ADS1198 - Low-Noise, 8 Channel, 16 Bit Analog Front End for ECG/EEG Measurements

The ADS1194/6/8 are a family of multichannel, simultaneous sampling, 16-bit, delta-sigma (ΔΣ) analog-to-digital converters (ADCs) with a built-in programmable gain amplifier (PGA), internal reference, and an onboard oscillator.

With its high levels of integration and exceptional performance, the ADS1194/6/8 family enables the creation of scalable medical instrumentation systems at significantly reduced size, power, and overall cost.

The ADS1194/6/8 have 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 ADS1194/6/8 operate at data rates as high as 8kSPS, 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 medical electrocardiogram (ECG).

Multiple ADS1194/6/8 devices can be cascaded in high channel count systems in a daisy-chain configuration.

Package options include a tiny 8mm × 8mm, 64-ball BGA and a TQFP-64. Both packages are specified over the temperature range of 0°C to +70°C.

• Eight Low-Noise PGAs and
  Eight High-Resolution ADCs (ADS1198)
• Low Power: 0.55mW/channel
• Input-Referred Noise:
  12µV_PP (150Hz BW, G = 6)
• Input Bias Current: 200pA
• Data Rate: 125SPS to 8kSPS
• CMRR: –105dB
• Programmable Gain: 1, 2, 3, 4, 6, 8, or 12
• Supports AAMI EC11, EC13, IEC60601-1, IEC60601-2-27, and IEC60601-2-51 Standards
• Supplies: Unipolar or Bipolar
  • Analog: 2.7V to 5.25V
  • Digital: 1.65V to 3.6V
• Built-In Right Leg Drive Amplifier, Lead-Off Detection, WCT, Test Signals
• Pace Detection Channel Select
• Built-In Oscillator and Reference
• Flexible Power-Down, Standby Mode
• SPI™-Compatible Serial Interface
• Operating Temperature Range:
  0°C to +70°C