JP2010133767A5

JP2010133767A5 -

Info

Publication number: JP2010133767A5
Application number: JP2008308425A
Authority: JP
Filing date: 2008-12-03
Publication date: 2012-01-26

Description

（１）本発明は、物理量を検出し、前記物理量の大きさに応じた検出信号を出力するセンサーと、前記センサーの前記検出信号に基づいて生成された制御信号により、カットオフ周波数を、第１の周波数又は前記第１の周波数よりも低い第２の周波数に設定可能なＶＣＶＳ型のローパスフィルターと、を含むことを特徴とする。 (1) The present invention detects the physical quantity, a sensor for outputting a detection signal corresponding to the magnitude of the previous SL physical quantity, a control signal generated based on the detection signal of the sensor, cut-off And a VCVS type low-pass filter capable of setting the frequency to a first frequency or a second frequency lower than the first frequency.

（８）本発明の物理量検出装置は、前記ローパスフィルターの出力信号をデジタル信号に変換するＡ／Ｄ変換部を含むようにしてもよい。
（９）本発明の物理量検出装置において、前記制御信号は、外部から供給されるようにしてもよい。 (8) The physical quantity detection device of the present invention may include an A / D converter that converts the output signal of the low-pass filter into a digital signal.
( 9 ) In the physical quantity detection device of the present invention, the control signal may be supplied from the outside.

Claims

A sensor for detecting a physical quantity, and outputs a detection signal corresponding to the magnitude of the previous SL physical quantity,
A VCVS type low-pass filter capable of setting a cutoff frequency to a first frequency or a second frequency lower than the first frequency by a control signal generated based on the detection signal of the sensor; A physical quantity detection device comprising:

In claim 1,
The low pass filter is
A first resistor connected to the output terminal of the sensor; a first terminal connected to a second terminal of the first resistor; and a first terminal connected to the first resistor. A first capacitor connected to the second terminal of the resistor, a first capacitor connected to the second terminal of the second resistor, and a second capacitor supplied with a reference voltage to the second terminal; A third capacitor having a first terminal connected to the second terminal of the second resistor, a non-inverting input terminal connected to the second terminal of the second resistor, and an inverting input terminal serving as an output terminal Is connected, the output terminal is connected to the second terminal of the first capacitor, the first terminal is connected to the second terminal of the third capacitor, and the second terminal is connected to the reference terminal. And a switch circuit to which a voltage is supplied. A physical quantity detection device, wherein a cutoff frequency is set to the first frequency or the second frequency by electrically disconnecting or connecting the first terminal and the second terminal of the H circuit. .

In claim 2,
The differential quantity amplifier has a gain of unity.

In claim 2 or 3,
The switch circuit is
A physical quantity detection device comprising: a MOSFET having a drain terminal or a source terminal connected to the first terminal or the second terminal, respectively, and the control signal supplied to a gate terminal.

In any one of claims 1 to 4,
Based on the detection signal of the sensor, it is determined whether the physical quantity detected by the sensor is larger or smaller than a threshold value. If the physical quantity detected by the sensor is larger than the threshold value, the cutoff frequency of the low-pass filter is set. A cut-off frequency setting unit that sets the first frequency and generates the control signal that sets the cut-off frequency of the low-pass filter to the second frequency when the physical quantity detected by the sensor is smaller than the threshold value. A physical quantity detection device comprising:

In claim 5,
The cutoff frequency setting unit is
The physical quantity detection device characterized in that the threshold value can be variably set.

In claim 5 or 6,
An A / D converter that converts the output signal of the low-pass filter into a digital signal;
The cutoff frequency setting unit is
A physical quantity detection device that determines whether the physical quantity detected by the sensor is larger or smaller than the threshold based on the digital signal.

In any one of Claims 1 thru | or 6,
A physical quantity detection device comprising an A / D conversion unit for converting an output signal of the low-pass filter into a digital signal.

In any one of claims 1 to 4,
The physical quantity detection device, wherein the control signal is supplied from the outside.