Datasheet
REV.
AD7665
–13–
TYPICAL CONNECTION DIAGRAM
Figure 5 shows a typical connection diagram for the AD7665. Different circuitry shown on this diagram is optional and is discussed below.
100nF
10F
100nF
10F
AVDD
10F
100nF
AGND DGND DVDD OVDD OGND
SER/PAR
CNVST
BUSY
SDOUT
SCLK
RD
CS
RESET
PD
REFGND
C
REF
2.5V REF
REF
50
D
CLOCK
AD7665
C/P/DSP
SERIAL
PORT
DIGITAL SUPPLY
(3.3V OR 5V)
ANALOG
SUPPLY
(5V)
DVDD
OB/2C
NOTE 8
BYTESWAP
DVDD
50k
100nF
1M
INA
100nF
U2
IND
INGND
ANALOG
INPUT
(10V)
C
C
2.7nF
U1
15
10F
NOTE 2
NOTE 1
NOTE 3
NOTE 7
NOTE 4
50
INC
INB
NOTE 6
NOTES
1. SEE VOLTAGE REFERENCE INPUT SECTION.
2. WITH THE RECOMMENDED VOLTAGE REFERENCES, C
REF
IS 47F. SEE VOLTAGE REFERENCE INPUT SECTION.
3. OPTIONAL CIRCUITRY FOR HARDWARE GAIN CALIBRATION.
4. FOR BIPOLAR RANGE ONLY. SEE SCALER REFERENCE INPUT SECTION.
5. THE AD8021 IS RECOMMENDED. SEE DRIVER AMPLIFIER CHOICE SECTION.
6. WITH 0V TO 2.5V RANGE ONLY. SEE ANALOG INPUTS SECTION.
7. OPTION. SEE POWER SUPPLY SECTION.
8. OPTIONAL LOW JITTER CNVST. SEE CONVERSION CONTROL SECTION.
+
+
+
++
+
+
AD8031
AD8021
50
ADR421
NOTE 5
WARP
IMPULSE
Figure 5. Typical Connection Diagram (±10 V Range Shown)
Table III. Output Codes and Ideal Input Voltages
Digital Output
Code (Hexa)
Straight Twos
Description Analog Input Binary Complement
Full-Scale Range
1
±10 V ±5 V ±2.5 V 0 V to 10 V 0 V to 5 V 0 V to 2.5 V
Least Significant Bit 305.2 µV 152.6 µV 76.3 µV 152.6 µV 76.3 µV 38.15 µV
FSR – 1 LSB 9.999695 V 4.999847 V 2.499924 V 9.999847 V 4.999924 V 2.499962 V FFFF
2
7FFF
2
Midscale + 1 LSB 305.2 µV 152.6 µV 76.3 µV 5.000153 V 2.570076 V 1.257038 V 8001 0001
Midscale 0 V 0 V 0 V 5 V 2.5 V 1.25 V 8000 0000
Midscale – 1 LSB –305.2 µV –152.6 µV –76.3 µV 4.999847 V 2.499924 V 1.249962 V 7FFF FFFF
–FSR + 1 LSB –9.999695 V –4.999847 V –2.499924 V 152.6 µV 76.3 µV 38.15 µV 0001 8001
–FSR –10 V –5 V –2.5 V 0 V 0 V 0 V 0000
3
8000
3
NOTES
1
Values with REF = 2.5 V; with REF = 3 V, all values will scale linearly.
2
This is also the code for an overrange analog input.
3
This is also the code for an underrange analog input.
C