Electrical Control Unit for an Automobile

• US 20070219671A1
• Filed: 05/23/2007
• Published: 09/20/2007
• Est. Priority Date: 12/17/2002
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: KANEKAWA, Nobuyasu, SAKURAI, Kohei, Watabe, Mitsuru, OYAMA, Katsuya, SASAKI, Shoji
• Granted Patent: US 7,480,549 B2
• Time in Patent Office: Days
• US Class Current: 700/297
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence
• CPC Class Codes: F02D 41/1494 Control of sensor heater
• CPC Class Codes: F02D 41/26 using computer, e.g. microprocessor
• CPC Class Codes: F02N 2300/302 using data communication
• CPC Class Codes: G06F 1/3215 Monitoring of peripheral devices

Abstract

An electrical control unit for an automobile of which standby current is smaller. In an electrical control unit for an automobile having a microcomputer, an input circuit, a driver circuit, and a power supply circuit, which is started by a wake-up signal from the circuit other than the ignition switch even when the ignition switch of the automobile is cut off, the microcomputer is started by shifting the power supply circuit from an inert state to an active state to generate the voltage for operating the microcomputer, and the predetermined processing is executed.

Claims

1. A power supply circuit comprising:

a first regulator which generates a voltage to operate an outside microcomputer by inputting a wake-up signal;

an OR circuit activating the first regulator by inputting at least one of the plural wake-up signals;

a wake-up factor determining resister to distinguish whether the first regulator is activated by which one of the plural wake-up signals; and

a second regulator which generates a voltage to be supplied to the wake-up factor determining resister during the time of sleep mode.

2. The power supply circuit according to claim 1, further comprising a communication circuit for communicating with the outside microcomputer, wherein the content distinguished by the wake-up factor determining resister is transmitted to the outside microcomputer via the communication circuit.

3. The power supply circuit according to claim 2, further comprising a timer circuit which includes a counter, a wake-up timing setting register, and a comparator, and outputs the wake-up signal when the value of the counter reaches a predetermined value set in the wake-up timing setting register.

4. The power supply circuit according to claim 3, wherein the outside microcomputer sets the value of the wake-up timing setting register of the timer circuit or reads the value of the counter.

5. The power supply circuit according to claim 3, further comprising:

a first outside power supply which inputs an electric power to the second regulator;

a second outside power supply which operates the timer circuit when the electric power is not supplied from the first outside power supply to the second regulator; and

a power supply switch means which generates a reset signal to be outputted to the outside microcomputer,

wherein the reset signal generating circuit outputs the reset signal to the outside microcomputer when the first regulator is activated.

9. The power supply circuit according to claim 1, further comprising a watch dog timer to prevent a runaway of an active program in the outside microcomputer.

10. The power supply circuit according to claim 1, further comprising a communication driver which sends or receives a communication signal via a communication line and a latch circuit which memorizes the level change of the communication signal.