General Description

AS7421 is a 64-channel near infrared digital spectrometer for spectral identification and spectral

footprint analysis used in consumer devices. The spectral response of the sensor is defined in the

wavelengths from approximately 750 nm to 1050 nm and the channels are equally distributed over the

mentioned range. Once a spectral measurement is started, all 64 channels are processed

automatically by 16 parallel sampling ADCs with four consecutive integration cycles.

AS7421 integrates Fabry-Perot filters into standard CMOS silicon via Nano-optic deposited

interference filter technology and its package provides a built in aperture and micro optics to control

the light entering the sensor array. In addition, the module provides a near infrared (NIR) light source

and an integrated LED driver to control it.

Control and Spectral data access is implemented through a serial I²C interface. A GPIO and an

interrupt signal are available to start/synchronize the spectral measurement as well as minimize I²C

traffic.

Features

Calibration library support which includes data

post-processing of spectral raw data

Data output options: raw data, absorbance

spectra, 1st derivative of absorbance spectra, 2nd

derivative of absorbance spectra

Applications

● Spectral material identification of goods and fabrics

● Moisture measurements in industrial or agricultural environments

● Brix and dry matter measurements of fruits (fruit ripeness)