Datasheet

Data Sheet AD7634
Rev. B | Page 19 of 32
TYPICAL CONNECTION DIAGRAM
Figure 27 shows a typical connection diagram for the AD7634 using the internal reference, serial data interface, and serial configuration
port. Different circuitry from that shown in Figure 27 is optional and is discussed in the following sections.
RD CS
100nF 100nF
AVDD
10µF 100nF
10
AGND DGND DVDD OVDD OGND
CNVST
BUSY
SDOUT
SDCLK
RESETPD
REFBUFIN
D
CLOCK
AD7634
DIGITAL
INTERFACE
SUPPLY
(2.5V, 3.3V, OR 5V)
ANALOG
SUPPLY (5V)
OVDD
DIGITAL
SUPPLY (5V)
IN+
IN–
NOTE 5
ANALOG
INPUT+
C
C
2.7nF
U1
NOTE 1
MODE[1:0]
D0/OB/2C
REFGND
REF
PDBUF
PDREF
100nF
NOTE 3
NOTE 4
NOTE 3
NOTE 7
10µF
10µF
C
REF
22µF
NOTES
1. ANALOG INPUTS ARE DIFFERENTIAL (ANTIPHASE). SEE ANALOG INPUTS SECTION.
2. THE AD8021 IS RECOMMENDED. SEE DRIVER AMPLIFIER CHOICE SECTION.
3. THE CONFIGURATION SHOWN IS USING THE INTERNAL REFERENCE. SEE VOLTAGE REFERENCE INPUT/OUTPUT SECTION.
4. A 22µF CERAMIC CAPACITOR (X5R, 1206 SIZE) IS RECOMMENDED (FOR EXAMPLE, PANASONIC ECJ4YB1A226M).
SEE VOLTAGE REFERENCE INPUT/OUTPUT SECTION.
5. OPTIONAL, SEE POWER SUPPLIES SECTION.
6. THE VCC AND VEE SUPPLIES SHOULD BE VCC = [VIN(MAX) + 2V] AND VEE = [VIN(MIN) – 2V] FOR BIPOLAR INPUT RANGES.
FOR UNIPOLAR INPUT RANGES, VEE CAN BE 0V. SEE POWER SUPPLIES SECTION.
7. OPTIONAL LOW JITTER CNVST, SEE CONVERSION CONTROL SECTION.
8. A SEPARATE ANALOG AND DIGITAL GROUND PLANE IS RECOMMENDED, CONNECTED TOGETHER DIRECTLY UNDER THE ADC.
SEE LAYOUT GUIDELINES SECTION.
ANALOG
INPUT–
NOTE 2
VCC
VEE
10µF
100nF
+7V TO +15.75V
SUPPLY
10µF
100nF
–7V TO –15.75V
SUPPLY
NOTE 6
HW/SW
SCCS
SCCLK
SCIN
BIPOLAR
TEN
SERIAL
PORT 1
SERIAL
PORT 2
WARP
IMPULSE
C
C
2.7nF
U1
NOTE 2
06406-027
15
15
33
AGND
DGND
NOTE 8
MicroConverter
®
/
MICROPROCESSOR/
DSP
Figure 27. Typical Connection Diagram Shown with Serial Interface and Serial Programmable Port