Semiconductor device, battery pack, and mobile terminal including voltage measurement, current measurement, and control

• US 9,759,778 B2
• Filed: 10/07/2014
• Issued: 09/12/2017
• Est. Priority Date: 11/14/2013
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Nagato, Hidekazu
• Primary Examiner(s): Prifti, Aurel
• Application Number:
  US14/508,596
• Publication Number:
  US 20150134981A1
• Time in Patent Office: 1,071 Days
• Field of Search: 320125, 320128, 320107, 320136, 320132, 320130, 320116, 307 18, 713340, 702 63
• CPC Class Codes: G01R 31/3842 combining voltage and current 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
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/3212 Monitoring battery levels, e.g. power saving mode being initiated when battery voltage goes below a certain level
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A semiconductor device includes a voltage measurement unit that measures an output voltage of a battery and a voltage on a power supply path between the battery and an internal circuit supplied with electric power from the battery, a current measurement unit that measures a discharge current of the battery, and a control unit that calculates a theoretical value of the output voltage in a normal measurement mode assuming that the discharge current measured in a large current measurement mode is a maximum available current of the battery in the large current measurement mode, and calculates an amount of maximum available power of the battery in the large current measurement mode based on the calculated theoretical value of the output voltage and the voltage on the power supply path measured in the large current measurement mode.

Claims

1. A semiconductor device comprising

a voltage measurement unit that measures an output voltage of a battery and a voltage on a power supply path between the battery and an internal circuit supplied with electric power from the battery;

a current measurement unit that measures a discharge current of the battery; and

a processor, executing program instructions stored in a non-transitory computer readable medium, that calculates a theoretical value of the output voltage in a normal measurement mode assuming that the discharge current measured in a large current measurement mode is a maximum available current of the battery in the large current measurement mode, and calculates an amount of maximum available power of the battery in the large current measurement mode based on the calculated theoretical value of the output voltage and the voltage on the power supply path measured in the large current measurement mode,

wherein the theoretical value of the output voltage is calculated according to an internal resistance of the battery, and a resistance on a side including the voltage measurement unit, current measurement unit, and the processor.

2. The semiconductor device according to claim 1, wherein the processor calculates an actual value of the output voltage in the normal measurement mode based on the calculated theoretical value of the output voltage and the voltage on the power supply path measured in the large current measurement mode, and calculates an amount of maximum available power of the battery in the large current measurement mode based on the calculated actual value of the output voltage.

3. The semiconductor device according to claim 1, further comprising a transistor that is provided on the power supply path and controls whether or not to supply the electric power of the battery to the internal circuit,

wherein the voltage measurement unit measures an output voltage of the transistor as a voltage on the power supply path.

4. The semiconductor device according to claim 1, wherein the voltage measurement unit measures, as a voltage on the power supply path, a voltage at an external terminal of the semiconductor device, the external terminal being provided on the power supply path.

5. The semiconductor device according to claim 1, wherein the voltage measurement unit measures, as a voltage on the power supply path, a voltage applied to the internal circuit.

6. The semiconductor device according to claim 1, wherein when the discharge current is equal to or less than a threshold current, the processor sets the normal measurement mode as a measurement mode, and when the discharge current exceeds the threshold current, the processor sets the large current measurement mode as the measurement mode.

11. The battery pack according to claim 1, wherein the voltage measurement unit measures, as a voltage on the power supply path, a voltage at an external terminal of the semiconductor device, the external terminal being provided on the power supply path.

12. The battery pack according to according to claim 1, wherein the voltage measurement unit measures, as a voltage on the power supply path, a voltage applied to the internal circuit.

13. The battery pack according to claim 1, wherein when the discharge current is equal to or less than a threshold current, the processor sets the normal measurement mode as a measurement mode, and when the discharge current exceeds the threshold current, the processor sets the large current measurement mode as the measurement mode.

7. A battery pack comprising:

the semiconductor device; and

the battery,

the semiconductor device comprising;

a voltage measurement unit that measures an output voltage of a battery and a voltage on a power supply path between the battery and an internal circuit supplied with electric power from the battery;

a current measurement unit that measures a discharge current of the battery; and

a processor, executing program instructions stored in a non-transitory computer readable medium, that calculates a theoretical value of the output voltage in a normal measurement mode assuming that the discharge current measured in a large current measurement mode is a maximum available current of the battery the large current measurement mode, and calculates an amount of maximum available power of the battery in the large current measurement mode based on the calculated theoretical value of the output voltage and the voltage on the power supply path measured in the large current measurement mode,

wherein the theoretical value of the output voltage is calculated according to an internal resistance of the battery, and a resistance on a side including the voltage measurement unit, current measurement unit, and the processor.

9. The battery pack according to claim 7, wherein the processor calculates an actual value of the output voltage in the normal measurement mode based on the calculated theoretical value of the output voltage and the voltage on the power supply path measured in the large current measurement mode, and calculates an amount of maximum available power of the battery in the large current measurement mode based on the calculated actual value of the output voltage.

10. The battery pack according to claim 7, further comprising a transistor that is provided on the power supply path and controls whether or not to supply the electric power of the battery to the internal circuit,

wherein the voltage measurement unit measures an output voltage of the transistor as a voltage on the power supply path.

8. A mobile terminal comprising;

a battery pack including a semiconductor device and a battery; and

the internal circuit driven by electric power supplied from the battery,

the semiconductor device comprising;

a voltage measurement unit that measures an output voltage of the battery and a voltage on a power supply path between the battery and an internal circuit supplied with electric power from the battery;

a current measurement unit that measures a discharge current of the battery; and

a processor, executing program instructions stored in a non-transitory computer readable medium, that calculates a theoretical value of the output voltage in a normal measurement mode assuming that the discharge current measured in a large current measurement mode is a maximum available current of the battery in the large current measurement mode, and calculates an amount of maximum available power of the battery in the large current measurement mode based on the calculated theoretical value of the output voltage and the voltage on the power supply path measured in the large current measurement mode,

wherein the theoretical value of the output voltage is calculated according to an internal resistance of the battery, and resistance on a side including the voltage measurement unit, current measurement unit, and the processor.

14. The mobile terminal according to claim 8, wherein the processor calculates an actual value of the output voltage in the normal measurement mode based on the calculated theoretical value of the output voltage and the voltage on the power supply path measured in the large current measurement mode, and calculates an amount of maximum available power of the battery in the large current measurement mode based on the calculated actual value of the output voltage.

15. The mobile terminal according to claim 8, further comprising a transistor that is provided on the power supply path and controls whether or not to supply the electric power of the battery to the internal circuit,

wherein the voltage measurement unit measures an output voltage of the transistor as a voltage on the power supply path.

16. The mobile terminal according to claim 8, wherein the voltage measurement unit measures, as a voltage on the power supply path, a voltage at an external terminal of the semiconductor device, the external terminal being provided on the power supply path.

17. The mobile terminal according to claim 8, wherein the voltage measurement unit measures, as a voltage on the power supply path, a voltage applied to the internal circuit.

18. The mobile terminal according to claim 8, wherein when the discharge current is equal to or less than a threshold current, the processor sets the normal measurement mode as a measurement mode, and when the discharge current exceeds the threshold current, the processor sets the large current measurement mode as the measurement mode.