# Authentication Device - TPM ## Description Revised PCB Layout with Updated USB, CH340G, and AT88SC0104CA Placement and Clean ERC/DRC ## Project Details - **Owner:** omgicorp - **Created:** 2/3/2026 - **Last Updated:** 2/3/2026 - **Visibility:** Public - **AT88SC0104CA I2C Pinout & Decoupling:** Package: 8-lead TSSOP (AT88SC0104CA-TH-T). I2C/TWI pins: Pin 3 = SDA/IO (open-drain serial data), Pin 6 = SCL/CLK (serial clock input), Pin 1 = GND, Pin 8 = VCC (2.7 V to 3.6 V). Pins 2,4,5,7 = NC (leave unconnected). Two-wire bus: up to 1 MHz; SDA requires pull-up to VCC; device shares common SDA/SCL bus with AT97SC3205T. Decoupling: place 0.1 µF (100 nF) low-ESR ceramic capacitor from VCC to GND within ~6 mm of the VCC pin, routing supply through the capacitor first, then into the device pin. For noisy environments, add an additional high-frequency bypass capacitor (0.01 µF–0.001 µF) in parallel with the 0.1 µF, placed adjacent to the primary capacitor. Keep return path short and on a solid ground reference plane. - **J1_pad_bbox:** Pads bounding box for USB4105-GF-A-060 connector J1 is defined by its pad set; explicit coordinates are not available from the current layout context, only pad membership. - **J1_bbox_coords:** [] - **Stackup:** Standard 4 Layer - **Net Class: USB_VBUS (Power Alias):** Power - **DRC Review Results:** Updated after latest DRC run on 4-layer stackup: No violations on minimum clearance, trace width, or annular ring. USB high-speed nets (USB_DP, USB_DN) meet spacing and differential-pair geometry within defined USB net class; no acute-angle stubs. Return paths for USB, I2C, TVS, and LDO sections are continuous on the GND plane with short via returns near J1, D1/D2, D3, and U4. LDO input/output decoupling (C1–C3, C4/C6/C7) is placed within recommended distance and has direct ground via access—no remaining DRC flags for spacing or unconnected copper in these areas. - **Net Class: 3V3:** Power - **Net Class: USB_DN:** USB - **System Architecture:** ```mermaid flowchart TD PWR3V3["3.3V"] --> AT97["AT97SC3205T"] PWR3V3 --> AT88["AT88SC0104CA"] AT97 -->|SDA/SCL| I2C["I2C Bus"] AT88 -->|SDA/SCL| I2C PWR5V["VBUS (USB 5V)"] --> USB4["USB4105GF A060"] USB4 -->|CC1| RPD1["5.1k CC PD"] USB4 -->|CC2| RPD2["5.1k CC PD"] USB4 -->|VBUS| SMF["SMF6.0A"] USB4 --> CH34["CH340G"] CH34 -->|D+| TVS1["USBLC6 2SC6"] CH34 -->|D-| TVS2["USBLC6 2SC6"] PWR3V3 --> CH34 GND["GND"] --- AT97 GND --- AT88 GND --- USB4 GND --- RPD1 GND --- RPD2 GND --- SMF GND --- TVS1 GND --- TVS2 GND --- CH34 ``` - **ERC Review Results:** Updated after latest ERC run: No remaining open power-input or unconnected-pin ERC errors. Previous issues on USB4105-GF-A-060 (J1), USBLC6-2SC6 (D1, D2), AT97SC3205T-X3A1C-20 (U1), and AT88SC0104CA-TH-T (U2) are now resolved by properly tying all power and reference pins to 3V3/GND and confirming TVS reference to the local ground plane. All I2C (SDA/SCL) and USB (DP/DN, VBUS, GND, CC) nets pass connectivity checks with no floating nodes or unintended shorts. - **Net Class: USB_DP:** USB - **Net Class: USB_VBUS:** USB - **Net Class: SDA:** I2C - **Net Class: GND:** Power - **Net Class: SCL:** I2C - **J2_bbox_coords:** [] - **DRC / ERC Last Run Timestamp:** 2026-02-04T00:00:00Z - **Copies:** 1 ## Key Components ### D1 — [USBLC6-2SC6](https://www.flux.ai/vasy_skral/usblc6-2sc6.md) - Role Details: ESD protection for USB D+ line - Manufacturer Name: STMicroelectronics - Package: SOT-23-6 - Quantity: 1 - Manufacturer Part Number: USBLC6-2SC6 - Role: Protection - Part Type: Protection - 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 - Diode Type: Zener - Purpose: ESD protection for USB D+ line **Pins:** - GND [pin 2] - I/O1 [pin 6] - I/O1 [pin 1] - I/O2 [pin 3] - I/O2 [pin 4] - VBUS [pin 5] ### D2 — [USBLC6-2SC6](https://www.flux.ai/vasy_skral/usblc6-2sc6.md) - Package: SOT-23-6 - Diode Type: Zener - Manufacturer Name: STMicroelectronics - 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 - Role Details: ESD protection for USB D- line - Quantity: 1 - Role: Protection - Manufacturer Part Number: USBLC6-2SC6 - Part Type: Protection - Purpose: ESD protection for USB D- line **Pins:** - GND [pin 2] - I/O1 [pin 6] - I/O1 [pin 1] - I/O2 [pin 3] - I/O2 [pin 4] - VBUS [pin 5] ### D3 — [SMF6.0A](https://www.flux.ai/lcsc/smf6p0a.md) - JLCPCB Part Class: Extended Part - LCSC Part Number: C2990428 - Manufacturer Name: Liown(里阳半导体) - Package or Case Code: SOD-123FL_L2.8-W1.9-LS3.7-RD - Manufacturer Part Number: SMF6.0A - Role: Protection - Diode Type: Zener - Part Type: Protection - Role Details: TVS for USB VBUS - Purpose: TVS protection for USB VBUS line - Package: SOD-123FL_L2.8-W1.9-LS3.7-RD - Quantity: 1 **Pins:** - 1 [pin 1] - 2 [pin 2] ### J1 — [USB4105-GF-A-060](https://www.flux.ai/adrian95/usb4105-gf-a-060.md) - Part Type: USB C - Manufacturer Name: GCT - Role Details: USB Type-C receptacle, CC management - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/5702/USB4105%20-%20Product%20Drawing.pdf - Purpose: USB Type-C receptacle - Role: Connector - License: https://creativecommons.org/licenses/by/4.0/ - Connector Type: USB Connectors - Connector Gender: Receptacle - Quantity: 1 - Manufacturer Part Number: USB4105-GF-A-060 **Pins:** - CC1 [pin A5] - CC2 [pin B5] - DN1 [pin A7] - DN2 [pin B7] - DP1 [pin A6] - DP2 [pin B6] - GND [pin B1_A12] - GND [pin A1_B12] - SBU1 [pin A8] - SBU2 [pin B8] - SHELL_GND [pin SH2] - SHELL_GND [pin SH4] - SHELL_GND [pin SH3] - SHELL_GND [pin SH1] - VBUS [pin A4_B9] - VBUS [pin B4_A9] ### J2 — [Pin Header 02x12 2.54mm Vertical](https://www.flux.ai/adrian95/pin-header-02x12-254mm-vertical.md) - Package: Through Hole - Role: Interface - Purpose: 2x12 header for key signals and power - Role Details: 2x12 breakout header for key IC signals and power - Quantity: 1 - Part Type: Connector - Connector Type: Headers and Wire Housings - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - Pin_1 [pin 1] - Pin_10 [pin 10] - Pin_11 [pin 11] - Pin_12 [pin 12] - Pin_13 [pin 13] - Pin_14 [pin 14] - Pin_15 [pin 15] - Pin_16 [pin 16] - Pin_17 [pin 17] - Pin_18 [pin 18] - Pin_19 [pin 19] - Pin_2 [pin 2] - Pin_20 [pin 20] - Pin_21 [pin 21] - Pin_22 [pin 22] - Pin_23 [pin 23] - Pin_24 [pin 24] - 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 — [Pin Header 01x02 2.54mm Vertical](https://www.flux.ai/jharwinbarrozo/pin-header-01x02-254mm-vertical.md) - Part Type: Connector - Package: Through Hole - Role: Connector - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: JTAG TMS placeholder **Pins:** - P1 [pin 1] - P2 [pin 2] ### J4 — [Pin Header 01x02 2.54mm Vertical](https://www.flux.ai/jharwinbarrozo/pin-header-01x02-254mm-vertical.md) - Role Details: JTAG TCK placeholder - Role: Connector - Package: Through Hole - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Connector **Pins:** - P1 [pin 1] - P2 [pin 2] ### J5 — [Pin Header 01x02 2.54mm Vertical](https://www.flux.ai/jharwinbarrozo/pin-header-01x02-254mm-vertical.md) - Package: Through Hole - Role Details: JTAG TDI placeholder - Part Type: Connector - License: https://creativecommons.org/licenses/by/4.0/ - Role: Connector **Pins:** - P1 [pin 1] - P2 [pin 2] ### J6 — [Pin Header 01x02 2.54mm Vertical](https://www.flux.ai/jharwinbarrozo/pin-header-01x02-254mm-vertical.md) - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: JTAG TDO placeholder - Package: Through Hole - Role: Connector - Part Type: Connector **Pins:** - P1 [pin 1] - P2 [pin 2] ### J7 — [Pin Header 01x02 2.54mm Vertical](https://www.flux.ai/jharwinbarrozo/pin-header-01x02-254mm-vertical.md) - Role Details: JTAG RESET placeholder - Part Type: Connector - Role: Connector - License: https://creativecommons.org/licenses/by/4.0/ - Package: Through Hole **Pins:** - P1 [pin 1] - P2 [pin 2] ### J8 — [Pin Header 01x02 2.54mm Vertical](https://www.flux.ai/jharwinbarrozo/pin-header-01x02-254mm-vertical.md) - Role Details: JTAG VTREF placeholder - Role: Connector - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Connector - Package: Through Hole **Pins:** - P1 [pin 1] - P2 [pin 2] ### J9 — [Pin Header 01x02 2.54mm Vertical](https://www.flux.ai/jharwinbarrozo/pin-header-01x02-254mm-vertical.md) - Package: Through Hole - Role Details: JTAG GND placeholder - Part Type: Connector - License: https://creativecommons.org/licenses/by/4.0/ - Role: Connector **Pins:** - P1 [pin 1] - P2 [pin 2] ### LED1 — [150060VS55040](https://www.flux.ai/adrian95/150060vs55040.md) - Role Details: Power indicator LED for 3.3V rail - Role: Power indicator LED for 3.3V rail - Datasheet URL: https://www.we-online.com/components/products/datasheet/150060VS55040.pdf - Purpose: Power indicator for 3.3V rail - Package: SMD_0603_1608Metric - Manufacturer Name: Würth Elektronik - Quantity: 1 - Part Type: LED - Manufacturer Part Number: 150060VS55040 - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - A [pin 2] - K [pin 1] ### U1 — [AT97SC3205T-X3A1C-20](https://www.flux.ai/lcsc/at97sc3205t-x3a1c-20.md) - Package: TSSOP-28_L9.7-W4.4-P0.65-LS6.4-BL - Purpose: I2C security token - Package or Case Code: TSSOP-28_L9.7-W4.4-P0.65-LS6.4-BL - Role Details: I2C security token, Fast Mode 400 kHz - Part Type: Integrated Circuit - LCSC Part Number: C2651724 - Manufacturer Name: MICROCHIP(美国微芯) - Quantity: 1 - Manufacturer Part Number: AT97SC3205T-X3A1C-20 - Role: Integrated Circuit **Pins:** - ~{LRESET} [pin 16] - ~{TWI_Wakeup} [pin 22] - ATest [pin 21] - ATest [pin 23] - ATest [pin 26] - GND [pin 4] - GND [pin 11] - GND [pin 18] - GND [pin 25] - GPIO [pin 17] - GPIO-Express-00 [pin 6] - NC [pin 5] - NC [pin 12] - NC [pin 13] - NC [pin 14] - NC [pin 15] - NC [pin 27] - NC [pin 28] - PIRQ [pin 20] - PP/GPIO/~{TWI_Wakeup} [pin 7] - SM_CLK [pin 2] - SM_DAT [pin 1] - TestBI/GPIO/XTAMPER [pin 9] - TestI [pin 8] - VCC [pin 3] - VCC [pin 10] - VCC [pin 19] - VCC [pin 24] ### U2 — [AT88SC0104CA-TH-T](https://www.flux.ai/lcsc/at88sc0104ca-th-t.md) - Manufacturer Part Number: AT88SC0104CA-TH-T - JLCPCB Part Class: Extended Part - Part Type: Integrated Circuit - Role Details: I2C security token, Fast Mode 400 kHz - Quantity: 1 - Manufacturer Name: MICROCHIP(美国微芯) - Role: Integrated Circuit - Package or Case Code: TSSOP-8_L4.4-W3.0-P0.65-LS6.4-BL - LCSC Part Number: C2659355 - Package: TSSOP-8_L4.4-W3.0-P0.65-LS6.4-BL - Purpose: I2C security token **Pins:** - CLK [pin 6] - GND [pin 1] - NC [pin 2] - NC [pin 4] - NC [pin 5] - NC [pin 7] - SDA [pin 3] - VCC [pin 8] ### U3 — [CH340G](https://www.flux.ai/kicad-part-library/ch340g.md) - Role: Integrated Circuit - Manufacturer Part Number: CH340G - Quantity: 1 - Package: SOIC-16_3.9x9.9mm_P1.27mm - Part Type: Integrated Circuit - Package or Case Code: SOIC-16_3.9x9.9mm_P1.27mm - Role Details: USB to UART bridge, 3.3 V I/O - Datasheet URL: http://www.datasheet5.com/pdf-local-2195953 - Purpose: USB-UART bridge **Pins:** - ~{CTS} [pin 9] - ~{DCD} [pin 12] - ~{DSR} [pin 10] - ~{DTR} [pin 13] - ~{RI} [pin 11] - ~{RTS} [pin 14] - GND [pin 1] - R232 [pin 15] - RXD [pin 3] - TXD [pin 2] - UD- [pin 6] - UD+ [pin 5] - V3 [pin 4] - VCC [pin 16] - XI [pin 7] - XO [pin 8] ### U4 — [MIC5504-3.3YM5](https://www.flux.ai/kicad-part-library/mic5504-3p3ym5.md) - Pin Name: VOUT - Role Details: LDO regulator for 3.3V rail - Datasheet URL: http://ww1.microchip.com/downloads/en/DeviceDoc/MIC550X.pdf - Package or Case Code: SOT-23-5 - Pin Type: Power Out - Purpose: LDO regulator for 3.3V rail - Role: Power Management - Manufacturer Part Number: MIC5504-3.3YM5 - Quantity: 1 - Manufacturer Name: Microchip Technology Inc. - Part Type: Linear Regulator **Pins:** - EN [pin 3] - GND [pin 2] - NC [pin 4] - VIN [pin 1] - VOUT [pin 5] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/omgicorp/authentication-device-tpm](https://www.flux.ai/omgicorp/authentication-device-tpm).* --- *Generated from [https://www.flux.ai/omgicorp/authentication-device-tpm](https://www.flux.ai/omgicorp/authentication-device-tpm)*