Part Number: TL331
I am using the TL331 for voltage comparison. It is supposed to output a high level when the input voltage is 5V and a low level when the input voltage is 4.5V. However, I have observed that when the input is 5V, IN+ reads 3.4V, but the output is a low level. Why is this happening?
Hello,
According to the datasheet Figure 5-31 and Figure 5-32, theoretically the different voltage between IN pin should be greater than 100 mV.
Please note that the rail-to-rail input of the TL331 only supports in to V-, and the maximum input voltage for each input pin is VCC-1.5V.
In your design , the voltage of IN- and IN+ are too high. It is recommended to reduce the input voltage and increase the threshold between IN+ and IN-.
TL331B, TL391B and TL331 Single Comparators datasheet (Rev. L)
