As a result of a comparator’s high open loop gain, there is a small band of input differential voltage where the output can toggle back and forth between “logic high” and “logic low” states. This can cause design challenges for inputs with slow rise and fall times or systems with excessive noise. These challenges can be overcome by adding hysteresis to the comparator.

Since the TLV3601 and TLV3602 only has a minimal amount of internal hysteresis, external hysteresis can be applied in the form of a positive feedback loop that adjusts the trip point of the comparator depending on its current output state. See the Implementing Hysteresis section for more details.

The TLV3603(E) on the other hand has a LE/HYS pin that can be used to increase or eliminate the internal hysteresis of the comparator. In order to increase the internal hysteresis of the TLV3603(E), connect a single resistor as shown in the adjusting hysteresis figure between the LE/HYS pin and VEE. A curve of hysteresis versus resistance is provided below to provide guidance in setting the desired amount of hysteresis. Likewise, for applications where no hysteresis is desired, the LE/HYS pin can be connected to VCC.

Figure 8-1 Adjustable Hysteresis with an External Resistor

Figure 8-2 V_HYST (mV) vs R_HYST (kΩ), V_CC = 5 V