# 5V Hazardous-Live LNK3204D Offline Buck
## Description
230 VAC to 5 V non-isolated offline buck using Power Integrations LNK3204D. Every net, including HAZ_5V and HAZ_RETURN, is hazardous live/mains-referenced; sealed internal use only with galvanically isolated test and programming equipment.
## Project Details
- **Owner:** ess461
- **Created:** 8/5/2026
- **Last Updated:** 8/5/2026
- **Visibility:** Public
- **Domain:** Power Supply
- **Power Requirements:** 0.6W non-isolated
- **Compliance:** Safety review required
- **Implementation Details:** All circuitry including 5 V rail and return is HAZARDOUS LIVE; sealed internal smart-plug use only; isolated programming and galvanically isolated instrumentation mandatory.
- **Operating Voltage:** 230V
## Key Components
### D1 — [1N4007RLG](https://www.flux.ai/jecstronic/1n4007rlg~07j.md)
- Functional Group: Hazardous Live Rectifier and EMI Filter
- Role: Rectification
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: Diode
- Datasheet URL: https://www.onsemi.com/pdf/datasheet/1n4001-d.pdf
- Manufacturer Name: onsemi
- Manufacturer Part Number: 1N4007RLG
- Role Details: HAZARDOUS LIVE 1000 V/1 A line rectifier; anode from fused line, cathode to positive HV bus
**Pins:**
- anode [pin 2]
- cathode [pin 1]
### D2 — [1N4007RLG](https://www.flux.ai/jecstronic/1n4007rlg~07j.md)
- Role Details: HAZARDOUS LIVE 1000 V/1 A return diode; anode to HAZ_RETURN, cathode to HAZ_N
- Manufacturer Part Number: 1N4007RLG
- Manufacturer Name: onsemi
- Datasheet URL: https://www.onsemi.com/pdf/datasheet/1n4001-d.pdf
- Functional Group: Hazardous Live Rectifier and EMI Filter
- Role: Rectification
- Part Type: Diode
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- anode [pin 2]
- cathode [pin 1]
### D3 — [UF4007](https://www.flux.ai/lcsc/uf4007~dqda.md)
- Role: Catch Diode
- Manufacturer Name: MDD(辰达半导体)
- Package or Case Code: DO-41_BD2.4-L4.7-P8.70-D0.9-RD
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2407291942_MDD-Microdiode-Semiconductor-UF4007_C960666.pdf
- LCSC Part Number: C960666
- Role Details: HAZARDOUS LIVE UF4007 1000 V/1 A, tRR <=75 ns; anode HAZ_RETURN, cathode HAZ_SW; MDCM only
- Product Info Url: https://lcsc.com/product-detail/Diodes-Rectifiers-Fast-Recovery_MDD-Microdiode-Electronics-UF4007_C960666.html
- JLCPCB Part Class: Extended Part
- Functional Group: Hazardous Live Offline Buck
- Manufacturer Part Number: UF4007
- Part Type: Diodes - Fast Recovery Rectifiers
**Pins:**
- A [pin 2]
- K [pin 1]
### D4 — [1N4007RLG](https://www.flux.ai/jecstronic/1n4007rlg~07j.md)
- Part Type: Diode
- Functional Group: Hazardous Live Offline Buck
- Role: Feedback Rectifier
- License: https://creativecommons.org/licenses/by/4.0/
- Role Details: HAZARDOUS LIVE feedback rectifier; anode HAZ_5V, cathode HAZ_SENSE
- Manufacturer Name: onsemi
- Datasheet URL: https://www.onsemi.com/pdf/datasheet/1n4001-d.pdf
- Manufacturer Part Number: 1N4007RLG
**Pins:**
- anode [pin 2]
- cathode [pin 1]
### F1 — [2010T200mA250V](https://www.flux.ai/lcsc/2010t200ma250v~pyp4.md)
- Package or Case Code: FUSE-TH_L8.5-W4.0-P5.08-D0.6
- Manufacturer Part Number: 2010T200mA250V
- LCSC Part Number: C2840857
- Manufacturer Name: WALTER(华德)
- Voltage Rating: 250V
- JLCPCB Part Class: Extended Part
- Role: Protection
- Functional Group: Mains Protection
- Current Rating: 0.2A
- Role Details: HAZARDOUS LIVE 200 mA time-delay fuse in series with HAZ_L; breaking-capacity coordination remains product-level requirement
- Part Type: Disposable fuses
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### J1 — [XY301V-A-5.0-2P](https://www.flux.ai/jharwinbarrozo/xy301v-a-50-2p~u6.md)
- Role: Power Conversion
- Part Type: Connector
- Manufacturer Name: Ningbo Xinlaiya Elec.
- Connector Positions: 2
- Voltage Rating: 300V
- Current Rating: 15A
- Manufacturer Part Number: XY301V-A-5.0-2P
- Datasheet URL: https://www.lcsc.com/datasheet/C557651.pdf?spm=wm.sxq.inf.ggs&lcsc_vid=E1BYV1AHFgUMXgFVQ1AMU1JVQFReXgIATwJfA10DFVkxVlNRT1dXXlVTQ1hbUjsOAxUeFF5JWBYZEEoBGA4JCwFIFA4DSA%3D%3D
- Role Details: HAZARDOUS LIVE mains input terminal; pin 1 HAZ_L, pin 2 HAZ_N; sealed enclosure only
- Connector Type: Screw terminal
- Functional Group: Mains Input
**Pins:**
- PIN1 [pin 1]
- PIN2 [pin 2]
### MOV1 — [V14E275P](https://www.flux.ai/lcsc/v14e275p~yv2u.md)
- Product Info Url: https://lcsc.com/product-detail/Varistors_Littelfuse_V14E275P_Littelfuse-V14E275P_C179017.html
- Manufacturer Part Number: V14E275P
- Functional Group: Mains Protection
- Part Type: Varistors
- Manufacturer Name: Littelfuse(美国力特)
- Voltage Rating: 275V
- JLCPCB Part Class: Extended Part
- Package or Case Code: RES-TH_L14.0-W4.9-P7.50-D0.8-S4.90
- Datasheet URL: https://www.littelfuse.com/assetdocs/littelfuse_ultramov_varistor_series_datasheet.pdf
- Role: Clamping
- LCSC Part Number: C179017
- Role Details: HAZARDOUS LIVE V14E275P 275 VAC MOV across HAZ_L_FUSED and HAZ_N, downstream of F1
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### U1 — [LNK3204D-TL](https://www.flux.ai/lcsc/lnk3204d-tl~7zfd.md)
- Manufacturer Name: Power Integrations(帕沃英蒂格盛)
- Manufacturer Part Number: LNK3204D-TL
- JLCPCB Part Class: Extended Part
- Package or Case Code: SO-8C_7P-L4.9-W3.9-P1.27-LS6.0-BL-PE3
- Role Details: HAZARDOUS LIVE LNK3204D standard buck; conservative 5 V/120 mA MDCM target; entire output mains-referenced
- LCSC Part Number: C567600
- Role: Power Conversion
- Part Type: DC-DC Converters
- Functional Group: Hazardous Live Offline Buck
**Pins:**
- BP/M [pin 1]
- D [pin 4]
- FB [pin 2]
- S [pin 7]
- S [pin 5]
- S [pin 6]
- S [pin 8]
*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/ess461/5v-hazardous-live-lnk3204d-offline-buck~ar](https://www.flux.ai/ess461/5v-hazardous-live-lnk3204d-offline-buck~ar).*
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*Generated from [https://www.flux.ai/ess461/5v-hazardous-live-lnk3204d-offline-buck~ar](https://www.flux.ai/ess461/5v-hazardous-live-lnk3204d-offline-buck~ar)*