A Programmable Ambient Light Sensor with Dark Current Compensation and Wide Dynamic Range

Area of Science:

• Integrated Circuits
• Sensor Technology
• Electronic Engineering

Background:

• Conventional ambient light sensors have limitations including large area, limited dynamic range, and susceptibility to dark current effects.
• Extending battery life in portable electronics is a key driver for ambient light sensor development.

Purpose of the Study:

• To propose a programmable ambient light sensor addressing limitations of conventional designs.
• To achieve dark current compensation and a wide dynamic range for improved performance.

Main Methods:

• Design and fabrication of a programmable ambient light sensor using a 0.18 µm standard CMOS process.
• Incorporation of built-in dark current compensation circuitry.
• Implementation of three selectable output-current gain modes for dynamic range control.

Main Results:

• The sensor exhibits low power consumption (7.7 µA in dark environments) and operates over a wide voltage (2-5 V) and temperature (-40-80 °C) range.
• Achieved a wide dynamic range with effective dark current suppression.
• Chip area is 663 µm × 652 µm.

Conclusions:

• The proposed ambient light sensor offers significant improvements over conventional designs.
• Its performance characteristics make it highly suitable for portable electronic products and fluorescent fiber-optic temperature sensors.