Metal foil resistors are one of the most accurate and stable types of resistors in electronic circuits, and their core advantages lie in:
Ultra high precision: accuracy can reach 0.01% or even higher;
Low temperature drift: The temperature coefficient (TCR) can be as low as ± 0.1ppm/℃;
Low noise: Extremely low current noise, suitable for sensitive scenes such as audio and sensors;
Long term stability: Annual resistance change rate<1ppm, lifespan exceeding 10 years.
The following is a detailed classification and technical analysis of metal foil resistors:
1、 Classified by accuracy level
High precision type (0.01%~0.1%)
Applications: Precision measuring instruments (such as six and a half multimeters), medical equipment (such as magnetic resonance imaging).
Representative models: Vishay Z-Coil series, Caddock USF series.
Ultra high precision type (<0.01%)
Applications: cutting-edge fields such as quantum computing, satellite navigation, atomic clocks, etc.
Technical parameters:
Accuracy: ± 0.005%
TCR：±0.05ppm/℃
Long term stability:<2ppm/year
Representative models: Vishay VHP202Z, Vishay VHP101.
2、 Classified by packaging form
Plug in (Through Hole)
Features: Pin soldering, suitable for high-power or high-voltage scenarios.
Application: Laboratory instruments, high-power power modules.
Packaging examples: TO-220, TO-247.
Surface mount (SMD)
Features: Surface mount, suitable for miniaturization and automated production.
Applications: portable devices, aerospace electronics.
Packaging examples: 2512, 2010, 0805 (supported by some models).
3、 Classified by special functions
Anti Sulfur
Features: Surface coating (such as gold plating) prevents corrosion by sulfur elements and avoids resistance drift.
Application: Automotive electronics (engine compartment), chemical environment.
Certification standard: Passed AEC-Q200 (automotive grade) or GJB 150A (military grade) testing.
Anti Surge type
Features: Enhanced structural design, capable of withstanding transient overcurrent (such as motor start-up shock).
Applications: Motor drives, inverters, industrial robots.
Technical parameters: The surge current withstand capacity can reach more than 10 times the rated current.
Low temperature drift type (Low TCR)
Features: TCR as low as ± 0.1ppm/℃, suitable for precise temperature control.
Application: Climate monitoring, laser temperature control.
Material: Made of manganese copper alloy or special nickel chromium alloy.
4、 Classified by material and process
Nickel chromium alloy foil resistor
Features: Low cost, TCR of about ± 2ppm/℃, suitable for general high-precision scenarios.
Application: Industrial instruments, communication equipment.
Representative model: Caddock USF series.
Manganese copper alloy foil resistor
Features: Extremely low TCR (± 0.1ppm/℃), excellent long-term stability.
Applications: Quantum computing, satellite navigation.
Representative model: Vishay VHP series.
5、 Typical application scenarios
precise measurement
Example: In a six and a half digit multimeter, a 0.01% precision metal foil resistor is used as the standard resistor.
EADS
Example: In satellite attitude control systems, ultra-high precision resistors ensure gyroscope stability.
medical equipment
Example: In magnetic resonance imaging (MRI), low noise resistance reduces image artifacts.
Automotive Electronics
Example: In the ECU (Engine Control Unit), the anti sulfurization resistor is suitable for high temperature and high humidity environments.
6、 Selection Guide
Precision priority: Choose models with 0.01% or higher precision, paired with low TCR materials (such as manganese copper).
High power scenario: Prioritize plug-in packaging and confirm whether the rated power meets P=Imax2 × R.
Harsh environment: Choose models that are resistant to vulcanization or surges, and obtain AEC-Q200 (automotive grade) certification.
Low temperature float requirement: Choose TCR<± 0.5ppm/℃ models, such as Vishay VHP series.
7、 Brand and representative model
brand
series
characteristic
Vishay
Z-Foil、VHP
Ultra high precision, TCR as low as ± 0.05ppm/℃
Caddock
USF
Nickel chromium alloy, high cost-effectiveness
ROHM
MCR
Thin film process with an accuracy of 0.1%
Yageo
AC
Copper alloy, resistant to sulfurization
Metal foil resistors are the core components of precision electronic devices, and their selection requires comprehensive accuracy TCR、 Packaging and special functional requirements. In cutting-edge fields such as quantum computing and satellite navigation, manganese copper alloys and ultra-high precision models are preferred; The anti sulfurization/anti surge characteristics need to be considered in automotive electronics or chemical environments; Portable devices require patch packaging to save space.