PASSIVE SOLUTIONS
Current Sensing Resistors Offer Small Size and High Temperature Operation 
Two 1W additions in 2512 and 1206 package

Vishay Intertechnology has extended its range of surface-mount current-sensing resistors with two new products. The new Power Metal Strip devices are the WSLT2512, for use at high temperatures of up to 275°C, and the WSLP1206, believed to be the industry’s first such device in the very small 1206 package size to be rated at 1W.

The WSLT2512, also a 1W device, is provided in the 2512 case size, and operates in a temperature range of -65°C to +275°C. This allows it to replace larger current-sensing resistors with a similar maximum operating temperature. Its robust specifications allow it to be used for current sensing and pulse applications in harsh, high-temperature environments, without sacrificing power rating or electrical performance.



It will be a particularly attractive solution in automotive engine controls, safety controls, multimedia electronics, climate controls, and anti-lock brakes; and industrial oil/gas well drilling, including down-hole test/measurement equipment.

Manufactured using proprietary techniques that result in extremely low resistance values (10mΩ to 500mΩ), a tight tolerance down to ±0.5%, and low TCR values down to ±75ppm/°C, the WSLT2512 features all-welded construction with a solid metal nickel-chrome alloy resistive element. The resistor offers low inductance values.

The WSLP1206 device also features a very low 1mΩ to 50mΩ resistance value range, and high-temperature performance up to 170°C. Like the WSLT2512, its primary use will be in replacing much larger current-sensing resistors, saving space on the circuit board that in turn will create smaller and lighter end products. It is intended for current sensing and pulse applications in DC/DC converters for computers, VRMs for laptops, Li-Ion battery safety and management; and electronic automotive systems, including engine controls, multimedia electronics, climate controls, and anti-lock brakes.



Also manufactured using techniques that maximise power handling and reduce resistance value, the WSLP1206 employs a solid metal nickel-chrome or manganese-copper alloy resistive element. It offers inductance values from 0.5nH to 5nH.

Both devices also provide an excellent frequency response to 50MHz, and low thermal EMF of less than 3μV/°C.

Features
  • Small form factor 1W current-sensing resistors
  • High-temperature handling: up to 275°C
  • Extremely low resistance values
    • 10mΩ to 500mΩ (WSLT2512)
    • 1mΩ to 50mΩ (WSLP1206)
  • Tight tolerance down to ±0.5%
  • Low TCR values down to ±75ppm/°C
  • All-welded construction
  • Solid metal resistive element: nickel-chrome or manganese-copper (WSLT1206 only)
  • Low inductance: 0.5nH to 5nH (WSLP1206); less than 5nH (WSLT2512)
  • Excellent frequency response to 50MHz
  • Low thermal EMF: less than 3µV/°C

Applications
  • Automotive electronics
    • Engine controls
    • Safety controls
    • Multimedia electronics
    • Climate controls
    • Anti-lock brakes
  • Industrial oil/gas well drilling
    • Down-hole test/measurement equipment
  • DC/DC converters for computers
  • VRMs for laptops
  • Li-Ion battery safety and management

For further information, including the WSLT1206 and WSLT2512 Datasheets, please click here.