# 24V PWM Interface & Relay Board ## Description Automotive 24V PWM-to-0–5V interface with isolated inputs, fail-safe heartbeat watchdog, and relay switching for an EPEC EC44 safety system. ## Project Details - **Owner:** alberto16260 - **Created:** 8/14/2026 - **Last Updated:** 8/15/2026 - **Visibility:** Public - **Domain:** Automotive - **Compliance:** ISO 26262 - **Operating Voltage:** 24V ## Key Components ### D1 — [SS56](https://www.flux.ai/lcsc/ss56~hea6.md) - Reverse Voltage: 60V - Forward Voltage: 0.55V - Part Type: Schottky Barrier Diodes (SBD) - LCSC Part Number: C65009 - Diode Type: Schottky Diode - Role: Reverse Polarity Protection - Manufacturer Name: MDD(Microdiode Semiconductor) - Package or Case Code: SMC_L6.9-W5.9-LS7.9-R-RD - Role Details: Series 60V 5A Schottky after input fuse - Datasheet URL: https://www.lcsc.com/datasheet/C65009.pdf?spm=wm.sxq.inf.ggs___wm.ssy.bg.0.xh&lcsc_vid=T1kIXgFeT1NaU1RXQFBbUlUHT1cKU1NXFVBeX1VSTlAxVlNRTlhaXlxfQlZWUjsOAxUeFF5JWBYZEEoKFBINSQcJGk4dAgUUFAk%3D - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: SS56 - JLCPCB Part Class: Extended Part - Functional Group: 24V Power **Pins:** - A [pin 1] - K [pin 2] ### D2 — [SMCJ36A-13-F](https://www.flux.ai/lcsc/smcj36a-13-f~ax3d.md) - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Diodes-Incorporated-SMCJ36A-13-F_C135164.pdf - LCSC Part Number: C135164 - Part Type: TVS - Package or Case Code: SMC_L6.9-W5.9-LS7.9-RD - Manufacturer Name: DIODES(美台) - Manufacturer Part Number: SMCJ36A-13-F - JLCPCB Part Class: Extended Part - Role Details: SMCJ36A from protected 24V to GND after fuse and polarity diode - Role: TVS Protection - Functional Group: 24V Power - Product Info Url: https://lcsc.com/product-detail/TVS_Diodes-Incorporated-SMCJ36A-13-F_C135164.html **Pins:** - A [pin 2] - K [pin 1] ### D3 — [SS34](https://www.flux.ai/collinsemasi/ss34~qf.md) - Manufacturer Name: NextGen Components Inc - Role: Flyback Diode - Functional Group: Relay Channel 1 - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Diode - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/5335/SMASS340000S34.pdf - Role Details: K1 coil flyback; cathode to protected 24V - Manufacturer Part Number: SS34 **Pins:** - A [pin 2] - C [pin 1] ### D4 — [SS34](https://www.flux.ai/collinsemasi/ss34~qf.md) - Role Details: K2 coil flyback; cathode to protected 24V - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: NextGen Components Inc - Role: Flyback Diode - Part Type: Diode - Functional Group: Relay Channel 2 - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/5335/SMASS340000S34.pdf - Manufacturer Part Number: SS34 **Pins:** - A [pin 2] - C [pin 1] ### D5 — [1N4148WQ-7-F](https://www.flux.ai/lcsc/1n4148wq-7-f~jsdf.md) - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Diodes-Incorporated-1N4148WQ-7-F_C500775.pdf - Manufacturer Part Number: 1N4148WQ-7-F - Package or Case Code: SOD-123_L2.7-W1.6-LS3.7-RD - Product Info Url: https://lcsc.com/product-detail/New-Arrivals_Diodes-Incorporated-1N4148WQ-7-F_C500775.html - Manufacturer Name: Diodes Incorporated - JLCPCB Part Class: Extended Part - Part Type: Switching Diode - LCSC Part Number: C500775 - Role Details: Anti-parallel clamp across U6 input LED - Functional Group: PWM1 Isolation - Role: LED Reverse Protection **Pins:** - A [pin 2] - C [pin 1] ### D6 — [1N4148WQ-7-F](https://www.flux.ai/lcsc/1n4148wq-7-f~jsdf.md) - Product Info Url: https://lcsc.com/product-detail/New-Arrivals_Diodes-Incorporated-1N4148WQ-7-F_C500775.html - Package or Case Code: SOD-123_L2.7-W1.6-LS3.7-RD - Part Type: Switching Diode - LCSC Part Number: C500775 - JLCPCB Part Class: Extended Part - Manufacturer Name: Diodes Incorporated - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Diodes-Incorporated-1N4148WQ-7-F_C500775.pdf - Role Details: Anti-parallel clamp across U7 input LED - Manufacturer Part Number: 1N4148WQ-7-F - Role: LED Reverse Protection - Functional Group: PWM2 Isolation **Pins:** - A [pin 2] - C [pin 1] ### D7 — [1N4148WQ-7-F](https://www.flux.ai/lcsc/1n4148wq-7-f~jsdf.md) - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Diodes-Incorporated-1N4148WQ-7-F_C500775.pdf - Functional Group: Heartbeat Watchdog - Manufacturer Part Number: 1N4148WQ-7-F - Product Info Url: https://lcsc.com/product-detail/New-Arrivals_Diodes-Incorporated-1N4148WQ-7-F_C500775.html - Package or Case Code: SOD-123_L2.7-W1.6-LS3.7-RD - JLCPCB Part Class: Extended Part - LCSC Part Number: C500775 - Part Type: Switching Diode - Manufacturer Name: Diodes Incorporated - Role Details: Anti-parallel clamp across U8 input LED - Role: LED Reverse Protection **Pins:** - A [pin 2] - C [pin 1] ### D8 — [1N4148WQ-7-F](https://www.flux.ai/lcsc/1n4148wq-7-f~jsdf.md) - Manufacturer Part Number: 1N4148WQ-7-F - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Diodes-Incorporated-1N4148WQ-7-F_C500775.pdf - Manufacturer Name: Diodes Incorporated - Part Type: Switching Diode - JLCPCB Part Class: Extended Part - LCSC Part Number: C500775 - Package or Case Code: SOD-123_L2.7-W1.6-LS3.7-RD - Functional Group: 40A Relay Contact Sensing - Product Info Url: https://lcsc.com/product-detail/New-Arrivals_Diodes-Incorporated-1N4148WQ-7-F_C500775.html - Role Details: Antiparallel reverse protection for U10 LED - Role: Protection **Pins:** - A [pin 2] - C [pin 1] ### D9 — [1N4148WQ-7-F](https://www.flux.ai/lcsc/1n4148wq-7-f~jsdf.md) - Functional Group: 40A Relay Contact Sensing - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Diodes-Incorporated-1N4148WQ-7-F_C500775.pdf - Manufacturer Part Number: 1N4148WQ-7-F - Package or Case Code: SOD-123_L2.7-W1.6-LS3.7-RD - Role: Protection - Product Info Url: https://lcsc.com/product-detail/New-Arrivals_Diodes-Incorporated-1N4148WQ-7-F_C500775.html - Manufacturer Name: Diodes Incorporated - Part Type: Switching Diode - Role Details: Antiparallel reverse protection for U11 LED - LCSC Part Number: C500775 - JLCPCB Part Class: Extended Part **Pins:** - A [pin 2] - C [pin 1] ### F1 — [SMD050F-2](https://www.flux.ai/adrian95/smd050f-2.md) - Mount: Surface Mount - Part Type: Circuit Protection Devices - Datasheet URL: https://www.littelfuse.com/assetdocs/littelfuse-ptc-smd-datasheet?assetguid=e664881a-0c68-4836-928b-7ed2f0c2a6da - Role Details: Input PPTC sized above <120mA expected load; verify hot derating - Functional Group: 24V Power - Manufacturer Part Number: SMD050F-2 - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Littelfuse - Role: Protection **Pins:** - ~ [pin 2] - ~ [pin 1] ### J1 — [KF128-5.08-2P-AA](https://www.flux.ai/lcsc/kf128-5p08-2p-aa~0pbi.md) - Connector Rows: 1 - Current Rating: 24A - Manufacturer Name: KEFA(科发) - Connector Pitch: 5.08mm - Connector Positions: 2 - Functional Group: 24V Power - JLCPCB Part Class: Extended Part - Role Details: +24V_IN and GND - LCSC Part Number: C474952 - Role: Power Input Connector - Part Type: Screw terminal - Manufacturer Part Number: KF128-5.08-2P-AA - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2408211511_Cixi-Kefa-Elec-KF128-5-08-2P-AA_C474952.pdf - Operating Temperature: -40℃~+105℃ - Product Info Url: https://lcsc.com/product-detail/New-Quadratic-Unclassified-Data_Cixi-Kefa-Elec-KF128-5-08-2P_C474952.html - Connector Type: Screw terminal - Package or Case Code: CONN-TH_P5.08_KF128-5.08-2P - Connector Gender: Female **Pins:** - 1 [pin 1] - 2 [pin 2] ### J10 — [282837-3](https://www.flux.ai/adrian95/282837-3~5mc.md) - Manufacturer Name: TE Connectivity AMP Connectors - Role: Relay Contact Connector - Datasheet URL: https://www.te.com/usa-en/product-282837-3.datasheet.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: 282837-3 - Functional Group: Relay Channel 2 - Symbol Style: parametric-v1 - Part Type: Connector - Role Details: K2B COM NO NC **Pins:** - Pin_1 [pin 1] - Pin_2 [pin 2] - Pin_3 [pin 3] ### J11 — [282837-3](https://www.flux.ai/adrian95/282837-3~5mc.md) - Datasheet URL: https://www.te.com/usa-en/product-282837-3.datasheet.pdf - Functional Group: 40A Relay Contact Sensing - Role Details: Diagnostic taps only; not rated or intended to carry 40A load current - Manufacturer Name: TE Connectivity AMP Connectors - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: 282837-3 - Part Type: Connector - Role: Sense Tap Connector - Symbol Style: parametric-v1 **Pins:** - Pin_1 [pin 1] - Pin_2 [pin 2] - Pin_3 [pin 3] ### J12 — [282837-3](https://www.flux.ai/adrian95/282837-3~5mc.md) - Part Type: Connector - Symbol Style: parametric-v1 - Role Details: CONTACT_NO_SENSE_N, CONTACT_NC_SENSE_N, isolated return - Manufacturer Part Number: 282837-3 - Role: Diagnostic Output Connector - License: https://creativecommons.org/licenses/by/4.0/ - Functional Group: 40A Relay Contact Sensing - Datasheet URL: https://www.te.com/usa-en/product-282837-3.datasheet.pdf - Manufacturer Name: TE Connectivity AMP Connectors **Pins:** - Pin_1 [pin 1] - Pin_2 [pin 2] - Pin_3 [pin 3] ### J2 — [KF128-5.08-2P-AA](https://www.flux.ai/lcsc/kf128-5p08-2p-aa~0pbi.md) - Current Rating: 24A - Manufacturer Name: KEFA(科发) - Connector Pitch: 5.08mm - Connector Positions: 2 - Connector Rows: 1 - Functional Group: PWM1 Isolation - JLCPCB Part Class: Extended Part - Part Type: Screw terminal - Manufacturer Part Number: KF128-5.08-2P-AA - LCSC Part Number: C474952 - Role Details: PWM1_24V and PWM1_RETURN - Package or Case Code: CONN-TH_P5.08_KF128-5.08-2P - Connector Type: Screw terminal - Role: Signal Input Connector - Connector Gender: Female - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2408211511_Cixi-Kefa-Elec-KF128-5-08-2P-AA_C474952.pdf - Product Info Url: https://lcsc.com/product-detail/New-Quadratic-Unclassified-Data_Cixi-Kefa-Elec-KF128-5-08-2P_C474952.html - Operating Temperature: -40℃~+105℃ **Pins:** - 1 [pin 1] - 2 [pin 2] ### J3 — [KF128-5.08-2P-AA](https://www.flux.ai/lcsc/kf128-5p08-2p-aa~0pbi.md) - Role: Signal Input Connector - Role Details: PWM2_24V and PWM2_RETURN - JLCPCB Part Class: Extended Part - Current Rating: 24A - Manufacturer Name: KEFA(科发) - Connector Pitch: 5.08mm - Connector Positions: 2 - Connector Rows: 1 - Package or Case Code: CONN-TH_P5.08_KF128-5.08-2P - Connector Type: Screw terminal - Connector Gender: Female - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2408211511_Cixi-Kefa-Elec-KF128-5-08-2P-AA_C474952.pdf - Product Info Url: https://lcsc.com/product-detail/New-Quadratic-Unclassified-Data_Cixi-Kefa-Elec-KF128-5-08-2P_C474952.html - Operating Temperature: -40℃~+105℃ - Part Type: Screw terminal - Manufacturer Part Number: KF128-5.08-2P-AA - LCSC Part Number: C474952 - Functional Group: PWM2 Isolation **Pins:** - 1 [pin 1] - 2 [pin 2] ### J4 — [KF128-5.08-2P-AA](https://www.flux.ai/lcsc/kf128-5p08-2p-aa~0pbi.md) - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2408211511_Cixi-Kefa-Elec-KF128-5-08-2P-AA_C474952.pdf - Operating Temperature: -40℃~+105℃ - Product Info Url: https://lcsc.com/product-detail/New-Quadratic-Unclassified-Data_Cixi-Kefa-Elec-KF128-5-08-2P_C474952.html - Connector Gender: Female - Role: Signal Input Connector - Package or Case Code: CONN-TH_P5.08_KF128-5.08-2P - Connector Type: Screw terminal - LCSC Part Number: C474952 - Part Type: Screw terminal - Manufacturer Part Number: KF128-5.08-2P-AA - JLCPCB Part Class: Extended Part - Connector Rows: 1 - Role Details: HEARTBEAT_24V and HEARTBEAT_RETURN - Connector Pitch: 5.08mm - Connector Positions: 2 - Functional Group: Heartbeat Watchdog - Current Rating: 24A - Manufacturer Name: KEFA(科发) **Pins:** - 1 [pin 1] - 2 [pin 2] ### J5 — [282837-3](https://www.flux.ai/adrian95/282837-3~5mc.md) - Manufacturer Name: TE Connectivity AMP Connectors - Datasheet URL: https://www.te.com/usa-en/product-282837-3.datasheet.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Functional Group: PWM Analog Filters - Role: Analog Output Connector - Manufacturer Part Number: 282837-3 - Symbol Style: parametric-v1 - Role Details: ANALOG_OUT1, ANALOG_OUT2, GND - Part Type: Connector **Pins:** - Pin_1 [pin 1] - Pin_2 [pin 2] - Pin_3 [pin 3] ### J6 — [KF128-5.08-2P-AA](https://www.flux.ai/lcsc/kf128-5p08-2p-aa~0pbi.md) - Product Info Url: https://lcsc.com/product-detail/New-Quadratic-Unclassified-Data_Cixi-Kefa-Elec-KF128-5-08-2P_C474952.html - Operating Temperature: -40℃~+105℃ - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2408211511_Cixi-Kefa-Elec-KF128-5-08-2P-AA_C474952.pdf - Connector Gender: Female - Connector Type: Screw terminal - Package or Case Code: CONN-TH_P5.08_KF128-5.08-2P - Role: Feedback Connector - LCSC Part Number: C474952 - Manufacturer Part Number: KF128-5.08-2P-AA - Part Type: Screw terminal - JLCPCB Part Class: Extended Part - Functional Group: Relay Feedback - Role Details: FEEDBACK_OUT open collector and FEEDBACK_RETURN emitter - Connector Rows: 1 - Connector Positions: 2 - Connector Pitch: 5.08mm - Current Rating: 24A - Manufacturer Name: KEFA(科发) **Pins:** - 1 [pin 1] - 2 [pin 2] ### J7 — [282837-3](https://www.flux.ai/adrian95/282837-3~5mc.md) - Manufacturer Part Number: 282837-3 - Role: Relay Contact Connector - Functional Group: Relay Channel 1 - Symbol Style: parametric-v1 - Part Type: Connector - Manufacturer Name: TE Connectivity AMP Connectors - Datasheet URL: https://www.te.com/usa-en/product-282837-3.datasheet.pdf - Role Details: K1A COM NO NC - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - Pin_1 [pin 1] - Pin_2 [pin 2] - Pin_3 [pin 3] ### J8 — [282837-3](https://www.flux.ai/adrian95/282837-3~5mc.md) - Role: Relay Contact Connector - Manufacturer Part Number: 282837-3 - Part Type: Connector - Symbol Style: parametric-v1 - Functional Group: Relay Channel 1 - Datasheet URL: https://www.te.com/usa-en/product-282837-3.datasheet.pdf - Role Details: K1B COM NO NC - Manufacturer Name: TE Connectivity AMP Connectors - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - Pin_1 [pin 1] - Pin_2 [pin 2] - Pin_3 [pin 3] ### J9 — [282837-3](https://www.flux.ai/adrian95/282837-3~5mc.md) - Manufacturer Name: TE Connectivity AMP Connectors - Datasheet URL: https://www.te.com/usa-en/product-282837-3.datasheet.pdf - Role: Relay Contact Connector - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: 282837-3 - Functional Group: Relay Channel 2 - Role Details: K2A COM NO NC - Symbol Style: parametric-v1 - Part Type: Connector **Pins:** - Pin_1 [pin 1] - Pin_2 [pin 2] - Pin_3 [pin 3] ### K1 — [G6K-2F-Y DC24](https://www.flux.ai/lcsc/g6k-2f-y-dc24~nk0q.md) - Package or Case Code: RELAY-SMD_G6K-2F-Y - Role: Signal Relay - Part Type: Power Relays - Functional Group: Relay Channel 1 - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2211282300_Omron-Electronics-G6K-2F-Y-DC24_C181935.pdf - Manufacturer Part Number: G6K-2F-Y DC24 - JLCPCB Part Class: Extended Part - Manufacturer Name: OMRON(欧姆龙) - LCSC Part Number: C181935 - Role Details: Channel 1 DPDT relay, 24V coil, common watchdog-controlled return - Product Info Url: https://lcsc.com/product-detail/Relays_OMRON_G6K-2F-Y-DC24V_G6K-2F-Y-DC24V_C181935.html **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] - 5 [pin 5] - 6 [pin 6] - 7 [pin 7] - 8 [pin 8] ### K2 — [G6K-2F-Y DC24](https://www.flux.ai/lcsc/g6k-2f-y-dc24~nk0q.md) - Manufacturer Name: OMRON(欧姆龙) - Product Info Url: https://lcsc.com/product-detail/Relays_OMRON_G6K-2F-Y-DC24V_G6K-2F-Y-DC24V_C181935.html - LCSC Part Number: C181935 - Package or Case Code: RELAY-SMD_G6K-2F-Y - Manufacturer Part Number: G6K-2F-Y DC24 - JLCPCB Part Class: Extended Part - Role Details: Channel 2 DPDT relay, 24V coil, common watchdog-controlled return - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2211282300_Omron-Electronics-G6K-2F-Y-DC24_C181935.pdf - Role: Signal Relay - Part Type: Power Relays - Functional Group: Relay Channel 2 **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] - 5 [pin 5] - 6 [pin 6] - 7 [pin 7] - 8 [pin 8] ### Q1 — [IRLZ44NPBF](https://www.flux.ai/jecstronic/irlz44npbf~kg9.md) - Role Details: Healthy watchdog enables common RELAY_GND; default pulldown forces OFF - Role: Relay Driver - Functional Group: Heartbeat Watchdog - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Infineon Technologies - Datasheet URL: https://www.mouser.com/datasheet/2/196/Infineon_IRLZ44N_DataSheet_v01_01_EN-3363447.pdf - Manufacturer Part Number: IRLZ44NPBF - Part Type: Transistor **Pins:** - D [pin 2] - G [pin 1] - S [pin 3] ### U1 — [LMR36520FADDAR](https://www.flux.ai/adrian95/lmr36520faddar~d6b.md) - Manufacturer Part Number: LMR36520FADDAR - License: https://creativecommons.org/licenses/by/4.0/ - Role: Buck Regulator - Manufacturer Name: Texas Instruments - Functional Group: 24V Power - Datasheet URL: https://www.ti.com/lit/ds/symlink/lmr36520.pdf - Role Details: 24V protected input to regulated +5V_BUCK using TI 5V reference design - Part Type: Integrated Circuit **Pins:** - BOOT [pin 7] - EN [pin 3] - EP [pin 9] - FB [pin 5] - PG [pin 4] - PGND [pin 1] - SW [pin 8] - VCC [pin 6] - VIN [pin 2] ### U10 — [PC817X2NSZ9F](https://www.flux.ai/lcsc/pc817x2nsz9f~p27u.md) - Product Info Url: https://lcsc.com/product-detail/DIP-Optocouplers_Sharp-Microelectronics-PC817X2NSZ9F_C390734.html - Functional Group: 40A Relay Contact Sensing - Role: Optocoupler - Part Type: Optocouplers - Phototransistor Output - LCSC Part Number: C390734 - Manufacturer Part Number: PC817X2NSZ9F - Role Details: COM-NO contact voltage sense; ON indicates voltage across contact/open path - Package or Case Code: DIP-4_L6.4-W4.6-P2.54-LS7.6-BL - JLCPCB Part Class: Extended Part - Manufacturer Name: SHARP(夏普) - Datasheet URL: https://www.lcsc.com/datasheet/lcsc_datasheet_1912111437_Sharp-Microelectronics-PC817X2NSZ9F_C390734.pdf **Pins:** - Anode [pin 1] - Cathode [pin 2] - Collector [pin 4] - Emitter [pin 3] ### U11 — [PC817X2NSZ9F](https://www.flux.ai/lcsc/pc817x2nsz9f~p27u.md) - Manufacturer Part Number: PC817X2NSZ9F - Package or Case Code: DIP-4_L6.4-W4.6-P2.54-LS7.6-BL - Role Details: COM-NC contact voltage sense; ON indicates voltage across contact/open path - JLCPCB Part Class: Extended Part - Functional Group: 40A Relay Contact Sensing - Manufacturer Name: SHARP(夏普) - Datasheet URL: https://www.lcsc.com/datasheet/lcsc_datasheet_1912111437_Sharp-Microelectronics-PC817X2NSZ9F_C390734.pdf - Product Info Url: https://lcsc.com/product-detail/DIP-Optocouplers_Sharp-Microelectronics-PC817X2NSZ9F_C390734.html - Role: Optocoupler - LCSC Part Number: C390734 - Part Type: Optocouplers - Phototransistor Output **Pins:** - Anode [pin 1] - Cathode [pin 2] - Collector [pin 4] - Emitter [pin 3] ### U2 — [MPQ2019GN-AEC1-P](https://www.flux.ai/monolithicpower/mpq2019gn-aec1-p~1o.md) - Role: Linear Regulator - Role Details: Protected 24V to +12V_ANALOG for OPA4171 and precision reference - Product Image Url: https://www.monolithicpower.com/pub/media/catalog/product/M/P/MPQ2019-AEC1_532_1.jpg - Datasheet URL: https://www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/MPQ2019GN-AEC1 - Manufacturer Part Number: MPQ2019GN-AEC1-P - Manufacturer Name: Monolithic Power Systems - Package or Case Code: SOIC-8_EP_MPQ2019_MNP - Functional Group: Analog Power - Product Info Url: https://www.monolithicpower.com/en/catalog/product/view/id/532?utm_source=ultralibrarian&utm_medium=component_search&utm_campaign=listing **Pins:** - EN [pin 5] - EPAD [pin 9] - FB [pin 8] - GND [pin 3] - NC [pin 2] - OUT [pin 1] - PG [pin 6] - PGDL [pin 7] - VIN [pin 4] ### U3 — [REF5050AQDRQ1](https://www.flux.ai/lcsc/ref5050aqdrq1~vb5w.md) - Functional Group: Analog Power - Manufacturer Part Number: REF5050AQDRQ1 - JLCPCB Part Class: Extended Part - Package or Case Code: SOIC-8_L4.9-W3.9-P1.27-LS6.0-BL - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Texas-Instruments-REF5050AQDRQ1_C138360.pdf - LCSC Part Number: C138360 - Role: Voltage Reference - Part Type: Voltage References - Manufacturer Name: TI(德州仪器) - Product Info Url: https://lcsc.com/product-detail/Voltage-References_TI_REF5050AQDRQ1_REF5050AQDRQ1_C138360.html - Role Details: Precision 5V_REF generated from +12V_ANALOG due required reference headroom **Pins:** - DNC [pin 1] - DNC [pin 8] - GND [pin 4] - NC [pin 7] - TEMP [pin 3] - TRIM/NR [pin 5] - VIN [pin 2] - VOUT [pin 6] ### U4 — [OPA4171AQPWRQ1](https://www.flux.ai/lcsc/opa4171aqpwrq1~rfgr.md) - LCSC Part Number: C2059179 - Role Details: Two unity-gain 9.96Hz Sallen-Key channels powered from 12V - Functional Group: PWM Analog Filters - Package or Case Code: TSSOP-14_L5.0-W4.4-P0.65-LS6.4-BL - JLCPCB Part Class: Extended Part - Role: Active Filter - Manufacturer Part Number: OPA4171AQPWRQ1 - Manufacturer Name: TI(德州仪器) **Pins:** - 1 [pin 1] - 1 [pin OUTA] - 14 [pin OUTD] - 4 [pin V+] - 7 [pin OUTB] - 8 [pin OUTC] - INA- [pin 2] - INA+ [pin 3] - INB- [pin 6] - INB+ [pin 5] - INC- [pin 9] - INC+ [pin 10] - IND- [pin 13] - IND+ [pin 12] - V- [pin 11] ### U5 — [TPS3823-50QDBVRQ1](https://www.flux.ai/lcsc/tps3823-50qdbvrq1~zats.md) - LCSC Part Number: C118974 - Functional Group: Heartbeat Watchdog - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2410010302_Texas-Instruments-TPS3823-50QDBVRQ1_C118974.pdf - Manufacturer Part Number: TPS3823-50QDBVRQ1 - Part Type: Monitors & Reset Circuits - Role: Watchdog - Product Info Url: https://lcsc.com/product-detail/Others_Texas-Instruments_TPS3823-50QDBVRQ1_Texas-Instruments-TI-TPS3823-50QDBVRQ1_C118974.html - JLCPCB Part Class: Extended Part - Role Details: 1.6s typical heartbeat timeout; push-pull /RESET drives relay MOSFET gate - Manufacturer Name: TI(德州仪器) - Package or Case Code: SOT-23-5_L3.0-W1.7-P0.95-LS2.8-BL **Pins:** - #MR [pin 3] - #RESET [pin 1] - GND [pin 2] - VDD [pin 5] - WDI [pin 4] ### U6 — [PC817X2NSZ9F](https://www.flux.ai/lcsc/pc817x2nsz9f~p27u.md) - LCSC Part Number: C390734 - Part Type: Optocouplers - Phototransistor Output - Role: Optocoupler - Product Info Url: https://lcsc.com/product-detail/DIP-Optocouplers_Sharp-Microelectronics-PC817X2NSZ9F_C390734.html - Role Details: PWM1 24V isolation, collector pulled to 5V_REF - Datasheet URL: https://www.lcsc.com/datasheet/lcsc_datasheet_1912111437_Sharp-Microelectronics-PC817X2NSZ9F_C390734.pdf - Manufacturer Name: SHARP(夏普) - JLCPCB Part Class: Extended Part - Functional Group: PWM1 Isolation - Package or Case Code: DIP-4_L6.4-W4.6-P2.54-LS7.6-BL - Manufacturer Part Number: PC817X2NSZ9F **Pins:** - Anode [pin 1] - Cathode [pin 2] - Collector [pin 4] - Emitter [pin 3] ### U7 — [PC817X2NSZ9F](https://www.flux.ai/lcsc/pc817x2nsz9f~p27u.md) - LCSC Part Number: C390734 - Part Type: Optocouplers - Phototransistor Output - Role: Optocoupler - Functional Group: PWM2 Isolation - Product Info Url: https://lcsc.com/product-detail/DIP-Optocouplers_Sharp-Microelectronics-PC817X2NSZ9F_C390734.html - Role Details: PWM2 24V isolation, collector pulled to 5V_REF - JLCPCB Part Class: Extended Part - Manufacturer Name: SHARP(夏普) - Datasheet URL: https://www.lcsc.com/datasheet/lcsc_datasheet_1912111437_Sharp-Microelectronics-PC817X2NSZ9F_C390734.pdf - Manufacturer Part Number: PC817X2NSZ9F - Package or Case Code: DIP-4_L6.4-W4.6-P2.54-LS7.6-BL **Pins:** - Anode [pin 1] - Cathode [pin 2] - Collector [pin 4] - Emitter [pin 3] ### U8 — [PC817X2NSZ9F](https://www.flux.ai/lcsc/pc817x2nsz9f~p27u.md) - Part Type: Optocouplers - Phototransistor Output - LCSC Part Number: C390734 - Product Info Url: https://lcsc.com/product-detail/DIP-Optocouplers_Sharp-Microelectronics-PC817X2NSZ9F_C390734.html - Role Details: Heartbeat isolation feeding TPS3823 WDI - Role: Optocoupler - JLCPCB Part Class: Extended Part - Manufacturer Name: SHARP(夏普) - Datasheet URL: https://www.lcsc.com/datasheet/lcsc_datasheet_1912111437_Sharp-Microelectronics-PC817X2NSZ9F_C390734.pdf - Functional Group: Heartbeat Watchdog - Manufacturer Part Number: PC817X2NSZ9F - Package or Case Code: DIP-4_L6.4-W4.6-P2.54-LS7.6-BL **Pins:** - Anode [pin 1] - Cathode [pin 2] - Collector [pin 4] - Emitter [pin 3] ### U9 — [PC817X2NSZ9F](https://www.flux.ai/lcsc/pc817x2nsz9f~p27u.md) - Part Type: Optocouplers - Phototransistor Output - LCSC Part Number: C390734 - Product Info Url: https://lcsc.com/product-detail/DIP-Optocouplers_Sharp-Microelectronics-PC817X2NSZ9F_C390734.html - Role: Optocoupler - Functional Group: Relay Feedback - JLCPCB Part Class: Extended Part - Manufacturer Name: SHARP(夏普) - Datasheet URL: https://www.lcsc.com/datasheet/lcsc_datasheet_1912111437_Sharp-Microelectronics-PC817X2NSZ9F_C390734.pdf - Manufacturer Part Number: PC817X2NSZ9F - Package or Case Code: DIP-4_L6.4-W4.6-P2.54-LS7.6-BL - Role Details: Open-collector isolated relay coil energized feedback **Pins:** - Anode [pin 1] - Cathode [pin 2] - Collector [pin 4] - Emitter [pin 3] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/alberto16260/24v-pwm-interface-and-relay-board~ia](https://www.flux.ai/alberto16260/24v-pwm-interface-and-relay-board~ia).* --- *Generated from [https://www.flux.ai/alberto16260/24v-pwm-interface-and-relay-board~ia](https://www.flux.ai/alberto16260/24v-pwm-interface-and-relay-board~ia)*