ACCELERATION SENSOR CIRCUIT

摘要

PROBLEM TO BE SOLVED: To decrease the remaining amount of zero-point compensation after the compensation by trimming adjustment more smaller. SOLUTION: This sensor circuit is constituted of a bridge circuit, wherein piezo resistors R1 -R4 , whose resistance values are changed is correspondence with applied acceleration, are connected to respective four sides, a power supply is connected between a pair of facing power supply terminals T3 and T4 and the output voltages of the acceleration sensor based on the change in the piezo resistors R1 -R4 are outputted from a pair of other output terminals T1 and T2 . Then, first resistors Rs1 and Rs2 , which are trimmed and adjusted as the zero-point compensating thick-film resistors, are connected in series with the respective piezo resistors R1 and R4 on the mutually neighboring two sides. Second resistors Rp1 and Rp2 , which are trimmed and adjusted based on the measured results of temperature characteristics as zero-point-temperature compensating thick-film resistors, are connected in parallel with the respective piezo resistors R2 and R3 on the other neighboring two sides. Third resistors Rp3 and Rp4 , whose temperature coefficients and resistance values are the same specification values as those of the second resistors Rp1 and Rp2 , are connected in parallel with the piezo resistors R1 and R4 , respectively.