A non-inverting comparator with hysteresis requires a two-resistor network and a voltage reference (V_REF) at the inverting input, as shown in Figure 7-5,

Figure 7-5 TLV3231 in a Non-Inverting Configuration With Hysteresis

The equivalent resistor networks when the output is high and low are shown in Figure 7-6.

Figure 7-6 Non-Inverting Configuration Resistor Networks

When V_IN is less than V_REF,, the output is low. For the output to switch from low to high, V_IN must rise above the V_IN1 threshold. Use Equation 4 to calculate V_IN1.

Equation 4.

When V_IN is greater than V_REF, the output is high. For the comparator to switch back to a low state, V_IN must drop below V_IN2. Use Equation 5 to calculate V_IN2.

Equation 5.

The hysteresis of this circuit is the difference between V_IN1 and V_IN2, as shown in Equation 6.

Equation 6.

For more information, please see Application Notes SNOA997 "Inverting comparator with hysteresis circuit" and SBOA313 "Non-Inverting Comparator With Hysteresis Circuit".