Best 24 bit ADC converters. All informations about performance related to cost, acquisition speed and real bit resolution.
Best 24 bit ADC converters: a Comparison table
24 bit ADC has many possible applications like:
Precision sensor transducers and transmitters: pressure, strain, flow and force measurement.
Temperature measurements, portable instrumentation, factory automation and process controls.
This is a list of the best 24 bit AD converters easily available from the market:
PGA programmable Gain Amplifier
This amplifier is embedded into the AD converter. The purpose is to gain input voltage and provide an high impedence path to the input signal. A Delta Sigma converter behave like a continuosly charged and discharged capacitor. PGA stage act like a buffer amplifier. This instrumentation amplifier stage improve noise performance lowering them.
Relation between noise, speed and noise free bit resolution
Noise decrease when PGA gain increase
Noise decrease when Speed decrease
Noise Free Resolution decrease when Speed increase
Dictionary
SPS = Sample Per Second. This is the number of measurements performed every second.
OSR = Over Sampling Ratio.
ENOB = Effective Number Of Bit
ER = Effective Resolution.
NFR = Noise Free Resolution.
“Noise-free resolution” is not the same as “effective resolution”. Effective resolution is based on the
RMS noise value, while noise-free resolution is based on a peak-to-peak noise value specified as 6.6
times the RMS noise value.
How to calculate Effective Resolution = Log2(FSR/rms noise), where
FSR is the full-scale input range (5V in bipolar mode with a 2.5V reference), and
rms noise is the input-referred rms noise .
How to calculate Noise Free Resolution = Log2(FSR/p-p noise)
How much “best 24 bit ADC converters” post worth? 12 men hours
Credits & useful links
Texas Instruments ADC selector page
Analog Devices ADC selector page
Maxim Integrated selector page
Strain sensor basics and signal conditioning tips
Strain gage theoretical background
Measuring strain with strain gages
Calibration of bridge standard for strain gauge bridge amplifier
