GPS PPS input and GPS PPS output

Overview

• The GPS PPS input has become a popular synchronization source in LiDAR designs.

• The PCIe-NPL54 will not generate a GPS PPS output signal unless a GPS PPS input source is present. The GPS PPS output simply mirrors the GPS PPS input.

GPS PPS input wiring

We have designed the GPS PPS input as an isolated input.

Interface	Single-Direction
Isolation Voltage	2500 Vrms
Rated Input Voltage	0V to 24V
Logic High Voltage	3.3V to 24V
Logic Low Voltage	0V to 1.5V
Operation Mode	Interruption (Rising Edge)

The onboard MCU divides the GPS PPS input into several framesync signals based on the NPL54 Framesync FPS settings. The rising edge of the GPS PPS input is used for calibration purposes, and the MCU's framesync will align with the GPS PPS input after several seconds.