Passive Components Blog
No Result
View All Result
  • Home
  • NewsFilter
    • All
    • Aerospace & Defence
    • Antenna
    • Applications
    • Automotive
    • Capacitors
    • Circuit Protection Devices
    • electro-mechanical news
    • Filters
    • Fuses
    • Inductors
    • Industrial
    • Integrated Passives
    • inter-connect news
    • Market & Supply Chain
    • Market Insights
    • Medical
    • Modelling and Simulation
    • New Materials & Supply
    • New Technologies
    • Non-linear Passives
    • Oscillators
    • Passive Sensors News
    • Resistors
    • RF & Microwave
    • Telecommunication
    • Weekly Digest

    Wk 18 Electronics Supply Chain Digest

    YAGEO Releases High Current SMD Common Mode Choke With Shape Core Construction

    Murata and NIMS Built New Database of Dielectric Material Properties

    Tariffs Crush Sales Sentiment in April 2025 ECST Results

    High-Density PCB Assemblies For Space Applications

    Solid State Polymer Multilayer Capacitors For High Temperature Application

    Graphene-Based BOSC Bank Of Supercapacitor Cells

    W-band Self-Biased Circulators for Next Gen VHTS Satellites

    Hybrid Energy Storage System for Nanosatellite Applications

    Trending Tags

    • Ripple Current
    • RF
    • Leakage Current
    • Tantalum vs Ceramic
    • Snubber
    • Low ESR
    • Feedthrough
    • Derating
    • Dielectric Constant
    • New Products
    • Market Reports
  • VideoFilter
    • All
    • Antenna videos
    • Capacitor videos
    • Circuit Protection Video
    • Filter videos
    • Fuse videos
    • Inductor videos
    • Inter-Connect Video
    • Non-linear passives videos
    • Oscillator videos
    • Passive sensors videos
    • Resistor videos

    Coupled Inductors in Multiphase Boost Converters

    VPG Demonstrates Precision Resistor in Cryogenic Conditions

    Comparison Testing of Chip Resistor Technologies Under High Vibration

    EMC Challenges for High Speed Signal Immunity and Low EMI

    MOSFET Gate Drive Resistors Power Losses

    Modified Magnetic Reluctance Equivalent Circuit and its Implications

    Improving Common Mode Noise Reduction while Decreasing BOM

    Die and Wire PCB Bonding Explained

    Rogowski Coil Current Sensor Explained

    Trending Tags

    • Capacitors explained
    • Inductors explained
    • Resistors explained
    • Filters explained
    • Application Video Guidelines
    • EMC
    • New Products
    • Ripple Current
    • Simulation
    • Tantalum vs Ceramic
  • Knowledge Blog
  • Suppliers
    • Who is Who
  • Events
  • Home
  • NewsFilter
    • All
    • Aerospace & Defence
    • Antenna
    • Applications
    • Automotive
    • Capacitors
    • Circuit Protection Devices
    • electro-mechanical news
    • Filters
    • Fuses
    • Inductors
    • Industrial
    • Integrated Passives
    • inter-connect news
    • Market & Supply Chain
    • Market Insights
    • Medical
    • Modelling and Simulation
    • New Materials & Supply
    • New Technologies
    • Non-linear Passives
    • Oscillators
    • Passive Sensors News
    • Resistors
    • RF & Microwave
    • Telecommunication
    • Weekly Digest

    Wk 18 Electronics Supply Chain Digest

    YAGEO Releases High Current SMD Common Mode Choke With Shape Core Construction

    Murata and NIMS Built New Database of Dielectric Material Properties

    Tariffs Crush Sales Sentiment in April 2025 ECST Results

    High-Density PCB Assemblies For Space Applications

    Solid State Polymer Multilayer Capacitors For High Temperature Application

    Graphene-Based BOSC Bank Of Supercapacitor Cells

    W-band Self-Biased Circulators for Next Gen VHTS Satellites

    Hybrid Energy Storage System for Nanosatellite Applications

    Trending Tags

    • Ripple Current
    • RF
    • Leakage Current
    • Tantalum vs Ceramic
    • Snubber
    • Low ESR
    • Feedthrough
    • Derating
    • Dielectric Constant
    • New Products
    • Market Reports
  • VideoFilter
    • All
    • Antenna videos
    • Capacitor videos
    • Circuit Protection Video
    • Filter videos
    • Fuse videos
    • Inductor videos
    • Inter-Connect Video
    • Non-linear passives videos
    • Oscillator videos
    • Passive sensors videos
    • Resistor videos

    Coupled Inductors in Multiphase Boost Converters

    VPG Demonstrates Precision Resistor in Cryogenic Conditions

    Comparison Testing of Chip Resistor Technologies Under High Vibration

    EMC Challenges for High Speed Signal Immunity and Low EMI

    MOSFET Gate Drive Resistors Power Losses

    Modified Magnetic Reluctance Equivalent Circuit and its Implications

    Improving Common Mode Noise Reduction while Decreasing BOM

    Die and Wire PCB Bonding Explained

    Rogowski Coil Current Sensor Explained

    Trending Tags

    • Capacitors explained
    • Inductors explained
    • Resistors explained
    • Filters explained
    • Application Video Guidelines
    • EMC
    • New Products
    • Ripple Current
    • Simulation
    • Tantalum vs Ceramic
  • Knowledge Blog
  • Suppliers
    • Who is Who
  • Events
No Result
View All Result
Passive Components Blog
No Result
View All Result

RLC Circuit Switching Response Explained

2.5.2025
Reading Time: 8 mins read
A A

This article based on Knowles Precision Devices blog explains how an RLC circuit responds to a switching pulse.

One of the fundamental roles of capacitors is charging and discharging energy predictably. Many electronics applications leverage capacitors to store energy and release it in a controlled pulse of current or voltage. Here, we’ll revisit how pulses are produced in a basic RLC circuit featuring a capacitor (C), inductor (L) and resistor (R). 

RelatedPosts

RF Inductors Key Characteristics and Applications

Stacked Ceramic Capacitors Improve Efficiency in Power and RF Applications

Capacitors in Pulse Forming Network

Series RLC Circuit

As mentioned above, a series RLC circuit, show in Figure 1, is made up of the three most common passive components in electronics engineering. When the capacitor is charged to an initial voltage (V0) and switched to discharge via the resistor and inductor (I0=0), three types of responses can occur depending on the component values involved.

Figure 1. Series RLC circuit with a switch

When assessing current in an RLC circuit, damping dictates which equation you should use to determine how current varies over time. Is the system overdamped, critically damped or underdamped? The damping ratio, ζ, places a system into one of these categories. 

Two RLC circuit parameters can be used to understand a system’s damping ratio: neper frequency and resonant angular frequency.

Neper Frequency 

The neper frequency refers to an exponential transience rate. In other words, how quickly is energy lost from the system?

Find the neper frequency α using: 

Resonant Angular Frequency 

The resonant angular frequency ω0 indicates what frequency a system will oscillate at: 

In combination, these parameters can be used to calculate the damping factor and identify which mathematical model would best represent the system’s behavior. 

Damping Factor 

Refocusing on the damping factor, the value for ζ places the system into one of three categories. There are three cases to consider: 

Case 1: Overdamped: ζ > 1 

Case 2: Critically Damped: ζ = 1 

Case 3: Under Damped: ζ < 1 

where:

Capacitor Discharge Current Theory derives solutions for current over time for each damping case. Here, we’ll leverage those results for the sake of example. 

Case 1: Overdamped Current Response 

When ζ > 1, apply the following equation: 

where:

To observe an overdamped response, shown in Figure 2, charge the capacitor to 10V and set C to 2.0μF, L to 5.0mH and R to 200Ω.

Figure 2. Current over time for an overdamped RLC circuit

Case 2: Critically Damped Current Response Case 3: Underdamped Current Response 

When ζ = 1, apply the following equation: 

To observe a critically damped response, shown in Figure 3, keep C and L the same and set R to 100Ω. As shown, critically damped cases typically have higher peak amplitudes than overdamped cases. 

Figure 3. Current over time for an underdamped RLC circuit

Case 3: Underdamped Current Response 

When ζ < 1, apply the following equation: 

To observe an underdamped response, shown in Figure 4, keep C and L the same and set R to 50Ω. With all over variables remaining constant over time, resistance drives damping. As resistance decreases, the damping ratio decreases and peaks get larger. In this case, oscillation and decay, a pair known as ringing, become more pronounced too. The damping ratio determines the rate at which decay occurs.  

Figure 4: Current over time for an underdamped circuit with 50Ω resistance (left) vs. 10Ω resistance (right) 

Peak current varies among damping cases, which is best observed on a single plot, Figure 5. 

Figure 5: Current over time for various damping ratios in an RLC circuit

The Impact of Capacitance on Circuit Response 

Changing resistance (Figure 3) has the most significant impact on damping ratio; however, changes in capacitance and inductance can also change the shape of the system response. 

Consider the earlier equation: 

where,

By rewriting ζ in terms of α and ω, you have: 

The damping ratio was 2.0 when values were set to C = 2.0µF, L = 5.0mH and R = 200Ω. By changing C to 1.0µF, the damping ratio is approximately 1.41. Since this is still considered an overdamped condition, you can use the equation for an overdamped case to compare 2.0µF and 1.0µF of capacitance, Figure 6. 

Figure 6: Current over time for an overdamped circuit with different capacitor values in an RLC circuit

The area under 1.0µF capacitance case is smaller, which is reasonable to expect from a smaller capacitor that stores less charge. 

Here, we’ve explored:  

  • The three relevant equations for current waveform in an RLC circuit
  • The cases in which those equations are valid (depending on the damping ratio range) 
  • How adjusting the capacitance value in the RLC circuit changes the shape of the waveform

Related

Source: Knowles Precision Devices

Recent Posts

YAGEO Releases High Current SMD Common Mode Choke With Shape Core Construction

5.5.2025
4

Murata and NIMS Built New Database of Dielectric Material Properties

5.5.2025
12

Tariffs Crush Sales Sentiment in April 2025 ECST Results

5.5.2025
8

Solid State Polymer Multilayer Capacitors For High Temperature Application

2.5.2025
11

Graphene-Based BOSC Bank Of Supercapacitor Cells

2.5.2025
11

Hybrid Energy Storage System for Nanosatellite Applications

1.5.2025
7

COTS-Plus Bulk Tantalum Capacitor for LEO Flight Platforms

29.4.2025
34

Würth Elektronik Offers New Power Supplies Development Kit

29.4.2025
27

Bourns Extends Shielded Power Inductors by Four New Series

29.4.2025
15

Shielding Cabinets

29.4.2025
13

Upcoming Events

May 6
19:00 - 20:00 CEST

Achieving Seamless 1.6 Tbps Interoperability for High BW HPC AI/ML SoCs

May 14
11:00 - 12:00 CEST

Reliable RIGID.flex PCBs for Critical Applications – Made in Europe

May 28
16:00 - 17:00 CEST

Power Over Data Line

View Calendar

Popular Posts

  • Buck Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • Flyback Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • Boost Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • Characterization of 70GHz Thin Film Chip Resistors

    0 shares
    Share 0 Tweet 0
  • LLC Resonant Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • Why Low ESR Matters in Capacitor Design

    0 shares
    Share 0 Tweet 0
  • SEPIC Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • What is a Dielectric Constant and DF of Plastic Materials?

    4 shares
    Share 4 Tweet 0
  • Ripple Current and its Effects on the Performance of Capacitors

    3 shares
    Share 3 Tweet 0
  • Dual Active Bridge (DAB) Topology Explained

    0 shares
    Share 0 Tweet 0

Newsletter Subscription

 

Passive Components Blog

© EPCI - Leading Passive Components Educational and Information Site

  • Home
  • Privacy Policy
  • EPCI Membership & Advertisement
  • About

No Result
View All Result
  • Home
  • Knowledge Blog
  • Premium Suppliers

© EPCI - Leading Passive Components Educational and Information Site

This website uses cookies. By continuing to use this website you are giving consent to cookies being used. Visit our Privacy and Cookie Policy.
Go to mobile version