A SPAD-based 3D imager with in-pixel TDC for 145ps-accuracy ToF measurement

I. Vornicu; R. Carmona-Galán; Á. Rodríguez-Vázquez

doi:10.1117/12.2078777

13 March 2015 A SPAD-based 3D imager with in-pixel TDC for 145ps-accuracy ToF measurement

I. Vornicu, R. Carmona-Galán, Á. Rodríguez-Vázquez

Proceedings Volume 9403, Image Sensors and Imaging Systems 2015; 94030I (2015) https://doi.org/10.1117/12.2078777
Event: SPIE/IS&T Electronic Imaging, 2015, San Francisco, California, United States

Abstract

The design and measurements of a CMOS 64 × 64 Single-Photon Avalanche-Diode (SPAD) array with in-pixel Time-to-Digital Converter (TDC) are presented. This paper thoroughly describes the imager at architectural and circuit level with particular emphasis on the characterization of the SPAD-detector ensemble. It is aimed to 2D imaging and 3D image reconstruction in low light environments. It has been fabricated in a standard 0.18μm CMOS process, i. e. without high voltage or low noise features. In these circumstances, we are facing a high number of dark counts and low photon detection efficiency. Several techniques have been applied to ensure proper functionality, namely: i) time-gated SPAD front-end with fast active-quenching/recharge circuit featuring tunable dead-time, ii) reverse start-stop scheme, iii) programmable time resolution of the TDC based on a novel pseudo-differential voltage controlled ring oscillator with fast start-up, iv) a global calibration scheme against temperature and process variation. Measurements results of individual SPAD-TDC ensemble jitter, array uniformity and time resolution programmability are also provided.

Citation Download Citation

I. Vornicu, R. Carmona-Galán, and Á. Rodríguez-Vázquez "A SPAD-based 3D imager with in-pixel TDC for 145ps-accuracy ToF measurement", Proc. SPIE 9403, Image Sensors and Imaging Systems 2015, 94030I (13 March 2015); https://doi.org/10.1117/12.2078777

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available