Power transmission device and electronic instrument

A power transmission device that includes a primary coil and electromagnetically couples the primary coil with a secondary coil of a power reception device to supply power to a load of the power reception device, the power transmission device comprising:

• a first coil connection terminal and a second coil connection terminal respectively connected to ends of the primary coil;
• a resonant capacitor that forms a series resonant circuit with the primary coil;
• a first power transmission driver and a second power transmission driver that drive the primary coil from the ends of the primary coil through the first coil connection terminal and the second coil connection terminal;
• and
• a control IC that outputs driver control signals to the first power transmission driver and the second power transmission driver,
• the first coil connection terminal, the second coil connection terminal, the resonant capacitor, the first power transmission driver, the second power transmission driver, and the control IC being provided on a mounting surface of a printed circuit board,
• the control IC being formed in the shape of a quadrangle that has a first side, a second side, a third side, and a fourth side, an output terminal of the driver control signal output to the first transmission driver being provided on the first side, an output terminal of the driver control signal output to the second transmission driver being provided on the second side adjacent to the first side, an input terminal that receives a signal waveform at the second coil connection terminal through a waveform detection wiring pattern being disposed on the third side opposite to the first side, and the control IC being disposed at a position shifted in a first direction with respect to a centerline that divides the printed circuit board in two and is parallel to the first side and the third side;
• the first coil connection terminal and the second coil connection terminal being disposed in a first row position on an end of the printed circuit board, and, when a direction opposite to the first direction is referred to as a second direction, the second coil connection terminal being disposed at a position shifted in the second direction with respect to the centerline;
• the resonant capacitor being disposed in a second row position between the first row position where the first coil connection terminal and the second coil connection terminal are disposed and a row position where the control IC is disposed;
• the first power transmission driver and the second power transmission driver being disposed between the first row position and the row position where the control IC is disposed, and the first transmission driver being disposed at a position shifted in the first direction with respect to the first side of the control IC;
• and
• the waveform detection wiring pattern extending from the third side of the control IC to the second coil connection terminal through an area of the printed circuit board shifted in the second direction with respect to the centerline.