Battery voltage monitoring apparatus

• US 9,341,679 B2
• Filed: 11/13/2012
• Issued: 05/17/2016
• Est. Priority Date: 01/05/2007
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Miyamoto, Manabu
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): TORRES RUIZ, JOHALI ALEJANDRA
• Application Number:
  US13/675,567
• Publication Number:
  US 20130106428A1
• Time in Patent Office: 1,281 Days
• Field of Search: 324/429, 324/433
• US Class Current: 1/1
• CPC Class Codes: G01R 15/04 Voltage dividers
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• 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 battery voltage monitoring apparatus for monitoring an assembled battery voltage, the assembled battery including a plurality of battery cells, the battery voltage monitoring apparatus including a plurality of input terminals, the plurality of input terminals being respectively coupled to the plurality of battery cells through a potential measurement line, a comparator having a hysteresis characteristic and including a first terminal and a second terminal, the second terminal receiving a reference voltage, and a current source, one end of the current source being coupled between one of the plurality of the input terminals and the first terminal.

Claims

1. A battery voltage monitoring apparatus monitoring an assembled battery voltage, the assembled battery including a plurality of battery cells, the battery voltage monitoring apparatus comprising:

a plurality of input terminals, the plurality of input terminals being respectively coupled to the plurality of battery cells through a potential measurement line;

a comparator having a hysteresis characteristic and comprising a first terminal and a second terminal, the second terminal receiving a reference voltage; and

a current source, one end of the current source being coupled between one of the plurality of the input terminals and the first terminal.

2. The battery voltage monitoring apparatus according to claim 1, further comprising:

a resistor coupled between one of the plurality of the input terminals and the first terminal; and

a switch coupled between one of the plurality of the input terminals and the first terminal, the switch being parallel to the resistor,

wherein a control terminal of the switch is coupled to an output of the comparator.

3. The battery voltage monitoring apparatus according to claim 1, further comprising a plurality of a current sources that include the current source,

wherein the plurality of the current sources are respectively coupled to the plurality of the input terminals.

4. The battery voltage monitoring apparatus according to claim 1, wherein the assembled battery include a first battery cell, a second battery cell, and a third battery cell,

wherein the plurality of input terminals includes a first input terminal, a second input terminal, a third input terminal, and a fourth input terminal,

wherein the first and second input terminals receive a voltage applied between both ends of the first battery cell,

wherein the second and third input terminals receive a voltage applied between both ends of the second battery cell, and

wherein the third and fourth input terminals receive a voltage applied between both ends of the third battery cell.

5. The battery voltage monitoring apparatus according to claim 4, wherein the first terminal of the comparator is coupled between the first input terminal and the second input terminal.

6. The battery voltage monitoring apparatus according to claim 5, wherein the comparator comprises a first comparator,

wherein the battery voltage monitoring apparatus further comprises a second comparator having a hysteresis characteristic and comprising a third terminal and a fourth terminal,

wherein the third terminal is coupled between the third input terminal and the fourth input terminal, and

wherein the fourth terminal receives a reference voltage.

7. The battery voltage monitoring apparatus according to claim 4, wherein the comparator comprises:

a first power supply terminal coupled to the first input terminal; and

a second power supply terminal coupled to the fourth input terminal.

8. The battery voltage monitoring apparatus according to claim 4, wherein the comparator comprises:

a first power supply terminal coupled to the first input terminal; and

a second power supply terminal coupled to the second input terminal.

9. The battery voltage monitoring apparatus according to claim 8, further comprising a level shifter circuit coupled to an output of the comparator.

10. The battery voltage monitoring apparatus according to claim 9, further comprising an output circuit that comprises a third power supply terminal coupled to the first terminal and a fourth power supply terminal coupled to the fourth terminal, the output circuit being connected to an output of the level shifter circuit.

11. The battery voltage monitoring apparatus according to claim 10, further comprising a delay circuit coupled between the comparator and the output circuit.