Datasheet

AD7685
Rev. C | Page 3 of 28
SPECIFICATIONS
VDD = 2.3 V to 5.5 V, VIO = 2.3 V to VDD, V
REF
= VDD, T
A
= –40°C to +85°C, unless otherwise noted.
Table 2.
A Grade B Grade C Grade
Parameter Conditions Min Typ Max Min Typ Max Min Typ Max Unit
RESOLUTION 16 16 16 Bits
ANALOG INPUT
Voltage Range IN+ − IN− 0 V
REF
0 V
REF
0 V
REF
V
Absolute Input Voltage IN+ −0.1 VDD +
0.1
−0.1 VDD +
0.1
−0.1 VDD +
0.1
V
IN− −0.1 +0.1 −0.1 +0.1 −0.1 +0.1 V
Analog Input CMRR f
IN
= 250 kHz 65 65 65 dB
Leakage Current at 25°C Acquisition phase 1 1 1 nA
Input Impedance See the
Analog Inputs section
See the
Analog Inputs section
See the
Analog Inputs section
ACCURACY
No Missing Codes 15 16 16 Bits
Differential Linearity Error −1 ±0.7 −1 ±0.5 +1.5 LSB
1
Integral Linearity Error −6 +6 −3 ±1 +3 −2 ±0.6 +2 LSB
Transition Noise REF = VDD = 5 V 0.5 0.5 0.45 LSB
Gain Error
2
, T
MIN
to T
MAX
±2 ±30 ±2 ±30 ±2 ±15 LSB
Gain Error Temperature Drift ±0.3 ±0.3 ±0.3 ppm/°C
Offset Error
2
, T
MIN
to T
MAX
VDD = 4.5 V to 5.5 V ±0.1 ±1.6 ±0.1 ±1.6 ±0.1 ±1.6 mV
VDD = 2.3 V to 4.5 V ±0.7 ±3.5 ±0.7 ±3.5 ±0.7 ±3.5 mV
Offset Temperature Drift ±0.3 ±0.3 ±0.3 ppm/°C
Power Supply Sensitivity VDD = 5 V ± 5% ±0.05 ±0.05 ±0.05 LSB
THROUGHPUT
Conversion Rate VDD = 4.5 V to 5.5 V 0 250 0 250 0 250 kSPS
VDD = 2.3 V to 4.5 V 0 200 0 200 0 200 kSPS
Transient Response Full-scale step 1.8 1.8 1.8 μs
AC ACCURACY
Signal-to-Noise Ratio f
IN
= 20 kHz,
V
REF
= 5 V
90 90 92 91.5 93.5 dB
3
f
IN
= 20 kHz,
V
REF
= 2.5 V
86 86 88 87.5 88.5 dB
Spurious-Free Dynamic
Range
f
IN
= 20 kHz −100 −106 −110 dB
Total Harmonic Distortion f
IN
= 20 kHz −100 −106 −110 dB
Signal-to-(Noise + Distortion) f
IN
= 20 kHz,
V
REF
= 5 V
89 90 92 91.5 93.5 dB
f
IN
= 20 kHz,
V
REF
= 5 V,
−60 dB input
32 33.5 dB
f
IN
= 20 kHz,
V
REF
= 2.5 V
86 85.5 87.5 87 88.5 dB
Intermodulation Distortion
4
−110 −115 dB
1
LSB means least significant bit. With the 5 V input range, 1 LSB is 76.3 μV.
2
See Terminology section. These specifications do include full temperature range variation but do not include the error contribution from the external reference.
3
All specifications in dB are referred to a full-scale input FS. Tested with an input signal at 0.5 dB below full-scale, unless otherwise specified.
4
f
IN1
= 21.4 kHz, f
IN2
= 18.9 kHz, each tone at −7 dB below full scale.