• (HVC Capacitor Technical Whitepaper: Engineering Replacement & Cross-Reference Guide for Murata Discontinued HV Series)

• (Engineering Selection Guide: Cross-Reference & Replacement Manual for Murata Discontinued HV Ceramic Capacitors)

1. Replacement Overview: The Ultimate Solution for Murata DHS/DHR Series Discontinuation

1.1 Current Situation and Challenges

Since Murata (Murata Manufacturing Co., Ltd.) officially announced the End-of-Life (EOL) for its DHS (bolt type) and DHR (lead type) high voltage ceramic capacitors in 2018, a severe disruption has occurred in the global supply chain. For R&D and procurement personnel involved with CT scanners, X-ray machines, industrial flaw detectors, and high voltage power supplies, the core pain points currently faced are:

• No parts for repair: Repair spare parts for existing equipment are exhausted.
• Design limitations: New projects struggle to find replacement parts that simultaneously meet electrical parameters and mechanical dimensions.
• Safety compliance risks: Replacing with non-original parts may lead to the invalidation of safety certifications (FDA/UL/CE).

1.2 HVC's Replacement Strategy: Pin-to-Pin Precision Replication

• HVC Capacitor has developed a "Drop-in Replacement" strategy for Murata's discontinued models. We do not require customers to alter their circuit designs or modify PCB layouts. Instead, we achieve seamless switching by providing products that are electrically identical (or superior) and physically dimensionally matched to Murata's.

This manual will detail the Mapping (correspondence) between Murata's core discontinued models and their HVC equivalents, and explain the technical logic behind the replacement.

1. DHS Series (Bolt Type / Doorknob) In-Depth Replacement Cross-Reference

The Murata DHS series (commonly known as "doorknob capacitors") is central to the voltage multiplier circuits in high-voltage generators for medical imaging equipment (CT/X-Ray). Key aspects for replacement include threaded terminal specifications, capacitor diameter, and the high-frequency loss performance of the N4700 dielectric.

2.1 Typical Model Cross-Reference Table

2.2 Technical Analysis of Replacement

• Dielectric Matching: Murata's "ZM" code corresponds to the industry-standard N4700 (Class I) dielectric. HVC's DL series fully adopts the N4700 formulation, ensuring low temperature drift (change rate <5% from -30℃ to +85℃) and low self-heating.
• Terminal Compatibility: Murata offers both metric (M) and imperial (B code) terminals. HVC's HVCT8G series molds support the full range of M4/M5/M6 and UNF 10-32 threads. Customers can specify their requirement when ordering, eliminating the need to replace busbars.

1. DHR Series (Lead Type / Radial) In-Depth Replacement Cross-Reference

The Murata DHR series consists of epoxy-encapsulated disc capacitors, widely used in handheld flaw detectors, electrostatic spray guns, and negative ion generators. Key aspects for replacement include lead pitch and encapsulation insulation.

3.1 Typical Model Cross-Reference Table

3.2 Technical Analysis of Replacement

• Encapsulation Upgrade: Murata's original products used beige or blue epoxy. HVC upgrades to high-density blue epoxy resin powder encapsulation, which is UL94V-0 flame retardant certified and offers stronger moisture resistance, having passed the double 85 test.
• Dimensional Fine-tuning: HVC can provide Compact Type or Standard Type diameter options based on the customer's PCB density, resolving installation interference issues.

1. Why is HVC an "Engineering-Grade" Replacement for Murata?

When performing model cross-referencing, engineers often ask: "Besides identical parameters, what other advantages does HVC offer?"

4.1 "Over-engineered" Voltage Rating

Murata's DHR/DHS series typically has a voltage upper limit of 50kV.

HVC's manufacturing process covers up to 100kV.

• Engineering Significance: When you use an HVC 40kV capacitor to replace a Murata 40kV capacitor, HVC is effectively utilizing internal design margins from a higher voltage class (e.g., 50kV or 60kV). This means HVC products offer higher reliability and longer lifespan at their rated voltage.

4.2 Low-Loss Advantage of N4700 Dielectric

In the high-frequency voltage multiplier circuits of X-ray machines, dielectric loss directly determines whether a capacitor will experience "thermal breakdown."

• Murata ZM Dielectric: \tan\delta \approx 0.2\%
• HVC N4700 Dielectric: \tan\delta \le 0.1\%
• Measured Data: At 100kHz high frequency, the temperature rise of HVC capacitors is 3-5℃ lower than Murata's.

4.3 Flexible Customization

As a large manufacturer, Murata is slower to respond to non-standard requirements. HVC offers Design-in level customization:

• Special Lead Pitch: Such as F=7.5mm or F=15mm.
• Special Leads: Providing lead cutting, bending (K-in/Out), dual leads, and other forming services.
• Special Voltage: Such as non-standard voltage ratings like 35kV, 60kV.

1. Quality Verification and Customer Endorsement (Verification)

HVC's replacement solutions are by no means "talk on paper" but have undergone rigorous verification by top global customers:

• CT/X-ray Machine Sector: HVC has successfully entered the supply chains of GE Healthcare, Philips, Siemens, and United Imaging Healthcare, replacing the DHS series for high-voltage oil tanks.
• Industrial Flaw Detection Sector: Japanese companies such as Nikon and Shimadzu have adopted HVC to replace the DHR series.
• Scientific Research Sector: ABB and multiple polytechnic university laboratories use HVC's 100kV capacitors to build Marx generators.

1. How to Obtain Samples and Technical Support

• *Supply chain security begins with the right selection.**

If you have discontinued Murata part numbers that require replacement, please contact HVC's replacement engineering team immediately. We promise:

1. To provide a detailed Cross-Reference report within 24 hours.

1. To provide samples for on-board testing free of charge.

1. Lifetime technical support and failure analysis services.