# Careful Silver Tricorder ## Description ESP32 I2S Audio Logger With Advanced USB-C VBUS Protection and Extensive Test Points ## Project Details - **Owner:** heixiaopengyou - **Created:** 11/24/2025 - **Last Updated:** 12/6/2025 - **Visibility:** Public - **System Architecture:** graph TD subgraph USB-C & Power USBC(USB-C Connector) CC1([CC1 5.1kΩ pull-down]) CC2([CC2 5.1kΩ pull-down]) ESD_DN([ESD Protection D+/D-]) USBC -- VBUS --> BQ(BQ24074) USBC -- GND --> BQ USBC -- D+ --> CH340E USBC -- D- --> CH340E USBC -- CC1 --> CC1 USBC -- CC2 --> CC2 end subgraph VBUS Protection Chain J2((USB-C VBUS)) PTC[PTC Fuse] TVS[Bidirectional TVS (<1pF)] EFuse[eFuse] U4IN(BQ24074 IN) J2 --> PTC --> TVS --> EFuse --> U4IN end subgraph Test-Point Subsystems TP_VBUS[Test Point: VBUS] TP_SYS[Test Point: SYS] TP_3V3[Test Point: 3.3V] TP_I2SWS[Test Point: I2S_WS] TP_SDSCK[Test Point: SD_SCK] TP_EN[Test Point: EN] TP_GND[Test Point: GND] end - **RF Keep-Out Area:** To be defined by layout for ESP32 and I2S audio lines, ensure no copper pours or traces except required signals. Refer to ESP32 datasheet for recommended keep-out around chip/antenna and sensitive I2S lines. - **ERC/DRC status:** Latest ERC and DRC results retrieved for review verification. - **Operating Voltage:** 3.3V - **Connectivity:** WiFi, Bluetooth, USB - **Power Tree Organization:** USB-C_IN → [VBUS Protection: PTC (F1), TVS (U8), eFuse (U9)] → BQ24074 (U4) → [SYS rail, Battery] → TPS560430 (U5) Buck → 3.3V Rail → Loads (ESP32, Peripherals, Logic, Test Points). Group protection elements (F1, U8, U9) with J2 and U4 input; group SYS and battery power with U5 and down-stream 3.3V loads (U1, U3, U7, LED2, etc.). Separate digital rails and test points for PCB layout guidance. RF keep-out for ESP32 and sensitive I2S/Audio traces as defined. - **Power Requirements:** USB, Battery - **Board Stackup:** Standard 4 Layer - **Software:** Arduino - **Inductor Saturation Margin:** Inductor saturation current (Isat) must be ≥ 1.2× regulator peak inductor current. Note: Select inductor so Isat ≥ 1.2 × I_peak with ripple current 20–40% of Iout for TPS560430 buck output. - **Domain:** Consumer Electronics - **Charge Current Target:** Target charge current for BQ24074 (U4). Note: Set based on battery, USB source, and safe ratings for protection circuit; typical 500–1000 mA for single-cell Li-ion.mA ## Key Components ### F1 — [MF-PSMF050X-2](https://www.flux.ai/adrian95/mf-psmf050x-2~hrr.md) - Role: Protection - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: PTC fuse for USB-C VBUS protection - Part Type: Fuse - Datasheet URL: https://www.bourns.com/docs/Product-Datasheets/mfpsmf.pdf - Manufacturer Part Number: MF-PSMF050X-2 - Manufacturer Name: Bourns Inc. **Pins:** - P1 [pin 1] - P2 [pin 2] ### J1 — [MEM2067-02-180-00-A](https://www.flux.ai/adrian95/mem2067-02-180-00-a~ilf.md) - Role: Connector - Datasheet URL: https://gct.co/files/specs/mem2067-spec.pdf - Manufacturer Name: GCT - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: MEM2067-02-180-00-A - Role Details: microSD card socket for SPI interface - Part Type: Connector **Pins:** - CD/DAT3 [pin 2] - CLK [pin 5] - CMD [pin 3] - DAT0 [pin 7] - DAT1 [pin 8] - DAT2 [pin 1] - SHIELD [pin 12] - SHIELD [pin 9] - SHIELD [pin 11] - SHIELD [pin 10] - VDD [pin 4] - VSS [pin 6] ### J2 — [2024100002](https://www.flux.ai/adrian95/2024100002~atk.md) - Role: Connector - Manufacturer Part Number: 2024100002 - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/834/202410002_Pkg_Spec.pdf - Manufacturer Name: Molex - Role Details: USB-C receptacle for power and data - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Connector **Pins:** - CC1 [pin A5] - CC2 [pin B5] - DA- [pin A7] - DA+ [pin A6] - DB- [pin B7] - DB+ [pin B6] - GND1 [pin A1] - GND2 [pin A12] - GND3 [pin B1] - GND4 [pin B12] - RX1- [pin B10] - RX1+ [pin B11] - RX2- [pin A10] - RX2+ [pin A11] - SBU1 [pin A8] - SBU2 [pin B8] - SHIELD1 [pin SH1] - SHIELD2 [pin SH2] - SHIELD3 [pin SH3] - SHIELD4 [pin SH4] - TX1- [pin A3] - TX1+ [pin A2] - TX2- [pin B3] - TX2+ [pin B2] - VBUS1 [pin A4] - VBUS2 [pin A9] - VBUS3 [pin B4] - VBUS4 [pin B9] ### J3 — [B2B-PH-K-S(LF)(SN)](https://www.flux.ai/jecstronic/b2b-ph-k-slfsn~nss.md) - Role Details: JST-PH 2-pin battery connector for Li-ion - Role: Connector - Datasheet URL: https://datasheet.lcsc.com/lcsc/1811151524_JST-Sales-America-B2B-PH-K-S-LF-SN_C131337.pdf - Part Type: Connector - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: JST Sales America - Manufacturer Part Number: B2B-PH-K-S(LF)(SN) **Pins:** - PIN1 [pin 1] - PIN2 [pin 2] ### LED2 — [APG1608QBC/D](https://www.flux.ai/jecstronic/apg1608qbcd~9qd.md) - Datasheet URL: https://www.kingbrightusa.com/images/catalog/SPEC/APG1608QBC-D.pdf - Manufacturer Name: Kingbright - Role Details: Status indicator for GPIO2 - Part Type: LED - Manufacturer Part Number: APG1608QBC/D - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - A [pin 2] - K [pin 1] ### SW1 — [B3FS-1050P](https://www.flux.ai/jharwinbarrozo/b3fs-1050p~hog.md) - Part Type: Switch - Role Details: Soft-latch pushbutton for U6 *PB control - Manufacturer Name: OMRON - Manufacturer Part Number: B3FS-1050P - Role: Switch - Datasheet URL: https://datasheet.lcsc.com/lcsc/1809271215_Omron-Electronics-B3FS-1050P_C231326.pdf **Pins:** - P1 - P2 ### TP_3V3 — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md) - Role Details: Test point for net 3.3V - Net Name: 3.3V **Pins:** - P1 ### TP_EN — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md) - Net Name: EN - Role Details: Test point for net EN **Pins:** - P1 ### TP_GND — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md) - Net Name: GND - Role Details: Test point for net GND **Pins:** - P1 ### TP_I2S_WS — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md) - Net Name: I2S_WS - Role Details: Test point for net I2S_WS **Pins:** - P1 ### TP_SD_SCK — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md) - Net Name: SD_SCK - Role Details: Test point for net SD_SCK **Pins:** - P1 ### TP_SYS — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md) - Role Details: Test point for net SYS - Net Name: SYS **Pins:** - P1 ### TP_VBUS — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md) - Net Name: VBUS - Role Details: Test point for net VBUS **Pins:** - P1 ### U1 — [ESP32-WROOM-32D](https://www.flux.ai/vasyl/esp32-wroom-32d~7py.md) - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Microcontroller - Manufacturer Name: Espressif Systems - Datasheet URL: https://www.espressif.com/sites/default/files/documentation/esp32-wroom-32d_esp32-wroom-32u_datasheet_en.pdf - Max Input Voltage: 3.6V - Manufacturer Part Number: ESP32-WROOM-32D - Role: Main MCU **Pins:** - 3.3V [pin 2] - AGND [pin 39] - CLK [pin 20] - CMD [pin 19] - EN [pin 3] - GND [pin 38] - GND [pin 15] - GND [pin 1] - IO0 [pin 25] - IO12 [pin 14] - IO13 [pin 16] - IO14 [pin 13] - IO15 [pin 23] - IO16 [pin 27] - IO17 [pin 28] - IO18 [pin 30] - IO19 [pin 31] - IO2 [pin 24] - IO21 [pin 33] - IO22 [pin 36] - IO23 [pin 37] - IO25 [pin 10] - IO26 [pin 11] - IO27 [pin 12] - IO32 [pin 8] - IO33 [pin 9] - IO34 [pin 6] - IO35 [pin 7] - IO4 [pin 26] - IO5 [pin 29] - NC [pin 32] - RXD0 [pin 34] - SD0 [pin 21] - SD1 [pin 22] - SD2 [pin 17] - SD3 [pin 18] - TXD0 [pin 35] - VN [pin 5] - VP [pin 4] ### U2 — [ESD224DQA](https://www.flux.ai/kicad-part-library/esd224dqa~nw.md) - Role: Protection - Datasheet URL: https://www.ti.com/lit/ds/symlink/esd224.pdf - Manufacturer Name: Texas Instruments Inc. - Manufacturer Part Number: ESD224DQA - Role Details: ESD protection for microSD interface - Package or Case Code: Diodes_UDFN-10_1.0x2.5mm_P0.5mm **Pins:** - ~ [pin 7] - ~ [pin 2] - ~ [pin 4] - ~ [pin 5] - ~ [pin 6] - ~ [pin 1] - ~ [pin 9] - ~ [pin 10] - VSS [pin 3] - VSS [pin 8] ### U3 — [CH340E](https://www.flux.ai/kicad-part-library/ch340e~64.md) - Datasheet URL: https://www.mpja.com/download/35227cpdata.pdf - Role Details: USB-UART Bridge - Max Input Voltage: 5.5V - Package or Case Code: MSOP-10_3x3mm_P0.5mm - Manufacturer Part Number: CH340E - Role: Interface **Pins:** - ~{CTS} [pin 5] - ~{RTS} [pin 4] - GND [pin 3] - RXD [pin 9] - TNOW [pin 6] - TXD [pin 8] - UD- [pin 2] - UD+ [pin 1] - V3 [pin 10] - VCC [pin 7] ### U4 — [BQ24074RGTT](https://www.flux.ai/lcsc/bq24074rgtt~fpyl.md) - Manufacturer Part Number: BQ24074RGTT - LCSC Part Number: C2861252 - Max Input Voltage: 10V - Package or Case Code: VQFN-16_L3.0-W3.0-P0.50-TL-EP1.7 - Role: Battery Charger - JLCPCB Part Class: Extended Part - Manufacturer Name: TI(德州仪器) - Part Type: Battery Management ICs - Role Details: Li-ion charger **Pins:** - ~{CE} [pin 4] - ~{CHG} [pin 9] - ~{PGOOD} [pin 7] - BAT [pin 2] - BAT [pin 3] - EN1 [pin 6] - EN2 [pin 5] - EP [pin 17] - ILIM [pin 12] - IN [pin 13] - ISET [pin 16] - ITERM [pin 15] - OUT [pin 10] - OUT [pin 11] - TMR [pin 14] - TS [pin 1] - VSS [pin 8] ### U5 — [TPS560430X3FDBVR](https://www.flux.ai/adrian95/tps560430x3fdbvr~ujz.md) - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: 3.3V Buck Regulator - Manufacturer Part Number: TPS560430X3FDBVR - Manufacturer Name: Texas Instruments - Max Input Voltage: 17V - Role: Power Conversion - Datasheet URL: https://www.ti.com/lit/ds/symlink/tps560430.pdf - Part Type: Integrated Circuit **Pins:** - CB [pin 1] - EN [pin 4] - FB [pin 3] - GND [pin 2] - SW [pin 6] - VIN [pin 5] ### U6 — [LTC2954CTS8-2#TRMPBF](https://www.flux.ai/jecstronic/ltc2954cts8-2trmpbf~hut.md) - Part Type: Integrated Circuit - Manufacturer Part Number: LTC2954CTS8-2#TRMPBF - Max Input Voltage: 15V - Role: Power Management - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: Soft-latch power switch - Manufacturer Name: Analog Devices Inc. - Datasheet URL: https://www.analog.com/media/en/technical-documentation/data-sheets/2954fb.pdf **Pins:** - *INT [pin 5] - *KILL [pin 8] - *PB [pin 2] - EN/*EN [pin 6] - GND [pin 4] - ONT [pin 3] - PDT [pin 7] - VIN [pin 1] ### U7 — [INMP441ACEZ-R7](https://www.flux.ai/jecstronic/inmp441acez-r7~mpw.md) - License: https://creativecommons.org/licenses/by/4.0/ - Role: Sensing (Shunt) - Part Type: Sensor - Datasheet URL: https://invensense.tdk.com/wp-content/uploads/2015/02/INMP441.pdf?ref_disty=digikey - Manufacturer Name: TDK InvenSense - Role Details: I2S digital microphone for audio input - Max Input Voltage: 3.6V - Manufacturer Part Number: INMP441ACEZ-R7 **Pins:** - CHIPEN [pin 8] - GND [pin 5] - GND [pin 6] - GND [pin 9] - L/R [pin 4] - SCK [pin 1] - SD [pin 2] - VDD [pin 7] - WS [pin 3] ### U8 — [WE-TVS-82400102](https://www.flux.ai/kicad-part-library/we-tvs-82400102~vb9.md) - Datasheet URL: https://www.we-online.com/components/products/datasheet/82400102.pdf - Package or Case Code: SOT-23-6 - Manufacturer Part Number: WE-TVS-82400102 - Package: SOT-23-6 - Role: Protection - Manufacturer Name: Texas Instruments Inc. - Role Details: Bidirectional low-capacitance TVS diode in VBUS protection chain **Pins:** - ~ [pin 1] - ~ [pin 3] - ~ [pin 4] - ~ [pin 5] - ~ [pin 6] - ~ [pin 2] ### U9 — [5V eFuse](https://www.flux.ai/corynrobinson/5v-efuse~ci.md) - Role: Protection - Voltage: 5V - Product Info Url: https://www.ti.com/product/TPS25200 - Manufacturer Part Number: TPS25200DRVR - Role Details: eFuse for USB-C VBUS overcurrent protection - Purchase Url: https://octopart.com/tps25200drvt-texas+instruments-38819194?r=sp - Datasheet URL: https://www.ti.com/lit/ds/symlink/tps25200.pdf?ts=1643733993618&ref_url=https%253A%252F%252Fwww.ti.com%252Fpower-management%252Fpower-switches%252Fefuse-hotswap-controllers%252Fproducts.html - Package or Case Code: 6-WSON - Manufacturer Name: Texas Instruments **Pins:** - *FAULT - EN - EPAD - GND - ILIM - IN - OUT *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/heixiaopengyou/careful-silver-tricorder~8f](https://www.flux.ai/heixiaopengyou/careful-silver-tricorder~8f).* --- *Generated from [https://www.flux.ai/heixiaopengyou/careful-silver-tricorder~8f](https://www.flux.ai/heixiaopengyou/careful-silver-tricorder~8f)*