SLVAG18 April   2025 TPSI3100 , TPSI3100-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Why DESAT Protection Is Needed
    1. 1.1 Key Considerations for DESAT Protection
  5. 2Key DESAT Circuit Components
    1. 2.1 Circuit Startup Behavior
  6. 3Design Example
    1. 3.1 Design Requirements
    2. 3.2 Threshold Equations
    3. 3.3 Given Parameters
    4. 3.4 Inserting Given Parameters into Equations
    5. 3.5 Solving Equations for Unknowns
    6. 3.6 Selecting Resistances to Satisfy Equations
    7. 3.7 Determining Blanking Capacitance
    8. 3.8 Final Component Values
    9. 3.9 Lab Testing
  7. 4Closing

3.3 Given Parameters

Select RLIM to limit diode forward current. Given the example HV diode I-V curve in Figure 3-2, selecting 54.9kΩ would limit VF to 0.7V. Please keep in mind that the TPSI3100 family has 25mW available for powering auxiliary circuitry, RLIM = 54.9kΩ consumes up to 5.26mW.

Example HV Diode I-V Curve Figure 3-2 Example HV Diode I-V Curve
Table 3-2 Given Design Parameter Values
PARAMETER VALUE
VCE (DESAT) 7.5V
VF (DIODE) 0.7V
VREF+ 1.23V
RLIM 54.9kΩ