SLOA338 March   2025 TSD5402-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction TO RESOLVER and LVDT sensors
  5. 2Conventional Excitation Amplifier
  6. 3Excitation Amplifier Using Class-D Amplifiers
  7. 4Class-D Resolver Excitation Design Details
    1. 4.1 Components Selection for the Power Stage
    2. 4.2 Input Filter Components Selection
  8. 5Practical Experiments
    1. 5.1 Test Setup
    2. 5.2 Output Waveforms for Default Conditions
    3. 5.3 Amplifier Transfer Function
    4. 5.4 Using PWM for Generating the Reference Signal
    5. 5.5 Thermal Image and Comparison Against the Linear Design
    6. 5.6 Output Spectrum
    7. 5.7 Total Harmonic Distortion (THD)
    8. 5.8 Fail Events
  9. 6Summary
  10. 7References

Abstract

Resolvers and Linear Variable Differential Transformers (LVDTs) are inductive transducers for position sensing in applications where robustness and reliability are key. LVDTs withstand extreme temperatures, vibrations, shocks and even radiation. Resolvers measure the angle of rotation. LVDT sensors linear movement. Both types of sensors require a single-tone sinusoidal excitation signal for the operation. Using linear amplifiers for this purpose is the most common design. However, in safety critical applications that require additional protection and diagnostic mechanisms, the system design becomes quickly complex. Alternatively, one can use switch-mode Class-D power amplifiers that integrate additional circuitry. This report debriefs application of the TSD5402-Q1 Class-D sensor driver amplifier that drives the resolver excitation winding.