Datasheet

–3–
REV. B
AD7851
A Grade: f
CLKIN
= 7 MHz (–40ⴗC to +85ⴗC), f
SAMPLE
= 333 kHz; K Grade: f
CLKIN
= 6 MHz (0ⴗC to 85ⴗC), f
SAMPLE
= 285 kHz; A and K Grade: f
CLKIN
= 5 MHz
(to 125ⴗC), f
SAMPLE
= 238 kHz; (AV
DD
= DV
DD
= 5.0 V ⴞ 5%, REF
IN
/REF
OUT
= 4.096 V External Reference; SLEEP = Logic High; T
A
= T
MIN
to T
MAX
,
unless otherwise noted.)
Parameter Version A
1
Version K
1
Unit Test Conditions/Comments
DYNAMIC PERFORMANCE
Signal-to-Noise + Distortion Ratio
3
(SNR) 77 78 dB min Typically SNR Is 79.5 dB.
V
IN
= 10 kHz, Sine Wave, f
SAMPLE
= 333 kHz.
Total Harmonic Distortion (THD) –86 –86 dB max V
IN
= 10 kHz, Sine Wave, f
SAMPLE
= 333 kHz,
typically –96 dB.
Peak Harmonic or Spurious Noise –87 –87 dB max V
IN
= 10 kHz, f
SAMPLE
= 333 kHz.
Intermodulation Distortion (IMD)
Second-Order Terms –86 –90 dB typ fa = 9.983 kHz, fb = 10.05 kHz, f
SAMPLE
= 333 kHz.
Third-Order Terms –86 –90 dB typ fa = 9.983 kHz, fb = 10.05 kHz, f
SAMPLE
= 333 kHz.
Full Power Bandwidth 20 20 MHz typ @ 3 dB.
DC ACCURACY
Resolution 14 14 Bits
Integral Nonlinearity ±2 ±1 LSB max
Differential Nonlinearity ±2 ±1 LSB max Guaranteed No Missed Codes to 14 Bits
Unipolar Offset Error ±10 ±10 LSB max Review: Adjusting the Offset Calibration
Positive Full-Scale Error ± 10 ±10 LSB max Register in the Calibration Registers section.
Negative Full-Scale Error ±10 ±10 LSB typ
Bipolar Zero Error ±1 ±1 LSB typ
ANALOG INPUT
Input Voltage Ranges 0 V to V
REF
0 V to V
REF
V AIN(+) – AIN(–) = 0 V to V
REF
, AIN(–) can be
biased up but AIN(+) cannot go below AIN(–).
±V
REF
/2 ±V
REF
/2 V AIN(+) – AIN(–) = –V
REF
/2 to +V
REF
/2, AIN(–)
should be biased up and AIN(+) can go below
AIN(–) but cannot go below 0 V.
Leakage Current ±1 ±1 µA max
Input Capacitance 20 20 pF typ
REFERENCE INPUT/OUTPUT
REF
IN
Input Voltage Range 4/V
DD
4/V
DD
V min/max Functional from 1.2 V.
Input Impedance 150 150 kΩ typ Resistor Connected to Internal Reference Node.
REF
OUT
Output Voltage 3.696/4.496 3.696/4.496 V min/max
REF
OUT
Temperature Coefficient 50 50 ppm/°C typ
LOGIC INPUTS
Input High Voltage, V
INH
V
DD
– 1.0 V
DD
– 1.0 V min
Input Low Voltage, V
INL
0.4 0.4 V max
Input Current, I
IN
±10 ±10 µA max V
IN
= 0 V or V
DD
.
Input Capacitance, C
IN
4
10 10 pF max
LOGIC OUTPUTS
Output High Voltage, V
OH
V
DD
– 0.4 V
DD
– 0.4 V min I
SOURCE
= 200 µA.
Output Low Voltage, V
OL
0.4 0.4 V max I
SINK
= 0.8 mA.
Floating State Leakage Current ± 10 ±10 µA max
Floating State Output Capacitance
4
10 10 pF max
Output Coding Straight (Natural) Binary Unipolar Input Range.
Twos Complement Bipolar Input Range.
CONVERSION RATE
Conversion Time 2.78 3.25 µs max 19.5 CLKIN Cycles.
Conversion + Track-and-Hold
Acquisition Time 3.0 3.5 µs max 21 CLKIN Cycles Throughput Rate.
SPECIFICATIONS
1, 2