Stereo DSP Amplifier

Created 4 project docs

Design Notes — Stereo DSP Amplifier

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Complete schematic and BOM draft created for the requested signal chain. PCB placement and routing were intentionally not performed.

Firmware Starter — ESP32-S3-WROOM-1-N16R8

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MCU module: ESP32-S3-WROOM-1-N16R8 Framework: Arduino-ESP32 3.x under PlatformIO

Board Bring-Up Plan — Stereo DSP Amplifier

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Current-limited bench supply capable of 18 V. Multimeter, oscilloscope, audio source, 4 Ω dummy loads/speakers, UART/USB-serial adapter if u...

Regulatory FCC/CE Notes — Stereo DSP Amplifier

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Draft design-stage notes. This board includes an ESP32-S3-WROOM-1-N16R8 Wi-Fi/BLE module, so wireless regulatory integration requirements ap...

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Implemented the complete schematic and BOM draft for the stereo DSP amplifier, without PCB placement or routing. Electrical ERC is clean; the remaining BOM/manufacturing issue is that generic passives, inductors, test points, and attenuation headers still need final orderable MPN/package selections before manufacturing.
Created/updated project files:
Open items:
  • Select final MPNs/packages for generic resistors, capacitors, inductors, test points, and jumper headers.
  • Verify the PCM1863DBT footprint pitch against TI’s DBT TSSOP-30 land pattern before layout.
  • Add final TI register configurations for PCM1863 and TAS5825M firmware.
Suggested next steps:
  1. Finalize passive/inductor/test-point MPNs to make the BOM manufacturing-ready.
  2. Review the schematic visually for signal-flow readability.
  3. Set the 150 mm × 150 mm four-layer board, stackup, and placement constraints.
  4. Start PCB placement only after you approve the schematic.
Finalize BOM and placement
Finalize passive MPNs
Verify PCM1863 footprint
Arrange schematic readability
Start PCB placement
Explain remaining risks

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Project Specification — Stereo DSP Amplifier
Project Overview
Status: Draft schematic phase. Design a 150 mm × 150 mm four-layer stereo DSP amplifier PCB using the specified signal chain and no major-component substitutions.
Intended Use
Prototype/validation audio amplifier board for balanced stereo inputs, ESP32-S3 real-time DSP, and 4 Ω speaker outputs. Initial operation may use an 18 V / 2 A adapter; power path should support a future 18 V / 5 A adapter.
What the Device Should Do
  • Accept two mono balanced 6.35 mm TRS line inputs.
  • Convert analog audio to 24-bit / 48 kHz digital audio.
  • Keep ESP32-S3 permanently in the I²S audio path for EQ, filters, delay, gain/mute, limiter, presets, Wi-Fi control, ADC/amp I²C setup, and fault monitoring.
  • Drive stereo 4 Ω speakers through a TAS5825M Class-D amplifier.
Main Features
  • Balanced TRS Left/Right inputs with ESD, RF filtering, AC coupling, and selectable 0 dB / −10 dB / −18 dB pad.
  • INA1650IPWR balanced receiver.
  • PCM1863DBT stereo ADC.
  • ESP32-S3-WROOM-1-N16R8 module.
  • TAS5825MRHBR Class-D amplifier.
  • 18 V input protection, regulator rails, bulk capacitance, and test points.
System Architecture
Diagram



  
    
  
  
    
  
















Left TRS balanced input
ESD, RF filter, AC coupling, selectable pad
Right TRS balanced input
INA1650 balanced receiver
PCM1863 stereo ADC
U3
U4
Left 4 ohm speaker
Right 4 ohm speaker
Hardware Subsystems
  • Analog input: two balanced TRS inputs, chassis/shield handling, low-capacitance ESD, symmetrical RF filters, AC coupling, selectable attenuation pad.
  • ADC/DSP: PCM1863 receives INA1650 outputs; ESP32-S3 is I²S master at BCLK 3.072 MHz and LRCLK 48 kHz.
  • Power amplifier: TAS5825M powered from 18 V PVDD with output filters and speaker terminal blocks.
  • Power: 18 V protected input, direct PVDD branch, regulated rails for analog, digital audio, ESP32, and amplifier digital supply.
  • Debug/test: test points for every rail, BCLK, LRCLK, ADC DOUT, amp SDIN, I²C, RESET, and FAULT.
Interfaces and Connections
  • Audio in: J1/J2 6.35 mm TRS; Tip=Hot+, Ring=Cold−, Sleeve=chassis/shield.
  • Speaker out: J4/J5 KF301-2P, 5.08 mm pitch.
  • Power in: J3 5.5 × 2.1 mm DC barrel jack, 18 V DC.
  • Digital audio: 48 kHz, 24-bit, 32-bit slot I²S; ESP32-S3 as clock master.
  • Control: I²C from ESP32-S3 to PCM1863 and TAS5825M; amplifier FAULT to ESP32-S3.
Power and Runtime Expectations
  • Input: 18 V DC.
  • TAS5825M PVDD powered directly from protected 18 V.
  • Initial 18 V / 2 A adapter is not expected to provide continuous 30 W + 30 W output.
  • Future power path target: 18 V / 5 A adapter capability.
Power Tree and Power Budget
Preliminary budget to be refined from datasheets during schematic entry:
  • 18V_IN_PROTECTED → TAS5825M PVDD, high-current path sized for 5 A.
  • 18V_IN_PROTECTED → buck/regulator rails for 5 V/3.3 V domains as required.
  • 3V3 expected loads include ESP32-S3 module, PCM1863 digital, TAS5825M digital/control, I²C pull-ups, and test/debug.
  • Analog audio rails for INA1650/PCM1863 analog supply will use low-noise regulation/filtering.
Diagram



  
    
  
  
    
  






















18 V DC barrel
Fuse, reverse polarity, TVS, bulk
18 V PVDD to TAS5825M
Switching pre-regulator
3.3 V digital rail
Low-noise analog rails
ESP32-S3
PCM1863 digital
TAS5825M digital
INA1650
PCM1863 analog
Manufacturing and Assembly Expectations
  • PCB: 150 mm × 150 mm, four layers.
  • Layer 2 must be a continuous ground plane.
  • Use official manufacturer-recommended land patterns for all ICs.
  • Do not perform PCB placement or routing until requested.
Firmware-Relevant Hardware Requirements
  • ESP32-S3 must implement DSP audio path, presets, Wi-Fi control, I²C configuration, FAULT monitoring, RESET handling, mute/gain, limiter, and delay.
  • Provide stable boot/reset strapping and programming/debug access.
Physical Design Expectations
  • ESP32 antenna at PCB edge with official keepout.
  • INA1650 close to TRS connectors.
  • Keep analog input/ADC away from amplifier switching nodes, output inductors, and DC/DC converters.
  • TAS5825M close to output filters and speaker connectors.
Important Design Decisions
  • Major signal-chain components are fixed by user requirement and must not be substituted.
  • ESP32-S3 is the I²S clock master.
  • Add 22–33 Ω source-series resistors on BCLK, LRCLK, ADC DOUT, and amplifier SDIN.
  • Schematic and BOM only in this phase; no placement/routing.
Assumptions
  • Support passives, protection parts, regulators, buttons, headers, and test points may be selected as needed.
  • Exact connector alternatives may be used only where the user explicitly allowed “or equivalent.”
  • Final output-filter values and regulator part choices must be verified against datasheets/reference designs.
Change Notes
  • Initial specification created from the pasted requirements on 2026-07-25.

  • Project Overview

  • Intended Use

  • What the Device Should Do

  • Main Features

  • System Architecture

  • Hardware Subsystems

  • Interfaces and Connections

  • Power and Runtime Expectations

  • Power Tree and Power Budget

  • Manufacturing and Assembly Expectations

  • Firmware-Relevant Hardware Requirements

  • Physical Design Expectations

  • Important Design Decisions

  • Assumptions

  • Change Notes

Stereo DSP Amplifier thumbnail
150 mm × 150 mm four-layer stereo DSP amplifier with balanced TRS inputs, INA1650 receiver, PCM1863 ADC, ESP32-S3 real-time I²S DSP, TAS5825M Class-D output, 18 V input power, protection, and test points.

Properties

Properties describe core aspects of the project.

Pricing & Availability

Distributor

Qty 1

Arrow

$10.80–$16.23

Digi-Key

$5.77

HQonline

$2.15

LCSC

$12.29

Mouser

$33.93

TME

$3.41

Verical

$14.91–$19.79

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