AD7890
Rev. C | Page 3 of 28
SPECIFICATIONS
VDD = 5 V, AGND = DGND = 0 V, REF IN = 2.5 V, fCLK IN = 2.5 MHz external, MUX OUT connect to SHA IN. All specifications TMIN to
TMAX, unless otherwise noted.
Table 1.
Parameter
A Versions1
B Versions
S Version
Unit
Test Conditions/Comments
DYNAMIC PERFORMANCE
Using external CONVST, any channel
Signal to (Noise + Distortion) Ratio2
70
dB min
fIN = 10 kHz sine wave, fSAMPLE = 100 kHz3
Total Harmonic Distortion (THD)2
77
dB max
fIN = 10 kHz sine wave, fSAMPLE = 100 kHz3
Peak Harmonic or Spurious Noise2
78
dB max
fIN = 10 kHz sine wave, fSAMPLE = 100 kHz3
Intermodulation Distortion
fa = 9 kHz, fb = 9.5 kHz, fSAMPLE = 100 kHz3
2nd Order Terms
80
dB typ
3rd Order Terms
80
dB typ
Channel-to-Channel Isolation2
80
dB max
fIN = 1 kHz sine wave
DC ACCURACY
Resolution
12
Bits
Min. Resolution for Which
No
Missing Codes Are Guaranteed
12
Bits
Relative Accuracy2
±1
±0.5
±1
LSB max
Differential Nonlinearity2
±1
LSB max
Positive Full-Scale Error2
±2.5
LSB max
Full-Scale Error Match4
2
LSB max
AD7890-2, AD7890-4
Unipolar Offset Error2
±2
LSB max
Unipolar Offset Error Match
2
LSB max
AD7890-10 Only
Negative Full-Scale Error2
±2
LSB max
Bipolar Zero Error2
±5
LSB max
Bipolar Zero Error Match
2
LSB max
ANALOG INPUTS
AD7890-10
Input Voltage Range
±10
Volts
Input Resistance
20
kΩ min
AD7890-4
Input Voltage Range
0 to 4.096
Volts
Input Resistance
11
kΩ min
AD7890-2
Input Voltage Range
0 to 2.5
Volts
Input Current
50
200
nA max
MUX OUT OUTPUT
Output Voltage Range
0 to 2.5
Volts
Output Resistance
AD7890-10, AD7890-4
3/5
kΩ min/kΩ max
AD7890-2
2
kΩ max
Assuming VIN is driven from low impedance
SHA IN INPUT
Input Voltage Range
0 to 2.5
Volts
Input Current
±50
nA max
REFERENCE OUTPUT/INPUT
REF IN Input Voltage Range
2.375/2.625
V min/V max
2.5 V ± 5%
Input Impedance
1.6
kΩ min
Resistor connected to internal reference node
Input Capacitance5
10
pF max
REF OUT Output Voltage
2.5
V nom
REF OUT Error @ 25°C
±10
mV max
TMIN to TMAX
±20
±25
mV max
REF OUT Temperature Coefficient
25
ppm/°C typ
REF OUT Output Impedance
2
kΩ nom