Datasheet

AD7655
Rev. B | Page 15 of 28
AVDD AGND DGND
DVDD
OVDD OGND
SER/PAR
CNVST
BUSY
SDOUT
SCLK
RD
CS
RESET
PD
REFGND
C
REF
2.5V REF
NOTE 1
REF
REF A
REF B
30Ω
D
CLOCK
AD7655
μC/μP/
DSP
SERIAL PORT
DIGITAL SUPPLY
(3.3V OR 5V)
ANALOG
SUPPLY
(5V)
DVDD
A/B
NOTE 7
BYTESWAP
DVDD
50kΩ
100nF
1MΩ
INA1
C
C
2.7nF
U1
NOTE 4
NOTE 5
50Ω
-
+
10Ω
2.7nF
U2
NOTE 4
NOTE 5
50Ω
-
+
10Ω
INAN
INA2
NOTE 2
NOTE 3
NOTE 6
AD780
10μF
100nF
+
100nF
+
100nF
+
10μF
50Ω
+
NOTES
1. SEE VOLTAGE REFERENCE INPUT SECTION.
2. WITH THE RECOMMENDED VOLTAGE REFERENCES, C
REF
IS 47μF. SEE VOLTAGE REFERENCE INPUT SECTION.
3. OPTIONAL CIRCUITRY FOR HARDWARE GAIN CALIBRATION.
4. THE AD8021 IS RECOMMENDED. SEE DRIVER AMPLIFIER CHOICE SECTION.
5. SEE ANALOG INPUTS SECTION.
6. OPTIONAL, SEE POWER SUPPLY SECTION.
7. OPTIONAL LOW JITTER CNVST. SEE CONVERSION CONTROL SECTION.
A0
INB1
2.7nF
U3
NOTE 4
NOTE 5
50Ω
-
+
10Ω
INBN
2.7nF
U4
NOTE 4
NOTE 5
50Ω
-
+
10Ω
INB2
ANALOG INPUT A1
ANALOG INPUT A2
ANALOG INPUT B1
A
NALOG INPUT B
2
C
C
C
C
C
C
10μF
1μF
03536-017
NOTE 1
Figure 17. Typical Connection Diagram (Serial Interface)