SNOSDF2 august 2023 TLV1851-Q1 , TLV1861-Q1
PRODMIX
The inverting comparator with hysteresis requires a three-resistor network that is referenced to the comparator supply voltage (VCC), as shown in Figure 8-3.
The equivalent resistor networks when the output is high and low are shown in Figure 8-3.
When VIN is less than VA, the output voltage is high (for simplicity, assume VO switches as high as VCC). The three network resistors can be represented as R1 || R3 in series with R2, as shown in Figure 8-4.
Equation 1 below defines the high-to-low trip voltage (VA1).
When VIN is greater than VA, the output voltage is low. In this case, the three network resistors can be presented as R2 || R3 in series with R1, as shown in Equation 2.
Use Equation 2 to define the low to high trip voltage (VA2).
Equation 3 defines the total hysteresis provided by the network.