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.