Research on Frequency Response Characteristics of TMR Sensor

In this paper, we discuss the key factors influencing the bandwidth of Tunnel Magnetoresistance (TMR) sensor, and the approaches of frequency response testing. We built frequency response test system for the TMR sensor based on the high frequency power amplifier and solenoid, with central magnetic field strength 1 Oe at the bandwidth of 10 MHz. Based on the system, 3 dB bandwidth of four kinds of TMR sensor plate are test. The results show that the Trial production of TMR sensor bandwidth is up to 5 MHz.