Electronic control apparatus for controlling driving of load by MOS FETs

• US 7,924,063 B2
• Filed: 08/27/2004
• Issued: 04/12/2011
• Est. Priority Date: 08/27/2003
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Itabashi, Toru, Kanayama, Mitsuhiro
• Primary Examiner(s): Donovan; Lincoln
• Assistant Examiner(s): Jager; Ryan C
• Application Number:
  US10/926,993
• Publication Number:
  US 20050046280A1
• Time in Patent Office: 2,419 Days
• Field of Search: 327/390, 327/437, 327/536, 327/537
• US Class Current: 327/108
• CPC Class Codes: H03K 17/063 in field-effect transistor switches
• CPC Class Codes: H03K 17/162 without feedback from the output circuit to the control circuit
• CPC Class Codes: H03K 17/693 Switching arrangements with several input- or output-terminals, e.g. multiplexers, distributors logic circuits H03K19/00; code converters H03M5/00, H03M7/00

Abstract

An ECU has a main IC and at least one auxiliary IC, with at least the auxiliary IC driving one or more MOS FETs to control supplying of power to respective electrical loads, e.g., in a vehicle. A stepped-up voltage, higher than the circuit power source voltage, is generated within the main IC and supplied to each auxiliary IC, for driving gate electrodes of the MOS FETs. Electrical noise produced by operation of a voltage step-up circuit in the main IC is effectively suppressed by elements that are coupled only to a power source terminal of the main IC alone.

Claims

1. An electronic control apparatus comprising:

a main integrated circuit, comprising;

a power source input terminal coupled to recieve an externally supplied power source voltage,

a voltage step-up circuit operating from said power source voltage supplied to said power source input terminal to produce a stepped-up voltage that is higher than said power source voltage, and

a stepped-up voltage output terminal coupled to receive said stepped-up voltage; and

at least one auxiliary integrated circuit, comprising;

a stepped-up voltage input terminal coupled to receive said stepped-up voltage from said stepped-up voltage terminal of said main integrated circuit,

a first drive circuit for selectively applying said stepped-up voltage to a gate electrode of a first MOS FET (metal-oxide semiconductor field effect transistor) that is connected in a current flow path of a first electrical load, to effect on and off switching of said first MOS FET,

a second drive circuit for selectively applying said stepped-up voltage to a gate electrode of a second MOS FET that is connected in a current flow path of a second electrical load, to effect on and off switching of said second MOS FET, and

a noise reduction circuit connected to said power source input terminal of said main integrated circuit but unconnected to said at least one auxiliary integrated circuit;

wherein;

said at least one auxiliary integrated circuit comprises a second power source input terminal coupled to receive said externally supplied power source voltage, and a second voltage step-up circuit operating from said power source voltage supplied to said second power source input terminal to produce a second stepped-up voltage that is higher than said power source voltage;

said second voltage step-up circuit is selectively set in an operative condition and an inoperative condition in accordance with whether or not a constituent element of said second voltage step-up circuit is connected to said auxiliary integrated circuit as an external component; and

when said second voltage step-up circuit is in said operative condition, said first drive circuit selectively applies said second stepped-up voltage to said gate electrode of said first MOS FET to effect said on and off switching of said first MOS FET, and said second drive circuit selectively applies said second stepped-up voltage to said gate electrode of said second MOS FET to effect said on and off switching of said second MOS FET.

2. An electronic control apparatus as claimed in claim 1, wherein said voltage step-up circuit comprises a charge pump circuit which performs switching of charges between a plurality of capacitors to generate said stepped-up voltage, and wherein said constituent element that is connectable to said at least one auxiliary integrated circuit as an external component comprises at least one of said capacitors of said charge pump circuit.

3. An electronic control apparatus as claimed in claim 1, wherein:

said at least one auxiliary integrated circuit comprises a second power source input terminal coupled to receive said externally supplied power source voltage, a control signal input terminal, a second voltage step-up circuit operating from said power source voltage supplied to said second power source input terminal to produce a second stepped-up voltage that is higher than said power source voltage;

said second voltage step-up circuit is selectively set in an operative condition and an inoperative condition in accordance with whether or not a predetermined signal is being externally applied to said control signal input terminal; and

when said second voltage step-up circuit is in said operative condition, said first drive circuit selectively applies said second stepped-up voltage to said gate electrode of said first MOS FET to effect said on and off switching of said first MOS FET, and said second drive circuit selectively applies said second stepped-up voltage to said gate electrode of said second MOS FET to effect said on and off switching of said second MOS FET.

4. An electronic control apparatus comprising:

a main integrated circuit, comprising;

a power source input terminal coupled to receive an externally supplied power source voltage,

a voltage step-up circuit operating from said power source voltage supplied to said power source input terminal to produce a stepped-up voltage that is higher than said power source voltage,

a stepped-up voltage output terminal coupled to receive said stepped-up voltage, and

a conductive path connected to the stepped-up voltage output terminal and extending externally from the main integrated circuit, and through which the stepped-up voltage is supplied; and

at least one auxiliary integrated circuit, comprising;

a stepped-up voltage input terminal coupled to receive said stepped-up voltage from said stepped-up voltage output terminal of said main integrated circuit through the conductive path,

a first drive circuit for selectively applying said stepped-up voltage to a gate electrode of a first MOS FET (metal-oxide semiconductor field effect transistor) that is connected in a current flow path of a first electrical load, to effect on and off switching of said first MOS FET,

a second drive circuit for selectively applying said stepped-up voltage to a gate electrode of a second MOS FET that is connected in a current flow path of a second electrical load, to effect on and off switching of said second MOS FET, wherein the first and second drive circuits receive the stepped-up voltage via the conductive path connected to the stepped-up voltage output terminal, and

a second power source input terminal coupled to receive said externally supplied power source voltage, and a second voltage step-up circuit operating from said power source voltage supplied to said second power source input terminal to produce a second stepped-up voltage that is higher than said power source voltage; and

a noise reduction circuit connected to said power source input terminal of said main integrated circuit but unconnected to said at least one auxiliary integrated circuit;

a control circuit for generating a command signal to control driving of said first and second electrical loads,

a power supply circuit coupled to receive said power source voltage from said power source voltage input terminal, for converting said power source voltage to an operating voltage, and

an operating voltage output terminal coupled to receive said operating voltage;

wherein said operating voltage is supplied from said operating voltage output terminal to said control circuit, for operating said control circuit, and said control circuit generates the command signal for controlling said drive circuit to selectively apply said stepped-up voltage to said gate electrodes of said first and second MOS FETs,

said at least one auxiliary integrated circuit comprises a second power source terminal coupled to receive said externally supplied power source voltage, and a second voltage step-up circuit operating from said power source voltage supplied to said second power source terminal to produce a second stepped-up voltage that is higher than said power source voltage;

for said at least one auxiliary integrated circuit, said second voltage step-up circuit is selectively set in an operative condition and an inoperative condition in accordance with whether or not a constituent element of said second voltage step-up circuit is connected to said auxiliary integrated circuit as an external component; and

when said second voltage step-up circuit is in said operative condition, each of said drive circuit of said auxiliary integrated circuit selectively applies said second stepped-up voltage to the gate electrode of a corresponding MOS FET to effect said on and off switching of said MOS FET.

5. An electronic control apparatus comprising:

a main integrated circuit, comprising;

a power source input terminal coupled to recieve an externally supplied power source voltage,

a voltage step-up circuit operating from said power source voltage supplied to said power source input terminal to produce a stepped-up voltage that is higher than said power source voltage, and

a stepped-up voltage output terminal coupled to receive said stepped-up voltage; and

at least one auxiliary integrated circuit, comprising;

a stepped-up voltage input terminal coupled to receive said stepped-up voltage from said stepped-up voltage output terminal of said main integrated circuit,

a first drive circuit for selectively applying said stepped-up voltage to a gate electrode of a first MOS FET (metal-oxide semiconductor field effect transistor) that is connected in a current flow path of a first electrical load, to effect on and off switching of said first MOS FET, and

a second drive circuit for selectively applying said stepped-up voltage to a gate electrode of a second MOS FET that is connected in a current flow path of a second electrical load, to effect on and off switching of said second MOS FET, and

a noise reduction circuit connected to said power source input terminal of said main integrated circuit

wherein;

said at least one auxiliary integrated circuit comprises a second power source input terminal coupled to receive said externally supplied power source voltage, and a second voltage step-up circuit operating from said power source voltage supplied to said second power source input terminal to produce a second stepped-up voltage that is higher than said power source voltage;

said second voltage step-up circuit is selectively set in an operative condition and an inoperative condition in accordance with whether or not a constituent element of said second voltage step-up circuit is connected to said auxiliary integrated circuit as an external component; and

when said second voltage step-up circuit is in said operative condition, said first drive circuit selectively applies said second stepped-up voltage to said gate electrode of said first MOS FET to effect said on and off switching of said first MOS FET, and said second drive circuit selectively applies said second stepped-up voltage to said gate electrode of said second MOS FET to effect said on and off switching of said second MOS FET.

6. An electronic control apparatus as claimed in claim 5, wherein said second voltage step-up circuit comprises a charge pump circuit which performs switching of charges between a plurality of capacitors to generate said stepped-up voltage, and wherein said constituent element that is connectable to said at least one auxiliary integrated circuit as an external component comprises at least one of said capacitors of said charge pump circuit.

7. An electronic control apparatus as claimed in claim 6, wherein:

said at least one auxiliary integrated circuit comprises a second power source input terminal coupled to receive said externally supplied power source voltage, a control signal input terminal, a second voltage step-up circuit operating from said power source voltage supplied to said second power source input terminal to produce a second stepped- up voltage that is higher than said power source voltage;

said second voltage step-up circuit is selectively set in an operative condition and an inoperative condition in accordance with whether or not a predetermined signal is being externally applied to said control signal input terminal; and

when said second voltage step-up circuit is in said operative condition, said first drive circuit selectively applies said second stepped-up voltage to said gate electrode of said first MOS FET to effect said on and off switching of said first MOS FET, and said second drive circuit selectively applies said second stepped-up voltage to said gate electrode of said second MOS FET to effect said on and off switching of said second MOS FET.

8. An electronic control apparatus comprising:

a main integrated circuit, comprising;

a power source input terminal coupled to receive an externally supplied power source voltage,

a voltage step-up circuit operating from said power source voltage supplied to said power source input terminal to produce a stepped-up voltage that is higher than said power source voltage,

a stepped-up voltage output terminal coupled to receive said stepped-up voltage, and

a conductive path connected to the stepped-up voltage output terminal and extending externally from the main integrated circuit, and through which the stepped-up voltage is supplied; and

a plurality of auxiliary integrated circuits each comprising;

a stepped-up voltage input te nnal coupled to receive said stepped-up voltage from said stepped-up voltage output terminal of said main integrated circuit through the conductive path,

a plurality of drive circuits, each of said drive circuits selectively applying said stepped-up voltage to a gate electrode of a corresponding MOS FET (metal-oxide semiconductor field effect transistor) that is connected in a current flow path of a corresponding electrical load, to effect on and off switching of said corresponding MOS FET, wherein the plurality of drive circuits receive that stepped-up voltage via the conductive path connected to the stepped-up voltage output terminal, and

a second power source input terminal coupled to receive said externally supplied power source voltage, and a second voltage step-up circuit operating from said power source voltage supplied to said second power source input terminal to produce a second stepped-up voltage that is higher than said power source voltage; and

a noise reduction circuit connected to said power source input terminal of said main integrated circuit.

9. An electronic control apparatus comprising a control circuit for generating command signals to separately control driving of respective ones of a plurality of electrical loads, wherein said electronic control apparatus comprises:

a main integrated circuit, said main integrated circuit comprising;

a power source input terminal coupled to receive an externally supplied power source voltage,

a voltage step-up circuit operating from said power source voltage supplied to said power source input terminal to produce a stepped-up voltage that is higher than said power source voltage,

a stepped-up voltage output terminal coupled to receive said stepped-up voltage,

a power supply circuit coupled to receive said power source voltage from said power source voltage input terminal, for converting said power source voltage to an operating voltage,

an operating voltage output terminal coupled to receive said operating voltage,

a conductive path connected to the stepped-up voltage output terminal and extending externally from the main integrated circuit, and through which the stepped-up voltage is supplied; and

a plurality of auxiliary integrated circuits, each comprising;

a stepped-up voltage input terminal coupled to receive said stepped-up voltage from said stepped-up voltage output terminal of said main integrated circuit through the conductive path,

a plurality of drive circuits, each controlled by a corresponding one of said command signals for selectively applying said stepped-up voltage to a gate electrode of a corresponding MOS FET (metal-oxide semiconductor field effect transistor) that is connected in a current flow path of a corresponding one of said plurality of electrical loads, to effect on and off switching of said corresponding MOS FET, wherein the plurality of drive circuits receive the stepped-up voltage via the conductive path connected to the stepped up voltage output terminal, and

a second power source input terminal coupled to receive said externally supplied power source voltage, and a second voltage step-up circuit operating from said power source voltage supplied to said second power source input terminal to produce a second stepped-up voltage that is higher than said power source voltage; and

a noise reduction circuit connected to said power source input terminal of said main integrated circuit.