Datasheet

REV. B
AD7821–SPECIFICATIONS
V
DD
= +5 V ⴞ 5%, GND = 0 V. Unipolar Input Range: V
SS
= GND, V
REF
(+) = 5 V,
V
REF
(–) = GND. Bipolar Input Range: V
SS
= –5 V ⴞ 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).
Parameter K Version
1
B, T Versions Unit Comments
UNIPOLAR INPUT RANGE
Resolution
2
88Bits
Total Unadjusted Error
3
±1 ±1 LSB max
Minimum Resolution for which
No Missing Codes are Guaranteed 8 8 Bits
BIPOLAR INPUT RANGE
Resolution
2
88Bits
Zero Code Error ±1 ±1 LSB max
Full Scale Error ±1 ±1 LSB max
Signal-to-Noise Ratio (SNR)
3
45 45 dB min V
IN
= 99.85 kHz Full-Scale Sine Wave with f
SAMPLING
= 500 kHz
Total Harmonic Distortion (THD)
3
–50 –50 dB max V
IN
= 99.85 kHz Full-Scale Sine Wave with f
SAMPLING
= 500 kHz
Peak Harmonic or Spurious Noise
3
–50 –50 dB max V
IN
= 99.85 kHz Full-Scale Sine Wave with f
SAMPLING
= 500 kHz
Intermodulation Distortion (IMD)
3
fa (84.72 kHz) and fb (94.97 kHz) Full-Scale Sine Waves
with f
SAMPLING
= 500 kHz
–50 –50 dB max Second Order Terms
–50 –50 dB max Third Order Terms
Slew Rate, Tracking
3
1.6 1.6 V/µs max
2.36 2.36 V/µs typ
REFERENCE INPUT
Input Resistance 1.0/4.0 1.0/4.0 kΩ min/kΩ max
V
REF
(+) Input Voltage Range V
REF
(–)/V
DD
V
REF
(–)/V
DD
V min/V max
V
REF
(–) Input Voltage Range V
SS
/V
REF
(+) V
SS
/V
REF
(+) V min/V max
ANALOG INPUT
Input Voltage Range V
REF
(–)/V
REF
(+) V
REF
(–)/V
REF
(+) V min/ max
Input Leakage Current ±3 ±3 µA max –5 V ≤ V
IN
≤ +5 V
Input Capacitance 55 55 pF typ
LOGIC INPUTS
CS, WR, RD
V
INH
2.4 2.4 V min
V
INL
0.8 0.8 V max
I
INH
(CS, RD)11µA max
I
INH
(WR)33µA max
I
INL
–1 –1 µA max
Input Capacitance
4
88pF max Typically 5 pF
MODE
V
INH
3.5 3.5 V min
V
INL
1.5 1.5 V max
I
INH
200 200 µA max 50 µA typ
I
INL
–1 –1 µA max
Input Capacitance
4
88pF max Typically 5 pF
LOGIC OUTPUTS
DB0–DB7, OFL, INT
V
OH
4.0 4.0 V min I
SOURCE
= 360 µA
V
OL
0.4 0.4 V max I
SINK
= 1.6 mA
I
OUT
(DB0–DB7) ±3 ±3 µA max Floating State Leakage
Output Capacitance
4
(DB0–DB7) 8 8 pF max Typically 5 pF
RDY
V
OL
0.4 0.4 V max I
SINK
= 2.6 mA
I
OUT
±3 ±3 µA max Floating State Leakage
Output Capacitance
4
88pF max Typically 5 pF
POWER SUPPLY
I
DD
5
20 20 mA max CS = RD = 0 V
I
SS
100 100 µA max CS = RD = 0 V
Power Dissipation 50 50 mW typ
Power Supply Sensitivity ±1/4 ±1/4 LSB max ±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–