This professional tool calculates parameters for DC-DC Boost Converters (Step-Up). It determines the minimum Inductance required for Continuous Conduction Mode (CCM) and sizing for output capacitors.

It includes a unique Component Sizing Guide that applies safety margins to help you select robust MOSFETs, Diodes, and Inductors for your SMPS design.

Specs & Margins

Input

Input (V_in)

Output (V_out)

Load (I_out)

Freq (f_sw)

kHz

Derating / Safety

Voltage Margin

Current Margin

Parasitics

Efficiency (η)

Target Ripple

Inductor I_sat

Cap ESR

mΩ

Inverting Buck-Boost Converter Schematic Diagram with MOSFET and Diode

Design Analysis

CCM Mode

Required Inductance (L)

— µH

—Peak I_pk

—Avg I_in

—Power Loss

Component Sizing Guide

Minimum rated values with applied safety margin

MOSFET V_DS — V

Diode V_R — V

Cap Voltage — V

MOSFET I_D — A

Diode I_F — A

Inductor I_sat — A

—Min C_out

—Total Ripple

—RHP Zero

Inductor Current (I_L)

Common Boost Configurations

Standard voltage conversion scenarios and typical component requirements.

Application	Input	Output	Duty Cycle	Switch Rating
Li-Ion to USB	3.7 V	5.0 V	~26%	> 10V
12V Bus to 24V	12 V	24 V	50%	> 30V
Laptop Charger (Auto)	12 V	19 V	37%	> 25V
LED Driver	24 V	48 V	50%	> 60V

Physics Explained

[Image of boost converter circuit diagram]

Component Derating

Using components at 100% of their rating reduces lifespan. A 20-30% safety margin (Derating) is standard engineering practice for SMPS reliability.

RHP Zero

The Right-Half-Plane Zero (RHPZ) is a dynamic instability in boost converters. Your control loop bandwidth must be significantly lower than f_RHPZ.

CCM vs DCM

CCM: Inductor current never hits zero (High power).
DCM: Inductor fully discharges every cycle (Low power/Light load).

How to Use

Set Operating Point

Define input/output voltages and load current. Ensure V_out > V_in. The tool assumes a standard non-isolated topology.

Set Safety Margins

Input your desired Voltage and Current margins (e.g., 25%). The Sizing Guide will automatically suggest minimum ratings.

Check Stability

Ensure your control loop crossover frequency is significantly lower than the calculated RHP Zero to prevent oscillation.