Datasheet
Table Of Contents
- FEATURES
- APPLICATIONS
- DESCRIPTION
- ABSOLUTE MAXIMUM RATINGS
- ELECTRICAL CHARACTERISTICS: AVDD = 5V
- ELECTRICAL CHARACTERISTICS: AVDD = 3V
- DIGITAL CHARACTERISTICS: TMIN to TMAX, DVDD = 2.7V to 5.25V
- FLASH CHARACTERISTICS: TMIN to TMAX, DVDD = 2.7V to 5.25V, unless otherwise specified.
- PIN CONFIGURATION
- TIMING SPECIFICATIONS
- TIMING SPECIFICATION TABLE
- TIMING SPECIFICATION TABLE
- TYPICAL CHARACTERISTICS
- OVERVIEW
- INPUT MULTIPLEXER
- TEMPERATURE SENSOR
- BURNOUT CURRENT SOURCES
- INPUT BUFFER
- IDAC1 AND IDAC2
- PGA
- PGA OFFSET DAC
- MODULATOR
- VOLTAGE REFERENCE INPUT
- ON-CHIP VOLTAGE REFERENCE
- VRCAP PIN
- CLOCK GENERATOR
- CALIBRATION
- DIGITAL FILTER
- DIGITAL I/O INTERFACE
- SERIAL PERIPHERAL INTERFACE
- DATA READY
- DSYNC OPERATION
- MEMORY
- REGISTER BANK
- RAM
- FLASH
- REGISTER MAP
- COMMAND DEFINITIONS
www.ti.com
ADS1218
SBAS187C – SEPTEMBER 2001 – REVISED SEPTEMBER 2005
DEC0 (Address 08
H
) Decimation Register (least significant 8 bits)
Reset value is set by Flash memory page 0. Factory programmed to 80
H
.
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
DEC07 DEC06 DEC05 DEC04 DEC03 DEC02 DEC01 DEC00
The decimation value is defined with 11 bits for a range of 20 to 2047. This register is the least significant 8 bits. The 3 most significant bits
are contained in the M/DEC1 register.
M/DEC1 (Address 09
H
) Mode and Decimation Register
Reset value is set by Flash memory page 0. Factory programmed to 07
H
.
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
DRDY U/ B SMODE1 SMODE0 WREN DEC10 DEC09 DEC08
bit 7 DRDY: Data Ready (Read Only)
This bit duplicates the state of the DRDY pin.
bit 6 U/ B: Data Format
0 = Bipolar
1 = Unipolar
U/ B ANALOG INPUT DIGITAL OUTPUT
0 +FS 0x7FFFFF
Zero 0x000000
–FS 0x800000
1 +FS 0xFFFFFF
Zero 0x000000
–FS 0x000000
bits 5-4 SMODE1: SMODE0: Settling Mode
00 = Auto
01 = Fast Settling filter
10 = Sinc2 filter
11 = Sinc3 filter
bit 3 WREN: Flash Write Enable
0 = Flash Writing Disabled
1 = Flash Writing Enabled
This bit and the WREN pin must both be enabled in order to write to the Flash memory.
bits 2-0 DEC10: DEC09: DEC08: Most Significant Bits of the Decimation Value
OCR0 (Address 0A
H
) Offset Calibration Coefficient (least significant byte)
Reset value is set by Flash memory page 0. Factory programmed to 00
H
.
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
OCR07 OCR06 OCR05 OCR04 OCR03 OCR02 OCR01 OCR00
25