Datasheet

–2–
REV. A
AD7856–SPECIFICATIONS
1, 2
Parameter A Version
1
K Version
1
Units Test Conditions/Comments
DYNAMIC PERFORMANCE f
IN
= 10 kHz
Signal to Noise + Distortion Ratio
3
(SNR) 78 78 dB min 79.5 dB typ
Total Harmonic Distortion (THD) –86 –86 dB max –95 dB typ
Peak Harmonic or Spurious Noise –87 –87 dB max –95 dB typ
Intermodulation Distortion (IMD)
Second Order Terms –86 –90 dB typ fa = 9.983 kHz, fb = 10.05 kHz
Third Order Terms –86 –90 dB typ fa = 9.983 kHz, fb = 10.05 kHz
Channel-to-Channel Isolation –90 –90 dB typ V
IN
= 25 kHz
DC ACCURACY Any Channel
Resolution 14 14 Bits
Integral Nonlinearity ±2 LSB max 4.096 V External Reference, V
DD
= 5 V
±2 LSB typ
Differential Nonlinearity ±2 LSB max Guaranteed No Missed Codes to 13 Bits.
±2 LSB typ
Offset Error ±10 LSB max
±10 ±5 LSB typ
Offset Error Match ±3 LSB max
Positive Full-Scale Error ±10 LSB max
±10 LSB typ
Positive Full-Scale Error Match ±2 LSB max
ANALOG INPUT
Input Voltage Ranges 0 to V
REF
0 to V
REF
Volts i.e., AIN(+) – AIN(–) = 0 to V
REF
, AIN(–) Can Be
Biased Up, but AIN(+) Cannot Go Below AIN(–)
Leakage Current ±1 ±1 µA max
Input Capacitance 20 20 pF typ
REFERENCE INPUT/OUTPUT
REF
IN
Input Voltage Range 4.096/V
DD
2.3/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
Tempco 20 20 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
±1 ±1 µA max Typically 10 nA, 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 ±1 ±1 µA max
Floating-State Output Capacitance
4
10 10 pF max
Output Coding Straight (Natural) Binary
CONVERSION RATE
Conversion Time 3.5 5.25 µs max 21 CLKIN Cycles
Track/Hold Acquisition Time 0.33 0.5 µs min
A Grade: f
CLKIN
= 6 MHz, (–40ⴗC to +105ⴗC), f
SAMPLE
= 285 kHz; K Grade:
f
CLKIN
= 4 MHz, (0ⴗC to +105ⴗC), f
SAMPLE
= 102 kHz; (AV
DD
= DV
DD
= +5.0 V ⴞ 5%,
REF
IN
/REF
OUT
= 4.096 V External Reference unless otherwise noted, SLEEP = Logic High; T
A
= T
MIN
to T
MAX
, unless otherwise noted.) Specifica-
tions apply for Mode 2 operation, standard 3-wire SPI interface; refer to Detailed Timing section for Mode 1 Specifications.