MINUTE SIGNAL PROCESSING CIRCUIT AND PRE-DETECTION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a minute signal processing circuit and a pre-detection circuit capable of processing a minute signal of large variation without being affected by the restriction on the common-mode input range of an amplifier part, having a small number of parts and the advantage of packaging. SOLUTION: The output voltage Vo of a vibration gyroscope 1 and the output voltage VDA of a D/A converter 4 are inputted to a circuit 2. CPU 3 controls the output voltage VDA of the D/A converter 4 when the output voltage Vωof the circuit 2 exceeds the dynamic range. Since an operational amplifier OP1 has an inverted input form, it is not affected by the restriction on the common-mode input range even when the output signal Vo of the vibration gyroscope 1 is fluctuated. This circuit 2 realizes the function of a low pass filter, an adder and an amplifier without being provided with plural operational amplifiers OP1. Consequently, a number of parts is reduced and the packaging space is ensured.