–2–
REV. D
AD7891–SPECIFICATIONS
(VDD = 5 V
5%, AGND = DGND = 0 V, REF IN = 2.5 V. All specifications TMIN to TMAX,
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
∞C70
7070dB min
TMIN to TMAX
70
dB min
Total Harmonic Distortion
4
–78
dB max
Peak Harmonic or Spurious Noise
4
–80
dB max
Intermodulation Distortion
4
fa = 9 kHz, fb = 9.5 kHz.
Second-Order Terms
–80
dB typ
Third-Order Terms
–80
dB typ
Channel-to-Channel Isolation
4
–80
dB max
DC ACCURACY
Any channel.
Resolution
12
Bits
Minimum Resolution for which
No Missing Codes Are Guaranteed
12
Bits
Relative Accuracy
4
±1
±0.75
±1
LSB max
Differential Nonlinearity
4
±1
LSB max
Positive Full-Scale Error
4
±3
LSB max
Positive Full-Scale Error Match
4, 5
0.6
LSB typ
1.5 LSB max.
Unipolar Offset Error
±4
LSB max
Input ranges of 0 V to 2.5 V, 0 V to 5 V.
Unipolar Offset Error Match
5
0.1
LSB typ
1 LSB max.
Negative Full-Scale Error
4
±3
LSB max
Input ranges of
±2.5 V, ±5V, ±10 V.
Negative Full-Scale Error Match
4, 5
0.6
LSB typ
1.5 LSB max.
Bipolar Zero Error
±4
LSB max
Input ranges of
±2.5 V, ±5V, ±10 V.
Bipolar Zero Error Match
5
0.2
LSB typ
1.5 LSB max.
ANALOG INPUTS
AD7891-1 Input Voltage Range
±5
±5V
Input applied to both VINXA and VINXB.
±10
V
Input applied to VINXA, VINXB = AGND.
AD7891-1 VINXA Input Resistance
7.5
k
W min
Input range of
±5V.
AD7891-1 VINXA Input Resistance
15
k
W min
Input range of
±10 V.
AD7891-2 Input Voltage Range
0 to 2.5
V
Input applied to both VINXA and VINXB.
0 to 5
V
Input applied to VINXA, VINXB = AGND.
±2.5
V
Input applied to VINXA, VINXB = REF IN
6.
AD7891-2 VINXA Input Resistance
1.5
k
W min
Input ranges of
±2.5 V and 0 V to 5 V.
AD7891-2 VINXA Input Current
±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
k
W min
Resistor connected to internal reference node.
Input Capacitance
5
10
pF max
REF OUT Output Voltage
2.5
V nom
REF OUT Error @ 25
∞C
±10
mV max
TMIN to TMAX
±20
mV max
REF OUT Temperature Coefficient
25
ppm/
∞C typ
REF OUT Output Impedance
5
k
W nom
See REF IN input impedance.
LOGIC INPUTS
Input High Voltage, VINH
2.4
V min
VDD = 5 V
± 5%.
Input Low Voltage, VINL
0.8
V max
VDD = 5 V
± 5%.
Input Current, IINH
±10
mA max
Input Capacitance
5 C
IN
10
pF max