Maxim Integrated Products, Inc.
MATCHED FILTER TECHNIQUES CONFIGURED TO FIRE LED USING A SLOPED RESPONSE

Abstract:

An electronic device comprising a matched filter to drive a LED module is disclosed. The matched filter receives an incoming rectangular pulse and outputs a modulated driving signal to drive the LED module. The optical output from the LED is captured by an optical sensor and converted to electrical signal for analysis. A decimation filter couples to the optical sensor in an effort of reducing sampling rate and quantization noise of the converted electrical signal. The modulated driving signal output from the matched filter keeps the LED current, thus LED light, matching the time-mirrored impulse response of the decimation filter to obtain or approach a theoretical maximum signal-to-noise (SNR) at a fixed amount of power.