# Shaggy Lime Dejarik ## Description Snowflake: USB‑C PD-Powered Air‑Conditioned Clothing Controller with Integrated XL1509‑ADJ Buck Converter (15 V to 9.3 V Peltier Output), NE555 PWM Fan Control, and LM393 Over‑Temperature Cutoff #USBPD #BuckConverter #Peltier #NE555 #LM393 #PWMControl #OverTemperature ## Project Details - **Owner:** tcy9653 - **Created:** 2/4/2026 - **Last Updated:** 2/4/2026 - **Visibility:** Public - **Connectivity:** USB - **Manufacturing Quantity Target:** 10 - **Domain:** Consumer Electronics - **System Architecture:** ```mermaid flowchart TD usb_c[USB-C PD Input] --> ip2721[IP2721 PD Decoy] ip2721 --> v15[15V Rail] v15 --> buck_pelt[XL1509-ADJ Buck (9.3V)] v15 --> buck_fan[XL1509-12 Buck (12V)] buck_pelt --> v93[9.3V Rail] buck_fan --> v12[12V Rail] v12 --> fan_pwm[NE555 PWM Fan Control] fan_pwm --> fan_out[Fan & MOSFET Drive] v93 --> comp[LM393 Over-Temp Comparator] comp --> pel_cutoff[Peltier P-MOSFET Cutoff] ``` - **Power Requirements:** USB ## Key Components ### D1 — [SS34](https://www.flux.ai/lcsc/ss34.md) - Max Reverse Voltage: 40V - Forward Voltage: 0.3V to 0.45V - Manufacturer Part Number: SS34 - Role Details: Freewheeling diode for buck converter switching node to output - Part Type: Diode - Manufacturer Name: UMW(友台半导体) - JLCPCB Part Class: Extended Part - Package: DO-214AC - LCSC Part Number: C2758511 - Package or Case Code: SMB_L4.3-W3.6-LS5.4-RD - Reverse Voltage: 40V - Diode Type: Schottky - Mount: Surface Mount - Role: Flyback / Freewheeling **Pins:** - A [pin 2] - K [pin 1] ### D2 — [SS34](https://www.flux.ai/lcsc/ss34.md) - Manufacturer Name: UMW(友台半导体) - JLCPCB Part Class: Extended Part - Part Type: Schottky Barrier Diodes (SBD) - Role: Flyback / Freewheeling - Manufacturer Part Number: SS34 - Package: DO-214AC - Forward Voltage: 0.3V to 0.45V - Diode Type: Schottky - Role Details: Freewheeling diode for fan 12V buck converter switch node to output - Package or Case Code: SMB_L4.3-W3.6-LS5.4-RD - Reverse Voltage: 40V - LCSC Part Number: C2758511 **Pins:** - A [pin 2] - K [pin 1] ### J1 — [WJ500V-5.08-2P](https://www.flux.ai/adrian95/wj500v-5p08-2p.md) - Datasheet URL: https://datasheet.lcsc.com/szlcsc/1912251636_Ningbo-Kangnex-Elec-WJ500V-5-08-2P_C8465.pdf - Part Type: Connector - Manufacturer Name: Ningbo Kangnex - Role: Connector - Role Details: Peltier output connector - Connector Type: Terminal Blocks - Manufacturer Part Number: WJ500V-5.08-2P **Pins:** - 1 [pin 1] - 2 [pin 2] ### J2 — [WJ500V-5.08-2P](https://www.flux.ai/adrian95/wj500v-5p08-2p.md) - Connector Positions: 2 - Connector Gender: Male - Part Type: Connector - Datasheet URL: https://datasheet.lcsc.com/szlcsc/1912251636_Ningbo-Kangnex-Elec-WJ500V-5-08-2P_C8465.pdf - Manufacturer Name: Ningbo Kangnex - Role: Connector - Manufacturer Part Number: WJ500V-5.08-2P - Role Details: Fan power output connector - Connector Type: Terminal Blocks - Connector Rows: 1 - Connector Pitch: 5.08mm **Pins:** - 1 [pin 1] - 2 [pin 2] ### U1 — [UJ20-C-V-G-SMT-P16-TR-65](https://www.flux.ai/adrian95/uj20-c-v-g-smt-p16-tr-65.md) - Role: Connector - Manufacturer Part Number: UJ20-C-V-G-SMT-P16-TR-65 - Role Details: USB-C receptacle 16-pin for PD input - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://www.cuidevices.com/product/resource/digikeypdf/uj20-c-v-g-smt-p16-tr-65.pdf - Package or Case Code: UJ20CVGSMTP16TR65 - Part Type: USB C - Manufacturer Name: Same Sky **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] ### U2 — [IP2721](https://www.flux.ai/kicad-part-library/ip2721.md) - Role: Power Management - Datasheet URL: https://datasheet.lcsc.com/lcsc/2006111335_INJOINIC-IP2721_C603176.pdf - Role Details: USB-C PD decoy controller for 15 V negotiation - Package or Case Code: TSSOP-16_4.4x5mm_P0.65mm - Manufacturer Part Number: IP2721 **Pins:** - CC1 [pin 13] - CC2 [pin 12] - GND [pin 5] - NC [pin 8] - NC [pin 15] - NC [pin 10] - NC [pin 6] - NC [pin 14] - NC [pin 4] - NC [pin 3] - NC [pin 9] - NC [pin 7] - SEL [pin 11] - VBUS [pin 16] - VBUSG [pin 1] - VIN [pin 2] ### U3 — [XL1509-ADJ](https://www.flux.ai/lcsc/xl1509-adj.md) - Package or Case Code: SOIC-8_L5.0-W4.0-P1.27-LS6.0-BL - Manufacturer Part Number: XL1509-ADJ - Package: SOIC-8 - Manufacturer Name: UMW(友台半导体) - Role Details: Adjustable Buck Converter for 9.3 V Peltier Supply - Part Type: DC-DC Converters - LCSC Part Number: C2681227 - Role: Power Management - JLCPCB Part Class: Extended Part **Pins:** - FEEDBACK [pin 3] - GND [pin 5] - GND [pin 6] - GND [pin 7] - GND [pin 8] - ON/OFF [pin 4] - OUTPUT [pin 2] - VIN [pin 1] ### U4 — [XL1509-12](https://www.flux.ai/lcsc/xl1509-12.md) - JLCPCB Part Class: Extended Part - Role: Power Management - Package: SOIC-8 - Package or Case Code: SOIC-8_L4.9-W3.9-P1.27-LS6.0-BL - Operating Voltage: 12V - LCSC Part Number: C2889160 - Manufacturer Name: UMW(广东友台半导体) - Role Details: Fixed 12V buck converter for fan stage - Manufacturer Part Number: XL1509-12 - Part Type: DC-DC Converters **Pins:** - FEEDBACK [pin 3] - GND [pin 5] - GND [pin 6] - GND [pin 7] - GND [pin 8] - ON/OFF [pin 4] - OUTPUT [pin 2] - VIN [pin 1] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/tcy9653/shaggy-lime-dejarik](https://www.flux.ai/tcy9653/shaggy-lime-dejarik).* --- *Generated from [https://www.flux.ai/tcy9653/shaggy-lime-dejarik](https://www.flux.ai/tcy9653/shaggy-lime-dejarik)*