TIDUF65 March   2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Consideration
    3. 2.3 Highlighted Products
      1. 2.3.1 TMCS1123
      2. 2.3.2 ADS7043
      3. 2.3.3 AMC1035
      4. 2.3.4 REF2033
  9. 3System Design Theory
    1. 3.1 Hall-Effect Current Sensor Schematic Design
    2. 3.2 Analog-to-Digital Converter
      1. 3.2.1 Delta-Sigma Modulator
        1. 3.2.1.1 Common-Mode Voltage Limit
        2. 3.2.1.2 Input Filter
        3. 3.2.1.3 Interface to MCU
      2. 3.2.2 12-bit SAR ADC
        1. 3.2.2.1 Common-Mode Voltage Limit
        2. 3.2.2.2 Input Filter
        3. 3.2.2.3 Interface to MCU
    3. 3.3 Power Supply and Reference Voltage
  10. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
    2. 4.2 Software Requirements
    3. 4.3 Test Setup
      1. 4.3.1 Precautions
    4. 4.4 Test Results
      1. 4.4.1 DC Performance
        1. 4.4.1.1 Output Voltage Noise and ENOB After A/D Conversion
        2. 4.4.1.2 Linearity and Temperature Drift
      2. 4.4.2 AC Performance
        1. 4.4.2.1 SNR Measurement
        2. 4.4.2.2 Latency Test
      3. 4.4.3 PWM Rejection
      4. 4.4.4 Overcurrent Response
      5. 4.4.5 Adjacent Current Rejection
      6. 4.4.6 Power Supply Rejection Ratio
      7. 4.4.7 Digital Interface
  11. 5Performance Comparison with Competitor’s Device
    1. 5.1 Effective Number of Bits
    2. 5.2 Latency
    3. 5.3 PWM Rejection
  12. 6Design and Documentation Support
    1. 6.1 Design Files
      1. 6.1.1 Schematics
      2. 6.1.2 BOM
      3. 6.1.3 PCB Layout Recommendations
        1. 6.1.3.1 Layout Prints
    2. 6.2 Tools and Software
    3. 6.3 Documentation Support
    4. 6.4 Support Resources
    5. 6.5 Trademarks
  13. 7About the Author

3.3 Power Supply and Reference Voltage

GUID-20240216-SS0I-G5LX-S6MP-3B78508TFD5M-low.svg Figure 3-7 Power Supply Schematic

TLV74033 and REF2033 are used in this design to power the devices on the board. For TLV74033, the device accepts up to 5.5V input voltage and generates a 3.3V rail for TMCS1123, ADS7043, and AMC1035 supply. Two parallel capacitors C23 (10μF) and C1 (100nF) are needed for noise decoupling, an output capacitor C3 (2.2μF) is needed for stable operation.

For REF2033, the device is powered by an external 5V supply and generates precise 3.3V output. This method can be an option to power the ADS7043 and perform as the reference of the ADC; conversely, the device can be connected to ADS7043 and to the negative input pin of the AMC1035 to form a pseudo-differential input in case the Hall sensor does not provide the reference output. Similarly with the TLV74033, C2 (100nF) is needed for decoupling and C4 and C5 (100nF) are used for stable operation.

The TMCS1123 can accept 3V to 5.5V supply voltage. In this design, the external 5V and the 3.3V output of the TLV74033 is designed for the supply source of the sensor. J1 is used for the power supply selection of the Hall sensor.