Hi all,
I am using the TL431AC to stable the supply voltage (approx. 5V) which will be used for reference set-points. I noticed that the input supply has to be 200mV higher than the input for it to output the calculated voltage. Is this normal? If not, what can cause this? is it the biasing current?
I now changed the resistor values. I used TI calculator for obtaining the values ( http://www.ti.com/tool/tl431calc ).
With reference to the schematic in the link below, R1 is 1.8ohms, R2 is a combination of 1K pot and 2.7Kohms, and R3 is 3.3Kohms. Are the values correct (especially R1) to obtain an output of 4.81V without having the "drop-down" voltage?
http://www.eleccircuit.com/wp-content/uploads/2010/04/adjustable-regulator-by-ic-tl431.jpg
Note: At the output I will be connecting four potentiometers with different values in parallel, which will be used to set different reference-points. The total parallel resistance is equal to 511ohms.
Thanks in advance.
I am using the TL431AC to stable the supply voltage (approx. 5V) which will be used for reference set-points. I noticed that the input supply has to be 200mV higher than the input for it to output the calculated voltage. Is this normal? If not, what can cause this? is it the biasing current?
I now changed the resistor values. I used TI calculator for obtaining the values ( http://www.ti.com/tool/tl431calc ).
With reference to the schematic in the link below, R1 is 1.8ohms, R2 is a combination of 1K pot and 2.7Kohms, and R3 is 3.3Kohms. Are the values correct (especially R1) to obtain an output of 4.81V without having the "drop-down" voltage?
http://www.eleccircuit.com/wp-content/uploads/2010/04/adjustable-regulator-by-ic-tl431.jpg
Note: At the output I will be connecting four potentiometers with different values in parallel, which will be used to set different reference-points. The total parallel resistance is equal to 511ohms.
Thanks in advance.