Schematic Design FAQs

Schematic Design

How can I label nets or create named connections in the schematic?

Ask Flux to name the nets.

Name the net between U1 pin 5 and J2 pin 3 I2C_SDA.
Rename net N7 to VBAT.

To do it in the UI:

Start a wire from a pin that has no connection. A menu opens next to the pin. Select Create a net or connect to an existing net and type the net name. Pins with the same net name are connected. Flux shows a power symbol for a net whose Net Type property is Power. To connect a pin to ground, select Connect to the GND net. For more information, see Connect nets without wires.

How do I create a circuit schematic and connect components in Flux?

Ask Flux to add the components and connect them.

Add an ESP32-S3 module, a USB-C connector, and a 3.3 V regulator, and connect them.
Connect the SDA and SCL pins of the sensor to the I2C pins of the microcontroller.

To do it in the UI:

  • Drag components from the Library tab onto the canvas.

  • Connect them by clicking on a pin and dragging to another pin.

  • Flux automatically assigns net names if you don’t label them. For more information, see Getting Started in Flux: Schematic Design Guide.

How do I create a bus (multi-wire connection) for signals in my schematic?

Ask Flux to set the bus properties.

Set the same Bus Group on the SPI signals of U1 so that Flux routes them together.

To do it in the UI:

Set the Bus Group and Bus Type properties on the terminals of the bus.

  • Bus Group: the bus or signal group of the terminal, for example SPI Bus, I2C Bus, or Data Bus. Give all terminals of one bus the same Bus Group. If a part has two buses of the same kind, give each bus a different value, for example USB_1 and USB_2.

  • Bus Type: the protocol standard of the bus, for example DDR3, PCIe 3.0, or HDMI. It sets the speed and routing requirements of the bus.

Flux uses these properties for length matching and to route the signals of the bus together. To show the signal order in the schematic, use net labels with names such as D0, D1, and D2. For more information, see Impedance Control.

Can I create reusable sub-circuits?

Ask Flux to create a module from a part of your design and publish it.

Create a new project with the buck converter from this schematic and publish it as a module.

You can also do it in the editor:

Section your schematic or create Modules—reusable sub-circuits that encapsulate part of your design.

Next to read:
PCB Design FAQs
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Schematic Design FAQsSchematic DesignHow can I label nets or create named connections in the schematic?How do I create a circuit schematic and connect components in Flux?How do I create a bus (multi-wire connection) for signals in my schematic?Can I create reusable sub-circuits?