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.
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 32kSPS, 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.
- 8 low-noise PGAs; 8 high-resolution ADCs
- Low power: 0.75m with channel
- Input-referred noise: 4µVPP (150Hz BW, G=6)
- Input bias current: 200pA
- Data rate: 250SPS to 32kSPS
- CMRR: –115dB
- Programmable gain: 1, 2, 3, 4, 6, 8, or 12
- Supplies: unipolar or bipolar
- Analog supply: 2.7V to 5.25V
- Digital supply: 1.65V to 3.6V
- Built-in right leg drive amplifier, lead-off detection, WCT, and
- Digital pace detection capability
- Built-in oscillator and reference
- Flexible power-down, standby mode
- SPI-compatible serial interface
- Operating temperature range: 0°C to +70°C
- Medical instrumentation (ECG and EEG), including:
- Patient monitoring: Holter, event, stress, vital signs ECG, and AED
- Bispectral index (BIS), evoked audio potential (EAP), sleep study monitor