ATtiny13A Buffered Electrical Bypass Quasi-IC

From the vendor

A plug-in module (two rows of five pins) that does a pedal's bypass the way a Boss compact does: an OPA1678 input and output buffer, a TMUX4053 analog switch, and an ATtiny13A that debounces the footswitch, keeps the state and lights the LED. It is wired for the firmware's 4053-with-mute scheme: a 5 ms mute between bypass and engage to keep the switching quiet. Surface-mount, made to be assembled by the fab; the first version of the module.

Fabrication notes from the designer: I used these with JLCPCB; their suitability for other fabricators is unknown. They were generated from the KiCad project via kicad-jlcpcb-tools. The files were generated on August 8, 2026; JLC/LCSC part numbers were valid at that time, but are subject to change. Some parts' orientation in the CPL file is incorrect; I had to manually fix the orientation of most polarized parts and ICs using JLC's web interface. This module was designed for automated assembly; successful hand-soldering is effectively impossible.