Datasheet

–2–
REV. D
AD7891–SPECIFICATIONS
(V
DD
= 5 V ⴞ 5%, AGND = DGND = 0 V, REF IN = 2.5 V. All specifications T
MIN
to T
MAX
,
unless otherwise noted.)
Parameter A Version
1
B Version Y Version Unit Test Conditions/Comments
DYNAMIC PERFORMANCE
2
Sample Rate = 454.5 kSPS
3
(AD7891-1),
500 kSPS
3
(AD7891-2). Any channel.
Signal-to-(Noise + Distortion) Ratio
4
@ 25∞C707070dB min
T
MIN
to T
MAX
70 70 70 dB min
Total Harmonic Distortion
4
–78 –78 –78 dB max
Peak Harmonic or Spurious Noise
4
–80 –80 –80 dB max
Intermodulation Distortion
4
fa = 9 kHz, fb = 9.5 kHz.
Second-Order Terms –80 –80 –80 dB typ
Third-Order Terms –80 –80 –80 dB typ
Channel-to-Channel Isolation
4
–80 –80 –80 dB max
DC ACCURACY Any channel.
Resolution 12 12 12 Bits
Minimum Resolution for which
No Missing Codes Are Guaranteed 12 12 12 Bits
Relative Accuracy
4
± 1 ± 0.75 ± 1 LSB max
Differential Nonlinearity
4
± 1 ± 1 ± 1 LSB max
Positive Full-Scale Error
4
± 3 ± 3 ± 3 LSB max
Positive Full-Scale Error Match
4, 5
0.6 0.6 0.6 LSB typ 1.5 LSB max.
Unipolar Offset Error ± 4 ± 4 ± 4 LSB max Input ranges of 0 V to 2.5 V, 0 V to 5 V.
Unipolar Offset Error Match
5
0.1 0.1 0.1 LSB typ 1 LSB max.
Negative Full-Scale Error
4
± 3 ± 3 ± 3 LSB max Input ranges of ± 2.5 V, ± 5V, ± 10 V.
Negative Full-Scale Error Match
4, 5
0.6 0.6 0.6 LSB typ 1.5 LSB max.
Bipolar Zero Error ± 4 ± 4 ± 4 LSB max Input ranges of ± 2.5 V, ± 5V, ± 10 V.
Bipolar Zero Error Match
5
0.2 0.2 0.2 LSB typ 1.5 LSB max.
ANALOG INPUTS
AD7891-1 Input Voltage Range
± 5 ± 5 ± 5V Input applied to both V
INXA
and V
INXB
.
± 10 ± 10 ± 10 V Input applied to V
INXA
, V
INXB
= AGND.
AD7891-1 V
INXA
Input Resistance 7.5 7.5 7.5 kW min Input range of ± 5V.
AD7891-1 V
INXA
Input Resistance 15 15 15 kW min Input range of ± 10 V.
AD7891-2 Input Voltage Range 0 to 2.5 0 to 2.5 0 to 2.5 V Input applied to both V
INXA
and V
INXB
.
0 to 5 0 to 5 0 to 5 V Input applied to V
INXA
, V
INXB
= AGND.
± 2.5 ± 2.5 ± 2.5 V Input applied to V
INXA
, V
INXB
= REF IN
6
.
AD7891-2 V
INXA
Input Resistance 1.5 1.5 1.5 kW min Input ranges of ± 2.5 V and 0 V to 5 V.
AD7891-2 V
INXA
Input Current ± 50 ± 50 ± 50 nA max Input range of 0 V to 2.5 V.
REFERENCE INPUT/OUTPUT
REF IN Input Voltage Range 2.375/2.625 2.375/2.625 2.375/2.625 V min/V max 2.5 V ± 5%.
Input Impedance 1.6 1.6 1.6 kW min Resistor connected to internal reference node.
Input Capacitance
5
10 10 10 pF max
REF OUT Output Voltage 2.5 2.5 2.5 V nom
REF OUT Error @ 25∞C ± 10 ± 10 ± 10 mV max
T
MIN
to T
MAX
± 20 ± 20 ± 20 mV max
REF OUT Temperature Coefficient 25 25 25 ppm/∞C typ
REF OUT Output Impedance 5 5 5 kW nom See REF IN input impedance.
LOGIC INPUTS
Input High Voltage, V
INH
2.4 2.4 2.4 V min V
DD
= 5 V ± 5%.
Input Low Voltage, V
INL
0.8 0.8 0.8 V max V
DD
= 5 V ± 5%.
Input Current, I
INH
± 10 ± 10 ± 10 mA max
Input Capacitance
5
C
IN
10 10 10 pF max