Figure 9-9. Ads1285Evm-Pdk Analog Inputs And Common-Mode Buffer - Texas Instruments ADS1285EVM-PDK User Manual

ADS1285EVM-PDK Bill of Materials, PCB Layout, and Schematics
Recommended input protection:
TPD4E1B06DCKR
+VINP1
R43
20
J12 R45
22.6k
1
+VINP1
2
3
-VINN1
GND
R46
22.6k
R47
20
-VINN1
+VINP2
R49
20
J13 R51
22.6k
1
+VINP2
2
This input is reserved
3
-VINN2
for the DAC1282
GND
R52
22.6k
R53
20
-VINN2
VOUTP_SWINP
DAC_SWOUTP
Connects to 'DC127_DAC' page
DAC_SWOUTN
J14
VOUTN_SWINN
Vocm
1
VOCM
2
GND
GND
Figure 9-9. ADS1285EVM-PDK Analog Inputs and Common-Mode Buffer Schematic
30 ADS1285EVM-PDK Evaluation Module
Place differential R C filter
stages close to ADC input pins
R44
AIN1P
20
C29
C0G/NP0
1000pF
C30
Vocm Connects to 'DC127_ADC' page
NP0
1nF
C31
C0G/NP0
1000pF
R48
AIN1N
20
R50
AIN2P
20
C32
C0G/NP0
1000pF
C33
Vocm
NP0
Connects to 'DC127_ADC' page
1nF
C34
C0G/NP0
1000pF
R54
AIN2N
20
R55
0
R56
0
R58
0
R59
0
Copyright © 2022 Texas Instruments Incorporated
R57 1.00k
C35
33nF
50V
AVDD1
C36
0.1uF AVSS
C37
3
R62
Vocm
4
1
37.4
C38 U9
1uF OPA369AIDCKT
AVSS TLV9041 can
AVSS replace
R64 0
To bypass buffer
Common-mode buffer
SBAU394A – APRIL 2022 – REVISED SEPTEMBER 2022
www.ti.com
AVDD1
R60
Vdiv 1.00M
33nF R61 10.0k Vdiv Power disspation:
50V 10.3 uW (2.5 uA @ 4.096V)
R63
1.00M
C39
1µF
AVSS AVSS
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