AD7923 datasheet(12/25 Pages) AD

Part #	AD7923

Description	4-Channel, 200 kSPS 12-Bit ADC Sequencer in 16-Lead TSSOP

PDF	25 Pages

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Manufacturer	AD [Analog Devices]

Direct Link	http://www.analog.com

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12 / 25 page

Data Sheet

AD7923

Rev. D | Page 11 of 24

Signal-to-(Noise + Distortion) (SINAD) Ratio

This is the measured ratio of SINAD at the output of the ADC.

The signal is the rms amplitude of the fundamental. Noise is the

sum of all nonfundamental signals up to half the sampling

frequency (fS/2), excluding dc. The ratio is dependent on the

number of quantization levels in the digitization process, the

more levels, the smaller the quantization noise. The theoretical

SINAD ratio for an ideal N-bit converter with a sine wave input

is given by

SINAD = (6.02N + 1.76) dB

Thus for a 12-bit converter, this is 74 dB.

Total Harmonic Distortion (THD)

THD is the ratio of the rms sum of harmonics to the

fundamental. For the AD7923, it is defined as

log

)

(

THD

where V1 is the rms amplitude of the fundamental and V2, V3,

V4, V5, and V6 are the rms amplitudes of the second through the

sixth harmonics.

AD7923 Datasheet(PDF) 12 Page - Analog Devices