  The SuperCDMS SNOLAB dark matter search experiment aims to be sensitive to
energy depositions down to O(1 eV). This imposes requirements on the
resolution, signal efficiency, and noise rejection of the trigger system. To
accomplish this, the SuperCDMS level-1 trigger system is implemented in an FPGA
on a custom PCB. A time-domain optimal filter algorithm realized as a finite
impulse response filter provides a baseline resolution of 0.38 times the
standard deviation of the noise, $\sigma_n$, and a 99.9% trigger efficiency for
signal amplitudes of 1.1 $\sigma_n$ in typical noise conditions. Embedded in a
modular architecture, flexible trigger logic enables reliable triggering and
vetoing in a dead-time-free manner for a variety of purposes and run
conditions. The trigger architecture and performance are detailed in this
article.
