–2–
AD7888–SPECIFICATIONS (V
DD = 2.7 V to 5.25 V, REFIN/REFOUT = 2.5 V External/Internal Reference unless
otherwise noted; fSCLK = 2 MHz (VDD = 2.7 V to 5.25 V); TA = TMIN to TMAX, unless otherwise noted.)
Parameter
A Version
1
B Version
1
Unit
Test Condition/Comment
DYNAMIC PERFORMANCE
Signal to Noise + Distortion Ratio2, 3 (SNR)
71
dB typ
fIN = 10 kHz Sine Wave, fSAMPLE = 125 kSPS
Total Harmonic Distortion
2 (THD)
–80
dB typ
fIN = 10 kHz Sine Wave, fSAMPLE = 125 kSPS
Peak Harmonic or Spurious Noise
2
–80
dB typ
fIN = 10 kHz Sine Wave, fSAMPLE = 125 kSPS
Intermodulation Distortion2 (IMD)
Second Order Terms
–78
dB typ
fa = 9.983 kHz, fb = 10.05 kHz, fSAMPLE = 125 kSPS
Third Order Terms
–78
dB typ
fa = 9.983 kHz, fb = 10.05 kHz, fSAMPLE = 125 kSPS
Channel-to-Channel Isolation2
–80
dB typ
fIN = 25 kHz
Full Power Bandwidth
2.5
MHz typ
@ 3 dB
DC ACCURACY
Any Channel
Resolution
12
Bits
Integral Nonlinearity
2
±2
±1
LSB max
Differential Nonlinearity
2
±2
–1/+1.5
LSB max
Guaranteed No Missed Codes to 11 Bits (A Grade)
Guaranteed No Missed Codes to 12 Bits (B Grade)
Offset Error
±6
LSB max
VDD = 4.75 V to 5.25 V (Typically
±3 LSB)
±4.5
LSB max
VDD = 2.7 V to 3.6 V (Typically
±2 LSB)
Offset Error Match
2
LSB typ
Gain Error
2
±2
LSB max
Typically 30 LSB with Internal Reference
Gain Error Match
2
3
LSB max
ANALOG INPUT
Input Voltage Ranges
0 to VREF
Volts
Leakage Current
±1
A max
Input Capacitance
38
pF typ
When in Track
4
pF typ
When in Hold
REFERENCE INPUT/OUTPUT
REFIN Input Voltage Range
2.5/VDD
V min/max
Functional from 1.2 V
Input Impedance
5
k
typ
Very High Impedance If Internal Reference Disabled
REFOUT Output Voltage
2.45/2.55
V min/max
REFOUT Tempco
±50
ppm/
°C typ
LOGIC INPUTS
Input High Voltage, VINH
2.4
V min
VDD = 4.75 V to 5.25 V
2.1
V min
VDD = 2.7 V to 3.6 V
Input Low Voltage, VINL
0.8
V max
VDD = 2.7 V to 5.25 V
Input Current, IIN
±10
A max
Typically 10 nA, VIN = 0 V or VDD
Input Capacitance, CIN
4
10
pF max
LOGIC OUTPUTS
Output High Voltage, VOH
ISOURCE = 200
A
VDD – 0.5
V min
VDD = 2.7 V to 5.25 V
Output Low Voltage, VOL
0.4
V max
ISINK = 200
A
Floating-State Leakage Current
±10
A max
Floating-State Output Capacitance
5
10
pF max
Output Coding
Straight (Natural) Binary
CONVERSION RATE
Throughput Time
16
SCLK Cycles
Conversion Time + Acquisition Time. 125 kSPS with
2 MHz Clock
Track/Hold Acquisition Time
2
1.5
SCLK Cycles
Conversion Time
14.5
SCLK Cycles
7.25
s (2 MHz Clock)
REV. C