Ricoh Company, Ltd.

Ricon Company, Ltd.

Kohichi Yano

Akihiko Fujiwara

A capacitor charging circuit and method including a plurality of serially connected capacitors and parallel monitor circuits connected in parallel on a one-to-one basis to the capacitors. Each one of parallel monitor circuits applies a direct-current source voltage to a capacitor and bypasses a charge current of the capacitor when the charge voltage of the capacitor exceeds a reference voltage. Each of the parallel monitor circuits includes a reference voltage circuit, a voltage detecting circuit, a comparator, a bypass switching circuit, and a voltage limiter. The reference voltage circuit generates the reference voltage. The voltage detecting circuit detects the charge voltage of the capacitor. The comparator compares the reference voltage with an output voltage from the voltage detecting circuit and controls the bypass switching circuit to bypass the charge voltage using the voltage limiter to limit a voltage applied to the bypass switching circuit.

Capacitor charging methods and apparatuses that use a secure parallel monitoring circuit

Integration and terminal arrangement of serially-connected parallel monitor circuits, capable of monitoring the terminal voltages of serially-connected capacitors, are disclosed. A semiconductor device has a predetermined number of parallel monitor circuits, corresponding to a number of capacitors existing in the system. The semiconductor device includes a number of capacitor terminals and transistor terminals distributed on a capacitor side surface or a capacitor side, and a number of connector terminals distributed on the side surface opposite to the capacitor side surface or the side opposite to the capacitor side.

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Kanagawa-ken, Japan

Kohichi Yano