Datasheet

AD7785
Rev. 0 | Page 5 of 32
Parameter AD7785B
1
Unit Test Conditions/Comments
SCLK, CLK, and DIN (Schmitt-
Triggered Input)
2
V
T
(+) 1.4/2 V min/V max DV
DD
= 5 V
V
T
(–) 0.8/1.7 V min/V max DV
DD
= 5 V
V
T
(+) − V
T
(−)
0.1/0.17 V min/V max DV
DD
= 5 V
V
T
(+) 0.9/2 V min/V max DV
DD
= 3 V
V
T
(–) 0.4/1.35 V min/V max DV
DD
= 3 V
V
T
(+) − V
T
(−)
0.06/0.13 V min/V max DV
DD
= 3 V
Input Currents
Input Capacitance
±10
10
μA max
pF typ
V
IN
= DV
DD
or GND
All digital inputs
LOGIC OUTPUTS (INCLUDING CLK)
V
OH
, Output High Voltage
2
DV
DD
− 0.6
V min DV
DD
= 3 V, I
SOURCE
= 100 μA
V
OL
, Output Low Voltage
2
0.4 V max DV
DD
= 3 V, I
SINK
= 100 μA
V
OH
, Output High Voltage
2
4 V min DV
DD
= 5 V, I
SOURCE
= 200 μA
V
OL
, Output Low Voltage
2
0.4 V max
DV
DD
= 5 V, I
SINK
= 1.6 mA (DOUT/RDY)/
800 μA (CLK)
Floating-State Leakage Current ±10 μA max
Floating-State Output Capacitance 10 pF typ
Data Output Coding Offset binary
SYSTEM CALIBRATION
2
Full-Scale Calibration Limit +1.05 × FS V max
Zero-Scale Calibration Limit
−1.05 × FS
V min
Input Span 0.8 × FS V min
2.1 × FS V max
POWER REQUIREMENTS
7
Power Supply Voltage
AV
DD
to GND
2.7/5.25 V min/max
DV
DD
to GND
2.7/5.25 V min/max
Power Supply Currents
I
DD
Current 140 μA max
110 μA typ @ AV
DD
= 3 V, 125 μA typ @ AV
DD
= 5 V,
unbuffered mode, external reference
185 μA max
130 μA typ @ AV
DD
= 3 V, 165 μA typ @ AV
DD
= 5 V,
buffered mode, gain = 1 or 2, external reference
400 μA max
300 μA typ @ AV
DD
= 3 V, 350 μA typ @ AV
DD
= 5 V,
gain = 4 to 128, external reference
500 μA max
400 μA typ @ AV
DD
= 3 V, 450 μA typ @ AV
DD
= 5 V,
gain = 4 to 128, internal reference
I
DD
(Power-Down Mode) 1 μA max
1
Temperature range is –40°C to +105°C.
2
Specification is not production tested, but is supported by characterization data at initial product release.
3
Following a calibration, this error is in the order of the noise for the programmed gain and update rate selected.
4
Recalibration at any temperature removes these errors.
5
Full-scale error applies to both positive and negative full-scale and applies at the factory calibration conditions (AV
DD
= 4 V, gain = 1, T
A
= 25°C).
6
FS[3:0] are the four bits used in the mode register to select the output word rate.
7
Digital inputs equal to DV
DD
or GND with excitation currents and bias voltage generator disabled.