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What is the full scale input range of an ADC?
Many Analog to Digital Converters (ADCs) are defined as having their input full scale input range (FSR) in terms of a differential (Vpp) or single-ended voltage (Vp). This is because an ADC samples a voltage seen between the true and complement analog inputs.
What is the purpose of a differential ADC?
A differential ADC measures the voltage difference between two inputs. This can be essential in certain applications as some measurement concepts require two output signals instead of one to quantify the physical property of interest.
Which is the best voltage to use for ADC?
The stability of the voltage provided as VREF over varying temperatures is very important. If not, then the ADC will give results that are skewed around the temperature at which it was first calibrated. V REF should also be a value that is close to the maximum value that the analog input on the ADC will see.
Is the ADC input impedance fixed or fixed?
While some systems seek to maximize the dynamic range of the ADC by using as much of the effective input full scale as possible, a saturated ADC will add distortion and provide poor performance data. Most ADCs have a fixed input impedance, although others may provide various selectable impedance values.
Why do we need differential signals in an ADC converter?
For best performance, reduce the input signal range to ensure that the ADC input range is not exceeded. Another key advantage of differential signals is the increased dynamic range. With power supplies dropping to 3.3V and lower, design engineers are looking for ways to achieve greater input dynamic range.
How is a sensor interfacing with an ADC?
Interfacing a sensor to an ADC requires matching the sensor/signal conditioning output with the ADC input. Voltage output sensors provide either a single-ended or differential output. For single-end signals, all the inputs are referenced to system ground.
Why are DC offsets bad for an ADC converter?
DC offset and/or noise in the signal path will decrease the dynamic range of the input signal. Single-ended inputs are ideal if the signal source and ADC are close to each other (i.e., on the same board so that signal traces can be kept as short as possible).