Datasheet

Data Sheet AD7982
Rev. B | Page 3 of 24
SPECIFICATIONS
VDD = 2.5 V, VIO = 2.3 V to 5.5 V, REF = 5 V, T
A
= 40°C to +85°C, unless otherwise noted.
Table 2.
Parameter Conditions Min Typ Max Unit
RESOLUTION 18 Bits
ANALOG INPUT
Voltage Range IN+ − IN− −V
REF
+V
REF
V
Absolute Input Voltage IN+, IN− −0.1 V
REF
+ 0.1 V
Common-Mode Input Range IN+, IN− V
REF
× 0.475 V
REF
× 0.5 V
REF
× 0.525 V
Analog Input CMRR f
IN
= 450 kHz 67 dB
Leakage Current at 25°C Acquisition phase 200 nA
Input Impedance See the Analog Inputs section
ACCURACY
No Missing Codes 18 Bits
Differential Linearity Error 0.85 ±0.5 +1.5 LSB
1
Integral Linearity Error −2 ±1 +2 LSB
1
Transition Noise REF = 5 V 1.05 LSB
1
Gain Error, T
MIN
to T
MAX
2
0.023 +0.004 +0.023 % of FS
Gain Error Temperature Drift ±1 ppm/°C
Zero Error, T
MIN
to T
MAX
2
±100 +700 µV
Zero Temperature Drift 0.5 ppm/°C
Power Supply Rejection Ratio VDD = 2.5 V ± 5% 90 dB
THROUGHPUT
Conversion Rate 0 1 MSPS
Transient Response
Full-scale step
290
ns
AC ACCURACY
Dynamic Range
V
REF
= 5 V
97
99
dB
3
V
REF
= 2.5 V 93 dB
3
Oversampled Dynamic Range
4
F
O
= 1 kSPS 129 dB
3
Signal-to-Noise f
IN
= 1 kHz, V
REF
= 5 V, T
A
= 25°C 95.5 98 dB
3
f
IN
= 1 kHz, V
REF
= 2.5 V, T
A
= 25°C 92.5 dB
3
Spurious-Free Dynamic Range f
IN
= 10 kHz −115 dB
3
Total Harmonic Distortion
5
f
IN
= 10 kHz −120 dB
3
Signal-to-(Noise + Distortion) f
IN
= 1 kHz, V
REF
= 5 V, T
A
= 25°C 97 dB
3
1
LSB means least significant bit. With the ±5 V input range, 1 LSB is 38.15 µV.
2
See Terminology section. These specifications include full temperature range variation but not the error contribution from the external reference.
3
All specifications expressed in decibels are referred to a full-scale input FSR and tested with an input signal at 0.5 dB below full scale, unless otherwise specified.
4
Dynamic range is obtained by oversampling the ADC running at a throughput F
s
of 1 MSPS followed by postdigital filtering with an output word rate of F
O
.
5
Tested fully in production at f
IN
= 1 kHz.