Subnano Pulse Driver Application

Designing with GaN FETs and ICs Assembly and Layout
1

Hi

Is there a gate driver and eGaN scheme available to generate subnano pulse say 500ps?

Regards,
Siyuan

2

Hi Siyuan,

Thank you for your email. Yes, EPC’s GaN FETs are very fast, especially the smaller ones and the EPC80xx series. Some of the FETs themselves could do such a narrow pulse. But, as you said, implementation is a challenge:

  • Gate Driver: The EPC ICs such as EPC21601, EPC21603, are specified to have greater than 1 ns of pulse width. TI has a very nice/fast GaN gate driver, for pulsed laser driving, but it also specifies over 1 ns pulses. Discrete gate drivers may be possible, to drive the GaN FET for a pulse width of less than 1 ns. But, we have no recommended circuit nor board that implements this.
  • Board Layout and Laser: Another key element, besides a fast FET and a fast gate driver with short pulse ability, is the PCB layout. Minimal loop inductance is key, because even a small amount affects such fast operation. Including the inductance of the laser package. One example layout is here… but again, the gate driver used doesn’t specify such a short pulse width: https://epc-co.com/epc/products/evaluation-boards/epc9144

best,
Brian Miller, EPC field applications engineer