Switching Converter Design Suite - DC-DC Converter Design Tool

📖 How to Use ▼

🎯 Getting Started

This tool helps you design DC-DC switching converters by calculating:

Inductor Value (L): Based on ripple current requirements and switching frequency
Capacitor Value (C): Output filter capacitor for voltage ripple control
Duty Cycle (D): PWM duty cycle required for voltage conversion
Efficiency Analysis: Power loss estimation from MOSFET RDS(on) and inductor ESR

🔄 Converter Topologies

Buck Converter (Step-Down):

Output Voltage: V_out = D × V_in
Use Case: 12V → 5V, 24V → 12V, battery regulation
Characteristics: Simple, efficient, common for power supplies

Boost Converter (Step-Up):

Output Voltage: V_out = V_in / (1 - D)
Use Case: 5V → 12V, battery backup systems, LED drivers
Characteristics: Discontinuous input current, higher output ripple

Buck-Boost Converter (Inverting):

Output Voltage: V_out = -V_in × D / (1 - D)
Use Case: Wide input range, negative voltage generation
Characteristics: Can step up or down, inverted polarity option

📐 Key Design Formulas

Inductor Calculation (Volt-Second Balance):

L = (V_L × t) / ΔI

Buck: L = (V_out × (V_in - V_out)) / (V_in × f × ΔI_L)
Boost: L = (V_in × D) / (f × ΔI_L)
Buck-Boost: L = (V_in × D) / (f × ΔI_L)

Capacitor Calculation:

C = ΔI_L / (8 × f × ΔV_out)

ΔI_L = Inductor ripple current (A)
f = Switching frequency (Hz)
ΔV_out = Output voltage ripple (V)

⚡ Efficiency & Losses

Conduction Losses:

MOSFET: P_MOSFET = I_out² × RDS(on) × D
Inductor: P_inductor = I_out² × ESR
Diode: P_diode = V_F × I_out × (1 - D)

Efficiency: η = P_out / (P_out + P_losses) × 100%

Note: This tool focuses on conduction losses. Real-world efficiency also includes switching losses, gate drive losses, and core losses.

💡 Design Tips

Ripple Current: Typical ΔI_L is 20-40% of output current for good efficiency
Switching Frequency: Higher frequency → smaller inductors/caps, but higher switching losses
Common Frequencies: 50-100kHz (general), 100-500kHz (compact), 1MHz+ (ultra-compact)
MOSFET Selection: Lower RDS(on) improves efficiency but costs more
Inductor Selection: Choose saturation current ≥ I_L,max = I_out + ΔI_L/2
Output Capacitor: Use low-ESR capacitors (ceramic, polymer) for best ripple performance

Converter Topology

Select the DC-DC converter type for your application

⬇️

Buck

Step-Down

V_out < V_in D = V_out/V_in

⬆️

Boost

Step-Up

V_out > V_in D = 1 - V_in/V_out

↕️

Buck-Boost

Inverting

Any V_out D = V_out/(V_in+V_out)

Design Parameters

Enter your converter specifications

Input Voltage (V_in) Volts (supports: mV, V, kV)

Output Voltage (V_out) Volts (supports: mV, V, kV)

Output Current (I_out) Amperes (supports: µA, mA, A, kA)

Switching Frequency (f_sw) Hertz (supports: Hz, kHz, MHz, GHz)

Ripple Current (% of I_out) Typically 20-40%

Output Ripple Voltage (ΔV_out) Volts (supports: µV, mV, V)

Efficiency Analysis (Optional)

Enter component parameters for loss calculation

MOSFET RDS(on) Ohms (supports: mΩ, Ω, kΩ)

Inductor ESR Ohms (supports: mΩ, Ω, kΩ)

Diode Forward Voltage (V_F) Volts (supports: mV, V) - Typical: Schottky 0.3-0.5V, Fast 0.7-1.0V

Design Results

⚙️ Operating Point

Duty Cycle (D): -

Output Power: -

Inductor Ripple Current: -

Peak Inductor Current: -

🧲 Required Components

                            Inductance (L):
                            -
                        

                            Capacitance (C):
                            -
                        

Inductor Saturation Current: -

Capacitor Voltage Rating: -

📊 Efficiency Analysis

MOSFET Loss: -

Inductor Loss: -

Diode Loss: -

Total Loss: -

                            Estimated Efficiency:
                            -
                        

⚠️ Note: This calculation includes only conduction losses. Real-world efficiency will be lower due to switching losses, gate drive losses, and magnetic core losses.

⚡ Switching Converter Design Suite