SBAU171D May   2010  – January 2016 ADS1198 , ADS1298

 

  1.   ADS1298ECG-FE/ADS1198ECG-FE
    1.     Trademarks
    2. 1 ADS1298ECG-FE/ADS1198ECG-FE Overview
      1. 1.1 Important Disclaimer Information
      2. 1.2 Introduction
      3. 1.3 Supported Features
      4. 1.4 Features Not Supported in Current Version
      5. 1.5 ADS1x98ECG-FE Hardware
      6. 1.6 Minimum System Requirements for ADS1x98ECG-FE Evaluation Software
    3. 2 Quick Start
      1. 2.1 Default Jumper/Switch Configuration
      2. 2.2 ADS1x98ECG-FE Operation
    4. 3 Using the ADS1298ECG-FE Software
      1. 3.1 Application User Menu
      2. 3.2 Top-Level Application Controls
      3. 3.3 About Tab
      4. 3.4 ADC Register Tab
        1. 3.4.1 Standby and Reset Controls
        2. 3.4.2 Channel Registers Tab (ADC Register)
          1. 3.4.2.1 Global Channel Registers
          2. 3.4.2.2 Channel Control Registers
        3. 3.4.3 LOFF and RLD Tab (ADC Register)
          1. 3.4.3.1 Lead-Off Detection and Current Direction Control Registers
          2. 3.4.3.2 Right Leg Drive Derivation Control Registers
        4. 3.4.4 GPIO and OTHER Registers Tab (ADC Register)
          1. 3.4.4.1 Wilson Central and Augmented Lead Registers
        5. 3.4.5 Register Map (ADC Register)
      5. 3.5 Analysis Tab
        1. 3.5.1 Scope Tab (Anaysis)
          1. 3.5.1.1 Zoom Tool
        2. 3.5.2 Histogram Tab (Analysis)
        3. 3.5.3 FFT Tab
        4. 3.5.4 ECG Tab (Analysis)
      6. 3.6 Save Tab
    5. 4 ADS1x98ECG-FE Input Signals
      1. 4.1 Input Short Testing
      2. 4.2 Internal Test Signals Input
      3. 4.3 Temperature Sensor
      4. 4.4 Normal Electrode Input
        1. 4.4.1 Capturing 12-Lead ECG Signals
      5. 4.5 MVDD Input, RLD Measurement, RLD Positive Electrode Driver, and RLD Negative Electrode Driver
      6. 4.6 Lead Derivation
      7. 4.7 Wilson Center Terminal (WCT)
      8. 4.8 Right Leg Drive
        1. 4.8.1 RLD Common Mode Voltage
        2. 4.8.2 Driving the RLD Cable Shield
      9. 4.9 PACE Detection
    6. 5 ADS1298ECG-FE/ADS1198ECG-FE Hardware Details
      1. 5.1 Jumper Description
      2. 5.2 Power Supply
      3. 5.3 Clock
      4. 5.4 Reference
      5. 5.5 Analog Output Signals
      6. 5.6 Digital Signals
      7. 5.7 Analog Input Signals
        1. 5.7.1 Patient Simulator Input
        2. 5.7.2 Arbitrary Input Signals
  2. ASchematics, BOM, Layout, and ECG Cable Details
    1. A.1 Overview
    2. A.2 ADS1x98ECG-FE Front-End Board Schematics
    3. A.3 Bill of Materials
      1. Table 13. Bill of Materials: ADS1x98ECG-FE
    4. A.4 Printed Circuit Board Layout
    5. A.5 ECG Cable Details
  3. BExternal Optional Hardware
    1. B.1 Optional External Hardware (Not Included)
    2. B.2 ADS1x98ECG-FE Power-Supply Recommendations
  4. CSoftware Installation
    1. C.1 Minimum Requirements
    2. C.2 Installing the Software

5.3 Clock

The ADS1298 has an on-chip oscillator circuit that generates a 2.048MHz clock (nominal). This clock can vary by ±5% over temperature. For applications that require higher accuracy, the ADS1298 also accepts an external clock signal. The ADS1298ECG-FE provides an option to test both internal and external clock configurations. For the external signal, circuitry is available to generate the external clock from an on-board oscillator or from an externally connected source.

The external oscillator included on the EVM is powered from DVDD, the same supply as the ADS1298. Care must be taken to ensure that the externally supplied clock oscillator can operate either with +1.8V or +3.0V, depending on the DVDD supply configuration. Table 9 shows the jumper settings for the three options for the ADS1298 clocks.

Table 9. CLK Jumper Options

ADS1298 Clock Internal Clock External OSC Clock External Clock
JP18 Not Installed 2-3 1-2
JP19 Don't Care 1-2 (Disable) Don't Care
2-3 (Enable)

A 2.048MHz oscillator installed on the EVM for +3V DVDD operation is FXO-HC735-2.048MHz. If operation at +1.8V DVDD is desired, the oscillator will need to be replaced. SiT8002AC-34-18E-2.048 is a possible oscillator for +1.8V DVDD operation. The EVM is shipped with the external oscillator enabled.