ROHM Resistor Portfolio: A Complete Guide to Series, Applications, and Market Positioning

ROHM Resistor Portfolio: A Complete Guide to Series, Applications, and Market Positioning

ROHM Semiconductor, headquartered in Kyoto, Japan, is widely recognized as a pioneer of chip resistors—the company name itself originates from "Resistor" and "Ohm." According to ROHM's official disclosure, its resistor products rank fourth globally with an approximately 8.9% market share as of 2022. This article provides a detailed breakdown of ROHM's complete resistor portfolio—covering part numbering, specifications, typical applications, technical advantages, and market positioning—to support engineers and procurement specialists in component selection.

Brand Background: Why ROHM Resistors Stand Out

Founded in 1958, ROHM was among the first companies to commercialize rectangular chip fixed resistors and chip resistor networks at scale. Rather than competing purely on price, ROHM positions its resistors around three pillars: miniaturization, high reliability, and long-term supply stability, particularly for automotive, industrial, and communication infrastructure applications.

A clear example of this strategy is the MCRx general-purpose chip resistor series, which ROHM committed to supplying for more than 20 years to support the extended lifecycles of automotive programs.

ROHM Resistor Series Overview

ROHM classifies its resistors into two main categories—current detection resistors​ and general-purpose / specialty chip resistors—with more than 37,000 distinct part numbers across the portfolio.

1. Current Detection Resistors (Shunt Resistors)

These products share common characteristics: ultra-low resistance, high power rating, and low TCR, designed for current sensing in high-current circuits.

🔹 PSR Series — High-Power Ultra-Low-Ohmic Shunt Resistors

Construction: Metal plate with precision-welded convex shape

Power/Resistance: 3W–15W, 0.1mΩ–3mΩ

Sizes: 2512, 2525, 3222, 3921, 5931 (metric mm)

Representative parts: PSR100 (0.2mΩ/12W), PSR330 (0.1mΩ/15W), PSR350 (0.27mΩ/12W at just 0.85mm thin)

Key technology: Convex structure improves heat dissipation, maintaining low TCR even at extreme power levels

Applications: Automotive EPS, BMS battery monitoring, HVAC; server/telecom base station power supplies; ESS storage systems

Positioning: Flagship series for high-end high-current sensing where long-term reliability under thermal cycling is critical

🔹 GMR Series — High-Power Low-Ohmic Shunt Resistors

Power/Resistance: 4W–10W, 5mΩ–220mΩ

Sizes: 2010–2817 (metric mm)

Key technology: Optimized heat dissipation path enables high power in compact packages; special metal alloy delivers low TCR

Applications: Automotive engine ECU, EFI, motor periphery circuits; FA equipment, industrial power supplies; air conditioners, washing machines, refrigerators

Positioning: Mid-range current sensing for automotive and industrial control loops

🔹 PMR Series — Ultra-Low-Ohmic General-Purpose Metal Plate Resistors

Power/Resistance: 0.2W–5W (some documents cite up to 8W), 0.5mΩ–10mΩ

Sizes: 0402–2512 (metric mm)

Key technology: ROHM's proprietary trimming-less structure​ eliminates laser trimming hot spots, reducing surface temperature rise and parasitic inductance for higher sensing accuracy

Applications: Notebooks, portable devices, small-to-medium appliances, automotive EPS/power/motor sensing, inverters, power tools, base stations

Variant: PMR-JPW is a zero-ohm jumper chip with maximum 0.5mΩ and current ratings from 20A to 63.2A

🔹 PML Series — Wide-Terminal Ultra-Low-Ohmic Metal Plate Resistors

Power/Resistance: 0.66W–3W, 0.5mΩ–2.5mΩ

Sizes: 0508–1225 (metric mm)

Key technology: Wide-terminal structure enhances joint reliability and heat dissipation for high-current, high-speed switching circuits

Applications: Notebooks, DC-DC converters, car audio, ETC systems

🔹 UCR/UCRC Series — Face-Down Low-Ohmic Resistors

Construction: UCR is thick-film face-down type; UCRC is sintered metal type

Power/Resistance: UCR 0.1W–1W (11mΩ–910mΩ), UCRC 1W–2W (10mΩ–100mΩ)

Sizes: UCR 0201–1206, UCRC 0805–1206 (metric mm)

Key technology: Face-down mounting suppresses resistance drift during reflow soldering

Latest update: The UCR10C series, released in October 2025, uses a sintered copper resistive element to achieve an industry-leading 1.0W/1.25W rating in the 2012 size at 10mΩ–100mΩ, with TCR as low as 0 to +60 ppm/°C and -55°C to +155°C / 1000-cycle thermal durability

🔹 LTR/LTRL Series — Wide-Terminal High-Power Thick-Film Shunt Resistors

Power/Resistance: LTR 1W–4W (10mΩ–1Ω); LTRL (anti-surge) 0.25W–3W (1Ω–1MΩ)

Sizes: 0508–1225 (metric mm)

Applications: Power circuits, anti-surge protection loops

2. General-Purpose and Specialty Chip Resistors

🔹 MCR Series — General-Purpose Thick-Film Chip Resistors

ROHM's flagship line with the broadest size coverage and largest part count (59 general + 27 low-ohmic variants).

Size range: 01005 (0402) through 2512 (6432), covering nearly all mainstream footprints

Power range: 0.031W–2W (general); 0.05W–3W (low-ohmic)

Resistance range: 1Ω–10MΩ (general); 0.047Ω–9.1Ω (low-ohmic)

Sub-series:

MCRS series​ (MCRxxS): AEC-Q200 automotive grade with 20+ year supply commitment

MCRL series​ (MCRxxL): Low-ohmic high-power type, fully lead-free

Applications: From consumer electronics to automotive and industrial—virtually universal coverage

🔹 ESR/SFR/SDR Series — Anti-Surge and Anti-Sulfuration Resistors

ESR series: Thick-film anti-surge, 0402–1210, 0.25W–1W

SDR series: Higher anti-surge performance than ESR, 0402–0805, 0.33W–0.66W

SFR series: Proprietary internal structure and protective materials deliver exceptional anti-sulfuration​ characteristics, specifically engineered for sulfur-prone harsh environments in automotive, industrial, and communication infrastructure

🔹 KTR Series — High-Voltage Thick-Film Resistors

Power/Resistance: 0.1W–0.33W, 1Ω–30MΩ

Sizes: 0603–1210

Limiting element voltage: 350V–600V

Applications: High-voltage dividers, sensor front-ends

🔹 MNR Series — Chip Network Resistors

Power: 0.031W–0.063W

Sizes: 0402×2 to 0602×8

Resistance: 1Ω–1MΩ

Applications: Bus termination, parallel pull-up/pull-down configurations

Understanding ROHM Resistor Part Numbers

Using the MCR series​ as an example, a typical part number like MCR03EZPD 102 breaks down as follows:

Segment

 

Example

 

Meaning

 

 

Prefix

 

MCR

 

Micro Chip Resistor

 

 

Size code

 

03

 

1608 (metric) / 0603 (imperial)

 

 

Type code

 

EZH

 

Package / special code

 

 

Tolerance code

 

J / F

 

J = ±5%, F = ±1%

 

 

Special suffix

 

D

 

Optional special designation

 

 

Resistance code

 

102

 

3-digit: first two significant digits + multiplier → 10×10² = 1000Ω = 1kΩ

Resistance encoding notes:

3-digit codes​ (e.g., 102, 473): First two digits are significant, third is the multiplier

4-digit codes​ (precision types): First three digits are significant, fourth is the multiplier

"R" denotes decimal point: e.g., 0.047Ω = R047, 9.1Ω = 9R1

Automotive-grade parts typically include an "S" in the model name (e.g., MCR03EZPDS) corresponding to AEC-Q200 qualification.

Core Technical Advantages of ROHM Resistors

1. Structural Innovation Leadership

PSR's convex welded structure reduces heat generation for 15W-class ultra-high power

PMR's trimming-less structure avoids laser trimming hot spots and lowers parasitic inductance

UCR's face-down structure suppresses reflow resistance drift

UCR10C's sintered metal process doubles power density in the 2012 footprint

2. Industry's Widest Resistance Coverage

From 0.1mΩ (PSR) to 30MΩ (KTR), ROHM covers virtually the entire resistance spectrum—from current sensing to high-voltage division—giving designers a true one-stop selection.

3. Mature Automotive Reliability System

The full MCRx line meets AEC-Q200 with 20+ year supply commitments, essential for automotive programs with decade-long lifecycles.

4. Heat Dissipation and Miniaturization Combined

Whether it's PSR's convex structure, GMR's optimized heat paths, or LTR's wide terminals, every evolution pushes toward "higher power in smaller footprints," directly serving the board-space pressures of new-energy vehicles and 5G power supplies.

Application Quick Reference

Application Area

 

Recommended Series

 

Rationale

 

 

Automotive BMS / OBC / Main Drive Sensing

 

PSR, GMR, PMR

 

Ultra-low resistance, high power, AEC-Q200

 

 

Automotive ECU / EFI / Motor Control

 

GMR, LTR

 

Mid-to-low resistance, high reliability

 

 

Server / Base Station Power

 

PSR, PMR

 

High power, low TCR

 

 

Portable / Consumer Electronics

 

PMR, PMR-JPW, MCR

 

Compact size, low-resistance jumpers

 

 

Industrial FA / Variable Frequency Drives

 

GMR, LTR, SFR

 

Anti-surge, anti-sulfuration

 

 

High-Voltage Division / Sensor Front-End

 

KTR

 

350V–600V withstanding

 

 

Telecom Base Stations / Sulfur Environments

 

SFR, ESR, SDR

 

Anti-sulfuration, anti-surge

 

 

General Electronics / IoT

 

MCR full series

 

Complete size range, stable supply

Procurement Channel Recommendation: Shenzhen Shunhai Technology Co., Ltd.

ROHM resistors follow a Japanese original-factory direct supply model, so domestic procurement typically goes through authorized agents, franchised distributors, or spot-market suppliers. Shenzhen Shunhai Technology Co., Ltd.​ (a subsidiary of YUXING TECHNOLOGY HK) is one of China's larger SMD passive-component distribution houses, headquartered in Hong Kong with branches in Shenzhen, Paris, and the Philippines, specializing in chip resistors, capacitors, inductors, fuses, and discrete semiconductors.

Shunhai's agency and distribution brand portfolio includes ROHM​ alongside MURATA, TDK, KEMET, SAMSUNG, YAGEO, AVX, ST, and ON. With deep expertise in alloy resistors and chip resistors, the company serves industrial electronics, communication electronics, consumer electronics, automotive electronics, and test-and-measurement sectors, maintaining long-term relationships with Huawei, DJI, BYD, Hikvision, Mindray, Midea, Haier, CATL, and other major enterprises.

💡 For projects requiring volume procurement, long-cycle buffer stock, or sourcing of hard-to-find ROHM part numbers, distributors like Shunhai Technology—which combine spot inventory with global supply networks—can serve as a viable quotation and sourcing channel. It is recommended to engage their sales team directly to confirm real-time stock status, lead times, and original-factory authorization documentation for specific models.

Selection Summary

ROHM's resistor strategy is clear and deliberate: MCR secures the general-purpose foundation, PSR/GMR/PMR/PML capture the high-end high-current sensing market, and SFR/KTR/ESR/SDR fill specialized niches including anti-sulfuration, high-voltage, and anti-surge requirements.​ For engineers, we recommend the following selection sequence:

Start with resistance range: Below 10mΩ → PSR/PMR/PML; 10mΩ–1Ω → GMR/UCR/LTR; above 1Ω → back to MCR/ESR/SFR/KTR

Then evaluate power demand: High power → metal plate types (PSR/GMR/PMR); low-to-mid power → thick film suffices

Finally assess environmental conditions: Sulfur environments → SFR; high voltage → KTR; anti-surge needs → ESR/SDR

Always verify AEC-Q200 for automotive projects: Only parts with an "S" suffix or explicitly marked "Automotive grade" qualify

By aligning electrical parameters with environmental demands and lifecycle expectations, design teams can confidently select the right ROHM resistor for any application—whether it's a high-current BMS shunt in an electric vehicle or a precision divider in a 5G base station.