Introduction

As the KOA RK92 Series high-voltage thick film resistors enter the End-of-Life (EOL) phase, finding an alternative that offers both Pin-to-Pin compatibility and guarantees long-term supply has become an urgent priority for the industry.

The HVC HVRGXP Series is an "expert-level" solution born to address this crisis. This article provides comprehensive answers to the 15 most critical questions for engineers and purchasing managers, covering physical compatibility, electrical performance, supply chain assurance, and special application scenarios.

Reference Tables: Quick Benchmark & Cross-Reference

The two tables below are the same blocks used in our other KOA RK92 English styles: the at-a-glance benchmark and practical cross-reference come from Style 2 (direct replacement models); the figures align with the detailed comparisons in Styles 3 and 4. They are included here so this FAQ page carries the key lookup data in one place.

At-a-glance benchmark: KOA RK92 vs HVC HVRGXP

KOA RK92 → HVC HVRGXP: cross-reference (same table as product page)

The matrix below is aligned with the official product article KOA RK92 / RK92D / RK92L replacement (2) (power, resistance, tolerance, TCR, body size, HVC type). The large KOA EOL part-number grid on that page is not duplicated here—open the link for the full index.

Note: HVRGXP codes denote the substrate / mechanical family for pin-to-pin fit. Last row follows the product page notation (high-ohm divider type). Verify against your BOM and the latest datasheet.

Part One: Basic Replacement and Compatibility

Q1: Can the HVRGXP Series directly replace KOA RK92? Is a board redesign necessary?

A: It can be directly replaced without any board redesign. From the outset of its development, HVC strictly replicated the physical dimensions of KOA RK92. Whether it's the pin pitch, component height, or thickness, all are maintained at a 1:1 consistency. This covers KOA's full range of specifications, including 9.6mm (small), 26mm (medium), and 30mm (large).

Q2: KOA original factory offers different lead forming (e.g., cut leads, bent leads). Does HVC support this?

A: Yes, we do. In addition to standard straight leads, HVC provides lead forming services. We can offer L-shaped bent leads, K-shaped bent leads, or cut-to-length leads according to your drawing requirements, ensuring a perfect match with your existing PCB assembly process.

Q3: My equipment still uses non-standard resistance values (e.g., 123MΩ). Can HVC produce these?

A: Yes, and without high thresholds. Before discontinuation, KOA only supported standard E24 resistance values. HVC possesses high-precision laser trimming production lines, turning "customization" into a "standard service." Any resistance value from 100Ω to 10GΩ can be produced, with extremely low Minimum Order Quantity (MOQ).

Q4: What level of accuracy can HVC achieve?

A: Superior to the original factory standard. KOA RK92 commonly offers ±5% (J-grade) and ±1% (F-grade) accuracy. The HVC HVRGXP Series not only covers these grades but also provides a ±0.5% (D-grade) precision option, meeting the demands of high-accuracy sampling circuits.

Part Two: Electrical Performance and Technical Advantages

Q5: How are the HVRGXP Series' voltage withstand and pulse withstand capabilities?

A: Superior to KOA RK92 original factory standards. HVC utilizes a 96% high-purity alumina substrate (KOA typically uses 85%-90%), combined with an optimized thick film structure, which increases pulse energy withstand capability by 20%. This makes it more suitable for electrostatic discharge (ESD) and lightning surge protection.

Q6: What are the advantages of the so-called "non-inductive design" in high-frequency applications?

A: Extremely low parasitic inductance, resulting in cleaner waveforms. Ordinary thick film resistors exhibit inductive properties at high frequencies. The HVC HVRGXP Series achieves microhenry (µH) level low inductance characteristics through computer-optimized serpentine printing paths, making it particularly suitable for high-frequency switching power supply feedback loops and pulse modulators.

Q7: How does the Voltage Coefficient of Resistance (VCR) perform?

A: Extremely low, ensuring linearity in high-voltage sampling. The voltage coefficient refers to the degree to which resistance changes as voltage increases. HVC optimizes its ruthenium-based paste formula to control VCR to < 5 ppm/V (some high resistance values < 2 ppm/V), which is crucial for high-voltage dividers above 10kV.

Q8: Is the Temperature Coefficient of Resistance (TCR) better than KOA's?

A: Yes, with less temperature drift. KOA RK92's standard TCR is typically ±200ppm/℃. The HVC HVRGXP Series, thanks to its high thermal conductivity substrate and quality paste, can achieve a standard TCR of ±100ppm/℃, with precision types reaching ±50ppm/℃. This ensures more stable resistance values in high-voltage circuits with significant heat generation.

Q9: Is the insulation layer reliable in high-humidity or harsh environments?

A: Vacuum epoxy encapsulation, passing the Double 85 test. HVC employs high-density epoxy resin vacuum encapsulation (Conformal Coating), eliminating air voids and pinholes. After continuous operation for 1000 hours in an 85℃ / 85%RH environment, the resistance drift rate is ≤ ±1%, effectively preventing surface flashover.

Q10: Can HVC resistors be used in "oil-immersed" cooling environments?

A: Absolutely. The epoxy resin encapsulation material used in the HVRGXP Series has excellent oil resistance and chemical corrosion resistance. It is highly suitable for use in oil-filled X-ray tube heads or oil-cooled high-voltage power supplies, as it will not react with or dissolve in insulating oil.

Part Three: Supply Chain and Commercial Value

Q11: KOA has discontinued production, can HVC guarantee supply? What is the lead time?

A: HVC commits to long-term stable supply, with a standard lead time of 4-6 weeks. SIP high-voltage resistors are a core strategic product line for HVC, belonging to long-lifecycle products. Compared to KOA's 20-30 week lead time before discontinuation, we have reduced it by 80%. For urgent orders, 2-week expedited delivery can be requested.

Q12: How does HVC's price compare to KOA's?

A: More competitive. As an original manufacturer, HVC eliminates complex distributor tiers. Under the same or even superior performance, our prices are typically 20%-30% lower than KOA's original factory prices, helping customers achieve technological upgrades while reducing BOM costs.

Q13: Are there any Minimum Order Quantity (MOQ) requirements?

A: Very flexible. We understand the needs of the repair market and R&D prototyping. For standard products, the MOQ is extremely low (usually 50-100pcs is sufficient); for custom resistance values, the MOQ is only 500-1000pcs, far below the industry average.

Q14: What tests are performed before shipment?

A: 100% full inspection. Every resistor undergoes the following before leaving the factory: 1. Precise resistance measurement; 2. Short-time overload test (2.5 times voltage); 3. Visual inspection. This ensures zero-defect delivery.

Q15: Will HVC discontinue this series in the future?

A: No. Unlike KOA's shift towards automotive-grade SMD components, HVC focuses on the high-voltage industrial and medical markets. SIP high-voltage resistors are our "cornerstone" product, and we commit to continuous supply for the next 15 years, ensuring the maintenance needs of long-life equipment.

Contact Information and Sample Request

Facing the discontinuation of KOA RK92, HVC is your most reliable "Plan B" and "Ultimate Solution."

To obtain datasheets, cross-reference tables, or request free samples, please contact the HVC Technical Support Team:

• Email: sales@hv-caps.com
• Product Center: www.hv-caps.com

Copyright © 2026 HVC Company. KOA and RK92 mentioned herein are registered trademarks of their respective holders, and this article is for technical compatibility and alternative selection guidance only.