ADS1217
A
D
S
1
2
1
7
SBAS260B – MAY 2002 – REVISED OCTOBER 2004
8-Channel, 24-Bit
ANALOG-TO-DIGITAL CONVERTER
FEATURES
DESCRIPTION
● 24 BITS NO MISSING CODES
● INL: 0.0012% of FSR (max)
● FULL-SCALE INPUT: ±2VREF
● PGA FROM 1 TO 128
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.
● 22 BITS EFFECTIVE RESOLUTION
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).
(PGA = 1), 19 BITS (PGA = 128)
● SINGLE CYCLE SETTLING MODE
● PROGRAMMABLE DATA OUTPUT RATES
UP TO 1kHz
● ON-CHIP 1.25V/2.5V REFERENCE
● ON-CHIP CALIBRATION
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.
● SPI COMPATIBLE
● POWER SUPPLY: 2.7V to 5.25V
● < 1mW POWER CONSUMPTION, VDD = 3V
APPLICATIONS
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.
● INDUSTRIAL PROCESS CONTROL
● LIQUID/GAS CHROMATOGRAPHY
● BLOOD ANALYSIS
● SMART TRANSMITTERS
● PORTABLE INSTRUMENTATION
● WEIGH SCALES
AGND AVDD
RDAC
VREFOUT
VRCAP
VREF+ VREF–
XIN
XOUT
8-Bit
IDAC2
IDAC
Clock Generator
● PRESSURE TRANSDUCERS
Voltage
Reference
8-Bit
IDAC
IDAC1
Offset
DAC
PDWN
DYSNC
RESET
A
IN0
AIN
AIN
AIN
AIN
AIN
AIN
AIN
1
2
3
4
5
6
7
Registers
Program-
Controller
2nd-Order
Modulator
mable
Digital
Filter
MUX
+
BUF
PGA
RAM
POL
SCLK
DIN
AINCOM
Serial Interface
DOUT
CS
Digital I/O
Interface
DRDY
BUFEN
DVDD DGND
D0 ... D7
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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.
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