
ACS - Revision 4.2
October 2008
2008 Semtech Corp.
www.semtech.com
Page 3
Section
Page
Table of contents
ADVANCED COMMUNICATIONS & SENSING
DATASHEET
SX8722
High gain acquisition for sensor interface
9.4.2.
Configuration flow ................................................................................................................................... 29
9.4.3.
Enable/disable PGAs .............................................................................................................................. 30
9.4.4.
PGA3 gain configuration ......................................................................................................................... 30
9.4.5.
PGA2 gain configuration ......................................................................................................................... 30
9.4.6.
PGA1 gain configuration ......................................................................................................................... 31
9.4.7.
Application example................................................................................................................................ 31
9.5.
Offset cancellation ......................................................................................................................................... 32
9.5.1.
Overview ................................................................................................................................................. 32
9.5.2.
Application example................................................................................................................................ 34
9.6.
ADC parameters ............................................................................................................................................ 35
9.6.1.
Overview ................................................................................................................................................. 35
9.6.2.
ADC settings ........................................................................................................................................... 36
9.7.
Measurement engine ..................................................................................................................................... 36
9.7.1.
Overview ................................................................................................................................................. 36
9.7.2.
Measurement engine settings................................................................................................................. 37
10. Default configuration.............................................................................................................................................. 38
10.1. ZoomingADC default settings ........................................................................................................................ 38
11. Advanced configuration ......................................................................................................................................... 39
11.1. Overview ........................................................................................................................................................ 39
11.2. Measurement engine ..................................................................................................................................... 40
11.2.1. Overview ................................................................................................................................................. 40
11.2.2. Functional flowchart ................................................................................................................................ 40
11.3. Control registers............................................................................................................................................. 41
11.3.1. SXCtrl1 - SX8722 Control register 1 ....................................................................................................... 41
11.3.2. SXCtrl2 - SX8722 Control register 2 ....................................................................................................... 41
11.3.3. SXCfgEn - Configuration enabling register ............................................................................................. 42
11.3.4. SXUpdated - Updated configuration register .......................................................................................... 42
11.3.5. Configuration register - measurement mode .......................................................................................... 42
11.4. Filtering .......................................................................................................................................................... 43
11.4.1. Filter types .............................................................................................................................................. 43
11.4.2. Configuration register - filtering............................................................................................................... 43
11.4.3. Filter size register.................................................................................................................................... 44
11.5. Alarms............................................................................................................................................................ 44
11.5.1. Configuration register - alarms................................................................................................................ 44
11.5.2. Alarm threshold registers ....................................................................................................................... 44
11.5.3. SXCtrl2 - SX8722 Control register 2 ....................................................................................................... 45
11.6. I2C EEPROM................................................................................................................................................. 46
11.6.1. Overview ................................................................................................................................................. 46
11.6.2. Schematic ............................................................................................................................................... 46
Not
Recommended
for
New
Designs