Lapis Semiconductor Co., Ltd.

Oki Semiconductor Co., Ltd.

Masaru Sekiguchi

Naoaki Sugimura

Hidekazu Kikuchi

Kouji Morita

A semiconductor device for measuring a voltage of a battery cell, including first and second nodes, and first and second battery voltage measurement units. The first node is configured to receive a first voltage, the first voltage being a voltage of a capacitor that accumulates an electric charge based on the voltage of the battery cell. The first battery voltage measurement unit measures the first voltage through a first path. The second node is configured to receive a second voltage based on the voltage of the battery cell, the second node being different from the first node. The second battery voltage measurement unit measures the second voltage through a second path that is different from the first path.

Semiconductor device, battery monitoring system, and diagnostic method for semiconductor device

A semiconductor device is performed a cell voltage measurement control for measuring each cell voltage of each target battery cell among a plurality of battery cells connected in series, using a difference voltage output circuit having first and second input terminals. In the measurement control, first and second connection states are formed with respect to each target battery cell so that each cell voltage is sequentially measured. Anode and cathode of each target battery cell are connected to the first and second input terminals in the first connection state, respectively, and the anode and cathode are connected to the second and first input terminal in a second connection state, respectively. Among the first and second connection states, a connection state that is first formed for a current target battery cell is the same as a connection state that has been last formed for a previous target battery cell.

Semiconductor device and a method for measuring a cell voltage

A battery monitoring system including: plural battery cell sets; and semiconductor devices, wherein: each of the semiconductor devices includes a measuring section, a high side communication section that is supplied with a drive voltage in a first voltage range, and, when a semiconductor device is present at a higher position that operates at a higher operating voltage than the operating voltage of the semiconductor device itself when measuring a battery cell set on the high side of the battery cell set measured by the semiconductor device itself, can perform communication with the high side semiconductor device, a low side communication section, and a communication level converter; the semiconductor device at the highest stage further includes a signal level determination section; and the first voltage range of the highest stage is set to a specific voltage range narrower than the first voltage range of another of the semiconductor devices.

Battery monitoring system and semiconductor device

A semiconductor device for monitoring batteries or cells connected in series has a selector switch that selects one of the batteries or cells and outputs voltages obtained from its positive and negative terminals. A pair of buffer amplifiers receives these voltages at high-impedance input terminals and output corresponding voltages to a level shifter. The level shifter generates an output voltage equal to the difference between the outputs of the buffer amplifiers. By preventing current flow between the selector switch and the level shifter, the buffer amplifiers reduce the output droop that occurs at the beginning of a voltage measurement, even if the semiconductor device is connected to the batteries or cells through a low-pass filter circuit with a comparatively large time constant. Measurement time is shortened accordingly.

Method and semiconductor device for monitoring battery voltages

A DA converter includes an IV conversion amplifier with output voltage having good linearity, to thus improve total harmonic distortion (THD) characteristics. In the DA converter, a first current path in which current flows due to differential switches being in the ON state in a differential switch section, and a second current path in which current flows due to differential switches being in the OFF state in the differential switch section are connected to the output side of the IV conversion amplifier. A first current flows in the first current path and a second current flows in the second current path. A current equal to the first current plus the second current that is of fixed current amount is drawn by an amplifier stage of the IV conversion amplifier.

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Yokohama, Japan

Masaru Sekiguchi