# Pico SLE4442 Emulator
## Description
RP2040 Raspberry Pi Pico replacement for the ATmega8 SLE4442 emulator, using PIO and protected 5 V smart-card interfaces.
## Project Details
- **Owner:** tmedford3
- **Created:** 8/14/2026
- **Last Updated:** 8/22/2026
- **Visibility:** Public
## Key Components
### D1 — [WE-TVS-82400102](https://www.flux.ai/kicad-part-library/we-tvs-82400102~vb9.md)
- Manufacturer Name: Texas Instruments Inc.
- Role: ESD Protection
- Role Details: 2.5pF max/channel protection for RESET and CLOCK; VDD tied to card +5V, GND to ground
- Datasheet URL: https://www.we-online.com/components/products/datasheet/82400102.pdf
- Functional Group: Card Connector,5V Level Interface
- Package or Case Code: SOT-23-6
- Manufacturer Part Number: WE-TVS-82400102
**Pins:**
- ~ [pin 5]
- ~ [pin 1]
- ~ [pin 4]
- ~ [pin 2]
- ~ [pin 3]
- ~ [pin 6]
### D2 — [WE-TVS-82400102](https://www.flux.ai/kicad-part-library/we-tvs-82400102~vb9.md)
- Manufacturer Part Number: WE-TVS-82400102
- Package or Case Code: SOT-23-6
- Functional Group: Card Connector,5V Level Interface
- Datasheet URL: https://www.we-online.com/components/products/datasheet/82400102.pdf
- Role Details: 2.5pF max/channel protection for DATA and AUX1; preserves high-frequency margin
- Manufacturer Name: Texas Instruments Inc.
- Role: ESD Protection
**Pins:**
- ~ [pin 5]
- ~ [pin 1]
- ~ [pin 4]
- ~ [pin 2]
- ~ [pin 3]
- ~ [pin 6]
### D3 — [WE-TVS-82400102](https://www.flux.ai/kicad-part-library/we-tvs-82400102~vb9.md)
- Role Details: 2.5pF max/channel protection for AUX2 and VPP; VDD rail pin clamps to card +5V. All inputs suitable for several-hundred-kHz margin.
- Datasheet URL: https://www.we-online.com/components/products/datasheet/82400102.pdf
- Role: ESD Protection
- Functional Group: Card Connector,5V Level Interface
- Package or Case Code: SOT-23-6
- Manufacturer Part Number: WE-TVS-82400102
- Manufacturer Name: Texas Instruments Inc.
**Pins:**
- ~ [pin 5]
- ~ [pin 1]
- ~ [pin 4]
- ~ [pin 2]
- ~ [pin 3]
- ~ [pin 6]
### J2 — ISO7816_EMULATOR_CONTACTS_8
- Mount: PCB
- Functional Group: Card Connector
- Part Type: Connectors
- Role: Smart Card Contact Interface
- Connector Positions: 8
- Manufacturer Name: Custom for tmedford3
- Role Details: C1 VCC, C2 RST, C3 CLK, C4 AUX1, C5 GND, C6 VPP, C7 I/O, C8 AUX2; footprint copies original KiCad-derived emulator contact geometry.
**Pins:**
- AUX1 [pin C4]
- AUX2 [pin C8]
- CLK [pin C3]
- GND [pin C5]
- I/O [pin C7]
- RST [pin C2]
- VCC [pin C1]
- VPP [pin C6]
### U1 — [Raspberry Pi Pico](https://www.flux.ai/jwace81/raspberry-pi-pico~ib.md)
- Manufacturer Name: Raspberry
- Datasheet URL: https://datasheets.raspberrypi.com/pico/pico-datasheet.pdf
- Power Requirements: VSYS 1.8-5.5V; design allowance about 150mA peak
- Role Details: RP2040 Pico module; PIO captures card signals. Power reader +5V into VSYS only; never connect 5V to GPIO. USB VBUS remains isolated from VSYS by Pico onboard Schottky.
- Role: Main Controller
- Functional Group: Pico MCU
- Manufacturer Part Number: SC0915
**Pins:**
- 3V3 [pin 36]
- 3V3_EN [pin 37]
- ADC_VREF [pin 35]
- GND [pin 13]
- GND [pin 18]
- GND [pin 3]
- GND [pin 38]
- GND [pin 28]
- GND [pin 33]
- GND [pin 23]
- GND [pin 8]
- GP0 [pin 1]
- GP1 [pin 2]
- GP10 [pin 14]
- GP11 [pin 15]
- GP12 [pin 16]
- GP13 [pin 17]
- GP14 [pin 19]
- GP15 [pin 20]
- GP16 [pin 21]
- GP17 [pin 22]
- GP18 [pin 24]
- GP19 [pin 25]
- GP2 [pin 4]
- GP20 [pin 26]
- GP21 [pin 27]
- GP22 [pin 29]
- GP26 [pin 31]
- GP27 [pin 32]
- GP28 [pin 34]
- GP3 [pin 5]
- GP4 [pin 6]
- GP5 [pin 7]
- GP6 [pin 9]
- GP7 [pin 10]
- GP8 [pin 11]
- GP9 [pin 12]
- RUN [pin 30]
- VBUS [pin 40]
- VSYS [pin 39]
### U2 — [SN74LVC1G07QDBVRQ1](https://www.flux.ai/lcsc/sn74lvc1g07qdbvrq1~ycmy.md)
- Part Type: Buffers / Drivers
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2005091811_Texas-Instruments-SN74LVC1G07QDBVRQ1_C507244.pdf
- Operating Voltage: 1.65-5.5V VCC; 5.5V tolerant I/O
- Package or Case Code: SOT-23-5_L2.9-W1.6-P0.95-LS2.8-BL
- Manufacturer Name: TI(德州仪器)
- Role Details: Powered at 3.3V; A driven by GP5; Y may be pulled to card +5V and can only sink DATA low. TI Ioff prevents back-powering when unpowered.
- Manufacturer Part Number: SN74LVC1G07QDBVRQ1
- JLCPCB Part Class: Extended Part
- Product Info Url: https://lcsc.com/product-detail/Logic-Buffers-Drivers-Receivers-Transceivers_Texas-Instruments-Texas-Instruments-SN74LVC1G07QDBVRQ1_C507244.html
- Functional Group: 5V Level Interface
- LCSC Part Number: C507244
- Role: Open-Drain Level Interface
**Pins:**
- ANT [pin 2]
- GND [pin 3]
- NC [pin 1]
- VCC [pin 5]
- Y [pin 4]
*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/tmedford3/pico-sle4442-emulator~49](https://www.flux.ai/tmedford3/pico-sle4442-emulator~49).*
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*Generated from [https://www.flux.ai/tmedford3/pico-sle4442-emulator~49](https://www.flux.ai/tmedford3/pico-sle4442-emulator~49)*