The Foil Resistors department at Vishay Precision Group has launched two ultra-high-precision Bulk Metal Foil resistors for power current sensing. The devices have low TCR of 0.05ppm/°C from 0 to +60°C and 0.2ppm/°C from -55 to +125°C, +25°C.
The devices also display a resistance tolerance to 0.01. The VPR5Z has power rating of 5W at +25°C for applications needing enhanced power, while the VPR7Z displays power rating of 7W and stability of 0.01% at 70°C for 2,000 hours at rated power for load life. They have a good resistance range from 5Ohms to 100kilohms and are not limited to standard and ‘as required’. Other features include a rise time of 1ns with no ringing, a thermal EMF of 0.05mW/°C typical, a thermal steadying time lower than 1s, minimal current noise of -40dB, and a voltage coefficient of below 0.1ppm/V.
The solutions tolerate electrostatic discharges of 25kV for enhanced dependability and feature a non-inductive non-capacitive design. They are ideal for applications such as battery chargers, current regulators, DC/DC converters, diagnostic equipment, electronic scales, motor controls and drivers, over current protection, pressure sensors, PWM input circuits, remote monitoring, satellite receivers, and voltage stabilizers in rugged environments like military and aerospace surveillance.
The Bulk Metal Z-Foil power current sensors can be used as replacements for wire wound devices and possesses the characteristics of wire but in an easy flat planar resistive path unlike normal wire wound products. Both come with four-terminals to help tap precision voltages from the resistors. They possess heavy fixed leads to transmit current via the resistor. The device does not change and does not have re-formation problems. They have minimal allowance for errors.
Source: www.vishaypg.com/