Other Parts Discussed in Thread: TINA-TI
Hi:
Below is digested from the TLV3502 data sheet:
8.1.1 Adding External Hysteresis
The TLV350x has a robust performance when used with a good layout. However, comparator inputs have little
noise immunity within the range of a specified offset voltage (±5 mV). For slow-moving or noisy input signals, the
comparator output can cause an undesirable switch state as input signals move through the switching threshold.
In such applications, the 6 mV of internal hysteresis of the TLV350x might not be sufficient. For greater noise
immunity, external hysteresis can be added by connecting a small amount of feedback to the positive input.
Figure 17 shows a typical topology used to introduce 25 mV of additional hysteresis, for a total of 31-mV
hysteresis when operating from a single 5-V supply. Use Equation 1 to calculate the approximate total hysteresis.
In the equation (1) , what is the V+? It's the power supply voltage (Vs)? or it is the reference voltage ( Vref in Figure 17 )?
thanks
Zhang