ADS1242
ADS1243
A
®
D
S
1
A
D
S
2
®
4
2
1
2
4
3
SBAS235B – DECEMBER 2001 – OCTOBER 2004
24-Bit
ANALOG-TO-DIGITAL CONVERTER
DESCRIPTION
FEATURES
● 24 BITS NO MISSING CODES
The ADS1242 and ADS1243 are precision, wide dynamic
range, delta-sigma, analog-to-digital (A/D) converters with
24-bit resolution operating from 2.7V to 5.25V supplies.
These delta-sigma, A/D converters provide up to 24 bits of no
missing code performance and effective resolution of 21 bits.
● SIMULTANEOUS 50Hz AND 60Hz REJECTION
(–90dB MINIMUM)
● 0.0015% INL
● 21 BITS EFFECTIVE RESOLUTION
(PGA = 1), 19 BITS (PGA = 128)
The 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
converter (DAC) provides an offset correction with a range of
50% of the FSR (Full-Scale Range).
● PGA GAINS FROM 1 TO 128
● SINGLE-CYCLE SETTLING
● PROGRAMMABLE DATA OUTPUT RATES
● EXTERNAL DIFFERENTIAL REFERENCE
OF 0.1V TO 5V
● ON-CHIP CALIBRATION
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 second-order
delta-sigma modulator and programmable FIR filter that pro-
vides a simultaneous 50Hz and 60Hz notch. The reference input
is differential and can be used for ratiometric conversion.
● SPI™ COMPATIBLE
● 2.7V TO 5.25V SUPPLY RANGE
● 600µW POWER CONSUMPTION
● UP TO EIGHT INPUT CHANNELS
● UP TO EIGHT DATA I/O
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
ADS1242 and ADS1243 are designed for high-resolution
measurement applications in smart transmitters, industrial
process control, weight scales, chromatography, and portable
instrumentation.
APPLICATIONS
● INDUSTRIAL PROCESS CONTROL
● LIQUID/GAS CHROMATOGRAPHY
● BLOOD ANALYSIS
● SMART TRANSMITTERS
VDD
VREF+
VREF–
XIN
XOUT
● PORTABLE INSTRUMENTATION
● WEIGHT SCALES
VDD
Clock Generator
2µA
Offset
DAC
AIN0/D0
AIN1/D1
AIN2/D2
AIN3/D3
AIN4/D4
AIN5/D5
AIN6/D6
A = 1:128
PGA
IN+
2nd-Order
Modulator
Digital
MUX
+
Controller
Registers
BUF
Filter
IN–
A
IN7/D7
ADS1243
Only
SCLK
DIN
Serial Interface
DRDY
2µA
DOUT
GND
CS
GND
PDWN
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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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.
Copyright © 2001-2004, Texas Instruments Incorporated
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