Circuit Issues
Templates
#0150I/ODRC cleanv1.0

Class-D audio amplifier 2.5 W mono

Filterless class-D mono amplifier with a bridge-tied speaker output, 2.5 W into a 4 ohm speaker at 5 V. The single-ended input is halved, low-pass filtered at about 29 kHz and AC coupled, ready for an audio signal from the MCU. The shutdown input is pulled down: the amplifier stays off until the MCU switches it on.

3D render of the 0150 Class-D audio amplifier 2.5 W mono KiCad design block
3D render (KiCad 10)
3D render of the 0150 Class-D audio amplifier 2.5 W mono KiCad design block
3D render, top view (KiCad 10)
Schematic of the 0150 Class-D audio amplifier 2.5 W mono KiCad design block
Schematic (KiCad 10)

Key specifications

  • Supply 2.0–5.5 V
  • 2.5 W into 4 ohm at 5 V, mono
  • Single-ended input with low-pass filter and AC coupling
  • Shutdown input, off by default

Seen in real hardware

Flossa AI Controller PCBA, 3D render, isometric view

Flossa AI Controller

Uses this block alongside 9 other templates · flossa.ai

Coming soon

This block is not available yet. It is released once its checks are complete. Planned price: €29.

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Planned package contents

  • KiCad 10 design block

    Schematic and PCB layout fragment; symbols and footprints embedded

  • BOM (CSV)

    Manufacturer part numbers and LCSC codes

  • Schematic PDF + README

    Interface, specs, population options and design notes

  • 3D models

    STEP models of the special parts; standard parts use KiCad’s 3D library

  • template.yaml

    Machine-readable interface and limits

PCB Composer

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About PCB Composer

Development status

Block ID0150
Block name0150-class-d-amp-2w5
Version1.0
StatusDRC clean – Schematic and layout pass the KiCad rule checks; not yet verified on hardware.
Open review items1 (0 blocking)
PCB layoutRule-checked layout fragment
FormatKiCad 10 design block (schematic + PCB)
Last change2026-11-03

Interface

Hierarchical labels the block exposes to the rest of your design. ${ID} is replaced per instance, so several copies can live on one sheet.

NetDirectionDescription
AMP_SUPPower inAmplifier supply 2.0–5.5 V
AMP_IN+InputAudio input (single ended)
~{AMP_SD}InputShutdown, low = off; pulled down (off by default)
SPEAKER${ID}_+OutputSpeaker +, bridge-tied output
SPEAKER${ID}_-OutputSpeaker −, bridge-tied output

FAQ

Which KiCad version do I need?

KiCad 10. The files are saved in the KiCad 10 format and are meant to be placed with KiCad’s Design Blocks feature (schematic block, then “Apply Design Block Layout” on the PCB).

Do I need the Circuit Issues part library?

No. Symbols are embedded in the schematic and footprints in the PCB, so the block opens on its own. Parts carry manufacturer part numbers and LCSC codes.

Is the layout production-ready?

The layout fragment passes the KiCad design rule check. Route it into your board and run DRC with your own fab rules.

Can I use the template in a commercial product?

The licence terms are published together with the first release.

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