AD7923 Analog Devices, AD7923 Datasheet - Page 11

• Manufacturer Part Number: AD7923
• Description: 4-Channel 200 kSPS, 12-Bit A/D Converter with Sequencer in 16-Lead TSSOP
• Manufacturer: Analog Devices

Specifications of AD7923

• Resolution (bits): 12bit
• # Chan: 4
• Sample Rate: 200kSPS
• Interface: Ser,SPI
• Analog Input Type: SE-Uni
• Ain Range: Uni (Vref),Uni (Vref) x 2
• Adc Architecture: SAR
• Pkg Type: SOP

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 (f
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
Thus for a 12-bit converter, this is 74 dB.
SINAD = (6.02N + 1.76) dB
S
/2), excluding dc. The ratio is dependent on the
Rev. C | Page 11 of 24
Total Harmonic Distortion (THD)
THD is the ratio of the rms sum of harmonics to the
fundamental. For the AD7923, it is defined as
where V
V
sixth harmonics.
4
, V
THD
5
, and V
(
1
dB
is the rms amplitude of the fundamental and V
)
=
6
are the rms amplitudes of the second through the
20
log
V
2
2
+
V
3
2
+
V
V
1
4
2
+
V
5
2
+
V
6
2
AD7923
2
, V
3
,