V
DD
= +5 V 5%, GND = 0 V. Unipolar Input Range: V
SS
= GND, V
REF
(+) = 5 V,
V
REF
(–) = GND. Bipolar Input Range: V
SS
= –5 V 5%, V
REF
(+) = 2.5 V,
V
REF
(–) = –2.5 V. These test conditions apply unless otherwise stated. All specifications T
MIN
to T
MAX
unless otherwise noted. Specifications
apply for RD Mode (Pin 7 = 0 V).
AD7821–SPECIFICATIONS
K Version
1
8
±
1
8
8
±
1
±
1
45
–50
–50
8
±
1
8
8
±
1
±
1
45
–50
–50
Parameter
UNIPOLAR INPUT RANGE
Resolution
2
Total Unadjusted Error
3
Minimum Resolution for which
No Missing Codes are Guaranteed
BIPOLAR INPUT RANGE
Resolution
2
Zero Code Error
Full Scale Error
Signal-to-Noise Ratio (SNR)
3
Total Harmonic Distortion (THD)
3
Peak Harmonic or Spurious Noise
3
Intermodulation Distortion (IMD)
3
B, T Versions
Units
Bits
LSB max
Bits
Bits
LSB max
LSB max
dB min
dB max
dB max
Comments
Slew Rate, Tracking
3
REFERENCE INPUT
Input Resistance
V
REF
(+) Input Voltage Range
V
REF
(–) Input Voltage Range
ANALOG INPUT
Input Voltage Range
Input Leakage Current
Input Capacitance
LOGIC INPUTS
CS, WR, RD
V
INH
V
INL
I
INH
(CS,
RD)
I
INH
(WR)
I
INL
Input Capacitance
4
MODE
V
INH
V
INL
I
INH
I
INL
Input Capacitance
4
LOGIC OUTPUTS
DB0–DB7,
OFL, INT
V
OH
V
OL
I
OUT
(DB0–DB7)
Output Capacitance
4
(DB0–DB7)
RDY
V
OL
I
OUT
Output Capacitance
4
POWER SUPPLY
I
DD5
I
SS
Power Dissipation
Power Supply Sensitivity
–50
–50
1.6
2.36
1.0/4.0
V
REF
(–)/V
DD
V
SS
/V
REF
(+)
V
REF
(–)/V
REF
(+)
±
3
55
–50
–50
1.6
2.36
1.0/4.0
V
REF
(–)/V
DD
V
SS
/V
REF
(+)
V
REF
(–)/V
REF
(+)
±
3
55
dB max
dB max
V/µs max
V/µs typ
kΩ min/kΩ max
V min/V max
V min/V max
V min/ max
µA
max
pF typ
V
IN
= 99.85 kHz Full-Scale Sine Wave with f
SAMPLING
= 500 kHz
V
IN
= 99.85 kHz Full-Scale Sine Wave with f
SAMPLING
= 500 kHz
V
IN
= 99.85 kHz Full-Scale Sine Wave with f
SAMPLING
= 500 kHz
fa (84.72 kHz) and fb (94.97 kHz) Full-Scale Sine Waves
with f
SAMPLING
= 500 kHz
Second Order Terms
Third Order Terms
–5 V
≤
V
IN
≤
+5 V
2.4
0.8
1
3
–1
8
3.5
1.5
200
–1
8
2.4
0.8
1
3
–1
8
3.5
1.5
200
–1
8
V min
V max
µA
max
µA
max
µA
max
pF max
V min
V max
µA
max
µA
max
pF max
Typically 5 pF
50
µA
typ
Typically 5 pF
4.0
0.4
±
3
8
0.4
±
3
8
15
100
50
±
1/4
4.0
0.4
±
3
8
0.4
±
3
8
20
100
50
±
1/4
V min
V max
µA
max
pF max
V max
µA
max
pF max
mA max
µA
max
mW typ
LSB max
I
SOURCE
= 360
µA
I
SINK
= 1.6 mA
Floating State Leakage
Typically 5 pF
I
SINK
= 2.6 mA
Floating State Leakage
Typically 5 pF
CS
=
RD
= 0 V
CS
=
RD
= 0 V
±
1/16 LSB typ, V
DD
= 4.75 V to 5.25 V,
(V
REF
(+) = 4.75 V max for Unipolar Mode)
NOTES
1
Temperature Ranges are as follows: K Version = –40°C to +85°C; B Version = –40°C to +85°C; T Version = –55°C to +125°C.
2
1 LSB = 19.53 mV for both the unipolar (0 V to +5 V) and bipolar (–2.5 V to +2.5 V) input ranges.
3
See Terminology.
4
Sample tested at +25°C to ensure compliance.
5
See Typical Performance Characteristics.
Specifications subject to change without notice.
–2–
REV. A
AD [ ANALOG DEVICES ]
