SNOSDG9 December 2024 TLV1922
PRODMIX
For minimum operating voltage of 3.3V, using the internal 2.5V reference directly causes the input common mode voltage range ((V+) - 2V) to be violated. If operation at 3.3V is desired, the 2.5V reference needs to be divided down externally so the voltage is less than (V+) - 2V (or 1.3V in this example). For the dual comparator where the 2.5V reference is internally connected, the output still operates in a known operating state but does not reflect the differential input condition when both inputs are outside the common mode range.
Furthermore, due to the fast output edge rates, bypass capacitors on the supply pin are critical to prevent supply ringing and false triggers and oscillations. Bypass the supply directly at each device with a low ESR 0.1µF ceramic bypass capacitor directly between the (V+) pin and ground pins. Narrow peak currents are drawn during the output transition time, particularly for the push-pull output device. These narrow pulses can cause un-bypassed supply lines and poor grounds to ring, possibly causing variation that can eat into the input voltage range and create an inaccurate comparison or even oscillations.
The device can be powered from both "split" supplies ((V+) &(V-)), or "single" supplies ((V+) and GND), with GND applied to the (V-) pin. Input signals must stay within the recommended input range for either type. Note that with a "split" supply the output can swing "low" (VOL) to (V-) potential and not GND.