摘要:
PROBLEM TO BE SOLVED: To provide an amplification device that implements a low input voltage and an improved characteristic.SOLUTION: The amplification device includes: first and second transimpedance amplifiers 21 for converting first and second current signals In(+), In(-) input from a pair of light receiving elements, respectively, to output first and second voltage signals Vo(-), Vo(+), respectively; a shunt circuit 24 for shunting each current of the first and second current signals In(+), In(-); an average value detection circuit for generating and outputting an average signal indicating an average voltage value of the first and second voltage signals Vo(-), Vo(+); and a control circuit 23 for controlling each current value of the first and second current signals In(+), In(-) shunted by the shunt circuit 24 on the basis of the average signal Vav and offset voltage values of the first and second voltage signals Vo(-), Vo(+).
摘要:
PROBLEM TO BE SOLVED: To provide a method and system for assisting success in initialization of a resonance micro-electromechanical system (MEMS), especially, a method for overcoming DC offset caused by ESD. SOLUTION: A system 20 includes a resonance sensor 24, a drive device 26, and a charge amplifier and a voltage gain circuit 28. At the time of startup, the charge amplifier and voltage gain circuit receive a signal from the resonance sensor, and generates a clock signal for driving to compensate for the signal about DC offset. By using this, a resonance sensor in an operation mode of stable condition is realized by the system. The circuit includes a plurality of gain switches that are toggle-switched so as to generate glitches in the signal related to the received signal. The glitches compensate for the DC offset. If the signal related to the received signal exceeds a reference signal, a comparator generates a clock signal related to a drive device. COPYRIGHT: (C)2010,JPO&INPIT
摘要:
PROBLEM TO BE SOLVED: To provide a gain control circuit that is not affected by DC offset, and can calculate the signal strength with high accuracy and adjust to targeted signal strength quickly and efficiently. SOLUTION: The gain control circuit includes: a power/energy calculation circuit 203 accumulating a first square value derived from square values of plural signal values in a time period; a DC offset power/energy calculation circuit 204 calculating a second square value that is a square value of a sum of the signal values in the time period, wherein the second square value is divided by a quantity of the signal values in the time period to generate a target offset value; and a DC offset cancel circuit 205, connected to the power/energy calculation circuit 203 and the DC offset power/energy calculation circuit 204, calculating a difference between the first square value and the target offset value. COPYRIGHT: (C)2009,JPO&INPIT