AD7817/AD7818 Data Sheet
Rev. E | Page 4 of 20
Parameter A Version
1
B Version
1
S Version
1
Unit Test Conditions/Comments
POWER REQUIREMENTS (AD7817 ONLY)
V
DD
5.5 5.5 5.5 V max For specified performance
2.7 2.7 2.7 V min
I
DD
Logic inputs = 0 V or V
DD
Normal Operation 2 2 2 mA max 1.6 mA typical
Using External Reference 1.75 1.75 1.75 mA max 2.5 V external reference connected
Power-Down (V
DD
= 5 V) 10 10 12.5 μA max 5.5 μA typical
Power-Down (V
DD
= 3 V) 4 4 4.5 μA max 2 μA typical
Auto Power-Down Mode V
DD
= 3 V
10 SPS Throughput Rate 6.4 6.4 6.4 μW typ
See the Power vs. Throughput
section for description of power
dissipation in auto power-down mode
1 kSPS Throughput Rate 48.8 48.8 48.8 μW typ
10 kSPS Throughput Rate 434 434 434 μW typ
Power-Down 12 12 13.5 μW max Typically 6 μW
DYNAMIC PERFORMANCE (AD7818 ONLY)
6
Sample rate = 100 kSPS, any channel,
f
IN
= 20 kHz
Signal-to-(Noise + Distortion) Ratio
2
57 dB min
Total Harmonic Distortion
2
–65 dB max −75 dB typical
Peak Harmonic or Spurious Noise
2
–67 dB typ −75 dB typical
Intermodulation Distortion
2
fa = 19.9 kHz, fb = 20.1 kHz
Second-Order Terms –67 dB typ
Third-Order Terms –67 dB typ
Channel-to-Channel Isolation
2
–80 dB typ f
IN
= 20 kHz
DC ACCURACY (AD7818 ONLY)
6
Any channel
Resolution 10 Bits
Minimum Resolution for Which No
Missing Codes are Guaranteed
10 Bits
Relative Accuracy
2
±1 LSB max
Differential Nonlinearity
2
±1 LSB max
Gain Error
2
±10 LSB max
Offset Error
2
±4 LSB max
TEMPERATURE SENSOR (AD7818 ONLY)
6
Measurement Error Internal reference V
REF
= 2.5 V
Ambient Temperature 25°C ±2 °C max
T
MIN
to T
MAX
±3 °C max
Measurement Error On-chip reference
Ambient Temperature 25°C ±2 °C max
T
MIN
to T
MAX
±3 °C max
Temperature Resolution 1/4 °C/LSB
ON-CHIP REFERENCE (AD7818 ONLY)
5
Nominal 2.5 V
Temperature Coefficient
3
30 ppm/°C typ
CONVERSION RATE (AD7818 ONLY)
6
Track-and-Hold Acquisition Time
4
400 ns max Source impedance < 10 Ω
Conversion Time
Temperature Sensor 27 μs max
Channel 1 9 μs max