Monolithic optical position encoder with on-chip photodiodes

Author

Aubert, Philippe ; Oguey, Henri J. ; Vuilleumier, Raymond

Author_Institution

Centre Suisse d´´Electron. et de Microtech., Neuchatel, Switzerland

Volume

23

Issue

2

fYear

1988

fDate

4/1/1988 12:00:00 AM

Firstpage

465

Lastpage

473

Abstract

A system that combines light sensors and analog and digital parts on the same CMOS chip has been fabricated. The optical and electrical properties of various photodiodes, which are fully compatible with a standard CMOS technology, are discussed. The current comparators use CMOS-compatible lateral bipolar transistors. The optical encoder also comprises a signal processor for code conversion, a serial or parallel output, and a self-test function. A 14-channel circuit which senses light signals at 880 nm with a power of 0.3-3 mW/cm² has been fabricated. Response time is shorter than 1 μs at all illumination levels. This circuit operates in the temperature range -55 to +125°C. Its current consumption is 8 mA at 5 V

Keywords

CMOS integrated circuits; angular measurement; encoding; integrated logic circuits; photodetectors; position measurement; -55 to 125 C; 1 mus; 14 bits; 5 V; 8 mA; 880 nm; ASIC; CMOS chip; CMOS-compatible lateral bipolar transistors; VLSI; code conversion; current comparators; current consumption; custom ICs; electrical properties; light sensors; on-chip photodiodes; optical encoder; optical position encoder; optical shaft encoders; parallel output; response time; self-test function; serial output; signal processor; standard CMOS technology; system on chip; temperature range; Bipolar transistors; Built-in self-test; CMOS technology; Circuits; Delay; Lighting; Optical sensors; Photodiodes; Sensor systems; Signal processing;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/4.1008

Filename

1008