SNVAA58 December   2022 ATL431 , ATL431LI , TL431 , TL431LI

 

  1.    Abstract
  2. 1Trademarks
  3. 2Comparator Mode
    1. 2.1 Input Threshold Voltage (VIT)
    2. 2.2 Output Levels (VOH , VOL)
    3. 2.3 Propagation Delay
  4. 3Design Parameters for Comparator Mode
    1. 3.1 IREF (Reference Current)
    2. 3.2 IKA (Cathode Current)
    3. 3.3 Stability
      1. 3.3.1 Load Capacitor (Cathode to Anode)
      2. 3.3.2 Compensation in Comparator Mode in Feedback of PWM Controller
  5. 4Design Example
    1. 4.1 Input Parameters
    2. 4.2 Specs of Comparator Mode
  6. 5Conclusion
  7. 6Revision History

2.1 Input Threshold Voltage (VIT)

The threshold voltage (VIT) for 431 shunt regulators in comparator mode is equal to the reference voltage of the device. Comparator changes the output state when input crosses VIT level. Table 2-1 lists VIT levels for 431 shunt regulators

Table 2-1 Typical VIT of Shunt Regulators
Devices Typical Threshold (VIT) in Comparator Mode (V)
TL431, TL431LI 2.495
ATL431, ATL431LI 2.5
TLV431, TLVH431 1.24