Other Parts Discussed in Thread: TLV7011
Regarding the rail to rail operational amplifier TLV314, I would like to ask you the following questions:
Background: Our company will build a comparator with a window on TLV314 to control the AD value of photosensitivity, thereby controlling the brightness of night lights. The specific principle is shown in the following figure:
Question 1- As shown in the schematic diagram, the working voltage of the entire module is 5V. The input voltage of the operational amplifier on pin 4 (-) varies between 0 and 4.4V depending on the resistance value of the photoresist. Does this input voltage meet the requirements?
Problem 2- Our circuit's operational amplifier used NJU77550F (JRC) to build a window comparator, but due to its lack of material, when using the TLV314 operational amplifier, we found that its window voltage needs to be adjusted. Why is this? What parameters are causing it?
|
PCN |
Window voltage corresponding to 2LUX photosensitivity value |
Window voltage corresponding to 6.5LUX photosensitivity value |
Resistance value corresponding to R4
|
|
NJU77550F |
0.245V |
0.965V |
9.1K |
|
TLV314 |
0.323V |
1.273V |
13K |
|
Note: When using TLV314, the window voltage should be raised slightly overall to obtain the corresponding photosensitive lumen value |
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