Semtech SX8724SEVK User manual

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Page 1
ADVANCED COMMUNICATIONS & SENSING USER GUIDE
SX8724SEVK
Evaluation Kit for SX8724S Data Acquisition System
ACS - Revision 1.0 May 2011
© Semtech Corp.
SX8724SEVK USER GUIDE
Evaluation Kit for SX8724S Data Acquisition System
Description
The SX8724SEVK is a platform for SX8724S evaluation
and sensing application prototyping. It consists of a
single board with the ZoomingADC device interfaced to
the computer through a USB gateway.
All SX8724S I/Os are available and placed on breakout
pads for easy access. The tool is intended to be the
interface between the sensor and the PC in order to
ease the handling of the SX8724S.
Equipment Needed
 PC with Windows XP or a latest version
 Powered USB 2.0 port
Features
 Evaluation Board
• Directly connects most types of sensors
• Extended temperature range from -40 to 125°C
• 2.4V to 5.5V operation
• Supply from 5V USB, externally or regulated 3.3V
• USB interface with gateway to the SX8724S
• On board master MCU with flash memory, access
to all IO
•Prototypingarea
• I/Os, board supplies and grounds placed on pads
 Graphical User Interface
• Easy settings through registers and controls
• System and device performance analysis tool
• Save and load configurations
•Logtofile
 SX8724S ZoomingADC System Evaluation
• Up to 16-bit differential data acquisition
• Programmable gain: (1/12 to 1000)
• Sensor offset compensation up to 15 times full
scale of input signal
• 3 differential or 6 single-ended signal inputs
• Programmable Resolution versus Speed versus
Supply current
• External reference input voltage
• Internal reference output
• Digital outputs to bias sensors
• Low-power (250 uA for 16b @ 500 S/s)
 Digital Interface
• Access to SPI signal
•ADCconversionready
•2GPIO
• Possibility to chain boards on the same bus
 Application Examples in this User Guide
• Interfacing your first pressure sensor
Ordering Informations
EVK Part Number Function
SX8724SEVK SX8724S (SPI) Evaluation

ACS - Revision 1.0 May 2011
© Semtech Corp. www.semtech.com
Page 2
Section Page
TABLE OF CONTENT
ADVANCED COMMUNICATIONS & SENSING USER GUIDE
SX8724SEVK
Evaluation Kit for SX8724S Data Acquisition System
GETTING STARTED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Evaluation Kit Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 Board Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4 Software Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1 About Microsoft .NET Framework. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5 Board Connection and Drivers Installation (first time) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
HARDWARE DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6 Board Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7 User Interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7.1 Prototyping Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
8 Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
8.1 Power Sources Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
8.2 Power Supply Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
9 USB Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
9.1 Gateway to SX8724S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
10 EVK Bill of Materials List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
11 Board Physical Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
GRAPHICAL USER INTERFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
12 Software Tool Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
13 Main Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
13.1 Menu Tool Bar. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
13.2 Window Tool Bar. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
13.3 Status Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
13.4 ZoomingADC controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
13.5 Voltage Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
13.6 Estimated Device Performances. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
13.7 Display Chart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
13.8 Log Data to File. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
14 ZoomingADC Data Display Window. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
14.1 ZoomingADC data display panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
14.2 Histogram Panel - Noise Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
14.3 Measured System Performances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
15 Registers Display Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
16 Verification Mode Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
APPLICATION EXAMPLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
17 Interfacing your first pressure sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
17.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
17.2 Pressure Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
17.3 Using the Evaluation Board and the GUI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
17.4 Reading the sensor using the GUI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

ACS - Revision 1.0 May 2011
© Semtech Corp. www.semtech.com
Page 3
Section Page
TABLE OF CONTENT
ADVANCED COMMUNICATIONS & SENSING USER GUIDE
SX8724SEVK
Evaluation Kit for SX8724S Data Acquisition System
17.5 Reference Voltage Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
17.6 ZoomingADC™ Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
17.7 ADC Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
17.8 Noise Cancellation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
17.9 LSB Equivalence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
17.10 ZoomingADC™ Benefits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

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ADVANCED COMMUNICATIONS & SENSING USER GUIDE
SX8724SEVK
Evaluation Kit for SX8724S Data Acquisition System
ACS - Revision 1.0 May 2011
© Semtech Corp.
GETTING STARTED
1Introduction
This section describes a typical configuration for operating the evaluation board of the SX8724S with
ZoomingADC.
The SX8724S is a signal conditioner based on Semtech's ultra low power ZoomingADC™ technology. It
directly connects most types of miniature sensors with a general purpose microcontroller.
The SX8724SEVK is a USB based evaluation tool designed to allow simple and easy evaluation of the
suitability of the SX8724S device for a given application.
The analog input signal can be entered either in differential or single ended. Refer to the datasheet for the
impact of driving an analog input in single or in differential.
2EvaluationKitContents
The SX8724SEVK evaluation kit consists of:
 a “Read me first” sheet
 an Evaluation Board
 one USB cable
 a CDROM containing:
• Software Installer including MS .NET framework 3.5 and USB drivers
• SX8724SEVK User Guide (this document)

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ADVANCED COMMUNICATIONS & SENSING USER GUIDE
SX8724SEVK
Evaluation Kit for SX8724S Data Acquisition System
ACS - Revision 1.0 May 2011
© Semtech Corp.
3 Board Overview
The picture below describes the main zones and functions accessible on the SX8724SEVK.
Figure 1. SX8724SEVK Board Overview
USB Gateway Interface
Isolate/connect device
Analog Interface
Prototyping Area
Acquisition Device
& Power Management
& Digital Interface

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ADVANCED COMMUNICATIONS & SENSING USER GUIDE
SX8724SEVK
Evaluation Kit for SX8724S Data Acquisition System
ACS - Revision 1.0 May 2011
© Semtech Corp.
4 Software Installation
If the evaluation kit is supplied with an insert sheet, follow the instruction on the insert sheet. The latest
software revision can be downloaded on Semtech website.
1. Put the CDROM in your computer and browse the contents of the CD, open the
SX8724xEvaluationKitSetup.exe file manually. It can be found in the root of the CD-ROM. Click on Next> to
start the installation
Figure 2. Installation Screen

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ADVANCED COMMUNICATIONS & SENSING USER GUIDE
SX8724SEVK
Evaluation Kit for SX8724S Data Acquisition System
ACS - Revision 1.0 May 2011
© Semtech Corp.
2. Choose the installation directory. The software must be installed on a local directory. Click on Next> to
confirm the path.
3. Follow the on-screen installation guidelines until the process is completed. Please note that .NET
Framework 3.5 and the PIC USB driver will be automatically installed if not detected on your computer.
(Administrator rights may be needed).
4. The GUI software and .Net Framework are now installed on your computer.
4.1 About Microsoft .NET Framework
The Microsoft .NET Framework 3.5 is required to run the software. The software installer will install the it
automatically if not present on your computer.
Details and installation information about the .NET Framework are available on Microsoft web site (http://
www.microsoft.com). Then go to the Download section.
There are multiple versions of the .NET Framework available from Microsoft, and they can be installed side-by-
side on the same computer. Contact your system administrator for more details.
Figure 3. Software Install Location

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ADVANCED COMMUNICATIONS & SENSING USER GUIDE
SX8724SEVK
Evaluation Kit for SX8724S Data Acquisition System
ACS - Revision 1.0 May 2011
© Semtech Corp.
5 Board Connection and Drivers Installation (first time)
1. Connect the board to the PC with the USB interface. The board is powered via the USB and will be
detected as new USB peripheral. Choose the “Install the software automatically (Recommended)” option
and click on the Next> button.
2. Windows will search for the associated driver and install the board as new peripheral.
3. Follow the on-screen installation guidelines until the process is completed. Driver compatibility screens
may appear during the installation procedure. Validate always by clicking the “Continue Anyway button”:
4. The drivers are now installed. The board and its dedicated software are ready to be used. Launch
SX8724xEVK software from the Windows Start menu.

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ADVANCED COMMUNICATIONS & SENSING USER GUIDE
SX8724SEVK
Evaluation Kit for SX8724S Data Acquisition System
ACS - Revision 1.0 May 2011
© Semtech Corp.
HARDWARE DESCRIPTION
6BoardSchematic
MOSI
SCLK
GND
SS
READY
VBOARD
VUSB
1
2
J8
GND
1
2
3
4
5
6
J1 AGND
0.1uF
C13
RB6
RB4
RC7
Ferrite
F2
VBUS 1
D- 2
D+ 3
GND 5
SHL D 4
J6
H2959CT-ND
Ferrite
F1
10uF
C3
NC
C6 1uF
C7
100nF
C8
1uF
C4
100nF
C5
D1
Re d
470R
R3
SHDN
3
NC
4
VSS
2
VOUT 5 VIN
1
U3 MCP1802
4.7pF
C1
4.7pF
C2
VLDO
OSC2
OSC1
W2
W3
RC5
RC4
RC3
RC2
RC1
RC0
RB5
RB7
W1
AGND
VBUS
VBOARD
PGD/D+
PGC/D-
PGD/D+
PGC/D-
VBATT
MCLR/VP P
1
2
3
4
J2 VPUMP
MISO/READY
RC6
VDD 1
RA5/I OCA5/OSC1/CLKIN
2RA4/AN3/I OCA3/OSC2/CLK OUT
3RA3/I OCA3/MCLR/VPP
4
RC5/CCP 1/P1A/T0CK I 5
RC4/P 1B/C12OUT/SRQ 6
RC3/AN7/P 1C/C12I N3-/PGM 7
RC6/AN8/SS/T13CK I /T1OSCI 8
RC7/AN9/SDO/T1OSCO 9
RB7/I OCB7/TX/CK
10 RB6/I OCB6/SCK /SCL
11 RB5/AN11/I OCB5/RX/DT
12 RB4/AN10/I OCB4/SDI /SDA
13
RC2/AN6/P 1D/C12I N2-/CVref/I NT2 14
RC1/AN5/C12I N1-/INT1/Vref- 15
RC0/AN4/C12I N+/INT0/Vref+ 16
VUSB 17
RA1/I OCA1/D- /PGC
18 RA0/I OCA0/D+/PGD
19
VSS
20
U2
PIC18F14K50-E/SS
Analog
POWER
l
SS
VEXT
USB
INTERFACES
Acquisition
GATEWAY
21
HC49
Y1
22pF
C9
22pF
C10
GND
12 MHz
1
2
3
4
5
6
J7
PI CK IT Serial
10KR1
GND
0RR2
VPP
VDD
GND
DAT
PCLK
T1G PGC/D-
VBOARD
PGD/D+
MCLR/VPP
VEXT
22nF
C14
PROG
GNDGND
GND
GND
GNDGND
GNDGNDGND
GND
GND
W28
W26
W29
W27
W25
MISO/READY
MOSI
SS
SCLK
10KR5
VBATT
BOARD VOLTAGE SELECTOR
W17
W18
W19
W20
GND
VBOARDVUSB
0.47uF
C11
0.1uF
C12
GND
RB6
RB4
RB5
RC2
RC1
RC0
W5
W6
W7
W8
W9
W10
W11
W12
W13
W14
W15
W16
VBOARD
RC5
RC4
RC3
RC6
RC7
RB7
W4
INTERFACES
MCLR/VPP
OSC2
OSC1
V_supply
MISO/READY
AC2
AC3
AC4
AC5
AC6
AC7
D0
D1
AC3
1
AC4
4
AC5
5
AC6
2
AC7
3
VBATT 6
VSS 7
READY 8
D1
9
SS 10
MISO/READY 11
D0
12
MOSI 13
SCK L 14
VPUMP 15
AC2
16
VSS 17
U1
S X8 724S
set_protocol
R7
AGND
VBOARD
RA5
RA4
RA3
RC5
RC4
RC3
RC6
RC7
RB7
RB6
RB5
RB4
RC2
RC1
BOOT LOADER
Wboot
1K
R4
GND
10K
W32READY

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ADVANCED COMMUNICATIONS & SENSING USER GUIDE
SX8724SEVK
Evaluation Kit for SX8724S Data Acquisition System
ACS - Revision 1.0 May 2011
© Semtech Corp.
7 User Interfaces
The analog interface gives access to the ZoomingADC inputs. The digital interface gives access to the GPIO
pins, the PC gateway connections and the power supplies. The analog and digital connections are available
on single row 2.54mm connectors and on the bare PCB next to the prototyping area.
The connections points are available for industrial PCB terminal blocks and on the bare PCB next to the
SX8724S
Figure 4. Analog Interface Schematic
Figure 5. SX8724S Interface on the Board
MOSI
SCLK
SS
READY
1
2
3
4
5
6
J1 AGND
0.1uF
C13
AGND
VBATT
1
2
3
4
J2 VPUMP
MISO/READY
Analog
Digital
SS
Acquisition
22nF
C14
INTERFACES
MISO/READY
AC2
AC3
AC4
AC5
AC6
AC7
D0
D1
AC3
1
AC4
4
AC5
5
AC6
2
AC7
3
VBATT 6
VSS 7
READY 8
D1
9
SS 10
MISO/READY 11
D0
12
MOSI 13
SCK L 14
VPUMP 15
AC2
16
VSS 17
U1
SX8724S
4
Analog interface Digital interface
+ Vref,in and Vref,out
Connect SX8724S
VBATT pin to supply
(or measure current)
Connect SX8724S READY
signal to gateway
Connect SPI interface to SX8724S
(pull-ups are on gateway side)