Exploring Quartz Crystal Load Capacitance of Timing Solutions

Why Is It Important to Frequency Control?

Every electronic system requires a reliable timing solution to operate accurately and efficiently. This is especially true for modern connected technology, automotive and general industrial solutions. The most reliable components used in circuits are made with quartz crystals because of the quality and accuracy they provide. Quartz crystals timing solutions provide unmatched reliability, stability and cost-effectiveness. Electronic components like MHz and kHz crystals are examples of these valuable timing solutions. When determining the correct timing solution for any application, there are many different parameters that will need to be evaluated: package size, frequency, operating temperature, tolerance, stability and load capacitance.

The success of applications can be dependent on the load capacitance being accurately matched, so it’s important to understand what it is, the effects it has on a system and how it is calculated.

What Is Load Capacitance?

Load capacitance is defined as the amount of external circuit capacitance in parallel with the crystal itself. As one of the more basic specifications of crystals, the load capacitance necessary for an application is going to need to be determined prior to choosing a crystal part number from a supplier.

When determining load capacitance, the crystals parallel-resonance mode is always above the series resonance frequency and characterized by inductive reactance.

An LC tank circuit is formed when the crystal’s inductance is in parallel with the load capacitance of the oscillator. The frequency of the oscillator is determined by this LC as well.

One thing to note: While Quartz Crystal oscillators are a leading timing solution option, one of the common drawbacks of these components is anti-resonance, or the adjusting of AC circuit components that produces fluctuations in current. Anti-resonance can occur when the net inductive component of the crystal model resonates with the crystal’s internal holder capacitance. Understanding this and considering the repercussions can cause for a smoother design and manufacturing process

What to Know About Load Capacitance and Connected Technology Solutions

The importance of load capacitance has been highlighted as a large factor in the success of a circuit. Inversely, it can be a culprit to many failures and malfunctions within systems. When designing systems, sourcing parts and assembling circuits, it is important to remember the following in regards to load capacitance:

It is imperative that the capacitance of your circuit matches the capacitance of the crystal. If these values do not match, your circuit will not be able to resonate at the correct frequency for proper function.

When working with a series-resonant crystal, load capacitance can be ignored. In these cases, the frequency of the oscillator is only determined by the motional inductance and motional capacitance, not the load capacitance.

To determine the load capacitance of a circuit, there are multiple different capacitances that are considered, including two capacitors (Pierce circuits), input capacitance, output capacitance and all other stray capacitances. All of these combine to provide the capacitance that is found on the crystal’s datasheet, which drives purchasing decisions when shopping for electronic components online or otherwise.

ECS Inc. Has All the Electronic Components Needed For Your Electronic Component Circuits

Offering various high-quality components that provide superior timing, reliability and performance to circuits, ECS Inc. is a leader in adding efficiency and precision to your connected technology solutions and other applications. The components you can find at ECS Inc. include:

These timing solutions and electronic components are easy to find on the ECS Inc. website. Utilize the Parametric Search and Search Inventory pages to specify the search for what is needed from the component. Narrow down potential options by different attributes including:

Series
Type
Package size
Height
Frequency
Load capacitance
ESR
Temperature range
Rating
Tolerance
Stability
And More!

After narrowing options down to the needs of the project at hand, you can identify the exact product that will fulfill the needs of your circuit. If you’re still needing a helping hand, additional questions can be passed to ECS Inc.’s sales representatives directly by phone or by completing the contact form online.

If you are ready to order your component(s), it is best to utilize our online tool to find a local distributor in your area. Components are specific and require precision, it is in your best interest to ensure you only work with trusted companies of ECS Inc. Working with our trusted partners guarantees you the highest quality and most accurate timing solutions and electronic components, even when shopping online!