PCB Controller: The Core Control Circuit in a PCB

PCB controller is essential electrochemical or electro-mechanical devices for interfacing users and circuit boards.

Printed circuit boards create compact electrical connections and provide mechanical support to attached components.

But they need controllers to collect user inputs and interpret the control signals to send to the components.

So, we will look at what a PCB controller is all about, beginning with its functions. Take a look!

What Is a PCB Controller?

PCB controllers are electronic circuits that run the operations of PCB, and they can be microcontrollers or integrated circuits. Often built into the PCB, these devices can have several features, such as I/O interfaces and power circuitry.

Since this is the brain of the system, you can program to perform various functions, such as signal processing, power management, and data acquisition. Most of them come preprogrammed to handle specific functions but you can reprogram them if using chips like FPGAs.

Two circuit boards with components soldered on board, including a QFP-packaged chip.

But by default, PCB controllers are responsible for handling the timing, controlling, and sequencing of the board’s operations.

Differences Between a PCB Controller and a PCB

A PCB is a solid or flexible board that houses a compactly designed circuit for electronic components.

But a PCB controller is an electronic component that runs the affairs of the PCB; you can mount it on the circuit board. It is usually a microcontroller, but you can also use a dedicated chip, PLC, or microprocessor.

Types of PCB Controllers

PCB controllers are usually designed to perform specific tasks, where they execute commands and regulate the board’s operations. Therefore, they come as either access controllers, level, flow, pressure, or programmable logic controllers, where the role or type of controller you use depends on the function of the board.

A programmable logic controller mounted on a control panel for industrial applications.

PCB Controller Functions

This controller has six functions.

PCB Control

The primary function of a PCB controller is to ensure all the board functions run smoothly.

So it connects to the memory, logic, and power components to ensure all inputs and outputs are in order.

Managing Pins and Other Connections

PCB controllers also manage connection pins by setting & governing data exchange rules.

This function means the board has the power to manage the host board interactions with other PCBs.

Controlling Data Flow

While managing pins and connections, the controller can regulate data flow across the board.

For instance, it can decide when and which components should receive data.

Controlling data flow is critical if the board has different sections that must exchange data.

A controller board for an elevator

The other three include:

• Power management
• Timing management
• Creating and managing the board’s configuration

Dimensions of PCB Controllers

A PCB controller’s size can vary depending on several factors, including the following.

Integration Level

PCB controllers that integrate multiple components into their package will be larger than those with few parts, resulting in larger dimensions. However, this factor depends on the size of the components, a factor often defined by the nanometer rating.

System Requirements

Circuit boards with multiple components and functions require more control, which means a controller with larger dimensions.

Available Space

You might require a larger controller to handle the board’s operations, but there is limited space on board. This leaves you with only one option, which is to pick a controller that fits.

A circuit board with slots left for soldering a microcontroller.

Package Type

Since the controller can have different forms, it can have different packages, such as QFP, CSP, and BGA. These packages have varying footprint sizes that make them larger or smaller. For instance, the gull-wing leads in QFP packages make them larger than BGA.

Design Considerations

The designer creating the PCB controller’s concept also has a role to play because he or she has variables like peripheral placement that can optimize space inside the device. The better the space utilization, the more compact the controller will be.

How Does a PCB Controller in Embedded Systems Work?

Embedded systems combine hardware and software to perform specific functions, more so in IoT applications. These include controlling traffic, monitoring moisture levels in agriculture, or home automation.

The control panel of a computer for home automation

While controlling these functions, embedded systems need controllers to manage their PCB functions. Some common PCB controller implementations in these embedded systems include Field Programmable Gate Arrays (FGPAs), microcontrollers, and microprocessors.

These controllers manage the various board functions, such as power supply, JTAG interfaces, peripherals, and clock signals (oscillators).

Factors To Consider When Selecting a PCB Controller

Power Requirements

PCB controllers have different applications that usually depend on the board they control.

So their power requirements also vary depending on their use.

For instance, industrial motor PCB controllers have higher power requirements than laptop board controllers.

Therefore, you should have a controller that matches the available power supply.

Compatibility

A PCB controller must be compatible with a board for it to send control signals from the sensed user input.

Check for software, hardware, and platform compatibility.

Memory Capacity

These devices have internal memories to store instructions and process more as a batch.

So the higher the internal memory capacity, the better the device, especially for controlling complex systems.

Reliability

Circuit boards, especially those designed for critical applications like medical and military uses, need maximum reliability.

But generally, always go for reliable controllers because downtimes can be costly and risky.

A PCB being tested for reliability (vibration testing)

Cost

The cost of a controller depends on its application. High-performance units are usually costlier than their low-performance counterparts.

We recommend picking a controller that matches the application to avoid underpowering or overpowering the board.

Overpowering the board is okay, but you’ll underutilize the controller and spend more money for no reason.

Ease of Use

A controller might be powerful and sufficient for the board but may not deliver if complex to use.

So always pick an easy-to-use controller to ensure maximum utilization, performance, and efficiency.

PCB Controller Materials

Considering the conductive tracks, a PCB controller can have traces etched from aluminum alloys, copper, or gold.

Copper is highly conductive, making it reliable for high-speed signal operations.

Gold is also conductive but is more resistant to corrosion. Although expensive, the material is ideal for harsh outdoor operations.

A circuit board with gold traces

Aluminum alloys are cheaper than gold and copper and provide superb static electricity protection. But they are not as durable.

Another thing. The controller’s size determines the material used.

Tiny controllers can function with thin, less conductive materials, but large controllers need thick, more conductive metals.

A PCB controller can be installed in the same circuit as the circuit board it is managing, or it can be built into a separate PCB, especially if there isn’t enough space.

Therefore, it requires several materials to build and assemble, which include the following.

Substrate Material

PCBs must have a base material to create a frame for holding the circuit and components. Most rigid PCB controllers have FR4 substrate boards, but you can use Rogers material for high-frequency circuits.

Various PCBs have FR4 flame-retardant substrate materials.

Copper

Copper is the conduction material that forms the laminated circuit and the exposed pads for attaching components.

Solder Mask

This material covers copper traces on the outer boundaries to insulate and protect them from oxidation.

Silkscreen

PCB controllers can have discrete components to support the chip or microcontroller, so you need this layer to indicate the component labels, part numbers, etc.

A tiny PCB with white visible silkscreen markings.

Surface Finish

The exposed copper pads will oxidize if left uncovered. You must use a surface finish like ENIG to protect the layer while providing superb flatness and excellent solderability.

Solder Paste

To attach the supporting components and even the controller on the board, you must use solder paste (or wire).

How To Design a PCB Controller

1. First, identify/determine the board controller requirements.
2. Second, find a suitable microcontroller.
3. Next, design the board layout.
4. Then, choose the most suitable controller components.
5. Test the unassembled PCB.
6. Assemble and test the board.
7. Finally, program, test, and debug the microcontroller.

General Purpose PCB Controller Best Design Practices

General-purpose PCB controllers usually require repairs or upgrades over time. So when designing them, we recommend splitting the board into separate modules.

For instance, you can have a microcontroller unit module and an I/O module.

With this setup, you can mount the I/O module in an enclosure (terminal rack).

Then install the MCU PCB in the I/O module. The distinct parts will separate the long-lasting modules from those that require frequent replacements.

A batch of automotive-printed circuit boards

So the I/O module will host passive components because they last longer than their active counterparts.

But the microprocessors, intelligent memory chips, and intelligent chip modules will reside on the microcontroller module.

They don’t last as long and may become obsolete quickly.

Since they are separate, ensure you have enough voltage to power the inter-board connectors.

Match these with enough ground pins to handle the return current.

PCB Controller Applications

You can find PCB controllers in these electronics.

• Consumer electronics devices
• Medical equipment (MRI, X-ray machines)

An MRI machine

• Industrial equipment
• Automotive equipment

A car headlight position control module

Embedded Systems

Embedded systems usually incorporate PCB controllers like Field Programmable Gate Arrays and microcontrollers internally.

These controllers communicate with I/O peripheral devices to receive input signals for controlling the board.

Wrap Up

As you can see, PCB controllers play a critical role in circuit boards.

They act as the intermediary between the user input (control signals) and the hardware.

However, you must consider several factors when selecting a board controller.

But instead of buying a ready-made unit, you can design the circuit for manufacturing. And we recommend contacting our technical team for guidance.

At OurPCB, we have the equipment and expertise to get the best PCB controller for your project.