Evm Analog Interface; Adc Supply, Input, Voltage Reference, And Digital Connections - Texas Instruments ADS8555EVM-PDK User Manual

EVM Analog Interface

2 EVM Analog Interface
The ADS8555EVM is an evaluation module built using a two-board modular EVM system. One board is a digital
controller (PHI), and the other board contains the ADC and associated analog circuitry. Both boards and the
associated cables form the ADS8555EVM-PDK.

2.1 ADC Supply, Input, Voltage Reference, and Digital Connections

Figure 2-1 shows the decoupling on AVDD, BVDD, HVDD, and HVSS and the voltage reference. The decoupling
capacitors match the recommendations in the
shortest possible connections to the decoupling capacitors and connects the ground end to the GND plane
using vias. The ADS8555 can use an external or internal voltage reference. This reference can be selected by
changing the position of JP06 to INT for internal or EXT for external.
signal and digital signal connections.
AVDD
C1
1µF
C2
1µF C6
C3 1µF
1µF C7
C4 1µF
1µF
GND GND
U 2B
26
AV DD AGND
34
AV DD AGND
35
AV DD AGND
40
AV DD AGND
41
AV DD AGND
46
AV DD AGND
47
AV DD AGND
50
AV DD AGND
60
AV DD AGND
AGND
AGND
BVDD
AGND
9
BV DD BGND
31
HVDD
HVDD HVSS
C28
1µF
ADS8555SPMR
C27
1µF
GND
GND
AVDD U6A
2
VIN
3
TEMP
C39
REF5025AIDGKR
100nF
GND
4 ADS8555EVM-PDK Evaluation Module
ADS8555 data
CH_A0 33
CONVST_A R97
23
49.9
C71
54
25 GND
10uF
32
CH_A1 36
37
38
43
CH_B0
39
44
49
CONVST_B R98
22
52
49.9
53
C72 56
55 GND
10uF
57
CH_B1
42
59
8
GND CH_C0
45
30 GND
HVSS
CONVST_C R99
49.9
C73
58
C5
GND
10uF
1µF
CH_C1
48
GND
TP8
VREF
JP06
EXT INT
R47 0
6
VOUT
5
TRIM/NR
4
GND
C37
1µF R48
0.22
C38
GND
10uF
GND
Figure 2-1. ADC Signal and Supply Connection
Copyright © 2021 Texas Instruments Incorporated
sheet. The layout (see
Figure 2-1
U 2A
18
CH_A0 BU SY/INT
27
RA NGE/XC LK
62
CONVS T_A HW/SW
63
REFEN/WR
24
REFC_A STB Y
28
RES ET
CH_A1
19
CS /FS
20
RD
29
CH_B0 WOR D/B YTE
61
PAR/S ER
CONVS T_B
17
DB0/SEL _A
16
REFC_B DB1/SEL _B
15
DB2/SEL _C
14
CH_B1 DB3/DCIN_C
13
DB4/DCIN_B
12
DB5/DCIN_A
11
CH_C 0 DB6/SC LK
10
DB7/HBEN/DCEN
21 7
CONVS T_C DB8/SDO_A
6
DB9/SDO_B
5
REFC_C DB10/SDO_C
4
DB11
3
CH_C 1 DB12
2
DB13/SDI
1
DB14/REFBU FEN
51 64
REFIO DB15
ADS8555SPMR
C40
470nF
25V
GND
SLAU298A – NOVEMBER 2009 – REVISED MAY 2021
www.ti.com
Figure 7-1) uses the
also shows the analog input
R71 BUSY/INT
R72 49.9 RANGE/XCLK
49.9 R73 HW/SW
R74 49.9 REFEN/WR
49.9 R75 ST BY
R76 49.9 RESET
49.9 R77 CS/FS
R46 49.9 ~RD_RETURN
R78 49.9 ~RD
49.9 R79 WORD/BYTE
R80 49.9 PAR/SER
49.9
R81 DB0/SEL_A
R82 49.9 DB1/SEL_B
49.9 R83 DB2/SEL_C
R84 49.9 DB3/DCIN_C
49.9 R85 DB4/DCIN_B
R86 49.9 DB5/DCIN_A
49.9 R87 DB6/SCLK
R35 49.9 SCLK_RET URN
49.9
R88 DB7/HBEN/DCEN
49.9 R89 DB8/SDO_A
R90 49.9 DB9/SDO_B
49.9 R91 DB10/SDO_C
R92 49.9 DB11
49.9 R93 DB12
R94 49.9 DB13/SDI
49.9 R95 DB14/REFBUFEN
R96 49.9 DB15
49.9
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