#!/usr/bin/env python3 """PM_K-1 monitor speaker amp (SKiDL): PAM8302A class-D -> SPK_P/SPK_N. DNP/optional. Run INSIDE the EDA container: cd hardware/eda && ./run.sh python3 ../eda/circuits/speaker.py Outputs ERC + hardware/kicad/speaker.net. Filterless 2.5W mono class-D for a built-in monitor (populated only on form factors that want one). Fed from MIX_OUT (the mixed click+input, single-ended into IN+; IN- AC-coupled to GND). Gain = 20*log(150k/(10k+RIN)); RIN=68k -> ~+5.7dB. SD pulled high = enabled (route SPK_SD to a GPIO if software shutdown is wanted). Output is BTL (filterless) to the speaker via the analog interconnect. PAM8302A SO-8 pinout (Diodes, verified): 1=SD 2=NC 3=IN+ 4=IN- 5=VO+ 6=VDD 7=GND 8=VO-. """ import os from skidl import * set_default_tool(KICAD9) P = Pin.types R = Part("Device","R", dest=TEMPLATE, footprint="Resistor_SMD:R_0402_1005Metric") def C(v, fp="Capacitor_SMD:C_0402_1005Metric"): return Part("Device","C", value=v, footprint=fp) p5, p3v3, gnd = Net("+5V"), Net("+3V3"), Net("GND") for n in (p5, p3v3): n.drive = POWER gnd.drive = POWER mix_out, spk_p, spk_n, spk_sd = Net("MIX_OUT"), Net("SPK_P"), Net("SPK_N"), Net("SPK_SD") PAM = Part(name="PAM8302A", tool=SKIDL, dest=TEMPLATE, ref_prefix="U", footprint="Package_SO:SOIC-8_3.9x4.9mm_P1.27mm", pins=[Pin(num=1,name="SD",func=P.INPUT),Pin(num=2,name="NC",func=P.NOCONNECT),Pin(num=3,name="IN+",func=P.INPUT), Pin(num=4,name="IN-",func=P.INPUT),Pin(num=5,name="VO+",func=P.OUTPUT),Pin(num=6,name="VDD",func=P.PWRIN), Pin(num=7,name="GND",func=P.PWRIN),Pin(num=8,name="VO-",func=P.OUTPUT)]) u = PAM(ref="U12") # supply u["VDD"] += p5; u["GND"] += gnd cb = C("1uF","Capacitor_SMD:C_0805_2012Metric"); p5 += cb[1]; cb[2] += gnd cd = C("100nF"); p5 += cd[1]; cd[2] += gnd # enable (SD high); route SPK_SD to a GPIO if desired rsd = R(value="100k"); spk_sd += rsd[1]; rsd[2] += p5; u["SD"] += spk_sd # single-ended input: MIX_OUT -> coupling cap + RIN -> IN+ ; IN- coupled to gnd (matched) cin = C("1uF","Capacitor_SMD:C_0805_2012Metric"); rin = R(value="68k") # ~+5.7dB mix_out += cin[1]; cin[2] += rin[1]; rin[2] += u["IN+"] cinm = C("1uF","Capacitor_SMD:C_0805_2012Metric"); u["IN-"] += cinm[1]; cinm[2] += gnd # filterless BTL output to speaker (via interconnect); add EMI ferrite/cap at layout if needed u["VO+"] += spk_p; u["VO-"] += spk_n ERC() out = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", "..", "kicad", "speaker.net")) generate_netlist(file_=out) print("Speaker netlist ->", out)