What Is the SEPIC DC-DC Converter Inductor and Capacitor Ripple Calculator?
The SEPIC converter allows an output DC voltage to be greater than, less than, or equal to the input voltage without polarity inversion.
Unlike conventional boost converters, the SEPIC features true galvanic shutdown because of the series AC coupling capacitor C1, eliminating flyback short-circuit risks.
This tool calculates nominal duty cycle, minimum inductance for continuous conduction mode (CCM), AC coupling capacitance, and peak switch voltage and current ratings.
How Does the SEPIC DC-DC Converter Inductor and Capacitor Ripple Calculator Work?
The calculation evaluates user-provided measurements using recognized domain equations, converts between measurement units, and adjusts for real-world efficiency factors.
SEPIC DC-DC Converter Inductor and Capacitor Ripple Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
Duty cycle is non-inverting buck-boost. Inductors limit ripple current, and coupling capacitor C1 withstands average DC voltage equal to Vin.
How to Use the SEPIC DC-DC Converter Inductor and Capacitor Ripple Calculator
- Enter your primary measurements in the input fields above.
- Select your preferred units (e.g. metric or imperial) if applicable.
- Review or adjust operational assumptions such as field efficiency.
- Click Calculate to instantly generate the full results breakdown and visual chart.
- Use the Reset button at any time to clear the form and test a new scenario.
Step-by-Step Example Calculation
Automotive 12V to 18V LED Driver SEPIC
Input Values:
Understanding Your Result
Your calculated result represents the realistic operational capacity or baseline output under the specified conditions. Comparing theoretical and effective outputs reveals the direct impact of turns, overlap, and practical downtime.
Factors That Affect the Result
Field terrain, operator experience, equipment maintenance, overlap margin, and weather conditions can significantly influence real-world output.
When Should You Use This Calculator?
Use this calculator whenever you need quick, verified estimates for job planning, budgeting, equipment sizing, or project timelines.
Assumptions & Limitations
- The MOSFET switch and output diode experience a voltage stress equal to Vin + Vout + Vd, requiring appropriately rated semiconductors.
- L1 and L2 can be wound on a single coupled magnetic core with 1:1 turns ratio, which cancels ripple current and reduces inductor size.
Frequently Asked Questions
Calculation Accuracy & Reference Note
This calculator implements verified, deterministic mathematical equations based on published standards. Results should be treated as professional engineering estimates; always verify critical operations with local equipment manuals and site inspections.