Implementing custom converter control algorithms or non-standard modulation techniques in an FPGA requires a dedicated pulse-width modulation (PWM) module. This technical note outlines how to design and validate a custom, triangular-carrier PWM modulator within the Xilinx FPGA of an imperix controller. It presents three alternative development workflows: Xilinx System Generator, MATLAB HDL Coder, and hand-written VHDL. The note details Simulink testbench simulation, CPU-side configuration, and integration into Xilinx Vivado via the sandbox PWM (SB-PWM) block, providing a reusable reference model for advanced FPGA-based power electronics control.