Datasheet

AD7908/AD7918/AD7928
Rev. D | Page 7 of 32
AD7928 SPECIFICATIONS
A
VDD
= V
DRIVE
= 2.7 V to 5.25 V, REF
IN
= 2.5 V, f
SCLK
= 20 MHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
Table 3.
Parameter B Version
1
Unit Test Conditions/Comments
DYNAMIC PERFORMANCE f
IN
= 50 kHz sine wave, f
SCLK
= 20 MHz
Signal-to-(Noise + Distortion) (SINAD)
2
70 dB min @ 5 V, B models
69.5 dB min @ 5 V, W models
69 dB min @ 3 V typically 70 dB
Signal-to-Noise Ratio (SNR)
2
70 dB min B models
69.5 dB min W models
Total Harmonic Distortion (THD)
2
−77 dB max @ 5 V typically −84 dB
−73 dB max @ 3 V typically −77 dB
Peak Harmonic or Spurious Noise −78 dB max @ 5 V typically −86 dB
(SFDR)
2
−76 dB max @ 3 V typically −80 dB
Intermodulation Distortion (IMD)
2
fa = 40.1 kHz, fb = 41.5 kHz
Second-Order Terms −90 dB typ
Third-Order Terms −90 dB typ
Aperture Delay 10 ns typ
Aperture Jitter 50 ps typ
Channel-to-Channel Isolation
2
−85 dB typ f
IN
= 400 kHz
Full Power Bandwidth 8.2 MHz typ @ 3 dB
1.6 MHz typ @ 0.1 dB
DC ACCURACY
2
Resolution 12 Bits
Integral Nonlinearity ±1 LSB max
Differential Nonlinearity −0.9/+1.5 LSB max Guaranteed no missed codes to 12 bits
0 V to REF
IN
Input Range Straight binary output coding
Offset Error ±8 LSB max Typically ±0.5 LSB
Offset Error Match ±0.5 LSB max
Gain Error ±1.5 LSB max
Gain Error Match ±0.5 LSB max
0 V to 2 × REF
IN
Input Range
−REF
IN
to +REF
IN
biased about REF
IN
with twos
complement output coding
Positive Gain Error ±1.5 LSB max
Positive Gain Error Match ±0.5 LSB max
Zero Code Error ±8 LSB max Typically ±0.8 LSB
Zero Code Error Match ±0.5 LSB max
Negative Gain Error ±1 LSB max
Negative Gain Error Match ±0.5 LSB max
ANALOG INPUT
Input Voltage Ranges 0 to REF
IN
V RANGE bit set to 1
0 to 2 × REF
IN
V RANGE bit set to 0, AV
DD
/V
DRIVE
= 4.75 V to 5.25 V
DC Leakage Current ±1 μA max
Input Capacitance 20 pF typ
REFERENCE INPUT
REF
IN
Input Voltage 2.5 V ±1% specified performance
DC Leakage Current ±1 μA max
REF
IN
Input Impedance 36 kΩ typ f
SAMPLE
= 1 MSPS
LOGIC INPUTS
Input High Voltage, V
INH
0.7 × V
DRIVE
V min
Input Low Voltage, V
INL
0.3 × V
DRIVE
V max
Input Current, I
IN
±1 μA max Typically 10 nA, V
IN
= 0 V or V
DRIVE
Input Capacitance, C
IN
3
10 pF max