Canon Kabushiki Kaisha

Masanori Kikuchi

Hiroyuki Mizuno

Hikaru Nomura

Takashi Numagi

Jin Miyasaka

A printed circuit board includes a power input terminal, a positive trunk line, a negative trunk line, a first switching circuit, a second switching circuit, a first positive wire, a second positive wire, a first capacitor, a second capacitor, and a bypass circuit. The first positive wire connecting the positive trunk line with the first switching circuit without passing through the second switching circuit. The second positive wire connecting the positive trunk line with the second switching circuit without passing through the first switching circuit. The first capacitor provided between the first positive wire and the negative trunk line. The second capacitor provided between the second positive wire and the negative trunk line. The bypass circuit connecting the first positive wire with the second positive wire.

Printed circuit board

A printed wiring board includes a first main wire having first inner layer wiring patterns which are wired on inner layers connected by first via conductors in series. In addition, a second main wire has second inner layer wiring patterns which are wired on the inner layers connected by second via conductors. The first inner layer wiring patterns and the second inner layer wiring patterns are wired so as to change the layer to the inner layer on the opposite side to each other. First and second branch wires are branched from the first and second via conductors, respectively.

Printed wiring board and printed circuit board

A first reception circuit and a second reception circuit are mounted on a printed circuit board, and receive signals via wiring thereof from a transmission circuit. The printed wiring board includes a trunk wiring, a first branched line branching from a first branch connection point, and a second branched line branching from a second branch connection point in order. A wiring area between the start end and the first branch connection point is divided into a first wiring portion and a second wiring portion, in order from the start end, and a wiring area between the first branch connection point and the second branch connection point is a third wiring portion. The characteristic impedance of the first wiring portion is set to equal or lower than the characteristic impedance of the third wiring portion, and the characteristic impedance of the second wiring portion is set higher than the characteristic impedance of the first wiring portion.

Printed circuit board and printed wiring board

A memory system is provided with a motherboard, and a memory controller and a plurality memory devices mounted on the motherboard. The motherboard comprises a unicursal-shape main wiring, and branch wirings branched from the main wiring to the respective memory devices. Further, the motherboard comprises an open stub wiring branched from a connecting point between a start end and a branch point of the main wiring. Thus, a ringing of a waveform of a signal received by a receiving circuit can be suppressed irrespective of a wiring length of the branch wiring.

In a printed circuit board, a semiconductor including plural power supply terminals and a semiconductor chip is mounted onto a mounting surface of a printed wiring board, and a bypass capacitor for reducting a power ground noise is provided. Another bypass capacitor, which is connected to the bypass capacitor only within an IC chip is provided to inhibit the power ground noise from causing not only a variation in timing of the IC chip and a malfunction thereof but also a malfunction of another IC chip and the generation of an EMI noise in a case where the power ground noise propagates to a power supply side.

Growing community of inventors

Yokohama, Japan

Masanori Kikuchi