SBVA097 February   2023 TLV758P

 

  1.   Abstract
  2.   Trademarks
  3. 1Theory of Operation
    1. 1.1 Current Limit and Foldback Behavior
    2. 1.2 Current Limit Circuit
  4. 2Current Limit Dring Dropout Operation
    1. 2.1 Bench Results
    2. 2.2 Current Limit vs Input Voltage
  5. 3Conclusion

3 Conclusion

This application report describes the current limit behavior for an LDO during dropout operation using the TLV758P device as an example. Based on the bench and simulation results for TLV758P, when kept out of dropout the current limit is within the range between 530 mA and 885 mA specified in the TLV758P data sheet. However, it was shown that due to the standard current limit circuit architecture, during dropout operation, the sense current decreases, therefore, increasing the trip point where the current limit circuit is enabled, while deep dropout operation results in an increase of current limit. This behavior comes into effect as the TLV758P is operated under the condition shown in Equation 2.

Equation 2. VIN – VOUT ≤ VDO