Understanding Window Detector Circuit: LM1414 vs. IC741 Comparison

[swty todd]

I am having a problem understanding the window detector ckt using a high precision comparator LM1414. Suppose Vut =7,Vlt=2 and if Vin=8,then C1 will be negatively saturated & C2 will be positively saturated , when I think both should be negatively saturated.

Searching on the net I came across this circuit of Window Detector using IC741 & the difference between the 2 ckts is that 741 ckt contains 2 extra diodes.I understood the working of the ckt using 741 …so I was wondering if they forgot to place diodes in the LM1414 ckt or the diodes already present in the LM1414 or is it something else that I can't see?

 

[Valkarie]

The circuit diagram you found for the window detector using the 741 op-amp includes two diodes, one at the inverting input and one at the output. These are used to prevent saturation when the input voltage is outside of the window threshold. The LM1414 is a high precision comparator, not an op-amp. It does not require any additional diodes for this circuit. The LM1414 can handle a wide input range and does not saturate when the input is outside of the window threshold.

 

[Mene]

First of all, it is important to understand that the LM1414 and IC741 are two different types of comparators, with different specifications and capabilities. The LM1414 is a high precision comparator, while the IC741 is a general purpose comparator. Therefore, the two circuits may have different designs and operating principles.

In the LM1414 circuit, the diodes may not be necessary because the comparator itself has built-in protection diodes. These diodes help to prevent the input voltage from exceeding the supply voltage, which can cause damage to the comparator. In the IC741 circuit, the diodes are added externally for this purpose.

Additionally, the LM1414 may have a different biasing scheme compared to the IC741, which could explain the difference in saturation behavior. Without knowing the exact details of the circuit and its specifications, it is difficult to say for sure why the two circuits behave differently.

It is also worth noting that the LM1414 is a newer and more advanced comparator compared to the IC741, so it is possible that it has different design features and capabilities that make it perform differently in certain situations.

In conclusion, the differences between the two circuits may be due to the different specifications and design features of the comparators used. It is important to carefully study and understand the datasheets of both components to fully understand their behavior in different circuits.