Comparators are very sensitive to input noise. For best results, adhere to the following layout guidelines.
- Use a printed-circuit-board (PCB) with a good, unbroken, low-inductance ground plane. Proper grounding (use of a ground plane) helps maintain specified device performance.
- To minimize supply noise for single and split supply, place decoupling capacitor arrays as close as possible to VCC.
- On the inputs and the output, keep lead lengths as short as possible to avoid unwanted parasitic feedback around the comparator. Keep inputs away from the output.
- Solder the device directly to the PCB rather than using a socket.
- For slow-moving input signals, take care to prevent parasitic feedback. A small capacitor (1000 pF or less) placed between the inputs can help eliminate oscillations in the transition region. This capacitor causes some degradation to propagation delay when impedance is low. The topside ground plane runs between the output and inputs.
- Use a 100 Ω termination resistor across the device's LVDS output.
- Use higher performance substrate materials such as Rogers.