SDAA391 June   2026 TPS922050 , TPS922051 , TPS922052 , TPS922053 , TPS922054 , TPS922055

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2EN/PWM Timing Design to Avoid Repeated Soft-Start
    1. 2.1 TPS922050/1 Fast PWM Dimming Behavior
    2. 2.2 TPS922052/3/4/5 Fast PWM Dimming Behavior
    3. 2.3 Timing Design Guideline
    4. 2.4 Test Verification and Results
  6. 3Peripheral Circuit Parameter Optimization
    1. 3.1 Compensation Network
    2. 3.2 C O U T
  7. 4Summary
  8. 5References

Abstract

LED-based fire-strobe products must generate a repeatable, high-intensity light pulse while minimizing input energy. The UL 1638 / ULC 526 update requires the rated light output to be based on a maximum 20-ms light pulse, which makes LED-current rise time a direct contributor to effective strobe efficiency. This application note explains how to use the TPS92205x buck LED driver family in short-pulse strobe designs, with emphasis on avoiding repeated device shutdown and soft-start during low-duty-cycle operation. A pre-conditioning EN/PWM pulse is introduced to prepare the internal reference and control loop before the main optical pulse. External compensation, output capacitance, and inductor selection are also discussed to help reduce current rise time while maintaining stable operation, acceptable overshoot.