JAJSIY6C December   2011  – April 2020 ADS1291 , ADS1292 , ADS1292R

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
    1.     ブロック概略図
  3. 3 概要
  4. 4 改訂履歴
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Noise Measurements
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  EMI Filter
      2. 8.3.2  Input Multiplexer
        1. 8.3.2.1 Device Noise Measurements
        2. 8.3.2.2 Test Signals (TestP and TestN)
        3. 8.3.2.3 Auxiliary Differential Input (RESP_MODN/IN3N, RESP_MODN/IN3P)
        4. 8.3.2.4 Temperature Sensor (TEMPP, TEMPN)
        5. 8.3.2.5 Supply Measurements (MVDDP, MVDDN)
        6. 8.3.2.6 Lead-Off Excitation Signals (LoffP, LoffN)
        7. 8.3.2.7 Auxiliary Single-Ended Input
      3. 8.3.3  Analog Input
      4. 8.3.4  PGA Settings and Input Range
        1. 8.3.4.1 Input Common-Mode Range
        2. 8.3.4.2 Input Differential Dynamic Range
        3. 8.3.4.3 ADC ΔΣ Modulator
      5. 8.3.5  Digital Decimation Filter
        1. 8.3.5.1 Sinc Filter Stage (sinx / x)
      6. 8.3.6  Reference
      7. 8.3.7  Clock
      8. 8.3.8  Data Format
      9. 8.3.9  Multiple Device Configuration
        1. 8.3.9.1 Standard Mode
      10. 8.3.10 ECG-Specific Functions
        1. 8.3.10.1 Input Multiplexer (Rerouting the Right Leg Drive Signal)
          1. 8.3.10.1.1 Input Multiplexer (Measuring the Right Leg Drive Signal)
        2. 8.3.10.2 Lead-Off Detection
          1. 8.3.10.2.1 DC Lead-Off
          2. 8.3.10.2.2 AC Lead-Off
          3. 8.3.10.2.3 RLD Lead-Off
          4. 8.3.10.2.4 Right Leg Drive (RLD DC Bias Circuit)
            1. 8.3.10.2.4.1 RLD Configuration With Multiple Devices
        3. 8.3.10.3 PACE Detect
        4. 8.3.10.4 Respiration
          1. 8.3.10.4.1 Internal Respiration Circuitry With Internal Clock (ADS1292R)
          2. 8.3.10.4.2 Internal Respiration Circuitry With External Clock (ADS1292R)
      11. 8.3.11 Setting the Device for Basic Data Capture
        1. 8.3.11.1 Lead-Off
    4. 8.4 Device Functional Modes
    5. 8.5 Programming
      1. 8.5.1 SPI Interface
        1. 8.5.1.1  Chip Select (CS)
        2. 8.5.1.2  Serial Clock (SCLK)
        3. 8.5.1.3  Data Input (DIN)
        4. 8.5.1.4  Data Output (DOUT)
        5. 8.5.1.5  Data Retrieval
        6. 8.5.1.6  Data Ready (DRDY)
        7. 8.5.1.7  GPIO
        8. 8.5.1.8  Power-Down and Reset (PWDN/RESET)
        9. 8.5.1.9  START
        10. 8.5.1.10 Settling Time
        11. 8.5.1.11 Continuous Mode
        12. 8.5.1.12 Single-Shot Mode
      2. 8.5.2 SPI Command Definitions
        1. 8.5.2.1  WAKEUP: Exit STANDBY Mode
        2. 8.5.2.2  STANDBY: Enter STANDBY Mode
        3. 8.5.2.3  RESET: Reset Registers to Default Values
        4. 8.5.2.4  START: Start Conversions
        5. 8.5.2.5  STOP: Stop Conversions
        6. 8.5.2.6  OFFSETCAL: Channel Offset Calibration
        7. 8.5.2.7  RDATAC: Read Data Continuous
        8. 8.5.2.8  SDATAC: Stop Read Data Continuous
        9. 8.5.2.9  RDATA: Read Data
        10. 8.5.2.10 Sending Multi-Byte Commands
        11. 8.5.2.11 RREG: Read From Register
        12. 8.5.2.12 WREG: Write to Register
    6. 8.6 Register Maps
      1. 8.6.1 User Register Description
        1. 8.6.1.1  ID: ID Control Register (Factory-Programmed, Read-Only) (address = 00h)
          1. Table 17. ID: ID Control Register (Factory-Programmed, Read-Only) Field Descriptions
        2. 8.6.1.2  CONFIG1: Configuration Register 1 (address = 01h)
          1. Table 18. CONFIG1: Configuration Register 1 Field Descriptions
        3. 8.6.1.3  CONFIG2: Configuration Register 2 (address = 02h)
          1. Table 19. CONFIG2: Configuration Register 2 Field Descriptions
        4. 8.6.1.4  LOFF: Lead-Off Control Register (address = 03h)
          1. Table 20. LOFF: Lead-Off Control Register Field Descriptions
        5. 8.6.1.5  CH1SET: Channel 1 Settings (address = 04h)
          1. Table 21. CH1SET: Channel 1 Settings Field Descriptions
        6. 8.6.1.6  CH2SET: Channel 2 Settings (address = 05h)
          1. Table 22. CH2SET: Channel 2 Settings Field Descriptions
        7. 8.6.1.7  RLD_SENS: Right Leg Drive Sense Selection (address = 06h)
          1. Table 23. RLD_SENS: Right Leg Drive Sense Selection Field Descriptions
        8. 8.6.1.8  LOFF_SENS: Lead-Off Sense Selection (address = 07h)
          1. Table 24. LOFF_SENS: Lead-Off Sense Selection Field Descriptions
        9. 8.6.1.9  LOFF_STAT: Lead-Off Status (address = 08h)
          1. Table 25. LOFF_STAT: Lead-Off Status Field Descriptions
        10. 8.6.1.10 RESP1: Respiration Control Register 1 (address = 09h)
          1. Table 26. RESP1: Respiration Control Register 1 Field Descriptions
        11. 8.6.1.11 RESP2: Respiration Control Register 2 (address = 0Ah)
          1. Table 27. RESP2: Respiration Control Register 2 Field Descriptions
        12. 8.6.1.12 GPIO: General-Purpose I/O Register (address = 0Bh)
          1. Table 28. GPIO: General-Purpose I/O Register Field Descriptions
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Power-Up Sequencing
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 PCB Layout
        1. 11.1.1.1 Power Supplies and Grounding
          1. 11.1.1.1.1 Connecting the Device to Unipolar (+3 V or +1.8 V) Supplies
          2. 11.1.1.1.2 Connecting the Device to Bipolar (±1.5 V or 1.8 V) Supplies
        2. 11.1.1.2 Shielding Analog Signal Paths
    2. 11.2 Layout Example
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 関連リンク
    2. 12.2 ドキュメントの更新通知を受け取る方法
    3. 12.3 サポート・リソース
    4. 12.4 商標
    5. 12.5 静電気放電に関する注意事項
    6. 12.6 Glossary
  13. 13メカニカル、パッケージ、および注文情報

8.3.10.2.1 DC Lead-Off

In this method, the lead-off excitation is with a dc signal. The dc excitation signal can be chosen from either an external pull-up or pull-down resistor or a current source or sink, as shown in Figure 38. One side of the channel is pulled to supply and the other side is pulled to ground. The internal current source and current sink can be swapped by setting the FLIP1 and FLIP2 bits in the LOFF_SENS register. In case of current source or sink, the magnitude of the current can be set by using the ILEAD_OFF[1:0] bits in the LOFF register. The current source or sink gives larger input impedance compared to the 10-MΩ pull-up or pull-down resistor.

ADS1291 ADS1292 ADS1292R ai_dc_leadoff_opt_bas502.gifFigure 38. DC Lead-Off Excitation Options

Sensing of the response can be done either by looking at the digital output code from the device or by monitoring the input voltages with an on-chip comparator. If either of the electrodes is off, the pull-up resistors and the pull-down resistors saturate the channel. By looking at the output code it can be determined that either the P-side or the N-side is off. To pinpoint which one is off, the comparators must be used. The input voltage is also monitored using a comparator and a 4-bit digital-to-analog converter (DAC) whose levels are set by the COMP_TH[2:0] bits in the LOFF register. The output of the comparators are stored in the LOFF_STAT register. These two registers are available as a part of the output data stream. (See the Data Output Protocol (DOUT) subsection of the SPI Interface section.) If dc lead-off is not used, the lead-off comparators can be powered down by setting the PD_LOFF_COMP bit in the CONFIG2 register.

An example procedure to turn on dc lead-off is given in the Lead-Off section.