Integrating Moving Average Filter Windows with Analog Converter Downsampling Rates
Aligning moving average filter lengths as integer multiples of ADC decimation rates eliminates aliasing foldover and maximizes noise bandwidth reduction.
Sample Rate Converter
Signal Processor
An electronic device or algorithm translates a digital signal from one sampling frequency to another while maintaining signal integrity. This sample rate converter is essential for integrating audio or sensor systems that operate at different internal clock rates. The conversion process must minimize the introduction of noise and distortion.
It can operate in either synchronous or asynchronous modes depending on the clock sources.
Filter Interpolation
The conversion involves interpolating the input signal to a higher frequency and then decimating it to the target rate. Low pass filtering is required during this process to prevent aliasing, where high frequency noise is folded back into the signal band. The design of these digital filters determines the overall quality and bandwidth of the output.
Quality Measurement
Laboratory testing uses high precision audio analyzers to measure the total harmonic distortion plus noise introduced by the converter. Dynamic range and frequency response are also evaluated to ensure no signal degradation occurs. These measurements are performed with various test signals to confirm performance under different conditions.
The converter must maintain a high signal to noise ratio over its entire operating band.
Clock Jitter
Variations in the sampling clocks can introduce phase noise and degrade the conversion accuracy. Using stable, low jitter clock sources is necessary to achieve high resolution. Proper clock synchronization minimizes these effects and ensures reliable operation.