ADS1217
ADS
121
7
SBAS260B – MAY 2002 – REVISED OCTOBER 2004
8-Channel, 24-Bit
ANALOG-TO-DIGITAL CONVERTER
FEATURES
q
24 BITS NO MISSING CODES
q
INL: 0.0012% of FSR (max)
q
FULL-SCALE INPUT:
±
2V
REF
q
PGA FROM 1 TO 128
q
22 BITS EFFECTIVE RESOLUTION
(PGA = 1), 19 BITS (PGA = 128)
q
SINGLE CYCLE SETTLING MODE
q
PROGRAMMABLE DATA OUTPUT RATES
UP TO 1kHz
q
ON-CHIP 1.25V/2.5V REFERENCE
q
ON-CHIP CALIBRATION
q
SPI COMPATIBLE
q
POWER SUPPLY: 2.7V to 5.25V
q
< 1mW POWER CONSUMPTION, V
DD
= 3V
DESCRIPTION
The ADS1217 is a precision, wide dynamic range, delta-
sigma, Analog-to-Digital (A/D) converter with 24-bit resolu-
tion operating from 2.7V to 5.25V supplies. The delta-sigma,
A/D converter provides up to 24 bits of no missing code
performance and effective resolution of 22 bits.
The eight input channels are multiplexed. Internal buffering
can be selected to provide a very high input impedance for
direct connection to transducers or low-level voltage signals.
Burnout current sources are provided that allow for the
detection of an open or shorted sensor. An 8-bit Digital-to-
Analog Converter (DAC) provides an offset correction with a
range of 50% of the FSR (Full-Scale Range).
The PGA (Programmable Gain Amplifier) provides selectable
gains of 1 to 128 with an effective resolution of 19 bits at a gain
of 128. The A/D conversion is accomplished with a 2nd-order,
delta-sigma modulator and programmable sinc filter. The
reference input is differential and can be used for ratiometric
measurements. The onboard current DACs operate indepen-
dently with the maximum current set by an external resistor.
The serial interface is SPI compatible. Eight bits of digital I/O
are also provided that can be used for input or output. The
ADS1217 is designed for high-resolution measurement appli-
cations in smart transmitters, industrial process control, weigh
scales, chromatography, and portable instrumentation.
AGND
AV
DD
R
DAC
V
REFOUT
V
RCAP
V
REF+
V
REF–
X
IN
X
OUT
APPLICATIONS
q
INDUSTRIAL PROCESS CONTROL
q
LIQUID/GAS CHROMATOGRAPHY
q
BLOOD ANALYSIS
q
SMART TRANSMITTERS
q
PORTABLE INSTRUMENTATION
q
WEIGH SCALES
q
PRESSURE TRANSDUCERS
IDAC2
8-Bit
IDAC
Clock Generator
Voltage
Reference
IDAC1
8-Bit
IDAC
Offset
DAC
PDWN
DYSNC
A
IN
0
A
IN
1
A
IN
2
A
IN
3
A
IN
4
A
IN
5
A
IN
6
A
IN
7
A
INCOM
Serial Interface
Digital I/O
Interface
POL
SCLK
D
IN
D
OUT
CS
DRDY
BUFEN
DV
DD
DGND
D0
... D7
MUX
BUF
+
PGA
2nd-Order
Modulator
Program-
mable
Digital
Filter
Controller
Registers
RAM
RESET
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Copyright © 2002-2004, Texas Instruments Incorporated
www.ti.com
BURR-BROWN [ BURR-BROWN CORPORATION ]
