TIDUDO6B May   2019  – October 2020

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Introduction to Parameters Measured Using TIDA-01580
    2. 1.2 High-Level System Description
    3. 1.3 Typical Applications
    4. 1.4 System Specifications and Design Features
    5. 1.5 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 AFE4900
      2. 2.2.2 CC2640R2F
      3. 2.2.3 TPS61099
      4. 2.2.4 TPS63036
      5. 2.2.5 TPD1E10B06
    3. 2.3 System Design Theory and Design Considerations
      1. 2.3.1  AFE4900 and Power Supply
      2. 2.3.2  CC2640R2F Microcontroller
      3. 2.3.3  PPG Measurement
      4. 2.3.4  ECG Measurement
        1. 2.3.4.1 Two-Electrode Configuration
        2. 2.3.4.2 Three-Electrode Configuration
      5. 2.3.5  Selecting TX Supply (TX_SUP) Value for Driving LEDs
      6. 2.3.6  Generating TX Supply for Driving LEDs
        1. 2.3.6.1 Programming Output Voltage
        2. 2.3.6.2 Maximum Output Current
        3. 2.3.6.3 Input and Output Capacitor Selection
        4. 2.3.6.4 Switching Frequency
        5. 2.3.6.5 WEBENCH® Simulation for TPS61099 Boost Converter
      7. 2.3.7  Generating RX Supply for AFE4900
        1. 2.3.7.1 Setting Output Voltage
        2. 2.3.7.2 Capacitor Selection
        3. 2.3.7.3 Output Current Limit
        4. 2.3.7.4 Inductor Selection
        5. 2.3.7.5 TINA-TI™ Simulation for TPS63036
      8. 2.3.8  Generating I/O Supply
      9. 2.3.9  Battery Input and Reservoir Capacitors
      10. 2.3.10 Battery Life Calculations
        1. 2.3.10.1 AFE4900 Current Consumption
        2. 2.3.10.2 CC2640R2F Current Consumption
        3. 2.3.10.3 On-State Current Calculations
        4. 2.3.10.4 Off-State Current Calculations (Considering Battery Voltage = 3 V)
      11. 2.3.11 External Memory
      12. 2.3.12 LED Indications
      13. 2.3.13 Connections Between Sensor Board and ECG Board
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Required Hardware and Software
      1. 3.1.1 Hardware
        1. 3.1.1.1 Connecting Optical Sensor and ECG Boards to Main Board
        2. 3.1.1.2 Difference Between PPG Sensor Boards
      2. 3.1.2 Software
        1. 3.1.2.1 Software Loading for TIDA-01580 Board (Transmit Side of BLE)
        2. 3.1.2.2 LabVIEW™ File Execution for Checking Measurement Data (Receive Side of BLE)
    2. 3.2 Testing and Results
      1. 3.2.1 Test Setup
      2. 3.2.2 Test Results
        1. 3.2.2.1 Heart-Rate Measurement Using PPG (Green LED) and ECG
        2. 3.2.2.2 SpO2 Measurement Using Red and IR LEDs
        3. 3.2.2.3 PTT Measurement
        4. 3.2.2.4 Lead-Off Detect
          1. 3.2.2.4.1 AC Lead-Off Detect
          2. 3.2.2.4.2 DC Lead-Off Detect
        5. 3.2.2.5 Low-Battery Indication
        6. 3.2.2.6 Waveforms for DC/DC Converters
        7. 3.2.2.7 Battery Life Test
  9. 4Design Files
    1. 4.1 Schematics
    2. 4.2 Bill of Materials
    3. 4.3 PCB Layout Recommendations
      1. 4.3.1  Layout for Main Board
      2. 4.3.2  Connection From PDs to AFE
      3. 4.3.3  Connections From LEDs to AFE
      4. 4.3.4  Connections From ECG PADs to AFE
      5. 4.3.5  Connections Between BT and AFE
      6. 4.3.6  Connections Between BT Antenna and Chip
      7. 4.3.7  Boost Converter
      8. 4.3.8  Buck-Boost Converter
      9. 4.3.9  Layouts for PPG Sensor Boards
      10. 4.3.10 Layout for ECG Sensor Board
      11. 4.3.11 Layout Prints
    4. 4.4 Altium Project
    5. 4.5 Gerber Files
    6. 4.6 Assembly Drawings
  10. 5Software Files
  11. 6Related Documentation
    1. 6.1 Trademarks
  12. 7About the Authors
  13.   Revision History

3.1.1.2 Difference Between PPG Sensor Boards

One PPG sensor board uses the SFH 7072 device from OSRAM. The default configuration for the PPG sensor board follows:

  • LED1 (green1) of the SFH7072 = connected to TX4 of the AFE4900 device
  • LED2 (green2) of the SFH7072 = not connected to the AFE4900 device
  • LED3 (red) of the SFH7072 = connected to TX2 of the AFE4900 device
  • LED4 (IR) of the SFH7072 = connected to TX3 of the AFE4900 device
  • The Dual_PD_Enable bit is set in the 0x4E register in the AFE4900 device (see Figure 3-7).
  • PD1 of the AFE4900 device is connected to Broadband PD, and PD2 of the AFE4900 device is connected to Infrared-Cut PD.

Registers to be read for getting raw data follow:

  • 0x2A – Raw PPG data from the red LED
  • 0x2B – Raw PPG data from the IR LED
  • 0x2C – Raw PPG data from the green LED
  • 0x2D – Raw ECG data
GUID-731D1FB8-D4BB-4A72-BFF0-0A01595A6F32-low.gifFigure 3-7 Timing and Settings for SFH 7072 PPG Sensor

The other PPG sensor board uses the OCS112 device from tBPC. The default configuration for the PPG sensor board follows:

  • LED1 (red) of the OCS112 device = connected to TX2 of the AFE4900 device
  • LED2 (IR) of the OCS112 device = connected to TX3 of the AFE4900 device
  • LED3 (green) of the OCS112 device = connected to TX4 of the AFE4900 device

Because this sensor has only one PD, the Dual_PD_Enable bit is not set in the 0x4E register in the AFE4900 device (see Figure 3-8). PD1 of the AFE4900 device is always connected to PD of the sensor.

Registers to be read for getting raw data follow:

  • 0x2A – Raw PPG data from the red LED
  • 0x2B – Raw PPG data from the IR LED
  • 0x2C – Raw PPG data from the green LED
  • 0x2D - Raw ECG data
GUID-F19C2089-A554-47B4-8115-9C345D4B6F33-low.gifFigure 3-8 Timing and Settings for OCS112 PPG Sensor
Note:

Figure 3-7 and Figure 3-8 are screen shots from the AFE4900EVM GUI (available at AFE4900EVM).