SNOAA46A June   2020  – April 2026 ATL431 , ATL431LI , ATL431LI-Q1 , ATL432 , ATL432LI , ATL432LI-Q1 , LM134 , LM234 , LM334 , LM4041-N , LM4051-N , REF200 , REF34 , REF34-Q1 , REF35 , REF35-Q1 , TL431 , TL431-Q1 , TL431LI , TL431LI-Q1 , TL432 , TL432-Q1 , TL432LI , TL432LI-Q1 , TLA431 , TLA432

 

  1.   1
  2.   Precision Current Sources and Sinks Using Voltage References
  3.   Trademarks
  4. 1Precision Voltage References
  5. 2Current Sink with Voltage References
    1. 2.1 Current Sink With the Shunt Voltage Reference ATL431LI (TL431 Equivalent)
    2. 2.2 Current Sink With Series Reference
    3. 2.3 Current Sink With REF3425
  6. 3Current Source With Voltage References
    1. 3.1 Current Source With the ATL431LI (TL431 Equivalent)
    2. 3.2 Current Sourcing With the LM4041-N
    3. 3.3 Current Source With Series Voltage Reference
  7. 4Summary
  8. 5References
  9. 6Revision History

3.1 Current Source With the ATL431LI (TL431 Equivalent)

The ATL431LI can also current source by connecting the load on the GND side. The main drawback of current sourcing the ATL431LI is that the accuracy of the current is a combination the ATL431LI bias current and the current through the transistor. For a more accurate current sink the IRs must be significantly larger than IKA bias current.

Current Sourcing with the ATL431LIFigure 3-2 Current Sourcing with the ATL431LI

This application circuit is explored in greater detail in SLYT768 with a stronger focus on the TLVH431 but the application concepts also applies to the ATL431LI and TL431.