] is a CCD mosaic requiring 64 differential output channels to be transmitted to electronics located over 2 m from the CCDs and digitized with less than 10 e- read noise at 1 MHz pixel rate. To minimize pixel overhead, the Reset Gate pulse is generated inside the dewar by a pin driver controlled by a very short pulse using an LVDS interface. Overlapping serial clocks spanning the entire pixel are made entirely triangular with slopes tuned to cancel substrate return current and minimize high frequency content to improve common rejection by the fully differential signal path. We document the trade between settling time after charge dump and linearity and illustrate the desirability of generating both Summing Well and Reset Gate edge close to the CCD. The parallel clocking overhead is exacerbated in ZTF by ganging multiple CCDs but is hidden by overlapping the parallel shift with pixel readout. To suppress fixed pattern due to the concurrent parallel clocks, slow overlapped triangular waveforms panning the entire line time are employed to null the substrate current, in the same manner as the serials. Both noise and speed requirements are exceeded on all 64 channels, with margin. At all pixel rates the median noise is as good as can be expected for differential transmission being √2 times the single sided noise published in the data sheet for the CCD231- C6 CCDs. Linearity is preserved even at 840 ns pixel time, and crosstalk is less than 10 ppm.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Additional Information:© 2018 Society of Photo-Optical Instrumentation Engineers (SPIE).
Subject Keywords:CCD, speed, noise, differential, feedthrough, correlated double sampling
Series Name:Proceedings of SPIE
Issue or Number:10709
Record Number:CaltechAUTHORS:20181207-145745430
Persistent URL:
Official Citation:Roger Smith, Stephen Kaye, "CCD speed-noise optimization at 1 MHz," Proc. SPIE 10709, High Energy, Optical, and Infrared Detectors for Astronomy VIII, 1070910 (7 August 2018); doi: 10.1117/12.2314261
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:91584
Deposited By: George Porter
Deposited On:07 Dec 2018 23:39
Last Modified:16 Nov 2021 03:42

Repository Staff Only: item control page