Contents
How can you reduce the quantization noise?
A new technique to reduce the effect of quantization noise in PCM speech coding is proposed. The procedure consists of using dither noise to ensure that the quantization errors can be modeled as additive signal-independent noise, and then reducing this noise through the use of a noise reduction system.
What is meant by quantization noise?
Quantization noise results when a continuous random variable is converted to a discrete one or when a discrete random variable is converted to one with fewer levels. In images, quantization noise often occurs in the acquisition process.
How to reduce system noise in ADC circuits?
ADC System Noise 3 Long Traces: Antenna ●Trace going into 10-bit ADC input is longer than a few inches Emitted Noise Ok, well, this is a common conversation that I have with people, customers and even engineers here at Microchip. A person will walk up to me and say, ‘you know, I have this 10-bit ADC board and I’m not getting 10 bits.
How many noise free bits are there in an ADC?
Consider a 16-bit ADC which has 15 noise-free bits at a sampling rate of 100 kSPS. Averaging two measurements of an unchanging signal for each output sample reduces the effective sampling rate to 50 kSPS—and increases the SNR by 3 dB and the number of noise-free bits to 15.5.
How can dithering improve the SFDR of an ADC?
Dithering can be used to improve SFDR of an ADC under certain conditions (see Further Reading 2–5). For example, even in a perfect ADC, some correlation exists between the quantization noise and the input signal. This correlation can reduce the SFDR of the ADC, especially if the input signal is an exact sub-multiple of the sampling frequency.
Can a higher resolution off-chip ADC be used?
For this reason, many systems employ a higher resolution off-chip ADC. However, there are techniques that can be used to achieve higher resolution measurements and SNR. This application note describes utilizing oversampling and averaging to increase the resolution and SNR of analog-to-digital conversions.