# RF-Harvested Audio Node ## Description Battery-less 2 mm cube audio node concept powered by inductive/RF harvesting, with MEMS microphone capture, RF SoC burst transmission, rectification, and ceramic buffer storage. ## Project Details - **Owner:** mmkmk - **Created:** 5/22/2026 - **Last Updated:** 5/22/2026 - **Visibility:** Public ## Key Components ### D1 — [SMS7621-060](https://www.flux.ai/lcsc/sms7621-060~4i36.md) - Manufacturer Name: SKYWORKS - Role Details: Low-barrier Schottky diode in experimental RF/inductive bridge rectifier. - Manufacturer Part Number: SMS7621-060 - Product Info Url: https://lcsc.com/product-detail/Schottky-Barrier-Diodes-SBD_SKYWORKS_SMS7621-060_SMS7621-060_C150873.html - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/1804250221_Skyworks-Solutions-SMS7621-060_C150873.pdf - Role: Rectification - Part Type: Schottky Barrier Diodes (SBD) - Package or Case Code: D0201-RD - LCSC Part Number: C150873 **Pins:** - 1 [pin 1] - 2 [pin 2] ### D2 — [SMS7621-060](https://www.flux.ai/lcsc/sms7621-060~4i36.md) - Package or Case Code: D0201-RD - Part Type: Schottky Barrier Diodes (SBD) - Role Details: Low-barrier Schottky diode in experimental RF/inductive bridge rectifier. - LCSC Part Number: C150873 - Role: Rectification - Product Info Url: https://lcsc.com/product-detail/Schottky-Barrier-Diodes-SBD_SKYWORKS_SMS7621-060_SMS7621-060_C150873.html - Manufacturer Part Number: SMS7621-060 - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/1804250221_Skyworks-Solutions-SMS7621-060_C150873.pdf - Manufacturer Name: SKYWORKS **Pins:** - 1 [pin 1] - 2 [pin 2] ### D3 — [SMS7621-060](https://www.flux.ai/lcsc/sms7621-060~4i36.md) - Role: Rectification - Part Type: Schottky Barrier Diodes (SBD) - Package or Case Code: D0201-RD - Role Details: Low-barrier Schottky diode in experimental RF/inductive bridge rectifier. - LCSC Part Number: C150873 - Manufacturer Name: SKYWORKS - Manufacturer Part Number: SMS7621-060 - Product Info Url: https://lcsc.com/product-detail/Schottky-Barrier-Diodes-SBD_SKYWORKS_SMS7621-060_SMS7621-060_C150873.html - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/1804250221_Skyworks-Solutions-SMS7621-060_C150873.pdf **Pins:** - 1 [pin 1] - 2 [pin 2] ### D4 — [SMS7621-060](https://www.flux.ai/lcsc/sms7621-060~4i36.md) - Role Details: Low-barrier Schottky diode in experimental RF/inductive bridge rectifier. - LCSC Part Number: C150873 - Role: Rectification - Part Type: Schottky Barrier Diodes (SBD) - Package or Case Code: D0201-RD - Manufacturer Name: SKYWORKS - Product Info Url: https://lcsc.com/product-detail/Schottky-Barrier-Diodes-SBD_SKYWORKS_SMS7621-060_SMS7621-060_C150873.html - Manufacturer Part Number: SMS7621-060 - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/1804250221_Skyworks-Solutions-SMS7621-060_C150873.pdf **Pins:** - 1 [pin 1] - 2 [pin 2] ### J1 — [Pin Header 01x02 2.54mm Vertical](https://www.flux.ai/jharwinbarrozo/generic-pin-header-01x02-2p54mm-vertical~4uy.md) - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Connector **Pins:** - P1 [pin 1] - P2 [pin 2] ### J2 — [Pin Header 02x05 2.54mm Vertical](https://www.flux.ai/adrian95/pin-header-02x05-254mm-vertical~83p.md) - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Connector **Pins:** - Pin_1 [pin 1] - Pin_10 [pin 10] - Pin_2 [pin 2] - Pin_3 [pin 3] - Pin_4 [pin 4] - Pin_5 [pin 5] - Pin_6 [pin 6] - Pin_7 [pin 7] - Pin_8 [pin 8] - Pin_9 [pin 9] ### J3 — [SMA-J-P-H-ST-EM1](https://www.flux.ai/jecstronic/sma-j-p-h-st-em1~0a1.md) - Manufacturer Name: Samtec Inc. - Manufacturer Part Number: SMA-J-P-H-ST-EM1 - Datasheet URL: http://suddendocs.samtec.com/catalog_english/sma.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Connector **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] ### J4 — [Pin Header 01x02 2.54mm Vertical](https://www.flux.ai/jharwinbarrozo/generic-pin-header-01x02-2p54mm-vertical~4uy.md) - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Connector **Pins:** - P1 [pin 1] - P2 [pin 2] ### MK1 — [SPK0641HT4H-1](https://www.flux.ai/jecstronic/spk0641ht4h-1~wss.md) - Role: Sensing (Shunt) - Role Details: PDM MEMS microphone for audio capture; powered from 3V3 with local non-piezoelectric bypass capacitor. - Datasheet URL: https://www.knowles.com/docs/default-source/model-downloads/spk0641ht4h-1-rev-a.pdf - Manufacturer Part Number: SPK0641HT4H-1 - Manufacturer Name: Knowles - Part Type: Microphone - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - CLOCK [pin 2] - DATA [pin 1] - GROUND [pin 5] - GROUND [pin 8] - GROUND [pin 7] - GROUND [pin 6] - SELECT [pin 3] - VDD [pin 4] ### S1 — [B3F-1000](https://www.flux.ai/adrian95/b3f-1000~hh8.md) - Manufacturer Part Number: B3F-1000 - Datasheet URL: https://omronfs.omron.com/en_US/ecb/products/pdf/en-b3f.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Omron Electronics Inc-EMC Div - Part Type: Switch **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### U1 — [EFR32MG22C224F512IM32-CR](https://www.flux.ai/lcsc/efr32mg22c224f512im32-cr~1u13.md) - JLCPCB Part Class: Extended Part - Manufacturer Name: SKYWORKS/SILICON LABS(芯科) - Part Type: RF Transceiver ICs - Package or Case Code: QFN-32_L4.0-W4.0-P0.4-BL-EP2.6 - Role Details: Main EFR32MG22 MCU/radio for PDM capture, voltage sensing, and 2.4 GHz packet bursts. - Manufacturer Part Number: EFR32MG22C224F512IM32-CR - Role: Signal Generation - LCSC Part Number: C1864135 **Pins:** - AVDD [pin 29] - DECOUPLE [pin 24] - DVDD [pin 28] - EP [pin 33] - HFXTAL_I [pin 7] - HFXTAL_O [pin 8] - IOVDD [pin 30] - PA00 [pin 17] - PA01 [pin 18] - PA02 [pin 19] - PA03 [pin 20] - PA04 [pin 21] - PA05 [pin 22] - PA06 [pin 23] - PAVDD [pin 13] - PB00 [pin 16] - PB01 [pin 15] - PB02 [pin 14] - PC00 [pin 1] - PC01 [pin 2] - PC02 [pin 3] - PC03 [pin 4] - PC04 [pin 5] - PC05 [pin 6] - PD00 [pin 32] - PD01 [pin 31] - RESETn [pin 9] - RF2G4_IO [pin 12] - RFVDD [pin 10] - RFVSS [pin 11] - VREGSW [pin 25] - VREGVDD [pin 26] - VREGVSS [pin 27] ### U2 — [AP2112K-3.3TRG1](https://www.flux.ai/adrian95/ap2112k-33trg1~zlq.md) - Manufacturer Name: Diodes Incorporated - License: https://creativecommons.org/licenses/by/4.0/ - Role: Power Conversion - Datasheet URL: https://www.diodes.com/assets/Datasheets/AP2112.pdf - Part Type: Integrated Circuit - Role Details: 3.3 V rail regulator sized for ~18.3 mA minimum peak budget with large margin; 600 mA rated output. - Manufacturer Part Number: AP2112K-3.3TRG1 - Symbol Style: parametric-v1 **Pins:** - EN [pin 3] - GND [pin 2] - NC [pin 4] - VIN [pin 1] - VOUT [pin 5] ### Y1 — [NX1612SB-38.4MHZ-EXS00A-CS10526](https://www.flux.ai/lcsc/nx1612sb-38p4mhz-exs00a-cs10526~ages.md) - Product Info Url: https://lcsc.com/product-detail/_Nihon-Dempa-Kogyo-EXS00A-CS10526_C280826.html - Manufacturer Name: NDK - LCSC Part Number: C280826 - JLCPCB Part Class: Extended Part - Manufacturer Part Number: NX1612SB-38.4MHZ-EXS00A-CS10526 - Part Type: Crystals - Datasheet URL: https://assets.lcsc.com/datasheet/szlcsc/Download-ISO9001-Certification.pdf - Package or Case Code: CRYSTAL-SMD_4P-L1.6-W1.2-BL **Pins:** - OSC1 [pin 1] - OSC2 [pin 3] - Thermistor [pin 4] - ThermistorandGND [pin 2] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/mmkmk/rf-harvested-audio-node~d2](https://www.flux.ai/mmkmk/rf-harvested-audio-node~d2).* --- *Generated from [https://www.flux.ai/mmkmk/rf-harvested-audio-node~d2](https://www.flux.ai/mmkmk/rf-harvested-audio-node~d2)*