SUSUMU Resistor Families: A Complete Technical Overview
SUSUMU Co., Ltd. (進工業株式会社) has spent more than six decades specializing in thin-film technology and resistive components. Its portfolio spans precision thin-film chip resistors, current-sensing resistors, alloy shunts, and high-frequency surface-mount parts. This article walks engineers and procurement teams through the brand background, full product family tree, key series, part-number decoding, applications, and positioning — followed by a recommended distributor.
SUSUMU Resistor Families: A Complete Technical Overview
SUSUMU Co., Ltd. (進工業株式会社) has spent more than six decades specializing in thin-film technology and resistive components. Its portfolio spans precision thin-film chip resistors, current-sensing resistors, alloy shunts, and high-frequency surface-mount parts. This article walks engineers and procurement teams through the brand background, full product family tree, key series, part-number decoding, applications, and positioning — followed by a recommended distributor.
Brand Background
Founded in Kyoto, Japan in 1964, SUSUMU focuses exclusively on thin-film R&D and electronic components manufacturing. The company is widely recognized as a specialist in thin-film resistor technology, built on four core competencies: thin-film deposition (plasma CVD, sputtering, vacuum evaporation), precision photo-etching, precision laser processing, and high-density packaging.
Manufacturing bases are located in Japan and China, with sales offices in Japan, the United States, China, Germany, Singapore, and Korea, supported by a global distributor network. The group holds ISO 9001, ISO 14001, and IATF 16949 certifications; all products comply with RoHS and REACH, using matte tin lead-free terminations.
SUSUMU's main product lines include thin-film surface-mount resistors, current-sensing resistors, metal-alloy shunts, power choke coils, and high-frequency surface-mount components such as chip attenuators and thermo-variable attenuators. The RG series is regarded across the industry as one of the most reliable and precise thin-film resistor families available.
Complete Product Family Tree
SUSUMU classifies its resistors into four major groups, each containing multiple sub-series.
1. Thin-Film Surface-Mount Resistors
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Series
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Positioning
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|---|---|
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URG
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Highest reliability and precision
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RG / RGH
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Ultra-high-precision metal-film, long-term stability benchmark
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RGA
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High-temperature thin-film (up to 230°C)
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RGT
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Wide temperature, high reliability, long-term stability
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RGV
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High-voltage and automotive grade, AEC-Q200 qualified
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RMA
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High-temperature-operation thin-film precision
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HRG / MRG
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High-reliability precision
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NRG
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Non-magnetic, for medical and strong magnetic fields
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PRG
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Wide-terminal high-power
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RR
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Precision-grade thin-film (classic volume series)
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RM
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Metal-film resistor networks
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RT
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Metal-film trimmable chip resistors
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RS
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Low-noise resistors for high-resolution audio
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Source:
2. Current-Sensing Surface-Mount Resistors
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Series
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Type
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|---|---|
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KRL
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Metal-foil low-ohmic (long-side / short-side / 4-terminal)
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PRL / RL
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Thin-film low-ohmic (long-side / short-side)
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YJP
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High-current chip jumper (< 0.3mΩ)
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Source:
3. Metal-Alloy Current-Sensing Resistors
Designed for high-power, low-TCR shunt applications.
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MSR / MSRPF2726 / MSRPF4026 / MSRPM1216 / MSRSF: high-precision low-TCR alloy current sensors, in both 4-terminal and long-terminal structures
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MBRAS: automotive-grade high-precision high-current alloy shunt
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MBRRC: high-precision high-current alloy shunt
Source:
4. High-Frequency Surface-Mount Components
Built on thin-film technology for broadband, low-noise performance.
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PAT series: precision chip attenuators (DC–10GHz, 0–10dB)
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P*V series: thermo-variable chip attenuators for RF GaAs amplifier temperature-drift compensation
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ATF / ATS-FD / HPT / PCS / PS / RFD series: high-frequency thin-film components
Source:
Key Series Explained
🎯 RG Series — SUSUMU's Flagship Precision Resistor
The RG series is SUSUMU's signature metal-film resistor. Using an inorganic protective film, it achieves a temperature coefficient of resistance (TCR) down to ±5ppm/°C, resistance tolerance down to ±0.02%, a resistance range of 10Ω–1MΩ, and package sizes from 0402 to 1206.
The long-term stability numbers are what set RG apart: under 85°C, 85%RH, 10% rated power, 90-minute on / 30-minute off cycling, the RG series is expected to drift less than 0.1% over 116 years — roughly eight times the lifespan of the RR series (about 14 years).
Primary applications: communication equipment, test and measurement, voltage references, automotive electronics — anywhere precision and longevity matter simultaneously.
🔬 RR Series — The Volume Precision Workhorse
RR is SUSUMU's classic precision thin-film line. TCR ranges from ±10 to ±100ppm/°C, tolerance from ±0.1% to ±1%, resistance range 10Ω–1MΩ, packages 0201–1210.
It offers an excellent balance of tolerance, TCR, current noise, and linearity, at a more accessible price point than RG — suitable for automotive, industrial test and measurement, and consumer electronics where cost control still matters.
⚙️ KRL Series — Metal-Foil Low-Ohmic Current Sensing
KRL comes in three structures:
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Long-side terminal: 0.5–10W, 1mΩ–500mΩ, TCR ±50–150ppm/°C
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Short-side terminal: 0.2–5W, 5mΩ–1Ω, TCR ±50–100ppm/°C
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4-terminal type: 1–5W, 1mΩ–500mΩ, TCR ±50–100ppm/°C
Source:
Its face-down construction, large resistive element, and proprietary thermal conductive adhesive yield a typical thermal resistance of about +19°C/W — less than half of comparable products — enabling smaller packages to carry equivalent rated power. Solder joints survive 3,000 cycles of −45°C/+125°C without cracking.
Notably, KRL is listed in NASA's NEPP (NASA Electronic Parts and Packaging) program as an Industry Leader Parts Manufacturer (ILPM) and approved as a standard COTS component — the second SUSUMU series (after RG) to earn this recognition.
Typical use: automotive electronics, AC/DC and DC/DC converters, motor drives, inverters, office automation equipment.
📐 PRL / RL Series — Thin-Film Low-Ohmic Current Sensing
Unlike KRL's metal-foil route, PRL/RL uses thin-film construction, again in long-side and short-side variants:
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PRL/RL (long-side): 1/3–2W, 1mΩ–100mΩ, TCR ±50–800ppm/°C
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RL (short-side): 1/8–1W, 10mΩ–100Ω, TCR ±100–500ppm/°C
Source:
Strengths include good heat dissipation, high temperature endurance, and low ESL / low noise — widely used in PCs, power adapters, inverters, variable-frequency drives, and automotive subsystems.
🌡️ RGA / RGT / RGV / RMA — Environmental & Automotive Branches
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RGA: high-temperature thin-film precision, up to 230°C operating
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RGT: wide-temperature, high-reliability, long-term-stable
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RGV: high-voltage and automotive grade, AEC-Q200 qualified, 1210 package supports 1000V, inorganic passivation improves long-term stability by approx. 30%
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RMA: high-temperature-operation thin-film precision, TCR down to 1ppm/°C, tolerance down to 0.01%, AEC-Q200 compliant
These fill the gaps for industrial high-temperature, automotive high-voltage, and aerospace environments.
🧲 NRG Series — Non-Magnetic Medical Grade
Built with non-magnetic materials for MRI and strong magnetic-field settings. TCR reaches ±5ppm/°C, with sulfur-resistant inorganic protection film, resistance range 10Ω–1MΩ.
🎵 RS Series — High-Resolution Audio Low-Noise Resistor
Specifically engineered for hi-fi audio signal chains, leveraging the low-noise nature of thin-film resistors in AV equipment and smartphones.
🧩 RM Series — Precision Metal-Film Resistor Networks
Single-package multi-resistor networks for circuits requiring precise relative ratios (voltage dividers, op-amp gain setting). They demonstrate ultra-reliability: less than ±0.1% drift after 10,000 hours at 85°C/85%RH or at 155°C.
📡 PAT / P*V Series — High Frequency & Attenuators
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PAT: single-element broadband attenuation, DC–10GHz, 0–10dB, sizes from 1005 to 3042
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P*V: thermo-variable chip attenuator for RF GaAs amplifier temperature-drift compensation, DC–6GHz
Part-Number Decoding
SUSUMU's naming logic follows a consistent pattern: series code + package size + resistance + tolerance/TCR + packaging. Three representative examples:
RG Example: RG1608N-203-W-T5
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RG: series (metal-film thin-film resistor)
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1608: metric package 1.6×0.8mm, imperial 0603
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N: TCR grade ±10ppm/°C
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203: E96 resistance code = 20kΩ
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W: tolerance ±0.05%
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T5: tape & reel, 5000pcs/reel
Source:
RR Example: RR0816P-104-D-T5
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RR: series
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0816: package 0603
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P: TCR ±25ppm/°C
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104: E24 code = 100kΩ
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D: tolerance ±0.5%
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T5: tape & reel, 5000pcs
Source:
KRL Example: KRL6432E-M-R010-F-T5
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KRL: series (metal-foil low-ohmic)
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6432: metric package 6.4×3.2mm, imperial 2512
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E: extended resistance code identifier
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M: tolerance ±1%
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R010: resistance 0.01Ω (R marks decimal point)
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F: tape & reel
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T5: TCR ±50ppm/°C
Source:
💡 Tip: E24 values use 3 digits (e.g., 104 = 100kΩ), E96 values use 4 digits (e.g., 4992 = 49.9kΩ), and "R" marks the decimal position. When placing orders, the TCR code, tolerance code, and packaging code are the three fields most prone to error — verify them against the manufacturer's ordering-information table.
Applications & Market Positioning
SUSUMU serves six primary industries: automotive, FA/robotics, measuring instruments, medical devices, consumer electronics, and communication equipment.
Mapping applications back to selection paths yields clear routes:
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Voltage reference / precision measurement: RG, URG, RM — precision and long-term stability are paramount
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Automotive BMS / motor drive / inverter: KRL, RGV, PRL/RL, MBRAS — AEC-Q200, temperature endurance, low TCR
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Medical / MRI: NRG, KRL — non-magnetic, low-noise, long-term stable
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Server power / 5G base station: KRL, PRL — mid-to-high-power shunts
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Smartphone / tablet / fast charging: PRL, RG — miniaturization, low-ohmic sensing
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Hi-fi audio: RS — low-noise signal chains
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RF circuits / front ends: PAT, P*V, ATF — broadband, low parasitics
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Aerospace / military: RG, KRL (both NASA NEPP certified)
Differentiation vs. Competitors
SUSUMU does not compete on thick-film commodity pricing nor on wirewound high-power — its focus stays on the high-end thin-film niche. Against peers such as Vishay, KOA, and Panasonic, SUSUMU's edges are:
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Ultra-high precision (±0.02%) and ultra-low TCR (±5ppm/°C) in the RG series
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Miniaturized current sensing (PRL delivers 1W in a 1206 package)
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Aerospace-grade reliability backing (both RG and KRL are on the NASA NEPP standard COTS list)
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A complete automotive-grade matrix (AEC-Q200 across RG, RGV, PRG, RL, KRL, etc.)
Selection Guidance
Tailor your choice to design priorities:
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Good-enough precision, cost sensitive → RR
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Reference source, instrument, must not drift for decades → RG or URG
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Automotive, temperature up to 150°C+ → RGV (high voltage), RGA (high temp), KRL (current sense)
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Large current shunt, minimize footprint → KRL long-side terminal
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Medical MRI or strong magnetic field → NRG
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Phones, fast chargers, IoT milliohm sensing → PRL/RL
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Audio signal chain, low noise → RS
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RF attenuation, temperature-drift compensation → PAT, P*V
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Aerospace / long-life industrial → RG, KRL (NASA or AEC-Q200 backed)
Two procurement notes worth flagging: E24/E96 resistance systems map to different part-number digit counts, and some special resistance/tolerance combinations are made-to-order with longer lead times — lock those part numbers early in the project phase.
Recommended Distributor: Shenzhen Shunhai Technology Co., Ltd.
Shenzhen Shunhai Technology Co., Ltd. distributes SUSUMU's full resistor portfolio — covering thin-film, current-sensing, and high-frequency families including RG, RR, KRL, PRL/RL, RGA, RGV, PRG, RM, RT, RS, and PAT. Services include:
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Genuine original stock with full datasheets and sample support
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Stable supply from prototype volumes through mass production
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Application-specific selection advice for automotive, medical, industrial power, and communication designs
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Alternative-part and lead-time coordination
For SUSUMU resistor quotations, inventory, or technical consultation, contact Shenzhen Shunhai Technology Co., Ltd. directly for detailed part-number information.