Switching Frequency Analysis

13:01

Project
Datasheet
Schematic
Simulator (Beta)

Fetching.

Using Schematic Tool.

Analy.

Preparing a simulation.

Looking for "oscillator frequency timing capacitor equation" in MC33063A,34063A.pdf

Looking for "timing capacitor charge and discharge current oscillator description" in MC33063A,34063A.pdf

Looking for "switching frequency or oscillator frequency range" in MC33063A,34063A.pdf

Searching for circuit models.

Analyzing circuit connections.

I'm considering whether the compatibility audit only applies to behavioral functions in our netlist. It seems that might not be the case. The model does use `u()`, which is included, but it's not something I authored, so it should be okay. I think I need to include `.print tran v(vout) v(Net2) v(net5)` and maybe that will be enough. However, it's worth pondering if I also need raw data for plotting around 4.

Considering simulation strategies.

Evaluating measurement strategies.

Estimating oscillator parameters.

Evaluating simulation parameters.

Running Simulator.

Analyzing voltage behavior.

Broaden measurement window.

Evaluating switch node behavior.

Considering measurement strategy.

Running Simulator.

Analyzing data retrieval and switching behavior.

Evaluating switching behavior and topologies.

Clarifying switching node for topology.

Analyzing switching node behavior.

Inspecting frequency behavior.

Measuring oscillation frequency.

Evaluating simulation setup.

Analyzing startup-switch-node behavior.

Determining switching frequency.

Calculating cycle characteristics.

Running Simulator.

Evaluating measurements and data.

Searching for simulation results.

Considering plot creation.

Analyzing plotting data.

Considering plot data.

Exploring simulation data.

Inspecting simulation data.

Running a longer simulation.

Considering plotting options.

Planning a two-panel figure.

Planning a final simulation.

Analyzing steady state transitions.

Running Simulator.

Calculating cycle period.

Planning a switch node plot.

Considering simulation data citations.

Summarizing switching characteristics.

Considering pulse-skipping behavior.

Clarifying plot details.

Summarizing results.

Simulation complete.

I simulated the exact circuit around IC1.

Results


MeasurementResult
Output voltage27.97 V
Startup switching frequency93.84 kHz
Startup period10.657 µs
Startup on-time4.187 µs
Startup off-time6.470 µs
Steady-state switch-node behaviorNo switching transitions observed
What this means
  • The switch node is Net 2, at the junction of L1, D1, and IC1 SwC.
  • During startup, IC1 switches normally at about 93.84 kHz.
  • In steady state, your converter is essentially unloaded except for the divider R4 and R3, so once C3 charges to regulation, switching mostly stops.
  • That is why the switch node sits near 12 V in the steady-state window instead of showing continuous pulses.
Switch-node plot
Image

Image

From the datasheet for IC1, the oscillator operating range is 100 Hz to 100 kHz, which is consistent with the simulated 93.84 kHz startup behavior using C2 = 1500 pF.
If you want, I can rerun it with a defined output load on VOUT so you can see a continuous steady-state switch waveform and cleaner on/off timing.
Simulate with load
Try heavier load
Check timing capacitor
Review output target
2 days

Ready.


D1
C2
Capacitance
1500pF
R3
Resistance
2.2kΩ
Feedback
Feedback
C3
Capacitance
330uF
R4
Resistance
47kΩ
R2
Resistance
180 Ω
L1
Inductance
170uH
IC1
Manufacturer Part Number
MC33063ADR
R1
Resistance
0.22 Ω
VOUT
GND


  • Ground
    A common return path for electric current. Commonly known as ground.
  • 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
  • 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
  • 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
  • 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
  • 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
  • Terminal
    Terminal
    An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.
  • RMCF0805JT47K0
    47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film #forLedBlink
  • 875105359001
    10uF Capacitor Aluminum Polymer 20% 16V SMD 5x5.3mm #forLedBlink #commonpartslibrary #capacitor #aluminumpolymer #radialcan
  • CTL1206FYW1T
    Yellow 595nm LED Indication - Discrete 1.7V 1206 (3216 Metric) #forLedBlink
MC33063A Step-Up Converter thumbnail
High-level step-up converter project that uses the MC34063A family to boost an input supply to a regulated output voltage for general DC power conversion and evaluation.

Properties

Properties describe core aspects of the project.

Pricing & Availability

Distributor

Qty 1

Arrow

$0.03–$0.28

Digi-Key

$0.26–$1.13

LCSC

$0.25

Mouser

$0.99

TME

$1.05

Verical

$0.02–$0.25

Assets

thumbnail-boost.png

thumbnail-boost.png

thumbnail-boostThumbnail

Controls