ELECTRONIC CONTROL SYSTEM AND POWER SUPPLY UNIT OF THE SYSTEM

• US 20090184700A1
• Filed: 01/23/2009
• Published: 07/23/2009
• Est. Priority Date: 01/23/2008
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Kanayama, Mitsuhiro
• Granted Patent: US 8,154,262 B2
• Time in Patent Office: Days
• US Class Current: 323/282
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 1/0045 Converters combining the concepts of switch-mode regulation and linear regulation, e.g. linear pre-regulator to switching converter, linear and switching converter in parallel, same converter or same transistor operating either in linear or switching mode
• CPC Class Codes: H02M 1/36 Means for starting or stopping converters
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A power supply unit for supplying electric current of a supply voltage to a control unit in an electronic control system has switching regulator dropping an input voltage to an intermediate voltage, a first series regulator producing electric current of the supply voltage from the intermediate voltage, and a second series regulator producing electric current of the supply voltage lower than electric current produced in the first series regulator During the standby mode of the control unit, an FET of the switching regulator is locked to the on state to accumulate electric charge in a capacitor of a smoothing circuit, while an output transistor of the first series regulator is locked to the off state. When a wake-up condition is satisfied in the control unit, the FET starts the switching operation, and the output transistor immediately starts the driving operation while using the charge supplied from the capacitor.

Claims

1. An electronic control system, comprising:

a power supply unit which receives an input voltage from an external power source through an input line and produces a supply voltage lower than the input voltage from the input voltage; and

a control unit which is transferred from a standby mode to a normal operation mode in response to satisfaction of a wake-up condition, receives a first quantity of electric current set at the supply voltage from the power supply unit through a supply line in the normal operation mode to consume the first quantity of electric current, and receives a second quantity of electric current of the supply voltage from the power supply unit through the supply line in the standby mode to consume the second quantity of electric current, the second quantity being smaller than the first quantity,

wherein the power supply unit comprises;

a voltage drop type switching regulator, having a capacitor, which applies the input voltage of the input line to a connection line in response to the standby mode of the control unit while accumulating electric charge in the capacitor, starts performing a switching operation in response to the satisfaction of the wake-up condition in the control unit to produce a transfer voltage on the connection line from the input voltage of the input line and to adjust the transfer voltage to an intermediate voltage, and performs the switching operation in response to the normal operation mode of the control unit to produce the intermediate voltage on the connection line from the input voltage of the input line; and

a series regulator which produces the supply voltage on the supply line from either the input voltage of the input line or the input voltage of the connection line applied by the switching regulator in case of the standby mode of the control unit, starts a voltage regulating operation for the transfer voltage of the connection line in response to the satisfaction of the wake-up condition while using the electric charge of the capacitor of the switching regulator, and produces the supply voltage on the supply line from the intermediate voltage of the connection line produced by the switching regulator in response to the normal operation mode of the control unit.

2. The electronic control system according to claim 1, wherein the voltage drop type switching regulator comprises:

a switching element, having an input terminal connected with the input line and an output terminal, which performs the switching operation to change the input voltage applied to the input terminal to a resultant voltage applied to the output terminal;

a smoothing circuit, having the capacitor with a first terminal connected with both the output terminal of the switching element and a connection line and a second terminal set at a certain voltage lower than the intermediate voltage, which smoothes the resultant voltage of the switching element to set the connection line at a smoothed voltage; and

a switching element control unit which locks the switching element to an on state in response to the standby mode of the control unit to apply the input voltage of the input terminal to the connection line, controls the switching element, in response to the satisfaction of the wake-up condition in the control unit, to start performing the switching operation and to change the transfer voltage of the connection line to the smoothed voltage, and adjusts the smoothed voltage of the connection line to the intermediate voltage in response to the normal operation mode of the control unit.

3. The electronic control system according to claim 2, wherein the switching regulator of the power supply unit further comprises:

a bootstrap circuit which generates a boot voltage higher than the input voltage when the switching element is turned on under control of the switching element control unit,

wherein the switching element control unit controls the switching operation of the switching element while using the boot voltage.

4. The electronic control system according to claim 1, wherein the series regulator comprises:

a first series regulator which prohibits, in response to the standby mode of the control unit, an electric current from being transmitted from the connection line to the supply line, starts the voltage regulating operation in response to the satisfaction of the wake-up condition, and produces the supply voltage applied to the supply line from the intermediate voltage of the connection line in response to the normal operation mode of the control unit to supply a third quantity of electric current of the supply voltage to the supply line, a sum of the second and third quantities being equal to the first quantity, the third quantity being larger than the second quantity, and

a second series regulator which produces the supply voltage applied to the supply line from the input voltage of the input line to supply the second quantity of electric current of the supply voltage to the supply line.

5. The electronic control system according to claim 4, wherein the first series regulator comprises:

an output transistor, having an input terminal connected with the connection line and an output terminal connected with the supply line, which performs a driving operation for an electric current supplied to the input terminal to supply a resultant electric current to the output terminal; and

an output transistor control unit which locks the output transistor to an off-state in response to the standby mode of the control unit and controls the driving operation of the output transistor in response to the satisfaction of the wake-up condition to start the voltage regulating operation, and produces the supply voltage applied to the supply line from the intermediate voltage of the connection line in response to the normal operation mode of the control unit.

6. The electronic control system according to claim 1, wherein the series regulator comprises:

an output transistor, having an input terminal connected with the connection line and an output terminal connected with the supply line, which performs a driving operation for an electric current supplied to the input terminal to output a resultant electric current to the output terminal;

a lower current supply control circuit which controls the driving operation of the output transistor in response to the standby mode of the control unit to produce the supply voltage applied to the output terminal of the output transistor from the input voltage of the input terminal of the output transistor, and to supply the second quantity of electric current of the supply voltage to the supply line; and

a higher current supply control circuit which controls the driving operation of the output transistor in response to the satisfaction of the wake-up condition to start the voltage regulating operation, and produces the supply voltage applied to the output terminal of the output transistor from the intermediate voltage of the connection line in response to the normal operation mode of the control unit to supply the first quantity of electric current of the supply voltage to the supply line.

7. The electronic control system according to claim 1, wherein the standby mode of the control unit is transferred to the normal operation mode in response to an elapse of a transfer period of time starting from the satisfaction of the wake-up condition, the switching element control unit adjusts the smoothed voltage of the connection line to the intermediate voltage until the elapse of the transfer period of time, and the series regulator produces the supply voltage applied to the supply line from the intermediate voltage of the connection line until the elapse of the transfer period of time.

8. The electronic control system according to claim 1, wherein the system is disposed in a vehicle.

9. The electronic control system according to claim 8, wherein the control unit controls electric power supplied from the external power source to a device of the vehicle.

10. A power supply unit which receives an input voltage from an external power source through an input line, produces a supply voltage lower than the input voltage from the input voltage, supplies a first quantity of electric current set at the supply voltage to a control unit set in a normal operation mode through a supply line, and supplies a second quantity of electric current set at the supply voltage to the control unit set in a standby mode through the supply line, the standby mode of the control unit being transferred to the normal operation mode in response to cancellation of the standby mode, the second quantity being smaller than the first quantity, comprising:

a voltage drop type switching regulator, having a capacitor, which applies the input voltage of the input line to a connection line in response to the standby mode of the control unit while accumulating electric charge in the capacitor, starts performing a switching operation in response to the cancellation of the standby mode in the control unit to produce a transfer voltage on the connection line from the input voltage of the input line and to adjust the transfer voltage to an intermediate voltage, and performs the switching operation in response to the normal operation mode of the control unit to produce the intermediate voltage on the connection line from the input voltage of the input line; and

a series regulator which produces the supply voltage on the supply line from either the input voltage of the input line or the input voltage of the connection line applied by the switching regulator in case of the standby mode of the control unit, starts a voltage regulating operation for the transfer voltage of the connection line in response to the cancellation of the standby mode in the control unit while using the electric charge of the capacitor of the voltage drop type switching regulator, and produces the supply voltage on the supply line from the intermediate voltage of the connection line produced by the switching regulator in response to the normal operation mode of the control unit.

11. The power supply unit according to claim 10, wherein the voltage drop type switching regulator comprises:

a switching element, having an input terminal connected with the input line and an output terminal, which performs the switching operation to change the input voltage applied to the input terminal to a resultant voltage applied to the output terminal;

a smoothing circuit, having the capacitor with a first terminal connected with both the output terminal of the switching element and a connection line and a second terminal set at a certain voltage lower than the intermediate voltage, which smoothes the resultant voltage of the switching element to set the connection line at a smoothed voltage; and

a switching element control unit which locks the switching element to an on state in response to the standby mode of the control unit to apply the input voltage of the input terminal to the connection line, controls the switching element, in response to the cancellation of the standby mode, to start performing the switching operation and to change the transfer voltage of the connection line to the smoothed voltage, and adjusts the smoothed voltage of the connection line to the intermediate voltage in response to the normal operation mode of the control unit.

12. The power supply unit according to claim 11, wherein the switching regulator of the power supply unit further comprises:

a bootstrap circuit which generates a boot voltage higher than the input voltage, when the switching element is turned on, under control of the switching element control unit,

wherein the switching element control unit controls the switching operation of the switching element while using the boot voltage.

13. The power supply unit according to claim 10, wherein the series regulator comprises:

a first series regulator which prohibits, in response to the standby mode of the control unit, an electric current from being transmitted from the connection line to the supply line, starts the voltage regulating operation in response to the cancellation of the standby mode in the control unit, and produces the supply voltage applied to the supply line from the intermediate voltage of the connection line in response to the normal operation mode of the control unit to supply a third quantity of electric current of the supply voltage to the supply line, a sum of the second and third quantities being equal to the first quantity, the third quantity being larger than the second quantity, and

a second series regulator which produces the supply voltage applied to the supply line from the input voltage of the input line to supply the second quantity of electric current of the supply voltage to the supply line.

14. The power supply unit according to claim 13, wherein the first series regulator comprises:

an output transistor, having an input terminal connected with the connection line and an output terminal connected with the supply line, which performs a driving operation for an electric current supplied to the input terminal to supply a resultant electric current to the output terminal; and

an output transistor control unit which locks the output transistor to an off-state in response to the standby mode of the control unit, controls the driving operation of the output transistor in response to the cancellation of the standby mode in the control unit to start the voltage regulating operation, and produces the supply voltage applied to the supply line from the intermediate voltage of the connection line in response to the normal operation mode of the control unit.

15. The power supply unit according to claim 13, wherein the first series regulator has a plurality of third series regulators serially connected with one another, and each third series regulator prohibits, in response to the standby mode of the control unit, an electric current from being transmitted from the connection line to the supply line, starts the voltage regulating operation in response to the cancellation of the standby mode in the control unit, and produces the supply voltage applied to the supply line from the intermediate voltage of the connection line to supply an electric current of the supply voltage to the supply line, a sum of quantities of the electric currents supplied from the third series regulators to the supply line being equal to the first quantity.

16. The power supply unit according to claim 10, wherein the series regulator comprises:

an output transistor, having an input terminal connected with the connection line and an output terminal connected with the supply line, which performs a driving operation for an electric current supplied to the input terminal to output a resultant electric current to the output terminal;

a lower current supply control circuit which controls the driving operation of the output transistor in response to the standby mode of the control unit to produce the supply voltage applied to the output terminal of the output transistor from the input voltage of the input terminal of the output transistor and to supply the second quantity of electric current of the supply voltage to the supply line; and

a higher current supply control circuit which controls the driving operation of the output transistor in response to the cancellation of the standby mode in the control unit to start the voltage regulating operation, and produces the supply voltage applied to the output terminal of the output transistor from the intermediate voltage of the connection line in response to the normal operation mode of the control unit to supply the first quantity of electric current of the supply voltage to the supply line.

17. The power supply unit according to claim 10, wherein the standby mode of the control unit is transferred to the normal operation mode in response to an elapse of a transfer period of time starting from the cancellation of the standby mode, the switching element control unit adjusts the smoothed voltage of the connection line to the intermediate voltage until the elapse of the transfer period of time, and the series regulator produces the supply voltage applied to the supply line from the intermediate voltage of the connection line until the elapse of the transfer period of time.