Switch circuit, selection circuit, and voltage measurement device

Patent metadata

Field	Value
Publication number	US-2016377685-A1
Application number	US-201615258018-A
Country	US
Kind code	A1
Filing date	Sep 7, 2016
Priority date	Apr 21, 2011
Publication date	Dec 29, 2016
Grant date	—

Abstract

Provided is a technique that contributes to the improvement of voltage measurement accuracy and uniform current consumption of a battery in a voltage measurement device. Switch circuits (SWP and SWN) include switch elements (MP 1 and MP 2 or MN 1 and MN 2 ) which are provided between an input terminal and an output terminal, and switch driving units ( 401 to 409 ) which are driven between a first power supply voltage (VCC or GND) and a second power supply voltage (GND or VCC), which are different from each other, with an input voltage interposed therebetween. The switch driving unit includes source follower circuits ( 401 and 404 ) having a drain side being connected to a first power supply terminal side that is supplied with the first power supply voltage, inputting a voltage based on the input voltage, and supplying a voltage generated in the output side to the switch element as a driving voltage for driving the switch element; and current control units ( 402 and 405 ) which open and close a current path between the output side of the source follower circuit and a second power supply terminal being supplied, with the second power supply voltage, in response to a control signal (ENABLE).

First claim

What is claimed is:

1 . A battery cell system, comprising:
a plurality of unit cells electrically connected in series or in an array; a selection circuit configured to select signal lines connected to both ends of any of the plurality of unit cells and connect the selected signal lines to a first output terminal and a second output terminal, in response to a control signal, the selection circuit comprising, with respect to each of the plurality of unit cells:
a first switch circuit that includes an input terminal connected to the signal line that is connected to one end of the unit cell and an output terminal connected to the first output terminal of the selection circuit, and configured to electrically connect the input terminal to the output terminal in response to the control signal; and
a second switch circuit that includes an input terminal connected to the signal line that is connected to the other end of the unit cell and an output terminal connected to the second output terminal of the selection circuit, and configured to electrically connect the input terminal to the output terminal in response to the control signal,
wherein the first switch circuit and the second switch circuit each include a switch element that is provided between the input terminal and the output terminal of the switch circuit, and a switch driving unit that drives the switch element in response to the control
wherein the switch driving unit is driven between a source power supply voltage and a second power supply voltage that are different from each other and different from an input voltage received at the input terminal, and
wherein the switch driving unit includes:
a source follower circuit disposed between a first power supply terminal being supplied with the first power supply voltage and a second power supply terminal being supplied with the second power supply voltage, inputs a voltage based on the input voltage, and supplies a voltage generated in the output side to the switch element as a driving voltage for driving the switch element, and
a current control unit that opens and closes a current path in which the source follower circuit between the first power supply terminal and the second power supply terminal is disposed, in response to the control signal; and

a measurement unit electrically connected to the and second output terminals of the selection circuit and configured to measure a voltage between the first and second output terminals.

2 . The battery cell system of claim 1 , wherein the first power supply voltage is based on a voltage of one end of one of the plurality of unit cells in a highest level of the series or array of unit cells

3 . The battery cell system of claim 1 ,
wherein the switch element includes
a first conductive type first MOS transistor having a drain terminal connected to the input terminal side and a gate terminal supplied with the driving voltage, and
a first conductive type second MOS transistor having a drain terminal connected to the output terminal side, a gate terminal connected to a gate terminal side of the first MOS transistor, and a source terminal connected in common with a source terminal of the first MOS transistor;
wherein the source follower circuit includes a second conductive type third MOS transistor having a drain terminal connected to the first power supply terminal side and a gate terminal connected to source terminal sides of the first MOS transistor and the second MOS transistor, and
a voltage generation unit having one end connected to a source terminal side of the third MOS transistor and the other end connected to the gate terminal sides of the first MOS transistor and the second MOS transistor, and configured to generating voltages in both ends based on a current to be supplied; and
wherein the current control unit is configured to open a current path between the other end of the voltage generation unit and the second power supply terminal when the control signal instructs turn-on of the switch element, and closes the current path when the control signal instructs turn-off of the switch element.

4 . The battery cell system of claim 3 , wherein
the plurality of unit cells includes a first block of adjacent unit cells equal to or greater than a predetermined potential and a second block of adjacent unit cells less than the predetermined potential, for switch elements in switch circuits corresponding to the first block, the first conductive type is P-type and the second conductive type is N-type, and for switch elements in switch circuits corresponding to the second block, the fir conductive type is N-type and the second conductive type is P-type.

5 . The battery cell system of claim 3 , wherein the switch driving unit further includes an off acceleration unit for forming a current path through which a current, which is smaller than a current flowing through a current path formed by the current control unit, flows, between the first power supply terminal and the source terminals of the first MOS transistor and the second MOS transistor, through the other end of the voltage generation unit and the gate terminals of the first MOS transistor and the second MOS transistor.

6 . The battery cell system of claim 3 , wherein the switch driving unit further includes an off acceleration unit, that forms a current, path through the other end of the voltage generation unit between the first power supply terminal and the source terminals of the first MOS transistor and the second MOS transistor, during a period in which the current control unit closes the current path.

7 . The battery cell system of claim 6 , wherein a period in which the off acceleration unit forms the current path is a portion of the period in which the current control unit closes the current path.

8 . The battery cell system of claim 6 , wherein a period in which the off acceleration unit forms the current path is a period corresponding to the period in which the current control unit closes the current path.

9 . A battery cell system, comprising:
two unit cells electrically connected in series; a selection circuit configured to select signal lines connected to both ends of one of the two unit cells and connect the selected signal lines to a first output terminal and a second output terminal, in response to a control signal, the selection circuit comprising, with respect to each of the two unit cells:
a first switch circuit that includes an input terminal connected to the signal line that is connected to one end of the unit cell and an output terminal connected to the first output terminal of the selection circuit, and configured to electrically connect the input terminal to the output terminal in response to the control signal; and
a second switch circuit that includes an input terminal connected to the signal line that is connected to the other end of the unit, cell and an output terminal connected to the second output terminal of the selection circuit, and configured to electrically connect the input terminal to the output terminal in response to control signal,
wherein the first switch circuit and the second switch circuit each include a switch element that is provided between the input terminal and the output terminal of the switch circuit, and a switch driving unit that drives the switch element in response to the control signal,
wherein the switch driving unit is driven between a first power supply voltage and a second power supply voltage that are different from each other and different from an input voltage received at the input terminal, and
wherein the switch driving unit includes:
a source follower circuit disposed between a power supply terminal being supplied with the power supply volta

Assignees

• Renesas Electronics Corp

Inventors

• Makino Ryosei
• Hayakawa Hirohiko

Classifications

• H03K17/693

  Switching arrangements with several input- or output-terminals, e.g. multiplexers, distributors (logic circuits H03K19/00; code converters H03M5/00, H03M7/00) · CPC title

• H03K17/6871

  the output circuit comprising more than one controlled field-effect transistor · CPC title

• H03K17/04

  Modifications for accelerating switching · CPC title

• G01R31/396 Primary

  Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery · CPC title

• G01R31/3835

  involving only voltage measurements · CPC title