TT Electronics Unveils a Line of Metal Foil Chip Resistors for Current Sensing
The new surface mounted metal foil chip resistors (MFC) exploit metal foil on ceramic technology for enhanced performance
TT’s new MFC series combines the surge tolerance of bulk alloy resistance elements with the heat diffusion characteristics of ceramic substrates.
Image courtesy of MFC Datasheet
The new series of surface mounted resistors feature less self heating and better surge tolerance than thick film resistors.
The physically tiny units are available in six sizes ranging from 0402 to 2512. This corresponds to approximately 1.05 by 0.55 by 0.55 mm for the 0402 to 6.55 by 3.3 by 0.95 mm for size 2312. The amount of power that these units can carry divided by their extremely small size work out to very impressive power densities.
The Purpose for the New Series of Resistors
As stated by Barry Peters, VP Product Management and Engineering, TT Electronics. “The development of our MFC series resistors was driven by the explosive growth of products that require control and monitoring of energy consumption, such as battery-operated portable and IoT devices.” He goes on to say that “To meet rising demands in this arena, TT has enhanced its current sense resistor portfolio with the debut of the MFC series, offering a wider range of sizes and values than many of our top competitors.”
Electrical Specifications
These units are available with resistances ranging from 2 to 200 milliohms. Precision is up to ±0.5%, and the temperature coefficient of resistance (TCR) is as tight as ±50ppm/°C.
A current sense resistor. Image courtesy of MFC Datasheet
As the table below indicates, each package size supports a range of resistances and tolerances, with considerable overlap.
| Package Size | 0402 | 0603 | 0805 | 1206 | 2010 |
2515 |
|||||
| Power Rating at 70℃ in watts | 0.25 | 0.5 | 0.25 | 0.75 | 0.5 | 1 | 0.75 | 1 | 1 |
2 |
|
|
5 second overload capacity |
2.25 | 2.5 | 2.25 | 3.75 | 2.5 | 5 | 3.75 | 5 | 5 |
8 |
|
| Resistance Range in milliohms | 10-50 | 3-100 | 30-100 | 3-100 | 30-100 | 3-100 | 30-100 | 3-100 | 30-100 | 101-220 |
2-100 |
| AEC-Q200 qualified | Y | Y | N | Y | N | Y | N | Y | N | Y | Y |
Applications
The new line of MFC resistors will find uses in medical, automotive and industrial applications including:
- Power supply monitoring
- DC motor control
- Automotive DC-DC conversion
- Actuator control
- LED drivers
- Portable device battery management systems
Physical Considerations
The metal foil resistive material is bonded onto an aluminum substrate. It is then connected to wraparound terminations which feature a nickel barrier and a 100% tin finish. Each resistor is measured before packing into tape.
These resistors operate over a temperature range of -55 to +155°C, with considerable power derating occurring at temperatures above 70℃
The resistor, as well as its marking, are resistant to the standard industrial cleaning solvents standard to printed circuit production.
Regulatory Concerns
- Many of the resistors are AEC-Q200 qualified, with exceptions pointed out in the table
- All parts are Pb-free and comply with EU Directive 2011/65/EU amended by (EU) 2015/863 (RoHS3)
