A new family of low-power, low-TCR electrically re-adjustable resistors from Microbridge Technologies Inc. is designed to compensate and calibrate precision analog circuits. Used with off-the-shelf National Instruments hardware (NI-cDAQ 9172), the devices, which are called Rejusters, can be employed to calibrate a wide variety of circuits in parallel. Other solutions exist for this task, but they have drawbacks, the company says. These include limited temperature and maximum frequency of operation, the need for power, or the need for a laser. Rejusters, however, operate to 125°C or higher and to 2 GHz or above. They require no power to run in the circuit, have no wiper resistance, and are adjustable to precision levels of 0.1% or better.
Rejustors are programmable resistors that can be used to solve analog compensation problems in the analog domain. They are analog resistors, user-programmed to a fixed resistance with high precision and stability. They can be adjusted hundreds of times and always maintain the last adjusted state even when placed in storage for extended periods. After trimming, these passive devices require no power to hold their value.
Rejusters are passive resistors made from the same polysilicon materials used in high-volume CMOS processing. Users can easily set them to the desired resistance value using simple calibration hardware and software algorithms. All members of the low-power Rejuster family are available off-the-shelf at a price of $0.99 for quantities of 1000. Each QFN package contains two Rejuster elements, making it easier to implement divider networks where the temperature coefficient of the resistors must be equally matched. For more information on Rejusters, checkout www.mbridgetech.com/resistor-technology/resistor-white-papers.php.