FEATURES
· 24 BITS NO MISSING CODES
· 0.0015% INL
· 22 BITS EFFECTIVE RESOLUTION (PGA = 1),
19 BITS (PGA = 128)
· 4K BYTES OF FLASH MEMORY
PROGRAMMABLE FROM 2.7V TO 5.25V
· PGA FROM 1 TO 128
· SINGLE CYCLE SETTLING MODE
· PROGRAMMABLE DATA OUTPUT RATES UP
TO 1kHz
· PRECISION ON-CHIP 1.25V/2.5V REFERENCE:
ACCURACY: 0.2%
DRIFT: 5ppm/°C
· EXTERNAL DIFFERENTIAL REFERENCE OF
0.1V TO 2.5V
· ON-CHIP CALIBRATION
· PIN-COMPATIBLE WITH ADS1216
· SPI™ COMPATIBLE
· 2.7V TO 5.25V
· < 1mW POWER CONSUMPTION

APPLICATIONS
· INDUSTRIAL PROCESS CONTROL
· LIQUID/GAS CHROMATOGRAPHY
· BLOOD ANALYSIS
· SMART TRANSMITTERS
· PORTABLE INSTRUMENTATION
· WEIGHT SCALES
· PRESSURE TRANSDUCERS

DESCRIPTION
The ADS1218 is a precision, wide dynamic range,
delta-sigma, Analog-to-Digital (A/D) converter with
24-bit resolution and Flash memory 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. Burnout 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 conversion. The on-board current DACs
(Digital-to-Analog Converters) operate independently 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 ADS1218 is designed for
high-resolution measurement applications in smart
transmitters, industrial process control, weight scales,
chromatography, and portable instrumentation.