Semiconductor device and battery monitoring system

• US 9,970,990 B2
• Filed: 03/13/2013
• Issued: 05/15/2018
• Est. Priority Date: 03/28/2012
• Status: Active Grant

• Current Assignee: LAPIS Semiconductor Co., Ltd. (ROHM Co., Ltd.)
• Original Assignee: LAPIS Semiconductor Co., Ltd. (ROHM Co., Ltd.)
• Inventors: Suzuki, Koji
• Primary Examiner(s): Dunn, Drew A
• Assistant Examiner(s): Zhou, Zixuan
• Application Number:
  US13/802,589
• Publication Number:
  US 20130257443A1
• Time in Patent Office: 1,889 Days
• Field of Search: 324426, 324433, 320116-119
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery

Abstract

A semiconductor device including: lines connected to lines between respective neighboring battery cells of plural battery cells connected in series; at each of the battery cells, a voltage detection portion that detects a battery voltage value of the battery cell based on a voltage provided by the lines connected to the high potential side of the battery cell and to the low potential side of the battery cell; and at each of the lines, a regulation portion that regulates current to make a first current and a second current cancel out, the first current being caused to flow in a first direction in the resistor element by the battery cell at the high potential side of the line, and the second current being caused to flow in a second direction in the resistor element by the battery cell at the low potential side of the line.

Claims

1. A semiconductor device comprising:

external terminals, each of the external terminals is connected to a terminal of a resistor element, wherein another terminal of the resistor element is connected to a connection portion of respective neighboring battery cells of a plurality of battery cells connected in series;

a plurality of lines connected to the external terminals;

a plurality of voltage detection portions, each of the plurality of voltage detection portions is set to correspond to each of the plurality of battery cells, respectively, each of the plurality of voltage detection portions detects a battery voltage value of the battery cell in accordance with a voltage provided by the line that is connected to the high potential side of the battery cell and the line that is connected to the low potential side of the battery cell; and

a plurality of regulation portions, at each of the plurality of lines, the plurality of regulation portions are set to correspond to each of the plurality of battery cells, respectively, a terminal of a regulation portion of the plurality of regulation portions is connected to a line that is connected to the high potential side of the battery cell, and another terminal of the regulation portion is connected to a line that is connected to the low potential side of the battery cell, and each regulation portion being connected in series, each of the plurality of regulation portions comprises a constant current source, the constant current source generates current to make a first current and a second current cancel out, the first current being caused to flow in a first direction in the resistor element by the battery cell in the line that is connected to the high potential side of the battery cell, and the second current being caused to flow in a second direction in the resistor element by another battery cell in the line that is connected to the low potential side of the battery cell.

2. The semiconductor device according to claim 1, wherein:

the regulation portion comprises;

a first constant current source that generates a constant current by reference to a ground potential; and

a second constant current source that generates a constant current by reference to a power supply potential, and

the voltage detection portion comprises;

a resistor and the first constant current source, which are connected in series between the line connected to the high potential side of the each battery cell and ground;

a reference voltage generation portion that is connected in series with the second constant current source between a power supply line and the line connected to the low potential side of each battery cell, and that generates a reference voltage from the constant current of the second constant current source; and

a comparison circuit that outputs a difference between the voltage of a junction between the resistor and first constant current source that are connected in series and the reference voltage.

3. The semiconductor device according to claim 2, wherein the reference voltage generation portion comprises a Zener diode, a resistor element, or both a resistor element and a diode.

4. The semiconductor device of claim 1, wherein the voltage detection portion comprises:

a resistor and the constant current source, which are connected in series between the line connected to the high potential side of the each battery cell and the line connected to the low potential side of the each battery cell, and

a comparison circuit that outputs a difference between the voltage of a junction between the resistor and constant current source that are connected in series and a predetermined reference voltage.

5. A battery monitoring system comprising:

a plurality of battery cells connected in series;

a noise removal portion comprising resistor elements and capacitor elements connected to high potential sides of the plurality of battery cells;

a plurality of lines connected, via the resistor elements of the noise removal portion, to lines between respective neighboring battery cells of the plurality of battery cells;

a plurality of voltage detection portions, each of the plurality of voltage detection portions is set to correspond to each of the plurality of battery cells, respectively, each of the plurality of voltage detection portions capable of detecting a battery voltage value of the battery cell in accordance with a voltage provided by the line that is connected to the high potential side of the battery cell and the line that is connected to the low potential side of the battery cell; and

a regulation portion at the plurality of lines, a terminal of the regulation portion is connected to a line that is connected to the high potential side of the battery cell, and another terminal of the regulation portion is connected to a line that is connected to the low potential side of the battery cell, the regulation portion configured to generate current to make a first current and a second current cancel out, the first current being caused to flow in a first direction in the resistor element by the battery cell in the line that is connected to the high potential side of the battery cell, and the second current being caused to flow in a second direction in the resistor element by another battery cell in the line that is connected to the low potential side of the battery cell, regardless of variations in battery voltages of the plurality of battery cells,

wherein;

the regulation portion comprises a constant current source and is set to correspond to each of the plurality of battery cells, respectively, each regulation portion being connected in series.

6. The battery monitoring system of claim 5, wherein the voltage detection portion comprises:

a resistor and the constant current source, which are connected in series between the line connected to the high potential side of the each battery cell and the line connected to the low potential side of the each battery cell, and

a comparison circuit that outputs a difference between the voltage of a junction between the resistor and constant current source that are connected in series and a predetermined reference voltage.