TIDUEY7 July   2021

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1  System Control and Processing
      2. 2.2.2  Analog Front End
      3. 2.2.3  Input Voltage Monitoring: 5 V, 20 V, 40 V, and ±5 V
      4. 2.2.4  Bidirectional Current Sense: ±2 A
      5. 2.2.5  Unipolar Current Sense: 0.25 A to 1 A
      6. 2.2.6  TMP461-SP: Local and Remote Temperature Sensing
      7. 2.2.7  NTC Thermistor Temperature Sensing
      8. 2.2.8  Adjustable Voltage Source
      9. 2.2.9  Fixed Output Current Source
      10. 2.2.10 Adjustable 4-mA Current Source
      11. 2.2.11 Power Tree and Power Sequencing
    3. 2.3 Highlighted Products
      1. 2.3.1  MSP430FR5969-SP
      2. 2.3.2  ADC128S102QML-SP
      3. 2.3.3  DAC121S101QML-SP
      4. 2.3.4  LMP7704-SP
      5. 2.3.5  INA901-SP
      6. 2.3.6  LM4050QML-SP
      7. 2.3.7  LM158QML-SP
      8. 2.3.8  LM139QML-SP
      9. 2.3.9  TMP461-SP
      10. 2.3.10 TPS7A4501-SP
      11. 2.3.11 TPS7H2201-SP
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Required Hardware and Software
      1. 3.1.1 Hardware
      2. 3.1.2 Software
    2. 3.2 Test Setup
      1. 3.2.1 Voltage Monitor Test Setup
      2. 3.2.2 Current Monitor Test Setup
    3. 3.3 Test Results
      1. 3.3.1 Voltage Measurement - Noise Floor Results
      2. 3.3.2 Voltage Measurement - Linearity Results
      3. 3.3.3 Current Measurement - Noise Floor Results
      4. 3.3.4 Current Measurement - Linearity Results
      5. 3.3.5 Analog Outputs
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Documentation Support
    3. 4.3 Support Resources
    4. 4.4 Trademarks
  10. 5About the Author

1 System Description

As Figure 2-1 and Figure 2-2 illustrate, the TIDA-010197 reference design is comprised of numerous subsystems including:

  • An MCU for system control and data processing
  • An analog front end (AFE) for signal conditioning for voltage, current, temperature measurements
  • Three analog outputs for sensor excitation, biasing networks, temperature sensing
  • System power management and sequencing

The ability to monitor voltage, current, and temperature has multiple value propositions, and is critical for maintaining reliable system operation in many applications. From a system health perspective, the ability to have accurate voltage, current, and temperature data for a board is an effective and relatively simple approach to get a relative metric on the health of a board. Changes in current, voltage, and temperature over time could indicate failure, or potential for failure, of some components. Another use case is operation with sensitive components such as many power amplifiers or thermoelectric coolers. The MCU monitors the current, voltage, or temperature (or all of these) of the power amplifier or thermoelectric cooler and triggers a recalibration if there is a deviation over a preset threshold at which a calibration was performed.

There are two variations of the signal chain. Details on the differences are found in the systems overview (Section 2.1).

  1. External ADC variation
    • Includes an external 12-bit SAR ADC, ADC128S102QML-SP, that offers a higher accuracy and higher speeds with a full scale range (FSR) of 5 V
  2. Integrated ADC variation
    • Utilizes the 12-bit SAR ADC integrated in the MSP430FR5969-SP for a more compact design with an FSR of 2.5 V

To power the TIDA-010197 reference design, there are two methods. The first method provides 5 V and 12 V from an external power supply. The other option supplies a single 5-V rail and utilizes the unregulated boost with LDO.