Datasheet

AD7890
Rev. C | Page 3 of 28
SPECIFICATIONS
V
DD
= 5 V, AGND = DGND = 0 V, REF IN = 2.5 V, f
CLK IN
= 2.5 MHz external, MUX OUT connect to SHA IN. All specifications T
MIN
to
T
MAX
, unless otherwise noted.
Table 1.
Parameter A Versions
1
B Versions S Version Unit Test Conditions/Comments
DYNAMIC PERFORMANCE
Using external
CONVST
, any channel
Signal to (Noise + Distortion) Ratio
2
70 70 70 dB min f
IN
= 10 kHz sine wave, f
SAMPLE
= 100 kHz
3
Total Harmonic Distortion (THD)
2
−77 −77 −77 dB max
f
IN
= 10 kHz sine wave, f
SAMPLE
= 100 kHz
3
Peak Harmonic or Spurious Noise
2
−78 −78 −78 dB max
f
IN
= 10 kHz sine wave, f
SAMPLE
= 100 kHz
3
Intermodulation Distortion
fa = 9 kHz, fb = 9.5 kHz, f
SAMPLE
= 100 kHz
3
2nd Order Terms −80 −80 −80 dB typ
3rd Order Terms −80 −80 −80 dB typ
Channel-to-Channel Isolation
2
−80 −80 −80 dB max f
IN
= 1 kHz sine wave
DC ACCURACY
Resolution 12 12 12 Bits
Min. Resolution for Which No
Missing Codes Are Guaranteed
12 12 12 Bits
Relative Accuracy
2
±1 ±0.5 ±1 LSB max
Differential Nonlinearity
2
±1 ±1 ±1 LSB max
Positive Full-Scale Error
2
±2.5 ±2.5 ±2.5 LSB max
Full-Scale Error Match
4
2 2 2 LSB max
AD7890-2, AD7890-4
Unipolar Offset Error
2
±2 ±2 ±2 LSB max
Unipolar Offset Error Match 2 2 2 LSB max
AD7890-10 Only
Negative Full-Scale Error
2
±2 ±2 ±2 LSB max
Bipolar Zero Error
2
±5 ±5 ±5 LSB max
Bipolar Zero Error Match 2 2 2 LSB max
ANALOG INPUTS
AD7890-10
Input Voltage Range ±10 ±10 ±10 Volts
Input Resistance 20 20 20 kΩ min
AD7890-4
Input Voltage Range 0 to 4.096 0 to 4.096 0 to 4.096 Volts
Input Resistance 11 11 11 kΩ min
AD7890-2
Input Voltage Range 0 to 2.5 0 to 2.5 0 to 2.5 Volts
Input Current 50 50 200 nA max
MUX OUT OUTPUT
Output Voltage Range 0 to 2.5 0 to 2.5 0 to 2.5 Volts
Output Resistance
AD7890-10, AD7890-4 3/5 3/5 3/5 kΩ min/kΩ max
AD7890-2 2 2 2 kΩ max Assuming V
IN
is driven from low impedance
SHA IN INPUT
Input Voltage Range 0 to 2.5 0 to 2.5 0 to 2.5 Volts
Input Current ±50 ±50 ±50 nA max
REFERENCE OUTPUT/INPUT
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 kΩ 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 ±25 mV max
REF OUT Temperature Coefficient 25 25 25 ppm/°C typ
REF OUT Output Impedance 2 2 2 kΩ nom