ADS
124
0
ADS
124
1
ADS1240
ADS1241
SBAS173C – JUNE 2001 – REVISED NOVEMBER 2003
24-Bit
ANALOG-TO-DIGITAL CONVERTER
FEATURES
q
24 BITS NO MISSING CODES
q
SIMULTANEOUS 50Hz AND 60Hz REJECTION
(–90dB MINIMUM)
q
0.0015% INL
q
21 BITS EFFECTIVE RESOLUTION
(PGA = 1), 19 BITS (PGA = 128)
q
PGA GAINS FROM 1 TO 128
q
SINGLE CYCLE SETTLING
q
PROGRAMMABLE DATA OUTPUT RATES
q
EXTERNAL DIFFERENTIAL REFERENCE
OF 0.1V TO 5V
q
ON-CHIP CALIBRATION
q
SPI™ COMPATIBLE
q
2.7V TO 5.25V SUPPLY RANGE
q
600
µ
W POWER CONSUMPTION
q
UP TO EIGHT INPUT CHANNELS
q
UP TO EIGHT DATA I/O
DESCRIPTION
The ADS1240 and ADS1241 are precision, wide dynamic range,
delta-sigma, Analog-to-Digital (A/D) converters with 24-bit resolution
operating from 2.7V to 5.25V power supplies. The delta-sigma A/D
converter provides up to 24 bits of no missing code performance and
effective resolution of 21 bits.
The input channels are multiplexed. Internal buffering can be
selected to provide very high input impedance for direct connection
to transducers or low-level voltage signals. Burnout current sources
are provided that allow for detection of an open or shorted sensor.
An 8-bit Digital-to-Analog (D/A) converter provides an offset cor-
rection with a range of 50% of the Full-Scale Range (FSR).
The Programmable Gain Amplifier (PGA) 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 modu-
lator and programmable Finite-Impulse Response (FIR) filter that
provides a simultaneous 50Hz and 60Hz notch. The reference input
is differential and can be used for ratiometric conversion.
The serial interface is SPI compatible. Up to eight bits of data
I/O are also provided that can be used for input or output. The
ADS1240 and ADS1241 are designed for high-resolution measure-
ment applications in smart transmitters, industrial process control,
weigh scales, chromatography, and portable instrumentation.
APPLICATIONS
q
q
q
q
q
q
INDUSTRIAL PROCESS CONTROL
WEIGH SCALES
LIQUID /GAS CHROMATOGRAPHY
BLOOD ANALYSIS
SMART TRANSMITTERS
PORTABLE INSTRUMENTATION
A
IN
0/D0
A
IN
1/D1
A
IN
2/D2
A
IN
3/D3
A
IN
4/D4
A
IN
5/D5
A
IN
6/D6
A
IN
7/D7
A
INCOM
MUX
AV
DD
AGND
V
REF+
V
REF–
X
IN
X
OUT
AV
DD
Clock Generator
2µA
Offset
DAC
A = 1:128
2nd-Order
Modulator
Digital
Filter
BUF
+
PGA
Controller
Registers
POL
SCLK
Serial Interface
D
IN
D
OUT
CS
AGND
BUFEN
DV
DD
DGND
PDWN
DSYNC
RESET
DRDY
ADS1241
Only
2µA
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 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 © 2001-2003, Texas Instruments Incorporated
www.ti.com
TI [ TEXAS INSTRUMENTS ]
