# 24v to 12v stepdown 100w ## Description 24–30 V to 12 V / 100 W Single-Layer Synchronous Buck Converter with Robust Protection ## Project Details - **Owner:** katzenbastler - **Created:** 1/17/2026 - **Last Updated:** 1/17/2026 - **Visibility:** Public - **System Architecture:** ```mermaid flowchart TD Input["Input (24-30 V)"] Fuse["Fuse"] TVSDiode["TVS diode"] ReversePolFET["Reverse-polarity FET"] BuckController["Microchip buck controller"] HighSideMOSFET["High-side MOSFET"] LowSideMOSFET["Low-side MOSFET"] Inductor["Inductor"] OutputCaps["Output capacitors"] FeedbackNet["Feedback network"] Input --> Fuse --> TVSDiode --> ReversePolFET --> BuckController BuckController --> HighSideMOSFET BuckController --> LowSideMOSFET HighSideMOSFET --> Inductor --> OutputCaps OutputCaps --> FeedbackNet --> BuckController ``` - **Stars:** 1 - **Copies:** 1 ## Key Components ### D1 — [SPHV36-01ETG-C](https://www.flux.ai/adrian95/sphv36-01etg-c~7wr.md) - Manufacturer Name: Littelfuse Inc. - Role Details: Input transient voltage suppression above maximum VIN - License: https://creativecommons.org/licenses/by/4.0/ - Role: Clamping - Datasheet URL: https://www.verical.com/datasheet/littelfuse-tvs-SPHV36-01ETG-C-895267.pdf - Manufacturer Part Number: SPHV36-01ETG-C - Part Type: Diode **Pins:** - A [pin 2] - C [pin 1] ### F1 — [S1206-FA-15.0A](https://www.flux.ai/lcsc/s1206-fa-15p0a~mf1s.md) - Part Type: Fuses - Manufacturer Name: SART(萨特) - Role: Protection - Package or Case Code: F1206 - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2312081043_SART-Nanjing-Sart-Tech-S1206-FA-15-0A_C183159.pdf - Role Details: Input fuse for overcurrent protection - Product Info Url: https://lcsc.com/product-detail/Surface-Mount-Fuses_15A-32V_C183159.html - LCSC Part Number: C183159 - Manufacturer Part Number: S1206-FA-15.0A - Package: F1206 - JLCPCB Part Class: Extended Part **Pins:** - 1 [pin 1] - 2 [pin 2] ### J1 — [1732720](https://www.flux.ai/jecstronic/1732720~jel.md) - Manufacturer Name: Phoenix Contact - Manufacturer Part Number: 1732720 - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/644/1732720.pdf - Silkscreen Pin 2: IN- - Role: Input power connector for IN+ and IN− - License: https://creativecommons.org/licenses/by/4.0/ - Silkscreen Pin 1: IN+ - Role Details: Input power connector for IN+ and IN− - Part Type: Connector **Pins:** - Pin_1 [pin 1] - Pin_2 [pin 2] ### J2 — [1732720](https://www.flux.ai/jecstronic/1732720~jel.md) - Connector Positions: 2 - Connector Type: Terminal Blocks - Manufacturer Name: Phoenix Contact - Manufacturer Part Number: 1732720 - Silkscreen Pin 2: OUT- - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/644/1732720.pdf - Role: Output power connector for OUT+ and OUT− - Silkscreen Pin 1: OUT+ - Part Type: Connector - Role Details: Output power connector for OUT+ and OUT− **Pins:** - Pin_1 [pin 1] - Pin_2 [pin 2] ### Q1 — [NCE60P50K](https://www.flux.ai/lcsc/nce60p50k~qdw0.md) - Package: TO-252-2(DPAK) - Role Details: Protects against input reverse voltage for 24–30 V supply - Role: Reverse Polarity Protection - Part Type: MOSFETs - Datasheet URL: https://www.lcsc.com/datasheet/lcsc_datasheet_1809291512_Wuxi-NCE-Power-Semiconductor-NCE60P50K_C130104.pdf - Product Info Url: https://lcsc.com/product-detail/MOSFET_NCE60P50K_C130104.html - Manufacturer Name: NCE(无锡新洁能) - Continuous Drain Current: 50A - Manufacturer Part Number: NCE60P50K - Transistor Type: 1 Piece P-Channel - JLCPCB Part Class: Extended Part - Operating Temperature: -55℃~+150℃ - LCSC Part Number: C130104 - Drain to Source Voltage: 60V - Power: 95W - Package or Case Code: TO-252-2_L6.6-W6.1-P4.57-LS9.9-TL-CW **Pins:** - D [pin 2] - G [pin 1] - S [pin 3] ### Rfb_bottom — [Generic Resistor](https://www.flux.ai/jharwinbarrozo/generic-resistor~3e.md) - Role Details: Feedback divider for U1, error amplifier input - Part Type: Resistor - Role: Voltage Division - Package: SMD_0603_1608Metric - Resistance: 41.2kΩ **Pins:** - P1 [pin 1] - P2 [pin 2] ### Rfb_top — [Generic Resistor](https://www.flux.ai/jharwinbarrozo/generic-resistor~3e.md) - Part Type: Resistor - Role Details: Feedback divider for U1, error amplifier input - Role: Voltage Division - Resistance: 100kΩ - Package: SMD_0603_1608Metric **Pins:** - P1 [pin 1] - P2 [pin 2] ### U1 — [SG2524N](https://www.flux.ai/jecstronic/sg2524n~mvh.md) - Manufacturer Name: Microchip Technology - Role: Power Conversion - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: SG2524N - Part Type: Integrated Circuit - Package: PDIP-16 - Datasheet URL: https://www.ti.com/general/docs/suppproductinfo.tsp?distId=10&gotoUrl=https%3A%2F%2Fwww.ti.com%2Flit%2Fgpn%2Fsg2524 - Role Details: Synchronous buck PWM controller for 24–30 V to 12 V conversion **Pins:** - COL1 [pin 12] - COL2 [pin 13] - COMP [pin 9] - CT [pin 7] - CURR_LIM- [pin 5] - CURR_LIM+ [pin 4] - EMIT1 [pin 11] - EMIT2 [pin 14] - GND [pin 8] - IN- [pin 1] - IN+ [pin 2] - OSC_OUT [pin 3] - REF_OUT [pin 16] - RT [pin 6] - SHUTDOWN [pin 10] - VCC [pin 15] ### U2 — [NCE6020AK](https://www.flux.ai/lcsc/nce6020ak~ohqj.md) - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2312011440_Wuxi-NCE-Power-Semiconductor-NCE6020AK_C108639.pdf - Manufacturer Name: NCE(无锡新洁能) - JLCPCB Part Class: Extended Part - Role: Switching - Product Info Url: https://lcsc.com/product-detail/MOSFET_NCE6020AK_C108639.html - Continuous Drain Current: 20A - LCSC Part Number: C108639 - Operating Temperature: -55℃~+175℃ - Power: 45W - Drain to Source Voltage: 60V - Manufacturer Part Number: NCE6020AK - Part Type: MOSFETs - Package or Case Code: TO-252-2_L6.6-W6.1-P4.57-LS10.1-TL-CW - Transistor Type: N-CHANNEL - Role Details: High-side MOSFET for synchronous buck converter **Pins:** - D [pin 2] - G [pin 1] - S [pin 3] ### U3 — [NCE6020AK](https://www.flux.ai/lcsc/nce6020ak~ohqj.md) - Drain to Source Voltage: 60V - Power: 45W - Role: Switching - Role Details: Low-side MOSFET for synchronous buck converter - Package or Case Code: TO-252-2_L6.6-W6.1-P4.57-LS10.1-TL-CW - Transistor Type: N-CHANNEL - Manufacturer Part Number: NCE6020AK - Part Type: MOSFETs - JLCPCB Part Class: Extended Part - Product Info Url: https://lcsc.com/product-detail/MOSFET_NCE6020AK_C108639.html - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2312011440_Wuxi-NCE-Power-Semiconductor-NCE6020AK_C108639.pdf - Manufacturer Name: NCE(无锡新洁能) - Operating Temperature: -55℃~+175℃ - Continuous Drain Current: 20A - LCSC Part Number: C108639 **Pins:** - D [pin 2] - G [pin 1] - S [pin 3] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/katzenbastler/24v-to-12v-stepdown-100w~yl](https://www.flux.ai/katzenbastler/24v-to-12v-stepdown-100w~yl).* --- *Generated from [https://www.flux.ai/katzenbastler/24v-to-12v-stepdown-100w~yl](https://www.flux.ai/katzenbastler/24v-to-12v-stepdown-100w~yl)*