Datasheet

AD7946
Rev. A | Page 3 of 24
SPECIFICATIONS
VDD = 4.5 V to 5.5 V, VIO = 2.3 V to VDD, REF = VDD, T
A
= −40°C to +85°C, unless otherwise noted.
Table 2.
Parameter Conditions Min Typ Max Unit
RESOLUTION 14 Bits
ANALOG INPUT
Voltage Range IN+ − IN− 0 REF V
Absolute Input Voltage IN+ −0.1 VDD + 0.1 V
IN− −0.1 0.1 V
Analog Input CMRR f
IN
= 200 kHz 65 dB
Leakage Current at 25°C Acquisition phase 1 nA
Input Impedance See the Analog Input section
ACCURACY
No Missing Codes 14 Bits
Differential Linearity Error −0.7 ±0.3 +0.7 LSB
1
Integral Linearity Error −1 ±0.4 +1 LSB
Transition Noise REF = VDD = 5 V 0.33 LSB
Gain Error
2
, T
MIN
to T
MAX
±0.3 ±6 LSB
Gain Error Temperature Drift ±1 ppm/°C
Offset Error
2
, T
MIN
to T
MAX
±0.3 ±6 LSB
Offset Temperature Drift ±1 ppm/°C
Power Supply Sensitivity VDD = 5 V ± 5% ±0.1 LSB
THROUGHPUT
Conversion Rate 0 500 kSPS
Transient Response Full-scale step 400 ns
AC ACCURACY
Signal-to-Noise f
IN
= 20 kHz, REF = 5 V 84.5 85 dB
3
f
IN
= 20 kHz, REF = 2.5 V 84 dB
Spurious-Free Dynamic Range f
IN
= 20 kHz −100 dB
Total Harmonic Distortion f
IN
= 20 kHz −100 dB
Signal-to-(Noise + Distortion) f
IN
= 20 kHz, REF = 5 V 84.5 85 dB
f
IN
= 20 kHz, REF = 5 V, −60 dB input 25 dB
Intermodulation Distortion
4
100 dB
1
LSB means least significant bit. With the 5 V input range, one LSB is 305.2 μV.
2
See the 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.