MLCC for High-Frequency Power Supplies SiC/GaN Adaptation High-Frequency Filtering Low-Loss Selection

author: 11

2026-05-25

With the wide application of SiC and GaN power devices, power supply operating frequencies have increased to 5MHz–20MHz. Traditional standard MLCCs cannot meet high-frequency operating conditions, often causing problems such as excessive loss, resonance i

MLCC for High-Frequency Power Supplies: SiC/GaN Adaptation, High-Frequency Filtering & Low-Loss Selection

Dongguan Musen Leyton Electronic Technology Co., Ltd.

High-Frequency MLCC, SiC/GaN Capacitor Adaptation, Low ESL/ESR Selection, High-Frequency Filter Design, MLCC for Switching Power Supplies

mu sen Introduction

With the wide application of SiC and GaN power devices, power supply operating frequencies have increased to 5MHz–20MHz. Traditional standard MLCCs cannot meet high-frequency operating conditions, often causing problems such as excessive loss, resonance interference, thermal failure, and unstable regulation.

For high-frequency applications, parasitic parameters, dielectric characteristics, and package size are critical to efficiency and stability. High-frequency power supplies require four core indicators: low ESR, low ESL, high SRF, and excellent capacitance retention at high frequencies. Conventional X5R, standard X7R, and large packages cannot meet the requirements of fast chargers, inverters, and energy-storage power supplies.

This article explains MLCC selection logic for high-frequency power supplies, adaptation rules for SiC/GaN circuits, combined filtering design, stress protection, and reliability optimization to solve resonance, heating, and EMI issues.

1. MLCC Performance Trends in High-Frequency Conditions

1.1 Electrical Changes with Increasing Frequency

Capacitance attenuation: Effective capacitance drops rapidly for conventional dielectrics
Increased loss: ESR rises with frequency, causing heat generation
Parasitic dominance: ESL becomes dominant and causes resonance spikes
Impedance transition: Beyond SRF, capacitor acts as an inductor and loses filtering function

1.2 Forbidden Components in High-Frequency Applications

X5R dielectric: High loss and poor temperature stability
Packages 1210 and above: High ESL and severe parasitic interference
Old expired inventory: Degraded high-frequency performance

2. Precise MLCC Dielectric & Package Selection

2.1 Dielectric Selection by Frequency

Operating Frequency	Recommended Dielectric	Core Advantages	Application Circuits
1–5MHz	Standard X7R	Cost-effective, controllable loss	General fast chargers, low-voltage inverters
5–10MHz	High-Frequency X8R	Low loss, stable at high temp & freq	GaN chargers, automotive power
Above 10MHz	C0G	No drift, ultra-low parasitics	High-frequency oscillation, sampling

2.2 Package Selection Principles

Higher frequency requires smaller packages to minimize ESL:

Below 10MHz: 0603 preferred (balance of current & parasitics)
Above 10MHz: 0402 preferred (optimal response)
High-current bus: Parallel small capacitors instead of single large package

CBB81 High Voltage Inverters

6KV 10KV Rated Safety Ceramic Capacitor 1NF 25KV

3. MLCC Application for SiC/GaN Power Circuits

3.1 Snubber Capacitors for Switches

Used to suppress voltage spikes and protect devices. Select C0G (100pF–1nF), placed close to device pins with very short traces.

3.2 Input & Output Filter Design

Combined filter: X8R for low-frequency ripple, C0G for high-frequency noise
Parallel arrangement: Distributes ripple current and reduces heating
Voltage derating: ≥1.8x for high-frequency spike environments

3.3 Gate Drive Circuit Requirements

Must use high-precision C0G dielectric with tolerance ≤±1% to avoid frequency shift and false triggering.

Through-hole aluminum electrolytic capacitors MP50V10M5X11

Through-hole aluminum electrolytic capacitors MP110477M1A0607VFL

4. High-Frequency PCB Layout & Pad Design

4.1 Layout Rules

Place MLCCs close to power IC pins to minimize loop area
Keep traces short and direct; avoid long meandering paths
Connect filter capacitor grounds directly to main ground plane

4.2 High-Frequency Pad Optimization

Minimize pad length to reduce parasitic inductance
Widen pad width for better heat dissipation
Maintain spacing between capacitors to avoid coupling

5. High-Frequency Fault Troubleshooting & Solutions

5.1 Excessive Heating & Low Efficiency

Cause: High dielectric loss, high ESL, overload

Solution: Replace with X8R/C0G; use parallel capacitors

5.2 Circuit Resonance & Instability

Cause: SRF falls within operating band

Solution: Use smaller packages with higher SRF; adjust value combination

5.3 EMI Failure

Cause: Poor high-frequency filtering, large radiation loop

Solution: Multi-value filtering; compact layout; low-loss dielectrics

5.4 Excessive Switching Spike Voltage

Cause: Poorly matched snubber capacitor

Solution: Use C0G snubber; optimize placement and discharge path

6. Incoming Inspection Standards for High-Frequency MLCC

Basic parameters: Capacitance tolerance meets dielectric standard
Parasitic parameters: ESR / ESL below datasheet limits
Resonance frequency: SRF higher than maximum operating frequency
Thermal stability: Stable capacitance after aging at 125℃

mu sen Application Summary

MLCC design for high-frequency power supplies focuses on low parasitics, low loss, and high stability. Select dielectrics and packages based on operating frequency, use combined filtering, and compact PCB layout to fully adapt to SiC/GaN applications.

Abandoning low-frequency selection logic prevents heating, resonance, and interference, improving efficiency and long-term reliability.

Our full series of high-frequency MLCCs includes 0402/0603 packages, low-loss X8R, and high-precision C0G types, supporting all high-frequency power supply designs with selection support and free samples.