ADS1298 24-Bit Analog-to-Digital Converter

Texas Instruments' ADS1298 is a multi-channel, simultaneous sampling, 24-bit, delta-sigma (ΔΣ) analog-to-digital converters (ADC) with a built-in programmable gain amplifier (PGA), internal reference, and an onboard oscillator. The ADS1298 incorporates all of the features that are commonly required in medical electrocardiogram (ECG) and electroencephalogram (EEG) applications.

With its high level of integration and exceptional performance, the ADS1298 enables the creation of scalable medical instrumentation systems at significantly reduced size, power, and overall cost. Multiple ADS1298 devices can also be cascaded in high channel count systems in a daisy-chain configuration.

Overview

The ADS1298 has a flexible input multiplexer per channel that can be independently connected to the internally-generated signals for test, temperature, and lead-off detection. Additionally, any configuration of input channels can be selected for derivation of the right leg drive (RLD) output signal. The ADS1298 operates at a data rate as high as 32 kSPS, thereby allowing the implementation of software pace detection. Lead-off detection can be implemented internal to the device, either with a pull-up/pull-down resistor or an excitation current sink/source. Three integrated amplifiers generate the Wilson Center terminal (WCT) and the Goldberger terminals (GCT) required for a standard 12-lead ECG.