Datasheet
7
8
9
10
11
12
24
23
22
21
20
19
13
14
15
16
17
18
6
5
4
3
2
1
R7 20Ω
1200pF
C6
R8 20Ω
1200pF
C7
1200pF
C8
R3 20Ω
1200pF
C2
R4 20Ω
1200pF
C3
R5 20Ω
1200pF
C4
R2 20Ω
1200pF
C1
10 F
REF
REFGND
AL_PD
1 F
DVDD
DGND
0.1 F
C11
C12 C13
50Ω
DOUT
AIN6
AIN5
AIN4
AIN3
AIN2
AIN1
AIN7
AINGND
NC
AGND
AGND
AVDD
AIN0
HVDD
HVSS
SCLK
DIN
CS
R9 20Ω
R6 20Ω
1 F
1 F
C15 C14
0.1 F 1 F
C9 C10
R1
1200pF
C5
Common Analog/Digital Ground Plane
ADS8638
Analog Signal Common
Analog Input Signals
Bipolar Power Supply
Digital Signals From/To Host
Digital
To/From
Host
Digital
Supply
Reference
Analog
Supply
ADS8634
ADS8638
SBAS541A –MAY 2011– REVISED AUGUST 2011
www.ti.com
PCB LAYOUT SCHEMATIC RECCOMENDATIONS
ADCs are mixed-signal devices. For maximum performance, proper decoupling, grounding, and proper
termination of digital signals is essential. Figure 95 and Figure 96 show the essential components around the
ADC. All capacitors shown are ceramic. These decoupling capacitors must be placed close to the respective
signal pins.
Figure 95. Reccomended Schematic for the ADS8638
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Product Folder Link(s): ADS8634 ADS8638