Supply Allocation Exposure across Dual Sourced Low Tier Commercial Sensor Topologies
Dual sourcing low tier commercial sensors demands matching ASIC DSP group delays and thermal offset drift profiles to prevent host control loop instability.
Sinc Filter Group Delay
Phase Timing
Digital signal processing stages in oversampling converters introduce a specific time lag between the input signal and the filtered output. The sinc filter group delay is a measure of this latency, representing the average time it takes for a signal to pass through the filter stages. This delay is constant across the entire passband of a sinc filter.
It is an important consideration in real time control loops.
Averaging Window
The filter works by taking the average of a fixed number of samples over a period of time. A larger window provides more noise rejection but increases the time lag. The group delay is usually equal to half the total window length.
This relationship allows designers to predict the system response time precisely.
Frequency Notch
Mathematical structures within the filter create zeros at multiples of the output data rate. These notches provide excellent rejection of line noise at 50 or 60 hertz. The shape of the frequency response looks like a sinking function.
This characteristic gives the filter its name.
Signal Path
In multi-stage systems, the total delay is the sum of the delays of each individual filter. This cumulative effect must be managed to ensure stability in feedback systems.