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Texas Instruments AFE4960 Analog Front End (AFE)

Texas Instruments AFE4960 Analog Front End (AFE) can be configured as either a 2-channel ECG receiver, a 1-channel ECG receiver, or a respiration impedance channel. The AFE signal chains can interface in a flexible manner with up to 4 electrodes. A right leg drive (RLD) amplifier output can be used to set the body bias. The AFE has DC lead biasing for lead on/off detection and AC lead biasing to measure lead impedance. Pacemaker pulse detection is supported on one channel.

All the signal chain outputs are converted by a single ADC in well-defined time slots and stored as 24-bit words in a 128-sample FIFO which can be read out using an SPI or an I2C interface. The Texas Instruments AFE4960 is a fully integrated solution to realize a 3-lead ECG system. Synchronized operation of two AFEs in parallel can be used to realize a 5-lead ECG.

Features

  • Supports ECG and respiration impedance measurement; configurable as 2-channel ECG or 1-channel ECG + 1-channel respiration
  • Can be used in IEC 60601-2-47:2012/(R)2016 and IEC 60601-2-27:2011(R)2016 compliant systems
  • 222µA/channel while operating as a two-channel ECG
  • Integrated Pace pulse detection on one channel
  • Supports a 3-lead ECG, extendable to 5 leads or higher by operating two or more AFEs in parallel
  • ECG signal chain
    • Single-channel ECG acquisition up to 2.048kHz
    • Two-channel ECG acquisition up to 1.36kHz/channel
    • RLD output to set body bias through a third electrode
    • Programmable INA gain from 2~12
    • > 1GΩ input impedance, CMRR > 100dB
    • Input noise (0.5-150Hz): 13µVpp at INA gain of 3; 5µVpp at INA gain of 12
    • Integrated 370Hz anti-aliasing low pass filter
    • Mode for Continuous lead on/off detection
    • Mode for Lead impedance measurement
  • Bio-Z signal chain
    • Measurement of Bio-impedance overexcitation frequency from 30kHz to 100kHz
    • A sine wave or square wave excitation
    • Respiration impedance measurement: 45mΩ-pp noise on a baseline impedance of 2kΩ
  • Dual-channel ECG channel
    • Bio-Z receiver configurable as a 2nd ECG channel
  • External clock and internal oscillator modes
  • FIFO with 128-sample depth, 24-bit word
  • SPITM, I2C interfaces: selectable by pin
  • 2.6mm × 2.6mm DSBGA, 0.4mm pitch
  • Supplies
    • Rx: 1.7-1.9V
    • IO: 1.7-1.9V

Applications

  • Wireless patches for in-patient and out-patient monitoring
  • Event monitors for arrhythmia detection
  • Hand-held ECG monitor
  • Portable multi-lead ECG
  • Patient vital sign monitoring: Holter, event, stress, and telemedicine

Functional Block Diagram

Block Diagram - Texas Instruments AFE4960 Analog Front End (AFE)
發佈日期: 2022-05-05 | 更新日期: 2022-06-22