Abstract: A semiconductor device has a plurality of external connection lead terminals including an input lead terminal, an output lead terminal, and an RF grounding lead terminal, a heat dissipation plate connected to the RF grounding lead terminal, a semiconductor device and a printed circuit board each mounted on the heat dissipation plate, and a mold resin for sealing the semiconductor device, the printed circuit board, and the heat dissipation plate such that at least a part of the back surface of the heat dissipation plate is exposed. The semiconductor device amplifies a signal inputted to the input lead terminal and outputs the amplified signal from the output lead terminal.

Abstract: A vehicular electronic apparatus contains a microcomputer, and a crystal oscillator for determining an operating frequency for the microcomputer. An oscillation frequency of the crystal oscillator is selected such that a frequency difference between a frequency of a broadcast wave received by a vehicular receiver and an oscillation frequency of the crystal oscillator or a higher harmonic of the oscillation frequency is 15 kHz or higher or 400 Hz or lower, to suppress an interference in receiving the broadcast wave.

Abstract: A vehicular electronic apparatus comprises a microcomputer, and a crystal oscillator for determining an operating frequency for the microcomputer. An oscillation frequency of the crystal oscillator being selected such that a frequency difference between a frequency of a broadcast wave received by a vehicular receiver and an oscillation frequency of the crystal oscillator or a higher harmonic of the oscillation frequency is 15 kHz or higher or 400 Hz or lower, to suppress an interference in receiving the broadcast wave.

Abstract: The power source filter circuit is provided with a first inductor and a second inductor connected in series between an input terminal and an output terminal, a first capacitor connected between the input terminal and a reference potential point, a second capacitor connected between a contact point that connects the first inductor with the second inductor and the reference potential point, a third capacitor connected between the output terminal and the reference point, and a first resistance and a second resistance having a small resistance value connected to the second inductor in parallel respectively.

Abstract: The power source filter circuit is provided with a first inductor and a second inductor connected in series between an input terminal and an output terminal, a first capacitor connected between the input terminal and a reference potential point, a second capacitor connected between a contact point that connects the first inductor with the second inductor and the reference potential point, a third capacitor connected between the output terminal and the reference point, and a first resistance and a second resistance having a small resistance value connected to the second inductor in parallel respectively.