# MacBook Air USB Audio Interface ## Description Simple bus-powered USB audio interface for MacBook Air and Ableton Live using a USB audio codec, stereo analog input and output path, monitoring buffer stages, USB-C power and data connectivity, and low-noise PCB guidance. ## Project Details - **Owner:** blueant - **Created:** 3/19/2026 - **Last Updated:** 3/19/2026 - **Visibility:** Public - **System Architecture:** ```mermaid flowchart TD USB["USB-C MacBook Host"] --> PWR["USB 5V Input and Protection"] USB --> CODEC["USB Audio Codec ADC DAC"] PWR --> REG["3.3V Low Noise Regulation"] REG --> CODEC INJ["Stereo Audio Input"] --> PRE["Input Buffer and Filter"] PRE --> CODEC CODEC --> MON["Monitor and Output Buffer"] MON --> OUTJ["Headphone or Line Output"] CODEC --> CLK["Clocking and Control Support"] REG --> PRE REG --> MON ``` - **Primary DAW:** Ableton Live - **Audio Class:** USB Audio Class, bus-powered - **Layout Notes:** Place USB-C and audio jacks on board edges, keep codec close to USB connector, isolate analog input/output traces from USB D+/D-, maintain continuous ground reference, and keep decoupling capacitors within a few millimeters of codec supply pins. - **Target Host:** MacBook Air ## Key Components ### D1 — [USBLC6-2SC6](https://www.flux.ai/vasy_skral/usblc6-2sc6.md) - Role: ESD Protection - Manufacturer Name: STMicroelectronics - Package: SOT-23-6 - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://www.st.com/content/ccc/resource/technical/document/datasheet/06/1d/48/9c/6c/20/4a/b2/CD00050750.pdf/files/CD00050750.pdf/jcr:content/translations/en.CD00050750.pdf - LCSC Part Number: C7519 - Part Type: Protection - Manufacturer Part Number: USBLC6-2SC6 - Role Details: Low-capacitance ESD array placed at the USB connector for D+ and D- **Pins:** - GND [pin 2] - I/O1 [pin 6] - I/O1 [pin 1] - I/O2 [pin 3] - I/O2 [pin 4] - VBUS [pin 5] ### J1 — [UJ20-C-V-G-SMT-P16-TR-65](https://www.flux.ai/adrian95/uj20-c-v-g-smt-p16-tr-65.md) - Part Type: USB C - Role Details: USB-C receptacle carrying USB 2.0 D+/D- and 5V VBUS for the bus-powered audio interface - Package or Case Code: UJ20CVGSMTP16TR65 - Datasheet URL: https://www.cuidevices.com/product/resource/digikeypdf/uj20-c-v-g-smt-p16-tr-65.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Same Sky - Manufacturer Part Number: UJ20-C-V-G-SMT-P16-TR-65 - Package: UJ20CVGSMTP16TR65 - Role: USB Connector **Pins:** - CC1 [pin A5] - CC2 [pin B5] - DN1 [pin A7] - DN2 [pin B7] - DP1 [pin A6] - DP2 [pin B6] - DUMMY_1 [pin 1] - DUMMY_2 [pin 2] - DUMMY_3 [pin 3] - DUMMY_4 [pin 4] - GND_1 [pin A1] - GND_2 [pin A12] - GND_3 [pin B1] - GND_4 [pin B12] - SBU1 [pin A8] - SBU2 [pin B8] - VBUS_1 [pin A4] - VBUS_2 [pin A9] - VBUS_3 [pin B4] - VBUS_4 [pin B9] ### U1 — [PCM2912APJTR](https://www.flux.ai/lcsc/pcm2912apjtr.md) - Part Type: Codec ICs - Manufacturer Name: TI(德州仪器) - Package: TQFP-32_L7.0-W7.0-P0.80-LS9.0-TL - Manufacturer Part Number: PCM2912APJTR - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2003092031_Texas-Instruments-PCM2912APJTR_C475497.pdf - Product Info Url: https://lcsc.com/product-detail/Codec-ICs_Texas-Instruments-Texas-Instruments-PCM2912APJTR_C475497.html - Role Details: Class-compliant USB audio codec for stereo capture and playback, bus powered from USB 5V - LCSC Part Number: C475497 - Role: USB Audio Codec - JLCPCB Part Class: Extended Part - Package or Case Code: TQFP-32_L7.0-W7.0-P0.80-LS9.0-TL **Pins:** - #PLAY [pin 32] - #REC [pin 31] - #SSPND [pin 29] - AGND [pin 13] - BGND [pin 1] - D- [pin 3] - D+ [pin 4] - DGND [pin 6] - FL [pin 9] - FR [pin 10] - HGND [pin 20] - MAMP [pin 23] - MBIAS [pin 17] - MMUTE [pin 30] - NC [pin 14] - PGND [pin 25] - POWER [pin 24] - TEST0 [pin 28] - TEST1 [pin 27] - VBUS [pin 2] - VCCA [pin 15] - VCCL [pin 19] - VCCP [pin 26] - VCCR [pin 21] - VCOM1 [pin 11] - VCOM2 [pin 12] - VDD [pin 5] - VIN [pin 16] - VOUTL [pin 18] - VOUTR [pin 22] - XTI [pin 8] - XTO [pin 7] ### U2 — [AP2112K-3.3TRG1](https://www.flux.ai/adrian95/ap2112k-33trg1.md) - Datasheet URL: Diodes Incorporated - Role Details: Auxiliary 3.3V LDO for optional support logic and future low-voltage analog control; main codec remains bus-powered from USB 5V - Manufacturer Part Number: AP2112K-3.3TRG1 - Part Type: Integrated Circuit - Package: SOT-25 - Manufacturer Name: https://www.diodes.com/assets/Datasheets/AP2112.pdf - Role: Regulator - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - EN [pin 3] - GND [pin 2] - NC [pin 4] - VIN [pin 1] - VOUT [pin 5] ### U3 — [TLV9062IDGKT](https://www.flux.ai/adrian95/tlv9062idgkt.md) - Role Details: Dual op-amp used for stereo line input conditioning and low-noise monitor/output support - Package: 8-VSSOP - Role: Audio Buffer - Manufacturer Name: Texas Instruments - Datasheet URL: https://www.ti.com/lit/ds/symlink/tlv9062.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: TLV9062IDGKT - Part Type: Operational Amplifier (OP-AMP) **Pins:** - IN1- [pin 2] - IN1+ [pin 3] - IN2- [pin 6] - IN2+ [pin 5] - OUT1 [pin 1] - OUT2 [pin 7] - V- [pin 4] - V+ [pin 8] ### Y1 — [ABM8-12.000MHZ-B2-T](https://www.flux.ai/adrian95/abm8-12p000mhz-b2-t.md) - Manufacturer Part Number: ABM8-12.000MHZ-B2-T - Role Details: Passive crystal resonator for the USB audio codec reference clock - Role: Clock Source - Package or Case Code: XTAL_ABM8-12.000MHZ-B2-T - Manufacturer Name: Abracon - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/6536/ABM8_Datasheet.pdf - Package: XTAL_ABM8-12.000MHZ-B2-T - Frequency: 12MHz - Part Type: Oscillator - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - ~ [pin 3] - ~ [pin 1] - GND [pin 2] - GND__1 [pin 4] ### Y1 — [ABMM-6.000MHZ-B2-T](https://www.flux.ai/lcsc/abmm-6p000mhz-b2-t.md) - LCSC Part Number: C179631 - JLCPCB Part Class: Extended Part - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Abracon-LLC-ABMM-6-000MHZ-B2-T_C179631.pdf - Manufacturer Name: ABRACON - Manufacturer Part Number: ABMM-6.000MHZ-B2-T - Role: Clock Source - Product Info Url: https://lcsc.com/product-detail/SMD-Crystals_ABRACON_ABMM-6-000MHZ-B2-T_6MHz-18pF-50ppm_C179631.html - Package: OSC-SMD_4P-L7.0-W5.0-BL_ABMM - Package or Case Code: OSC-SMD_4P-L7.0-W5.0-BL_ABMM - Role Details: 6 MHz crystal resonator connected to the USB audio codec XTI and XTO pins - Part Type: Crystals **Pins:** - ~{OE} [pin 1] - GND [pin 4] - GND [pin 2] - OUT [pin 3] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/blueant/macbook-air-usb-audio-interface](https://www.flux.ai/blueant/macbook-air-usb-audio-interface).* --- *Generated from [https://www.flux.ai/blueant/macbook-air-usb-audio-interface](https://www.flux.ai/blueant/macbook-air-usb-audio-interface)*