Other Parts Discussed in Thread: LM4766,
Hi Support Team,
Could you please let me confirm how to set the output voltage of the LM4766? I'd like to make the output voltage as close as possible to -5V with an input voltage of 5V.
According to Equation (5) In the datasheet, It seems possible by setting R1 to 155kOhm and R2 to 50kOhm. (Vout = -1.22 x (155+50)/50 = -5.0 [V] ) ()
However, according to section 8.2.2.2 of the data sheet, "the output characteristic of this circuit can be approximated by an ideal voltage source in series with a resistance. The voltage source equals –(VIN)." I think it says that it can be simplified as a series of voltage source -(Vin) and Rout. This indicates that Vout does not become -5V when Vin = 5V due to the voltage drop of "i x Rout". (I'd like to know also Rsw because it is essential for calculating Rout but it isn't written in the data sheet.)
In this way, it seems that the descriptions in Equation (5) and 8.2.2.2 are inconsistent. Could you please explain it? In addition, what is the minimum value of Vout that LM4766 can output when Vin = 5V?
Thank you for your help.
Best Regards,
Taito Takemura