Does the output voltage of the LT3045-1 vary with the load resistance

Does the output voltage of the LT3045-1 vary with the load resistance?

I want the input voltage to be 5.3V and the output voltage to be 5V and 500mA. I simulated the output voltage of LT3045-1 in LTspice and found that when Rset= 49.9K, the Vout does not have to be 5V and will change with the change of load.When the load is 10 Ω, the output is 5 V, 500 ma, when the load is 5 Ω, output is about 3.5 V, 700 ma, when output load is 15 Ω, output is 5.5 V, 300 ma.Isn't the output voltage related to Rset? Why does it change with the load resistance?Is there no stable voltage output?

  • +1
    •  Analog Employees 
    on Jan 13, 2021 12:27 AM 10 days ago

    You made a mistake when you reported the results of the RLOAD = 15 Ohms test.  For your RLOAD = 15 Ohms test, you should have said VOUT is 5V and the output current is 333mA and those results are correct.  The output current of the LT3045-1 is limited to approximately 700mA for your conditions, so when RLOAD is 5 Ohms the output current is close to 700mA and the output voltage is close to 3.5V.