Performance evaluation of LIDAR demonstrator

In our three years of work, we have achieved the realization of a Firing unit board with the GaN and driver in a system in package. Three different boards were realized: A first board with only the resistor, the second one with the resistor and a shunt resistor and a third board with the laser diode and a shunt resistor. A DC-DC was realized for the supply while a control unit was realized for the control of the input signals of the driver.Unfortunately, no measurements of the firing unit have been done yet as we are still waiting for the chip to be completed. The DC-DC and the control unit board have been measured and tested. LIDAR application is the most attractive and efficient solution for this market. The challenges of LIDAR application consist in the development of the electronics generating a current pulse of 50A that lasts for less than 5ns. The technical area of this activity is fully autonomous self-driving car, and in particular what helps an autonomous vehicle to understand the world around it.

In questa tesi, sono state realizzate tre diverse board: un DC-DC per il supply, un control unit per programmare i segnali d'ingresso del driver, un firing unit che contiene il chip principale(driver e GaN). Abbiamo usato il nitruro di galio perché è meglio adatto del silicio ad alte frequenze. L'obbiettivo principale è di raggiungere 50A di picco di corrente con soli 5ns di pulse. Sono stati usati Altium design per il disegno delle board e Ansys per l'evaluazione delle induttanze parassite. Questo ultimo crea diversi problemi e può limitare il raggiungimento del picco di corrente. Quindi bisogna fare il layout tenendo molta attenzione ai parassiti