4 layers

Boards in 1 GitHub repository, designed in KiCad, that use the LM7321MF by Texas Instruments (-15V~15V -40℃~+125℃ 1.1mA 1.2uA 100dB 15nV/√Hz@2kHz 18V/us 2.5V~32V 200nA 20MHz 2uV/℃ 65mA 700uV Rail-to-Rail Input, Rail-to-Rail Output Single-channel SOT-23-5 Precision Op Amps ROHS). See how each wires it, with its parts, size, README and files; the LM7321MF’s symbol, footprint and pinout are on its own page.

