DIO20872B

Version 1.2, Oct 2024

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7. Application Information

Important notice: Validation and testing are the most reliable ways to confirm system functionality. The

application information is not part of the specification and is for reference purposes only.

7.1. Hysteresis

If the applied differential input voltage is near the offset voltage of the comparator, the basic comparator

configuration may oscillate or produce a noisy "chatter" output. This oscillation usually occurs when the

input signal is moving very slowly across the switching threshold of the comparator.

Adding hysteresis or positive feedback can prevent the problem.

The hysteresis transfer curve is shown in Figure 7. This curve is a function of three components: VTH, VOS,

and VHYST:

• VTH is the actual set voltage or threshold trip voltage.

• VOS is the internal offset voltage between VIN+ and VIN–. This voltage is added to VTH to form the actual

trip point at which the comparator must respond to change output states.

• VHYST is the hysteresis (or trip window) that is designed to reduce comparator sensitivity to noise.

Figure 7. Hysteresis transfer curve

7.1.1. Inverting comparator with hysteresis

The inverting comparator with hysteresis requires a three-resistor network that is referenced to the

comparator supply voltage (VCC), as shown in Figure 8.

Figure 8. Inverting configuration with hysteresis