STE X2 Capacitors Featured in Fast Charging Component Roundup

STE MPX/X2 capacitors appeared in Chongdiantou's January 2024 overview of safety capacitors for fast chargers. The original article covered three manufacturers: STE, KYET and DGCX. This English edition covers each supplier’s X2 product range, construction and reported applications, while distinguishing the historical article from later STE specifications.

The report showed a device marked MPX275VAC X2 and described compact packaging for chargers, adapters and power modules. It also referred to STE components observed in earlier teardowns. Those observations concern particular samples; they do not establish a purchasing relationship, endorsement or an identical component choice across a brand's products.

The original report and the later specification

Chongdiantou's January article listed a capacitance range of 0.001–2.2 µF and AC voltage options of 275, 305 and 310 V. STE subsequently issued the MPX/X2 specification dated April 8, 2024, which lists the broader values below. The later document supplies a more specific technical reference for this adaptation; it does not change what the January article originally reported.

These specifications describe the component family, not a statement that every capacitance is supplied in every voltage and package combination. The appropriate dimensional table and exact part specification determine the available option.

Across-line filtering in a compact power supply

An X2 capacitor provides capacitance across the supply lines as part of an interference-suppression network. Its performance depends on the complete filter, the converter's noise sources and the wiring arrangement. Package size is relevant to a compact charger, but it is only one selection constraint.

The rated AC voltage must suit continuous operating conditions. The five-second DC withstand value in the datasheet describes a different test and must not be used as a continuous voltage allowance. Capacitance tolerance, local temperature, lead spacing and body dimensions must also fit the design.

The source highlighted flame-retardant packaging and approval coverage. STE's cited datasheet contains a safety-approval table, including entries divided by capacitance range for some certification systems. Engineers should confirm the certificate scope for their intended part and destination market. A resin flammability classification is distinct from component approval, and neither establishes approval of the finished charger.

Selection information for engineers

The article's practical message is that electrical and mechanical specifications need to be reviewed together. Define the required capacitance, supply-voltage range and temperature conditions before choosing a package. Then evaluate the filter in the assembled product, including its conducted-emissions performance and the required discharge behavior after disconnection.

The original feature also announced STE's participation in the spring 2024 Asia Charging Expo. That announcement is retained as historical context; it is not a current exhibition invitation.

For current product enquiries, visit the MPX/X2 series page and request the exact part specification, dimensions and applicable certificates. The selected component still requires qualification under the conditions of the intended power supply. MPX/X2 series page

KYET: MKP-X2 film capacitors

The KYET profile describes thirteen years of product and process development at the time of publication. Its portfolio includes 310 V, 350 V and 380 V safety capacitors, wireless-charging capacitors, MMKP82 double-sided metallized resonant capacitors and compact MPB boxed products. It also lists film, X/Y safety and ceramic capacitors, varistors and thermistors for applications from fast charging and household appliances to industrial, medical, automotive and communications equipment.

The source describes ISO 9001:2015 management certification, product approval and environmental-compliance statements, patents, and engineering assistance with circuit development, capacitor selection, customization and failure analysis. It names Midea, AUX, Gree, Haier, Belkin and Flyco in its historical supply-chain discussion, and Tongda Group, Steelmate and Edison Opto as cooperation references. These are attributed statements from the original profile, not confirmation of current contracts or endorsements.

MKP-X2 uses a non-inductive winding of metallized polypropylene film, tinned copper-clad steel leads, a plastic case and epoxy sealing. The photographed component is marked MKP-X2 224 K 310VAC. The accompanying specification gives 310 VAC, −40 to +110°C, 0.001–4.7 µF and ±10% tolerance. The article also describes 350 V and 380 V versions with an internally series-connected film construction for demanding across-line applications.

The report emphasizes insulation resistance, self-healing and interference suppression, and lists CQC, UL and ENEC approvals. Its prose contains a “25 kV” pulse claim without usable test conditions; this is not adopted as a verified rating. The translated source table preserves the actual voltage-proof entries, including their different conditions for a compact version. A higher voltage marking alone does not establish suitability for an application.

DGCX: X2 capacitors for EMI suppression and specified dropper circuits

The DGCX profile dates the company to 2008 and describes a 35-mu production site in Heyuan, Guangdong. Its range includes X2 and other film capacitors, leaded and surface-mount Y capacitors, varistors and thermistors. The stated markets include lighting, solar generation, industrial supplies, adapters, phone chargers and portable power. The profile distinguishes compact capacitors for GaN charging from energy-storage products developed for low loss, current capability and humidity/temperature endurance.

Chongdiantou reports ISO 9001:2015 and ISO 14001:2015 management certifications and safety approvals for specified capacitor and varistor products. Those statements, along with RoHS and REACH claims, remain historical descriptions of the supplier's reported coverage.

The photographed X2 part is marked MPX 0.1 µF K X2 and 40/110/56/B. The source describes metallized polypropylene construction, self-healing behavior and capacitance stability under sustained load. Its reported range is 0.001–4.7 µF, with 275, 300, 305 and 310 VAC options and operation from −40 to +110°C. The accompanying approval table preserves the voltage and capacitance scope printed in that source image.

DGCX's section specifically discusses versions intended for capacitive-dropper circuits on 100–240 VAC supplies, including LED modules, small-appliance controls and radar sensors, as well as conventional interference suppression. This application statement must not be generalized to every X2 capacitor: a dropper circuit needs a part specified for its continuous series duty.

The original's exhibition notices relate to the March 20–22, 2024 Asia Charging Expo. Its KYET and DGCX subsections contain repeated STE company wording, so that apparent copy error is not reproduced as a claim that all three stands belonged to STE. The related-reading links cover KYET wireless-charging capacitors and DGCX EMI components.

Technical reference

• STE MPX/X2 specification, revision 2024-04-08, pp. 1–2.

Figures and tables from the original report

The following figures retain their original captions, markings and historical context. Transcribed tables present the values shown in the published images; product selection should use the specifications for the selected part.

Source: revision 2018-04-29, page 1. This records that edition and does not establish current certificate status or the approval scope of a specific part.

Voltage-proof and insulation-resistance conditions are retained as printed; confirm the applicable conditions with the manufacturer.

Standard identifiers are transcribed as printed. Merged capacitance and voltage cells are repeated for each row. This historical image does not establish current approval scope.

Related reading cited by the original report

Chinese source titles are retained below. 小身材，大能量，STE松田电子推出贴片Y电容 新突破！专为无线充而生，科雅ZZEC系列电容打入奥鹏户外电源供应链！ 成希电子电容"三剑客"，优化EMI的绝佳选择 10家电容企业参加2024（春季）亚洲充电展 10家无线充工厂将在2024（春季）亚洲充电展发布数百款新品 7大快充、无线充电方案企业闪耀2024春季亚洲充电科技盛典 36家芯片企业强势集结2024亚洲充电展 46家专精特新企业参加2024（春季）亚洲充电展