I. High-Voltage Input Capacitors: The Core Selection Key for PD Fast Chargers/GaN Chargers

In PD fast charging and GaN power supply architectures, the high-voltage input electrolytic capacitor is a core component determining the overall stability, temperature rise, and lifespan of the device, undertaking functions such as bus energy storage, ripple absorption, and voltage stabilization. As fast charging upgrades towards miniaturization, high power, and high frequency, traditional capacitors can no longer simultaneously meet the stringent requirements for size, capacitance, ESR, and reliability.

ymin has launched the KCX, KCG, KCM, and KCM (T) series of liquid aluminum electrolytic capacitors for this scenario, providing a standardized and highly reliable solution for high-voltage input terminals with small size, high capacitance, low ESR, and high withstand voltage characteristics.

II. Key Pain Points and Technical Challenges in Capacitor Selection

1. Space Constraints: 65W–100W+ chargers are often less than 20mm thick, making traditional capacitors too large; reducing size results in insufficient capacitance, leading to bus fluctuations.

2. Severe High-Frequency Heat Generation: At GaN switching frequencies of hundreds of kHz, ESR directly determines self-heating. High ESR can cause uncontrolled temperature rise and reduced lifespan.

3. High Ripple and Surge Stress: Frequent plugging and unplugging, power grid fluctuations, and lightning surges place higher demands on capacitor ripple withstand capability and voltage withstand margin.

4. Difficulty Balancing Reliability and Cost: Reliance on imported capacitors increases BOM costs and delivery times; low-cost solutions are prone to early failures and increased return rates.

Selection Misconceptions: Focusing only on voltage withstand and capacitance while ignoring ESR, ripple withstand capability, dimensional efficiency, and high-temperature lifespan can easily introduce reliability issues in high-frequency GaN solutions.

III. YMIN's Technological Advantages and Series Selection

Core Technological Advantages

High Capacitance Density: Three-dimensional aluminum foil process, increasing capacitance by 30%~50% for the same volume.

Ultra-miniaturization: Optimized space utilization, reducing volume by approximately 40% compared to traditional products.

Ultra-low ESR: Low-resistance electrolyte + lightning protection structure, ESR as low as 2.3mΩ@100kHz.

High Voltage and High Temperature Resistance: Maximum withstand voltage of 540V, operating temperature of 105℃/115℃, with ample margin.

Series Selection

Series	Temp / Life	Application Scenarios	Core Advantages
KCX	105℃ / 3000h	Standard PD Fast Charging	Small form factor, high capacitance, lightning strike resistance, high ripple current handling
KCG	115℃ / 2000h	High temperature / low ESR scenarios	Higher temperature resistance, lower ESR, high reliability
KCM	105℃ / 3000h	High power density applications	Ultra-small form factor, high voltage rating ≥520V, low ESR
KCM(T)	105℃ / 3000h	High margin designs	Ultra-high voltage rating ≥540V, extreme miniaturization

YMIN KCX/KCM Series | Industry-First High Voltage, Small Size: Core Choice for PD Fast Charging/GaN Chargers

IV. Official Selection Recommendations and Application Summary

Three Official Selection Principles

1. Determine Size First, Then Capacitance and Voltage Ratio: Given the structural space constraints, prioritize the solution with the highest capacitance density within that size.

2. GaN High-Frequency Solutions Must Prioritize ESR and Ripple: ESR and ripple capabilities directly determine temperature rise and lifespan; simultaneous verification is necessary in the initial stages of the solution development.

3. Reserve Voltage and Temperature Margin: It is recommended to reserve a voltage margin of ≥20%, prioritizing models with lightning protection and high ripple.

Applications and Summary

YMIN KCX/KCG/KCM/KCM (T) series have been mass-produced and used in 30W–150W GaN fast charging products from leading brands such as ANKER, Xiaomi, and Tecs, achieving a balance between small size, high capacitance, low ESR, and high reliability.

PD fast charging and GaN chargers have entered a stage of comprehensive competition in terms of power density, efficiency, temperature rise, and reliability. High-voltage input capacitors need to be selected based on factors such as size efficiency, ESR, ripple capability, and surge margin. YMIN provides customers with stable and reliable optimized solutions through mature solutions and original manufacturer technical support.