SBAS934A June   2020  – December 2021 TMAG5170-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Thermal Information
    4. 6.4 Recommended Operating Conditions
    5. 6.5 Electrical Characteristics
    6. 6.6 Magnetic Characteristics
    7. 6.7 Power up Timing
    8. 6.8 SPI Interface Timing
    9. 6.9 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Magnetic Flux Direction
      2. 7.3.2 Sensor Location
      3. 7.3.3 Magnetic Range Selection
      4. 7.3.4 Update Rate Settings
      5. 7.3.5 ALERT Function
        1. 7.3.5.1 Interrupt and Trigger Mode
        2. 7.3.5.2 Magnetic Switch Mode
      6. 7.3.6 Threshold Count
      7. 7.3.7 Diagnostics
        1. 7.3.7.1  Memory CRC Check
        2. 7.3.7.2  ALERT Integrity Check
        3. 7.3.7.3  VCC Check
        4. 7.3.7.4  Internal LDO Under Voltage Check
        5. 7.3.7.5  Digital Core Power-on Reset Check
        6. 7.3.7.6  SDO Output Check
        7. 7.3.7.7  Communication CRC Check
        8. 7.3.7.8  Oscillator Integrity Check
        9. 7.3.7.9  Magnetic Field Threshold Check
        10. 7.3.7.10 Temperature Alert Check
        11. 7.3.7.11 Analog Front-End (AFE) Check
        12. 7.3.7.12 Hall Resistance and Switch Matrix Check
        13. 7.3.7.13 Hall Offset Check
        14. 7.3.7.14 ADC Check
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operating Modes
        1. 7.4.1.1 Active Mode
        2. 7.4.1.2 Standby Mode
        3. 7.4.1.3 Configuration Mode (DEFAULT)
        4. 7.4.1.4 Sleep Mode
        5. 7.4.1.5 Wake-Up and Sleep Mode
        6. 7.4.1.6 Deep-Sleep Mode
    5. 7.5 Programming
      1. 7.5.1 Data Definition
        1. 7.5.1.1 Magnetic Sensor Data
        2. 7.5.1.2 Temperature Sensor Data
        3. 7.5.1.3 Magnetic Sensor Offset Correction
        4. 7.5.1.4 Angle and Magnitude Data Definition
      2. 7.5.2 SPI Interface
        1. 7.5.2.1 SCK
        2. 7.5.2.2 CS
        3. 7.5.2.3 SDI
        4. 7.5.2.4 SDO
          1. 7.5.2.4.1 Regular 32-Bit SDO Read
          2. 7.5.2.4.2 Special 32-Bit SDO Read
        5. 7.5.2.5 SPI CRC
        6. 7.5.2.6 SPI Frame
          1. 7.5.2.6.1 32-Bit Read Frame
          2. 7.5.2.6.2 32-Bit Write Frame
    6. 7.6 Register Map
      1. 7.6.1 TMAG5170 Registers
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Selecting the Sensitivity Option
      2. 8.1.2 Temperature Compensation for Magnets
      3. 8.1.3 Sensor Conversion
        1. 8.1.3.1 Continuous Conversion
        2. 8.1.3.2 Trigger Conversion
        3. 8.1.3.3 Pseudo-Simultaneous Sampling
      4. 8.1.4 Error Calculation During Linear Measurement
      5. 8.1.5 Error Calculation During Angular Measurement
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
        1. 8.2.1.1 Gain Adjustment for Angle Measurement
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
    3. 8.3 Do's and Don'ts
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.1.4 Error Calculation During Linear Measurement

The TMAG5170-Q1 offers independent configurations to perform linear position measurements in X, Y, and Z axes. To calculate the expected error during linear measurement, the contributions from each of the individual error sources must be understood. The relevant error sources include sensitivity error, offset, noise, cross axis sensitivity, hysteresis, nonlinearity, drift across temperature, drift across life time, and so forth. For a 3-axis Hall solution like the TMAG5170-Q1, the cross-axis sensitivity and hysteresis error sources are insignificant. Use Equation 15 to estimate the linear measurement error calculation at room temperature.

Equation 15. E r r o r L M _ 25 C = B × S E N S E R 2 + B o f f 2 + N R M S _ 25 2 B × 100 %

where

  • ErrorLM_25C is total error in % during linear measurement at 25°C.
  • B is input magnetic field.
  • SENSER is sensitivity error at 25°C.
  • Boff is offset error at 25°C.
  • NRMS_25 is RMS noise at 25°C.

In many applications, system level calibration at room temperature can nullify the offset and sensitivity errors at 25°C. The noise errors can be reduced by further digital averaging the sensor data in a microcontroller. Use Equation 15 to estimate the linear measurement error across temperature after calibration at room temperature.

Equation 16. E r r o r L M _ T e m p = B × S E N S D R 2 + B o f f _ D R 2 + N R M S _ T e m p 2 B × 100 %

where

  • ErrorLM_Temp is total error in % during linear measurement across temperature after room temperature calibration.
  • B is input magnetic field.
  • SENSDR is sensitivity drift from value at 25°C.
  • Boff_DR is offset drift from value at 25°C.
  • NRMS_Temp is RMS noise across temperature.

If room temperature calibration is not performed, sensitivity and offset errors at room temperature must also account for total error calculation across temperature (see Equation 17).

Equation 17. E r r o r L M _ T e m p _ N C a l = B × S E N S E R 2 + B × S E N S D R 2 + B o f f 2 + B o f f _ D R 2 + N R M S _ T e m p 2 B × 100 %

where

  • ErrorLM_Temp_NCal is total error in % during linear measurement across temperature without room temperature calibration.

The table below summarizes linear measurement error estimate for z-axis with magnetic field range of ±50mT and CONV_AVG =101b:

Table 8-1 Total Error Examples During Linear Measurement
Input Field 50mT Input Field 25mT
Error % for z sensor at 25°C without any calibration 2.6% 2.8%
Error % for z sensor across temperature after 25°C calibration 3.0% 3.6%
Error % for z sensor across temperature without 25°C calibration 4.0% 4.5%
Note: In this section, error sources such as system mechanical vibration, magnet temperature gradient, nonlinearity, lifetime drift, and so forth, are not considered. The user must take these additional error sources into account while calculating overall system error budgets.