8-Channel, 24-Bit
ANALOG-TO-DIGITAL CONVERTER
FEATURES
a71 24 BITS NO MISSING CODES
a71 0.0015% INL
a71 22 BITS EFFECTIVE RESOLUTION
(PGA = 1), 19 BITS (PGA = 128)
a71 PGA FROM 1 TO 128
a71 SINGLE CYCLE SETTLING MODE
a71 PROGRAMMABLE DATA OUTPUT RATES
UP TO 1kHz
a71 ON-CHIP 1.25V/2.5V REFERENCE
a71 EXTERNAL DIFFERENTIAL REFERENCE
OF 0.1V TO 2.5V
a71 ON-CHIP CALIBRATION
a71 SPI™ COMPATIBLE
a71 2.7V TO 5.25V
a71 < 1mW POWER CONSUMPTION
DESCRIPTION
The ADS1216 is a precision, wide dynamic range, delta-sigma, Analog-
to-Digital (A/D) converter with 24-bit resolution 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. Burn out current sources are
provided that allow for the detection of an open or shorted sensor. An 8-
bit Digital-to-Analog (D/A) converter 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 second-order delta-
sigma modulator and programmable sinc filter. The reference input
is differential and can be used for ratiometric cancellation. The on-
board current DACs (Digital-to-Analog Converters) operate inde-
pendently 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 ADS1216 is
designed for high-resolution measurement applications in smart
transmitters, industrial process control, weight scales, chromatogra-
phy, and portable instrumentation.
APPLICATIONS
a71 INDUSTRIAL PROCESS CONTROL
a71 LIQUID/GAS CHROMATOGRAPHY
a71 BLOOD ANALYSIS
a71 SMART TRANSMITTERS
a71 PORTABLE INSTRUMENTATION
a71 WEIGHT SCALES
a71 PRESSURE TRANSDUCERS
AD
S1
21
6
SPI is a registered trademark of Motorola.
BUF PGA
A = 1:128
+
1.25V or
2.5V
Reference
Clock Generator
Registers
Serial Interface
2nd-Order
Modulator
RAM
Digital I/O
Interface
AGND AV
DD
IN+
IN–
R
DAC
V
REFOUT
V
RCAP
V
REF+
V
REF–
X
IN
X
OUT
DSYNCPDWN RESET DRDYD7BUFENDGNDDV
DD
...D0
SCLK
POL
D
IN
D
OUT
CS
MUX
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
IDAC1
Controller
Program-
mable
Digital
Filter
2µA
AV
DD
8-Bit
IDAC
IDAC2
8-Bit
IDAC
Offset
DAC
AGND
2µA
ADS1216
SBAS171B – JUNE 2001
www.ti.com
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 © 2000, Texas Instruments Incorporated
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.