24-Bit
ANALOG-TO-DIGITAL CONVERTER
FEATURES
a71 24 BITS NO MISSING CODES
a71 SIMULTANEOUS 50Hz AND 60Hz REJECTION
(–90dB MINIMUM)
a71 0.0015% INL
a71 21 BITS EFFECTIVE RESOLUTION
(PGA = 1), 19 BITS (PGA = 128)
a71 PGA GAINS FROM 1 TO 128
a71 SINGLE CYCLE SETTLING
a71 PROGRAMMABLE DATA OUTPUT RATES
a71 EXTERNAL DIFFERENTIAL REFERENCE
OF 0.1V TO 5V
a71 ON-CHIP CALIBRATION
a71 SPI™ COMPATIBLE
a71 2.7V TO 5.25V SUPPLY RANGE
a71 600µW POWER CONSUMPTION
a71 UP TO EIGHT INPUT CHANNELS
a71 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
a71 INDUSTRIAL PROCESS CONTROL
a71 WEIGH SCALES
a71 LIQUID/GAS CHROMATOGRAPHY
a71 BLOOD ANALYSIS
a71 SMART TRANSMITTERS
a71 PORTABLE INSTRUMENTATION
BUF PGA
A = 1:128
+
Clock Generator
Serial Interface
2nd-Order
Modulator
AGNDAV
DD
V
REF+
V
REF–
X
IN
X
OUT
DSYNCPDWN RESET DRDYBUFEN DGNDDV
DD
SCLK
POL
D
IN
D
OUT
CS
MUX
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
Controller Registers
Digital
Filter
2µA
AV
DD
Offset
DAC
AGND
2µA
ADS1241
Only
A
D
S
12
41
A
D
S
12
40
ADS1240
ADS1241
SBAS173C – JUNE 2001 – REVISED NOVEMBER 2003
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 © 2001-2003, 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.
All trademarks property of their respective owners.