Datasheet AD7171 (Analog Devices) - 10

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Data Sheet AD7171 OUTPUT NOISE AND RESOLUTION SPECIFICATIONS
Table 7 shows the rms noise of the AD7171. The numbers The noise-free bits, or p-p resolution, are defined as given are for a 5 V and a 3 V reference. These numbers are Noise-Free Bits = ln(FSR/Peak-to-Peak Noise)/ln(2) typical and are generated with a differential input voltage of 0 V. The corresponding p-p resolution is also listed along with the where FSR is the full-scale range and is equal to 2 × VREF/gain. effective resolution (ENOB). Note that the effective resolution is
Table 7. RMS Noise and Resolution of the AD7171
calculated using the rms noise, whereas the p-p resolution is based
VREF = VDD RMS Noise P-P Noise P-P Resolution ENOB
on the p-p noise. The p-p resolution represents the resolution 5 V 11.5 μV 76 μV 16 bits 16 bits for which there is no code flicker. These numbers are typical. 3 V 6.9 μV 45 μV 16 bits 16 bits The effective number of bits (ENOB) is defined as ENOB = ln(FSR/RMS noise)/ln(2) Rev. C | Page 9 of 16 Document Outline FEATURES INTERFACE APPLICATIONS FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS TIMING CHARACTERISTICS Timing Diagrams ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS OUTPUT NOISE AND RESOLUTION SPECIFICATIONS ADC CIRCUIT INFORMATION OVERVIEW FILTER, DATA RATE, AND SETTLING TIME GAIN POWER-DOWN/RESET (PDRST\) ANALOG INPUT CHANNEL BIPOLAR CONFIGURATION DATA OUTPUT CODING REFERENCE DIGITAL INTERFACE GROUNDING AND LAYOUT APPLICATIONS INFORMATION TEMPERATURE SYSTEM SIGNAL CONDITIONING CIRCUIT OUTLINE DIMENSIONS ORDERING GUIDE