How does Sigma Delta ADC work?
A delta-sigma ADC first encodes an analog signal using high-frequency delta-sigma modulation, and then applies a digital filter to form a higher-resolution but lower sample-frequency digital output. In both cases, the temporary use of a lower-resolution signal simplifies circuit design and improves efficiency.
What is ODR in ADC?
The sampling frequency passed to the modulator sets the sampling frequency FMOD. The modulator outputs data to the digital filter at this rate, in turn the digital filter (typically low- pass, with some decimation) provides data at the output data rate (ODR).
What is decimation in ADC?
Decimation is a method of observing only a periodic portion of the ADC samples, while ignoring the rest. The result is to reduce the sample rate of the ADC. For example, a decimate-by-4 mode would mean (total samples)/4, while all other samples are effectively discarded.
What is the use of Sigma Delta ADC?
Modern Sigma-delta converters offer high resolution, high integration, low power consumption, and low cost, making them a good ADC choice for applications such as process control, precision temperature measurements, and weighing scales.
How does a 1 bit ADC work?
A popular technique in telecommunications and high fidelity music reproduction is single bit ADC and DAC. This latch insures that the output is synchronized with the clock, thereby defining the sampling rate, i.e., the rate at which the 1 bit output can update itself.
What is the output of sigma delta modulator if the input signal is ADC signal?
The output of the sigma-delta modulator is a 1-bit data stream at the sampling rate, which can be in the megahertz range. The purpose of the digital-and-decimation filter ( 9) is to extract information from this data stream and reduce the data rate to a more useful value.
How does decimation filter work?
Loosely speaking, “decimation” is the process of reducing the sampling rate. In practice, this usually implies lowpass-filtering a signal, then throwing away some of its samples. “Downsampling” is a more specific term which refers to just the process of throwing away samples, without the lowpass filtering operation.
What is difference between interpolation and decimation?
Sampling rate conversion systems are used to change the sampling rate of a signal. The process of sampling rate decrease is called decimation, and the process of sampling rate increase is called interpolation.
How does dual slope ADC operate?
In dual slope type ADC, the integrator generates two different ramps, one with the known analog input voltage VA and another with a known reference voltage –Vref. Hence it is called a s dual slope A to D converter.
How does a dual slope ADC work?
Dual-Slope ADC Architecture A dual-slope ADC (DS-ADC) integrates an unknown input voltage (VIN) for a fixed amount of time (TINT), then “de-integrates” (TDEINT) using a known reference voltage (VREF) for a variable amount of time (see Figure 2).
How is a delta-sigma converter used in a quantizer?
A delta-sigma converter uses many samples from the modulator to produce a stream of 1-bit codes. The delta-sigma ADC accomplishes this task by using an input-signal quantizer running at a high sample rate. Like all quantizers, the delta-sigma modulator takes an input and produces a stream of digital values that represents the voltage of the input.
What is the decimation rate of an ADC?
The ADC is set up to run with the sinc5 + sinc1 filter with a decimation rate of 32. All five conversion outputs have some overlap in the modulator inputs that define the filter output, thus, none are independent from each other.
What kind of software is used for ADC?
Eval+ is a single piece of software downloadable from the ADI website, which can be used to configure, analyze, and select the ADC with or without hardware. The software, running with hardware, will operate as per the standard evaluation board.
What are the advantages of the ad717x device?
The AD717x devices maximize dynamic range for designers of critically noise sensitive instrumentation circuits, enabling reduction or elimination of preceding amplifier gain in signal conditioning stages. The devices can also run at high speed and offer lower settling times than before.