Title:
SQUARE CIRCUIT AND SIGNAL PROCESSING CIRCUIT USING IT
Document Type and Number:
Japanese Patent JP3747153
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a signal processing circuit, which is applied for a physical quantity sensor that has sensitivity in all directions, with good accuracy, a low-cost and simple design.
SOLUTION: A pulse-length modulated rectangular wave, which corresponds to a quantity change that is a detected value of a physical quantity sensor 10, is adjusting amplified by quantity corresponds to a quantity change in amplitude of the wave. Subsequently, a switch 23 converts the wave into a product of the changes of pulse length and amplitude, and then outputs. The product corresponds to the square of a quantity change corresponding to a quantity change of the pulse-length modulated rectangular wave. In addition, each detected value in X and Y axes of the physical quantity sensor 10 is converted into a product as described above, and then all products are added by an adder 12 to calculate the sum of the squares. With this circuit design, a square value, which is an absolute value independent on direction of physical quantity, can be outputted. Therefore, a signal processing circuit, which is applied for a physical sensor that has sensitivity in all directions, can perform the above- described operations, and be provided with a low-cost and simple design.
Inventors:
Junichiro Matsui
Application Number:
JP2000360610A
Publication Date:
February 22, 2006
Filing Date:
November 28, 2000
Export Citation:
Assignee:
Japan Aviation Electronics Industry Co., Ltd.
International Classes:
G01D1/02; G06G7/20; (IPC1-7): G06G7/20; G01D1/02
Domestic Patent References:
| JP54095151A | ||||
| JP58034865B2 |
Attorney, Agent or Firm:
Shinsuke Ozeki