Datasheet

–2–
Parameter AD7782B Unit Test Conditions
ADC CHANNEL SPECIFICATION
Output Update Rate 19.79 Hz nom
ADC CHANNEL
No Missing Codes
2
24 Bits min
Resolution 16 Bits p-p ±160 mV Range, RANGE = 0
18 Bits p-p ±2.56 V Range, RANGE = 1
Output Noise See Table I
Integral Nonlinearity ±10 ppm of FSR max Typically 2 ppm
Offset Error ±3 µV typ AIN(+) = AIN(–) = 2.5 V
Offset Error Drift vs. Temperature ±10 nV/°C typ
Full-Scale Error ±10 µV typ V
DD
= 3 V
Gain Drift vs. Temperature ±0.5 ppm/°C typ
Power Supply Rejection (PSR) 100 dB typ Input Range = ±160 mV, V
IN
= 1/16 V
85 dB typ Input Range = ±2.56 V, V
IN
= 1 V
ANALOG INPUTS
Differential Input Voltage Ranges ±160 mV nom RANGE = 0
±2.56 V nom RANGE = 1
ADC Range Matching ±2 µV typ Input Voltage = 159 mV on Both Ranges
Absolute AIN Voltage Limits GND + 100 mV V min
V
DD
– 100 mV V max
Analog Input Current
2
DC Input Current ±1 nA max
DC Input Current Drift ±5 pA /°C typ
Normal-Mode Rejection
2, 3
@ 50 Hz 60 dB min 50 Hz ± 1 Hz
@ 60 Hz 94 dB min 60 Hz ± 1 Hz
Common-Mode Rejection Input Range = ±160 mV, V
IN
= 1/16 V
@ DC 105 dB min 125 dB typ, 110 dB typ when Input Range = ±2.56 V
@ 50 Hz
2
100 dB min 50 Hz ± 1 Hz
@ 60 Hz
2
100 dB min 60 Hz ± 1 Hz
REFERENCE INPUT
REFIN Voltage 2.5 V nom REFIN = REFIN(+) – REFIN(–)
REFIN Voltage Range
2
1V min
V
DD
V max
Absolute REFIN Voltage Limits
2
GND – 30 mV V min
V
DD
+ 30 mV V max
Average Reference Input Current 0.5 µA/V typ
Average Reference Input Current Drift ±0.01 nA/V/°C typ
Normal-Mode Rejection
2, 3
@ 50 Hz 60 dB min 50 Hz ± 1 Hz
@ 60 Hz 94 dB min 60 Hz ± 1 Hz
Common-Mode Rejection Input Range = ±160 mV, V
IN
= 1/16 V
@ DC 100 dB typ
@ 50 Hz 110 dB typ 50 Hz ± 1 Hz
@ 60 Hz 110 dB typ 60 Hz ± 1 Hz
LOGIC INPUTS
All Inputs Except SCLK and XTAL1
2
V
INL
, Input Low Voltage 0.8 V max V
DD
= 5 V
0.4 V max V
DD
= 3 V
V
INH
, Input High Voltage 2.0 V min V
DD
= 3 V or 5 V
SCLK Only (Schmitt-Triggered Input)
2
V
T(+)
1.4/2 V min/V max V
DD
= 5 V
V
T(–)
0.8/1.4 V min/V max V
DD
= 5 V
V
T(+)
– V
T(–)
0.3/0.85 V min/V max V
DD
= 5 V
V
T(+)
0.95/2 V min/V max V
DD
= 3 V
V
T(–)
0.4/1.1 V min/V max V
DD
= 3 V
V
T(+)
– V
T(–)
0.3/0.85 V min/V max V
DD
= 3 V
(V
DD
= 2.7 V to 3.6 V or 4.75 V to 5.25 V, REFIN(+) = 2.5 V; REFIN(–) = GND; GND = 0 V;
XTAL1/XTAL2 = 32.768 kHz Crystal; all specifications T
MIN
to T
MAX
unless otherwise noted.)
FSR
REFIN
Gain
=
×2 1 024.
AD7782–SPECIFICATIONS
REV. A