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.
SPI is a trademark of Motorola.
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| Resolution (Bits) | 24 |
| Sample rate (max) (ksps) | 0.78 |
| Number of input channels | 8 |
| Interface type | SPI |
| Architecture | Delta-Sigma |
| Input type | Differential |
| Multichannel configuration | Multiplexed |
| Rating | Catalog |
| Reference mode | External, Internal |
| Input voltage range (max) (V) | 5.25 |
| Input voltage range (min) (V) | 0 |
| Features | 50/60 Hz Rejection, Excitation Current Sources (iDACs), GPIO, Oscillator, PGA, Temp Sensor |
| Operating temperature range (°C) | -40 to 85 |
| Power consumption (typ) (mW) | 0.8 |
| Analog supply (min) (V) | 2.7 |
| Analog supply voltage (max) (V) | 5.25 |
| Digital supply (min) (V) | 2.7 |
| Digital supply (max) (V) | 5.25 |
| TQFP (PFB) | 48 | 81 mm² 9 x 9 |