MOSFET Switch Design Request

3:30

Chat History

Project

Help

Library

Considering user request.

Planning component recommendations.

Working with symbols and components.

Planning for user needs.

Deciding between PLAN and CONSULT.

Choosing CONSULT for user needs.

Using Knowledge Base Tool.

Reading docs about How do I edit a component symbol and change or label its pins in Flux, and map symbol pins to footprint pads? Also how do I search the library and inspect pin names (G, S, D) before placing?.

Searching for components.

Dispatching Library tool to find: "N-channel MOSFET SOT-23 logic-level, suitable for 5 V gate drive, low RDS(on), GSD pinout labeled"

Dispatching Library tool to find: "P-channel MOSFET SOT-23 logic-level, suitable for 5 V gate drive, low RDS(on), GSD pinout labeled"

Dispatching Library tool to find: "100k resistor"

Dispatching Library tool to find: "100 ohm resistor"

Dispatching Library tool to find: "Schottky diode 1 A for flyback protection"

Creating search plan for: "N-channel MOSFET SOT-23 logic-level, suitable for 5 V gate drive, low RDS(on), GSD pinout labeled"

Creating search plan for: "P-channel MOSFET SOT-23 logic-level, suitable for 5 V gate drive, low RDS(on), GSD pinout labeled"

Creating search plan for: "100k resistor"

Creating search plan for: "100 ohm resistor"

Creating search plan for: "Schottky diode 1 A for flyback protection"

Searching.

Found 58 results.

Searching: "Schottky diode 1 A for flyback protection"

Found 45 results.

Searching: "N-channel MOSFET SOT-23 logic-level, suitable for 5 V gate drive, low RDS(on), GSD pinout labeled"

Found 55 results.

Searching: "100k resistor"

Searching.

Found 48 results.

Searching: "100 ohm resistor"

Searching.

Found 45 results.

Searching: "P-channel MOSFET SOT-23 logic-level, suitable for 5 V gate drive, low RDS(on), GSD pinout labeled"

Searching.

Found 60 results.

Searching: "N-channel MOSFET SOT-23 logic-level, suitable for 5 V gate drive, low RDS(on), GSD pinout labeled"

Searching.

Found 59 results.

Searching: "N-channel MOSFET SOT-23 logic-level, suitable for 5 V gate drive, low RDS(on), GSD pinout labeled"

Found 52 results.

Searching: "P-channel MOSFET SOT-23 logic-level, suitable for 5 V gate drive, low RDS(on), GSD pinout labeled"

Searching.

Found 88 results.

Searching: "P-channel MOSFET SOT-23 logic-level, suitable for 5 V gate drive, low RDS(on), GSD pinout labeled"

Finished searching for components.

Planning for component queries.

Here’s a solid way to start your 5 V MOSFET switch, plus how to get a G–S–D‑labeled MOSFET or edit one.

Recommended topology for 5 V (with unknown load)

Default to a low-side N‑MOSFET switch.
Wiring:
- Load high side to +5 V, load low side to MOSFET drain.
- MOSFET source to GND.
- Logic drive to gate.
- Add a gate-to-source resistor to prevent a floating gate (100 kΩ is a common starting point for high‑impedance enables).
- Add a small series gate resistor (about 100 Ω) to tame edge ringing.
- If the load is inductive (motor, relay, solenoid), add a flyback diode across the load: cathode to +5 V, anode to the load/MOSFET side.

Parts you can use right away N‑channel SOT‑23, logic‑level (G–S–D labeled in symbol/footprint):

Supporting passives (examples):

Gate pulldown: RMCF0603FT100K (100 kΩ, 0603)
Gate series: RC0603FR-07100RL (100 Ω, 0603)
Flyback diode (if inductive): SS14_R1_00001 (SMA) or PMEG4010BEA,115 (SOD‑323)

How to edit or create a symbol with G, S, D pins (Flux docs) This is the most relevant entry I found related to the topic (quoted verbatim):

“2- Creating a Symbol

The symbol is the schematic representation of your component. For detailed instructions on creating custom symbols, please refer to our working with symbols tutorial.

Key aspects of symbol creation include:

Designing a clear, recognizable shape
Properly positioning pins
Adding labels and designators
Following industry standard conventions when possible

3- Creating a Footprint

The footprint defines the physical layout of your component on the PCB. For detailed instructions on creating custom footprints, please refer to our working with footprints tutorial.” Source

Next info I need to finish the design for you

Max load current (peak and average)?
Gate drive voltage (3.3 V logic or 5 V)?
Load type (resistive or inductive)? If inductive, what kind?

Once you share those, I can size the passives and finalize the MOSFET choice.

25 days

cornfedjoe

3.3V for the gate drive voltage and resistive load type

25 days

flux

1:31

Chat History

Project

DRAIN

Planning MOSFET switch.

Querying knowledge base.

Clarifying tool usage.

Recommending components.

Clarifying the plan.

Using Knowledge Base Tool.

Creating the plan summary.

I’ll build a 5 V low-side MOSFET switch driven by a 3.3 V control signal.

Plan:

Add a logic‑level N‑MOSFET plus gate series and pulldown resistors.
Wire: +5V→LOAD→Drain; Source→Ground; IN→series R→Gate; pulldown Gate→Ground.
Ensure G–S–D labeling and footprint pin mapping match.
Name nets and update the project description.
Run ERC/DRC and availability checks.

Click Start to execute, and share your max load current if you know it.

Specify load current

Pick resistor values

Prefer footprint

Ask about P-channel vs N-channel

Flux wiring question

25 days

Ready to start.

Show Plan

SOURCE

DRAIN

GATE

Reviews

Ground
A common return path for electric current. Commonly known as ground.
jharwinbarrozo
20.5M
Net Portal
Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
jharwinbarrozo
43.0M
Power Net Portal
Wirelessly connects power nets on schematic. Identical to the net portal, but with a power symbol. Used to organize schematics and separate functional blocks. To wirelessly connect power net portals, give them the same designator. #portal #power
jharwinbarrozo
11.4M
Generic Resistor
A generic fixed resistor for rapid developing circuit topology. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard resistor values: 1.0Ω 10Ω 100Ω 1.0kΩ 10kΩ 100kΩ 1.0MΩ 1.1Ω 11Ω 110Ω 1.1kΩ 11kΩ 110kΩ 1.1MΩ 1.2Ω 12Ω 120Ω 1.2kΩ 12kΩ 120kΩ 1.2MΩ 1.3Ω 13Ω 130Ω 1.3kΩ 13kΩ 130kΩ 1.3MΩ 1.5Ω 15Ω 150Ω 1.5kΩ 15kΩ 150kΩ 1.5MΩ 1.6Ω 16Ω 160Ω 1.6kΩ 16kΩ 160kΩ 1.6MΩ 1.8Ω 18Ω 180Ω 1.8KΩ 18kΩ 180kΩ 1.8MΩ 2.0Ω 20Ω 200Ω 2.0kΩ 20kΩ 200kΩ 2.0MΩ 2.2Ω 22Ω 220Ω 2.2kΩ 22kΩ 220kΩ 2.2MΩ 2.4Ω 24Ω 240Ω 2.4kΩ 24kΩ 240kΩ 2.4MΩ 2.7Ω 27Ω 270Ω 2.7kΩ 27kΩ 270kΩ 2.7MΩ 3.0Ω 30Ω 300Ω 3.0KΩ 30KΩ 300KΩ 3.0MΩ 3.3Ω 33Ω 330Ω 3.3kΩ 33kΩ 330kΩ 3.3MΩ 3.6Ω 36Ω 360Ω 3.6kΩ 36kΩ 360kΩ 3.6MΩ 3.9Ω 39Ω 390Ω 3.9kΩ 39kΩ 390kΩ 3.9MΩ 4.3Ω 43Ω 430Ω 4.3kΩ 43KΩ 430KΩ 4.3MΩ 4.7Ω 47Ω 470Ω 4.7kΩ 47kΩ 470kΩ 4.7MΩ 5.1Ω 51Ω 510Ω 5.1kΩ 51kΩ 510kΩ 5.1MΩ 5.6Ω 56Ω 560Ω 5.6kΩ 56kΩ 560kΩ 5.6MΩ 6.2Ω 62Ω 620Ω 6.2kΩ 62KΩ 620KΩ 6.2MΩ 6.8Ω 68Ω 680Ω 6.8kΩ 68kΩ 680kΩ 6.8MΩ 7.5Ω 75Ω 750Ω 7.5kΩ 75kΩ 750kΩ 7.5MΩ 8.2Ω 82Ω 820Ω 8.2kΩ 82kΩ 820kΩ 8.2MΩ 9.1Ω 91Ω 910Ω 9.1kΩ 91kΩ 910kΩ 9.1MΩ #generics #CommonPartsLibrary
jharwinbarrozo
1.5M
Generic Capacitor
A generic fixed capacitor ideal for rapid circuit topology development. You can choose between polarized and non-polarized types, its symbol and the footprint will automatically adapt based on your selection. Supported options include standard SMD sizes for ceramic capacitors (e.g., 0402, 0603, 0805), SMD sizes for aluminum electrolytic capacitors, and through-hole footprints for polarized capacitors. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard capacitor values: 1.0pF 10pF 100pF 1000pF 0.01uF 0.1uF 1.0uF 10uF 100uF 1000uF 10,000uF 1.1pF 11pF 110pF 1100pF 1.2pF 12pF 120pF 1200pF 1.3pF 13pF 130pF 1300pF 1.5pF 15pF 150pF 1500pF 0.015uF 0.15uF 1.5uF 15uF 150uF 1500uF 1.6pF 16pF 160pF 1600pF 1.8pF 18pF 180pF 1800pF 2.0pF 20pF 200pF 2000pF 2.2pF 22pF 20pF 2200pF 0.022uF 0.22uF 2.2uF 22uF 220uF 2200uF 2.4pF 24pF 240pF 2400pF 2.7pF 27pF 270pF 2700pF 3.0pF 30pF 300pF 3000pF 3.3pF 33pF 330pF 3300pF 0.033uF 0.33uF 3.3uF 33uF 330uF 3300uF 3.6pF 36pF 360pF 3600pF 3.9pF 39pF 390pF 3900pF 4.3pF 43pF 430pF 4300pF 4.7pF 47pF 470pF 4700pF 0.047uF 0.47uF 4.7uF 47uF 470uF 4700uF 5.1pF 51pF 510pF 5100pF 5.6pF 56pF 560pF 5600pF 6.2pF 62pF 620pF 6200pF 6.8pF 68pF 680pF 6800pF 0.068uF 0.68uF 6.8uF 68uF 680uF 6800uF 7.5pF 75pF 750pF 7500pF 8.2pF 82pF 820pF 8200pF 9.1pF 91pF 910pF 9100pF #generics #CommonPartsLibrary
jharwinbarrozo
1.5M
Generic Inductor
A generic fixed inductor for rapid developing circuit topology. *You can now change the footprint and 3D model at the top level anytime you want. This is the power of #generics
jharwinbarrozo
15.4k
Terminal
An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.
natarius
RMCF0805JT47K0
47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film #forLedBlink
jharwinbarrozo
1.2M
875105359001
10uF Capacitor Aluminum Polymer 20% 16V SMD 5x5.3mm #forLedBlink #commonpartslibrary #capacitor #aluminumpolymer #radialcan
jharwinbarrozo
1.2M
CTL1206FYW1T
Yellow 595nm LED Indication - Discrete 1.7V 1206 (3216 Metric) #forLedBlink
jharwinbarrozo
1.1M