Datasheet

REV. C
AD7816/AD7817/AD7818
–3–
Parameter A Version Unit Test Conditions/Comments
DYNAMIC PERFORMANCE (AD7818 Only) 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 typ
Peak Harmonic or Spurious Noise
2
–67 dB typ –75 dB typ
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) 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
1
Measurement Error External 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
REFERENCE INPUT
3, 4
(AD7816 Only)
REF
IN
Input Voltage Range
3
2.625 V max 2.5 V + 5%
2.375 V min 2.5 V – 5%
Input Impedance 50 kΩ min
Input Capacitance 10 pF max
ON-CHIP REFERENCE
5
Nominal 2.5 V
Temperature Coefficient
3
30 ppm/°C typ
CONVERSION RATE
Track/Hold Acquisition Time
4
400 ns max Source Impedance < 10 Ω
Conversion Time
Temperature Sensor 27 µs max
Channel 1 9 µs max (AD7818 Only)
POWER REQUIREMENTS
V
DD
5.5 V max For Specified Performance
2.7 V min
I
DD
Logic Inputs = 0 V or V
DD
Normal Operation 2 mA max 1.3 mA typ
Using External Reference 1.75 mA max 2.5 V External Reference Connected
Power-Down (V
DD
= 5 V) 10.75 µA max 6 µA typ
Power-Down (V
DD
= 3 V) 4.5 µA max 2 µA typ
Auto Power-Down Mode V
DD
= 3 V
10 SPS Throughput Rate 6.4 µW typ See Power vs. Throughput Section for
1 kSPS Throughput Rate 48.8 µW typ Description of Power Dissipation in
10 kSPS Throughput Rate 434 µW typ Auto Power-Down Mode
Power-Down 13.5 µW max Typically 6 µW
AD7816/AD7818
6
–SPECIFICATIONS
1
(V
DD
= 2.7 V to 5.5 V, GND = 0 V, REF
IN
= 2.5 V unless
otherwise noted)