Datasheet

AD7678
Rev. A | Page 3 of 28
SPECIFICATIONS
Table 2. –40°C to +85°C, V
REF
= 4.096 V, AVDD = DVDD = 5 V, OVDD = 2.7 V to 5.25 V, unless otherwise noted.
Parameter Conditions Min Typ Max Unit
RESOLUTION 18 Bits
ANALOG INPUT
Voltage Range V
IN+
– V
IN–
–V
REF
+V
REF
V
Operating Input Voltage V
IN+
, V
IN–
to AGND –0.1 AVDD + 0.1 V
Analog Input CMRR f
IN
= 100 kHz 65 dB
Input Current 100 kSPS Throughput 4 μA
Input Impedance
1
THROUGHPUT SPEED
Complete Cycle 10 μs
Throughput Rate 0 100 kSPS
DC ACCURACY
Integral Linearity Error –2.5 +2.5 LSB
2
Differential Linearity Error –1 +1.75 LSB
No Missing Codes 18 Bits
Transition Noise V
REF
= 5 V 0.7 LSB
Zero Error, T
MIN
to T
MAX
–40 ±40 LSB
Zero Error Temperature Drift ±0.5 ppm/°C
Gain Error, T
MIN
to T
MAX
3
–0.048 See Note 3 +0.048 % of FSR
Gain Error Temperature Drift ±1.6 ppm/°C
Power Supply Sensitivity AVDD = 5 V ± 5% ±4 LSB
AC ACCURACY
Signal-to-Noise f
IN
= 2 kHz, V
REF
= 5 V 101 dB
4
V
REF
= 4.096 V 98 100 dB
f
IN
= 10 kHz, V
REF
= 4.096 V 99.5 dB
f
IN
= 45 kHz, V
REF
= 4.096 V 98 dB
Dynamic Range V
IN+
= V
IN–
= V
REF
/2 = 2.5 V 103 dB
Spurious-Free Dynamic Range f
IN
= 2 kHz 120 dB
f
IN
= 10 kHz 117 dB
f
IN
= 45 kHz 110 dB
Total Harmonic Distortion f
IN
= 2 kHz –118 dB
f
IN
= 10 kHz –115 dB
f
IN
= 45 kHz –110 dB
Signal-to-(Noise + Distortion) f
IN
= 2 kHz 100 dB
f
IN
= 2 kHz, –60 dB Input 41 dB
–3 dB Input Bandwidth 900 kHz
SAMPLING DYNAMICS
Aperture Delay 2 ns
Aperture Jitter 5 ps rms
Transient Response Full-Scale Step 8.5 μs
Overvoltage Recovery 8.5 μs
REFERENCE
External Reference Voltage Range REF 3 4.096 AVDD + 0.1 V
REF Voltage with Reference Buffer REFBUFIN = 2.5 V 4.05 4.096 4.15 V
Reference Buffer Input Voltage Range REFBUFIN 1.8 2.5 2.6 V
REFBUFIN Input Current –1 +1 μA
REF Current Drain 100 kSPS Throughput 42 μA