Texas Instruments ADS8555EVM-PDK User manual

User’s Guide
ADS8555EVM-PDK Evaluation Module
ABSTRACT
This user's guide describes the operation and use of the ADS8555 evaluation module (EVM). The ADS8555 is
a 6-channel, simultaneous sampling, 16-bit successive approximation (SAR) analog-to-digital converter (ADC).
Each input channel on the device can support true bipolar input ranges up to ±12 V. The device includes a
programmable, internally buffered voltage reverence. The ADC includes a serial programming interface (SPI)
interface and a parallel interface (word and byte mode) for data communication. Device configuration is achieved
through simple static digital input pins (hardware mode) or through communications to the SPI interface (control
register configuration in software mode). This user's guide covers the circuit description, schematic diagram, and
bill of materials for the ADS8555 circuit board. This EVM hardware and software can also be used to support
the ADS8556, ADS8557, and ADS8558 devices from this family. Other devices can be tested by desoldering the
ADC and reprogramming the EVM (see Section 6.3). Detailed instructions for using other family members are
provided later in this document.
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Table of Contents
1 ADS8555EVM-PDK Overview.................................................................................................................................................3
1.1 ADS8555EVM-PDK Features............................................................................................................................................ 3
1.2 ADS8555EVM Features.....................................................................................................................................................3
2 EVM Analog Interface.............................................................................................................................................................4
2.1 ADC Supply, Input, Voltage Reference, and Digital Connections...................................................................................... 4
2.2 ADC Amplifier Drive........................................................................................................................................................... 5
3 Digital Interface.......................................................................................................................................................................6
3.1 Parallel Interface................................................................................................................................................................ 6
3.2 Serial Interface (SPI)..........................................................................................................................................................6
3.3 I2C Bus and EEPROM....................................................................................................................................................... 6
3.4 Connections to the PHI Connector.....................................................................................................................................7
4 Power Supplies....................................................................................................................................................................... 8
4.1 External Power Connections and Test Points.................................................................................................................... 8
4.2 Low-Dropout Regulator (TPS7A3001 for HVSS)............................................................................................................... 8
4.3 Low-Dropout Regulator (TPS7A4700 for AVDD, HVDD)................................................................................................... 9
5 Installing the ADS8555EVM Software................................................................................................................................. 10
6 ADS8555EVM Operation...................................................................................................................................................... 12
6.1 Connecting the Hardware and Running the GUI..............................................................................................................12
6.2 Jumper Settings for the ADS8555EVM............................................................................................................................13
6.3 Modifying Hardware and Using Software to Evaluate Other Devices in the Family.........................................................14
6.4 EVM GUI Global Settings for ADC Control and Registers............................................................................................... 15
6.5 Time Domain Display....................................................................................................................................................... 16
6.6 Frequency Domain Display.............................................................................................................................................. 17
6.7 Histogram Display............................................................................................................................................................ 18
7 Bill of Materials, Layout, and Schematics.......................................................................................................................... 19
7.1 Bill of Materials.................................................................................................................................................................19
7.2 Board Layout....................................................................................................................................................................22
7.3 Schematics.......................................................................................................................................................................23
8 Revision History................................................................................................................................................................... 26
Trademarks
Keysight™ is a trademark of Keysight Technologies.
LabVIEW™ is a trademark of National Instruments.
Microsoft® and Windows® are registered trademarks of Microsoft Corporation.
All trademarks are the property of their respective owners.
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1 ADS8555EVM-PDK Overview
This document describes how to connect the EVM to your computer and test equipment to evaluate device
performance and understand device features. The document also describes how to install and use the
associated evaluation module software.
1.1 ADS8555EVM-PDK Features
Figure 1-1 shows the proper component connection for the ADS8555EVM. The ADS8555 evaluation module kit
includes the following features:
• Hardware and software required for diagnostic testing as well as accurate performance evaluation of the
ADS8555 ADC.
• Digital and analog interface power with universal serial bus (USB) power. External power is required for the
high-voltage ±15-V supply.
• Easy-to-use evaluation software for the 64-bit Microsoft® Windows®7, Windows® 8, and Windows® 10
operating systems.
• Precision host interface (PHI) controller translates the USB (2.0) or higher to parallel or serial digital
communications.
Signal
Source
Included in kit
ADS8555EVM
PHI Board
xx
xx
x
x
x
x
x
xx
xx
xx
xx
xx
ADS8555
GUI
Signal
Source
+15V, -15V, GND
Figure 1-1. System Connection for Evaluation
1.2 ADS8555EVM Features
• Six input channels connected to external single-ended signals that are source applied to subminiature version
A (SMA) connectors or headers.
• Serial and parallel interface connects to the PHI controller via a 60-pin connector (J2).
• High-voltage power supplies (HVDD and HVSS) are not included. Connect common lab supplies via screw
terminal J1.
• Analog low-voltage supplies (AVDD = 5 V) are generated using an external 15-V supply and a low-dropout
regulator (LDO). HVDD (12-V supply) is also generated using the 15-V supply and an LDO. HVSS (–12-V
supply) is generated using the –15-V supply and an LDO.
• Digital low-voltage supply (DVDD = 3.3 V) is generated using USB power from the PHI controller.
• Integrated or external voltage reference options are available.
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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 ADS8555 data sheet. The layout (see Figure 7-1) uses 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. Figure 2-1 also shows the analog input
signal and digital signal connections.
49.9
R81
49.9
R82
49.9
R83
DB0/SEL_A
DB1/SEL_B
DB2/SEL_C
DB3/DCIN_C
DB4/DCIN_B
DB5/DCIN_A
DB6/SCLK
DB7/HBEN/DCEN
DB8/SDO_A
DB9/SDO_B
DB10/SDO_C
DB11
DB12
DB13/SDI
DB14/REFBUFEN
DB15
49.9
R84
49.9
R85
49.9
R86
49.9
R87
49.9
R88
49.9
R89
49.9
R90
49.9
R91
49.9
R92
49.9
R93
49.9
R94
49.9
R95
49.9
R96
DB0/SEL_A 17
DB1/SEL _B 16
DB2/SEL_C 15
DB3/DCIN_C 14
DB4/DCIN_B 13
DB5/DCIN_A 12
DB6 /SC LK 11
DB7/HBEN /DCEN 10
DB8/SDO_A 7
DB9/SDO_B 6
DB10/SDO_C 5
DB11 4
DB12 3
DB13/SDI 2
DB14/REFBU F EN 1
DB15 64
CON VS T_A
23
CON VS T_B
22
CON VS T_C
21
CH_A0
33
CH_A1
36
CS /FS 19
RD 20
STB Y 24
BUSY/INT 18
HW/SW 62
PAR/S E R 61
RA NG E/XC LK 27
REFEN /WR 63
REFIO
51
RES ET 28
WOR D/ B YTE 29
CH_B0
39
CH_B1
42
CH_ C 0
45
CH_ C 1
48
REFC_A
54
REFC_B
56
REFC_C
58
ADS8555SPMR
U2A
49.9
R80 49.9
R7949.9
R78
49.9
R77
49.9
R76 49.9
R75
49.9
R74 49.9
R7349.9
R72 49.9
R71 BUSY/INT
HW/SW
REFEN/WR
ST BY
CS/FS
~RD
WORD/BYTE
PAR/SE R
RESET
RANGE/XCLK
CH_A0
CH_B0
CH_C0
CH_A1
CH_B1
CH_C1
AV DD
26
AV DD
34
AV DD
35
AV DD
40
AV DD
41
AV DD
46
AV DD
47
AV DD
50
AV DD
60
BV DD
9
HVDD
31
AGN D 25
AGN D 32
AGN D 37
AGN D 38
AGN D 43
AGN D 44
AGN D 49
AGN D 52
AGN D 53
AGN D 55
AGN D 57
AGN D 59
BGN D 8
HVSS 30
ADS8555SPMR
U2B
GND
AVDD
10uF
C71
GND
GND
GND
10uF
C72
10uF
C73
49.9
R97
49.9
R98
49.9
R99
CONVST_A
CONVST_B
CONVST_C
1µF
C1
1µF
C2
1µF
C3
1µF
C4
GND
1µF
C5
1µF
C6
GND
1µF
C7
GND
HVSSHVDD
1µF
C27
GND
GND
1µF
C28
BVDD
GND
49.9
R35 SCLK_RET URN
49.9
R46 ~RD_RETURN
VIN
2
TEMP
3 GND 4
TRIM/NR 5
VOUT 6
REF5025AIDGKR
U6A
GND
0.22
R48
EXT
10uF
C38
GND
AVDD
1µF
C37
TP8
VREF
0
R47
INT
1
2
3
JP06
100nF
C39
GND
470nF
25V
C40
GND
Figure 2-1. ADC Signal and Supply Connection
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2.2 ADC Amplifier Drive
Figure 2-2 shows the op amp configuration for each ADC drive input. The default configuration is a noninverting
buffer configuration. The gain of this circuit can be adjusted by changing R03 and R02 as needed. C02 can
be used to limit the amplifier bandwidth or compensate the amplifier. R01 and C01 can also be used to create
a low-pass filter. Jumper JP00 can be used to completely bypass the amplifier. This diagram only shows one
channel, but this circuit is repeated six times. For other channels, see Figure 7-2.
GND
HVDD
HVSS
GND
1. 00k
R01
TP10
A0in
0
R03
1. 00k
R02
DNP
GND
100pF
C02
DNP
1
2
3
JP00
TP9
A0
GND
GND
100nF
C03
100nF
C04
GND
CH_A0
1
2
3
4
5
OPA209AIDBVR
U00
24.9
R04
1000pF
C01
AMP
BYPS
1
2
3 4 5
J00
220pF
C05
Figure 2-2. Amplifier Drive Circuit
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3 Digital Interface
As noted in Section 1.1, the EVM interfaces with the PHI and communicates with the computer over the
USB. There are two devices on the EVM with which the PHI communicates: the ADS8555 ADC (over SPI or
parallel) and the EEPROM (over I2C). The electrically erasable programmable read-only memory (EEPROM)
comes preprogrammed with the information required to configure and initialize the ADS8555 platform. When the
hardware is initialized, the EEPROM is no longer used.
3.1 Parallel Interface
The parallel interface signals are generated on the PHI controller and are connected through J2. Each of these
signals has a 47-Ω resistor between the device and the controller to slow down the signal edges in order to
minimize signal overshoot. The digital signals can be monitored on the J3, J4, and J5 test headers.
3.2 Serial Interface (SPI)
The ADS8555 ADC uses SPI serial communication in mode 1 (CPOL = 0 and CPHA= 1). Because the serial
clock (SCLK) frequency can be as fast as 36 MHz, the ADS8555EVM offers 47-Ω resistors between the
controller and device to aid with signal integrity. Typically, in high-speed SPI communication, fast signal edges
can cause overshoot; these 47-Ω resistors slow down the signal edges in order to minimize signal overshoot.
3.3 I2C Bus and EEPROM
The circuit shown in Figure 3-1 is used with the EVM controller (PHI) for EVM identification. This circuit is not
required by the ADS8555 for operation. The switch (S1) is write protected and does not need to be changed for
EVM operation.
EVM_ID_SDA
EVM_ID_SCL
EVM_ID_P WR
GND
2
1
3
S1
10.0k
R101
100nF
C74
GND
EVM_ID_P WR
GND
0
R102 EVM_ID_WP
A0
1
A1
2
A2
3
VSS
4 SDA 5
SCL 6
WP 7
VCC 8
U3
BR24G32FVT-3AGE2
Figure 3-1. I2C Bus and EEPROM
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3.4 Connections to the PHI Connector
Connector J2 is used to connect the PHI digital controller printed circuit board (PCB) to the ADS8555EVM. This
connector has all the digital signals as well as the BVDD supply. The power for the BVDD supply is from the
USB connection. This connector also provides I2C signals that are used on the EEPROM identification circuit.
The digital signals can be monitored on the J3, J4, and J5 test headers. Figure 3-2 provides a schematic
showing the various connections to the PHI connector.
10 uF
C75
GND
BVDD
3. 6V
D7
Zener
GND GND
1 1
3 3
5 5
7 7
9 9
11 11
13 13
15 15
17 17
19 19
21 21
23 23
25 25
27 27
29 29
31 31
33 33
35 35
37 37
39 39
41 41
43 43
45 45
47 47
49 49
51 51
53 53
55 55
57 57
59 59
2
2
4
4
6
6
8
8
10
10
12
12
14
14
16
16
18
18
20
20
22
22
24
24
26
26
28
28
30
30
32
32
34
34
36
36
38
38
40
40
42
42
44
44
46
46
48
48
50
50
52
52
54
54
56
56
58
58
60
60
GND
MP1
GND
MP2 GND MP3
GND MP4
J2
QTH-030-01-L-D-A
EVM_ID_ SDA
EVM_ID_ SCL
EVM_ID_WP
DB3/DCIN_C
DB4/DCIN_B
DB0/SEL_A
DB1/SE L_B
DB6/SCLK
DB7/HBEN/ DCEN
DB8/SDO_A
DB9/SDO_B
DB10/S DO_C
DB11
DB12
DB13/SDI
DB14/REFBUFEN
DB15
1 2
3 4
5 6
J5
TSW-103-07-G-D
PAR/SER
HW/SW
REFEN/ WR
WORD/BYTE
STBY
~RD
CS/FS
BUSY/INT
RESET
RANGE/XCLK
DB2/SE L_C
DB5/DCIN_A
1 2
3 4
5 6
7 8
9 10
11 12
13 14
15
17
19
21
23
25
27
29
31
16
18
20
22
24
26
28
30
32
J3
TSW-116-07-G-D
1 2
3 4
5 6
7 8
9 10
11 12
13 14
15
17
19
16
18
20
J4
TSW-110-07-G-D
CONVST_A
CONVST_B
CONVST_C
GND
GND
GND
WORD/BYTE
CONVST_B
CS/FS
DB3/DCIN_C
DB4/DCIN_B
DB0/SE L_A
DB1/SE L_B
DB6/SCLK
DB7/HBEN/ DCEN
DB8/SDO_A
DB9/SDO_B
DB10/S DO_C
DB11
DB12
DB13/SDI
DB14/REFBUFEN
DB15
DB2/SE L_C
DB5/DCIN_A
SCLK_RE TURN
~RD
BUSY/INT
RESET
STBY
RANGE/XCLK
PAR/SER
~RD_RETURN
CONVST_C
CONVST_A
HW/SW
REFEN/ WR
EVM_ID_PWR
BVDD
BVDD
100k
R55
10 0k
R56
10 0k
R57
100k
R50
100k
R49
TP1
5. 5V
DNP
Figure 3-2. Connections to PHI Connector
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4 Power Supplies
The ADS8555 device uses four power supplies: AVDD (5 V), BVDD (3.3 V), HVDD (12 V), and HVSS (–12 V).
The two high-voltage power supplies require an external ±15-V supply and are connected on a screw terminal
strip (J1). The ±15-V supplies are regulated from ±15 V to ±12 V for HVDD and HVSS. The digital voltage supply
(BVDD), is generated with the USB power. The analog supply (AVDD) is generated using the external 15-V
supply and an LDO to generate 5 V.
4.1 External Power Connections and Test Points
The screw terminal block J1 is used to connect the external high voltage supplies. These supplies are not
provided in the evaluation module kit and the expectation is that a low-noise lab supply is used to provide this
power (for example, Keysight™ E3632A). The high-voltage supplies have transient voltage suppressor diodes to
help protect the ADC from transients. These supplies are typically connected to ±15 V. For details on operation,
see the ADS8555 data sheet. Figure 4-1 also shows how each supply has a light-emitting diode (LED) monitor
for quick verification that power is applied.
Green
12
D4
APT2012LZGCK
HVSS HVDD
GND GND
HVSS HVDD
AVDD
Green
12
D5
APT2012LZGCK
GND
6. 65k
R20
AVDD
Green
1 2
D3
APT2012LZGCK
BVDD
Green
12
D6
APT2012LZGCK
GND
6. 65k
R30
BVDD
10.0k
R18
10.0k
R19
GND
D1
SMAJ 15A
GND
D2
SMAJ 15A
GND
10µF
C20
10µF
C26
-15V+15V
1
2
3
J1
Figure 4-1. External Power Connections and Test Points
4.2 Low-Dropout Regulator (TPS7A3001 for HVSS)
As shown in Figure 4-2, the –15-V external power is connected to the TPS7A3001 LDO to generate –12 V. This
LDO output can be programmed to different voltages by changing the feedback network R6 and R7. This LDO
was selected for low noise and flexibility.
OUT 1
F B 2
NC
3
GND 4
EN
5
NR /SS
6
DN C
7
IN
8
PAD 9
TPS7A30 01DRBR
U4
-15 V
GND
10 .0k
R7
50 V
10 nF
C17
50 V
10 nF
C19
GND
25 V
10 uF
C16
GND
TP3
-15V
25 V
10 uF
C18
GND
0
R5
0
R4
HVSS
93 .1k
R6
Figure 4-2. Low-Dropout Regulator (TPS7A3001 for HVSS)
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4.3 Low-Dropout Regulator (TPS7A4700 for AVDD, HVDD)
The 15-V external power is connected to two LDOs (TPS7A4700RGWR). One LDO generates AVDD (5 V), and
one generates HVDD (12 V). As shown in Figure 4-3, the TPS7A4700RGWR LDO output can be programmed
to different voltages by installing or uninstalling the resistors connected on pins 4-12. This LDO was selected for
low noise and flexibility.
0
R16
0
R8
25V
22uF
C8
100k
R3
1µF
25V
C10
25V
10uF
C9
0
R17
DNP
0
R15
DNP
0
R10
0
R9
DNP
+15V
TP2
+15V
0
R2
0
R1 OUT 1
NC 2
SENSE 3
6P4V2
4
6P4V1
5
3P2V
6
GND 7
1P6V
8
0P8V
9
0P4V
10
0P2V
11
0P1V
12
EN
13
NR 14
IN
15
IN
16
NC 17
NC 18
NC 19
OUT 20
PAD 21
TPS7A 4700RGWR
U1
GND
GND
GND
GND
0
R27
0
R26
DNP
HVDD
0
R40
DNP
0
R36
25V
22uF
C29
100k
R29
1µF
25V
C36
25V
10uF
C30
0
R45
DNP
0
R39
0
R38
DNP
0
R37
DNP
0
R28
0
R25 OUT 1
NC 2
SENSE 3
6P4V2
4
6P4V1
5
3P2V
6
GND 7
1P6V
8
0P8V
9
0P4V
10
0P2V
11
0P1V
12
EN
13
NR 14
IN
15
IN
16
NC 17
NC 18
NC 19
OUT 20
PAD 21
TPS7A 4700RGWR
U5
GND
GND
GND
GND
AVDD+15V
Figure 4-3. Low-Dropout Regulator (TPS7A4700 for AVDD, HVDD)
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5 Installing the ADS8555EVM Software
Download the latest version of the EVM GUI installer from the Tools and Software folder of the ADS8555EVM
and run the GUI installer to install the EVM GUI software on your computer. Accept the license agreements and
follow the on-screen instructions shown in Figure 5-1 to complete the installation.
Figure 5-1. ADS8555 Software Installation Prompts
As a part of the ADS8555EVM GUI installation, a prompt with a Device Driver Installation (as shown in Figure
5-2) appears on the screen. Click Next to proceed.
Figure 5-2. Device Driver Installation Wizard Prompts
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