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What is the output of a comparator circuit?
A comparator circuit compares two voltages and outputs either a 1 (the voltage at the plus side; VDD in the illustration) or a 0 (the voltage at the negative side) to indicate which is larger. Comparators are often used, for example, to check whether an input has reached some predetermined value.
What is the correct output condition for non-inverting comparator?
As the non-inverting (positive) input of the comparator is less than the inverting (negative) input, the output will be LOW and at the negative supply voltage, -Vcc resulting in a negative saturation of the output.
What is the output of a comparator amplifier?
The comparator output only takes one of two possible states: “high state or low state”. In order to explain the circuit operation, voltage vA is assumed at its high state (assuming the opposite is also possible, in order to reach the same result). Operational amplifiers are supplied at ± V cc.
When does the voltage of a comparator go to zero?
At t = τ = R 1 .C 1, voltage v B reaches and drops below zero (v B becomes slightly < 0). The output state of the comparator shifts from the high state to the low state. Moreover, at this precise instant, the value of voltage v B goes to − V CC due to the abrupt passage of v A from + V CC to − V CC.
How is a voltage comparator connected to a power supply?
Here, the open collector output from the voltage comparator is connected to a voltage source via a single pull-up resistor (and an LED for indication) which pulls the single output high to the power supply. When the output switch is HIGH it creates a high impedance path, therefore no current flows as V OUT = Vcc.
When to use positive feedback around an op-amp comparator?
The use of positive feedback around an op-amp comparator means that once the output is triggered into saturation at either level, there must be a significant change to the input signal VIN before the output switches back to the original saturation point.