KR20220085539A - Apparatus and method for diagnosing over current of peak and hold injector driver - Google Patents

Abstract

An apparatus and method for diagnosing overcurrent of a peak-and-hold injector driver are disclosed. An apparatus for diagnosing overcurrent of a peak-and-hold injector driver according to an aspect of the present invention includes a driving unit for driving an external load, a current sensing unit sensing a driving current flowing through the load, and a driving detected by the current sensing unit A comparison unit that compares the current with one or more threshold levels preset for peak and hold driving control of the load, respectively, and the time it takes for the driving current to reach the threshold level through the comparison unit and a controller for measuring an on-state time, comparing the on-state time with a preset reference on-state time, and diagnosing an overcurrent based on the comparison result.

Description

APPARATUS AND METHOD FOR DIAGNOSING OVER CURRENT OF PEAK AND HOLD INJECTOR DRIVER

The present invention relates to an apparatus and method for diagnosing overcurrent of a peak-and-hold injector driver, and more particularly, to an apparatus and method for diagnosing overcurrent of a peak-and-hold injector driver, capable of diagnosing overcurrent in peak-and-hold current control of a peak-and-hold injector driver, and it's about how

In general, in automobiles, various actuators belonging to an electronically controlled fuel injection device are electronically controlled through an engine control unit, and combustion is performed by changing the air-fuel ratio of a mixer according to the use environment or driving conditions of the engine. It performs the function of optimizing the state. Such an actuator is driven by controlling and supplying current through a driving circuit, and stable driving of the actuator has a very important effect on vehicle safety.

Therefore, it is important that the current is precisely monitored and controlled in order to accurately control the actuator.

However, due to the recent increase in electronic components such as engine controllers (ECUs) and actuators, problems such as overcurrent failures occur frequently, which may affect vehicle safety is increasing. In particular, due to a short circuit to battery (SCB) failure, it may cause a problem when the actuator's driving current is ideally supplied compared to a predetermined specification.

When an overcurrent (SCB) occurs in the peak & hold current control of the peak and hold injector driver, the drive current first reaches the peak threshold level in the peak state before reaching the overcurrent threshold level, In the hold state, when the hold threshold level is first reached, the driving unit is turned off, so there is a problem in that the overcurrent cannot be detected. That is, when an overcurrent occurs in a wire connected to an external load, the overcurrent cannot be detected by turning off the driver before the current increases to the overcurrent level.

The background technology of the present invention is disclosed in Republic of Korea Patent Publication No. 10-1030958 (announced on April 18, 2011, title of invention: overcurrent protection circuit of a low voltage regulator).

The present invention has been devised to solve the above problems, and an object of the present invention is to diagnose an overcurrent of a peak-and-hold injector driver and a method for diagnosing an overcurrent in the peak-and-hold current control of the peak-and-hold injector driver. is to provide

The problem to be solved by the present invention is not limited to the problem(s) mentioned above, and another problem(s) not mentioned will be clearly understood by those skilled in the art from the following description.

An apparatus for diagnosing overcurrent of a peak-and-hold injector driver according to an aspect of the present invention includes a driving unit for driving an external load, a current sensing unit sensing a driving current flowing through the load, and a driving detected by the current sensing unit A comparison unit that compares the current with one or more threshold levels preset for peak and hold driving control of the load, respectively, and the time it takes for the driving current to reach the threshold level through the comparison unit and a controller for measuring an on-state time, comparing the on-state time with a preset reference on-state time, and diagnosing an overcurrent based on the comparison result.

In the present invention, the control unit determines whether the on-state time is equal to or less than the reference on-state time, counts the number of times the on-state time becomes equal to or less than the reference on-state time continuously, and the counted number is preset If the number of times is greater than the reference number, overcurrent may occur.

In the present invention, the control unit turns on the driving unit for a preset maximum on-state time when the occurrence of the overcurrent is terminated, and determines whether the driving current exceeds a preset overcurrent threshold level during the maximum on-state time, Based on the judgment result, it is possible to finally diagnose the occurrence of overcurrent.

In the present invention, when the driving current exceeds the overcurrent threshold level, the controller measures the excess time, and when the excess time exceeds a preset overcurrent detection reference time, the controller may finally diagnose as overcurrent.

In the present invention, the overcurrent detection reference time may be less than the maximum on-state time.

In the present invention, the control unit may turn off the driving unit during the final diagnosis of the overcurrent.

In the present invention, the driving unit may be a low-side switch connected to the load to control a driving current flowing through the load.

In the present invention, the controller includes, during a preset peak hold time, a peak phase that controls the driving part by PWM (Pulse Width Modulation) so that the driving current is maintained at a peak threshold level according to a preset base frequency, and the The overcurrent may be diagnosed in at least one of a hold phase in which the driving unit is PWM-controlled so that the driving current is maintained at a preset hold threshold level with a value smaller than the peak threshold level according to the base frequency.

A method for diagnosing overcurrent of a peak-and-hold injector driver according to another aspect of the present invention comprises the steps of: detecting, by a sensing unit, a driving current flowing through a load; Comparing each with one or more threshold levels preset for control, measuring, by a control unit, an on-state time that is a time taken for the driving current to reach the threshold level, and the control unit measuring the on-state time and comparing with a set reference on-state time, and diagnosing the overcurrent based on the comparison result.

In the present invention, in the step of diagnosing the overcurrent, the control unit determines whether the on-state time is equal to or less than the reference on-state time, and counts the number of times the on-state time becomes equal to or less than the reference on-state time in succession, , when the counted number is equal to or greater than a preset reference number, it may be determined that the overcurrent has occurred.

In the present invention, in the step of diagnosing the overcurrent, the controller turns on the driving unit for a preset maximum on-state time when the occurrence of the overcurrent is terminated, and a preset overcurrent of the driving current during the maximum on-state time It is determined whether the threshold level is exceeded, and the occurrence of overcurrent can be finally diagnosed based on the determination result.

In the present invention, in the step of diagnosing the overcurrent, when the driving current exceeds the overcurrent threshold level, the controller measures the excess time, and when the excess time exceeds a preset overcurrent detection reference time, The final diagnosis can be made with overcurrent.

In the present invention, the overcurrent detection reference time may be less than the maximum on-state time.

After diagnosing the overcurrent, the method may further include, by the controller, turning off the driving unit.

In the present invention, in the step of diagnosing the overcurrent, the control unit performs PWM (Pulse Width Modulation) control of the driving unit so that the driving current is maintained at a peak threshold level according to a preset base frequency during a preset peak hold time. Overcurrent in at least one of a peak phase and a hold phase that PWM controls the driving unit so that the driving current is maintained at a preset hold threshold level with a value smaller than the peak threshold level according to the base frequency can be diagnosed

An apparatus and method for diagnosing overcurrent of a peak-and-hold injector driver according to an embodiment of the present invention provides an on-state time, which is the time it takes for a driving current to reach a preset threshold level for peak-and-hold driving control. By diagnosing overcurrent by measuring (ON time), when an overcurrent occurs in peak-and-hold current control, it can be detected quickly and accurately to turn off the injector driver to prevent circuit burnout.

On the other hand, the effects of the present invention are not limited to the above-mentioned effects, and various effects may be included within the range obvious to those skilled in the art from the description below.

1 is a circuit diagram illustrating an overcurrent diagnosis apparatus of a peak-and-hold injector driver according to an embodiment of the present invention.
FIG. 2 is a timing diagram illustrating a process in which peak-and-hold driving control is performed in the overcurrent diagnosis apparatus of the peak-and-hold injector driver according to an embodiment of the present invention.
3 is a timing diagram for explaining a case where an overcurrent occurs in a hold phase according to an embodiment of the present invention.
4 is a timing diagram illustrating an overcurrent diagnosis method according to an embodiment of the present invention.
5 is a flowchart illustrating a method for diagnosing an overcurrent of a peak-and-hold injector driver according to an embodiment of the present invention.

Hereinafter, an apparatus and method for diagnosing overcurrent of a peak-and-hold injector driver according to an embodiment of the present invention will be described with reference to the accompanying drawings. In this process, the thickness of the lines or the size of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of the user or operator. Therefore, definitions of these terms should be made based on the content throughout this specification.

Implementations described herein may be implemented in, for example, a method or process, an apparatus, a software program, a data stream, or a signal. Although discussed only in the context of a single form of implementation (eg, discussed only as a method), implementations of the discussed features may also be implemented in other forms (eg, as an apparatus or program). The apparatus may be implemented in suitable hardware, software and firmware, and the like. A method may be implemented in an apparatus such as, for example, a processor, which generally refers to a computer, a microprocessor, a processing device, including an integrated circuit or programmable logic device, and the like. Processors also include communication devices such as computers, cell phones, portable/personal digital assistants (“PDA”) and other devices that facilitate communication of information between end-users.

1 is a circuit diagram illustrating an apparatus for diagnosing an overcurrent of a peak-and-hold injector driver according to an embodiment of the present invention, and FIG. 2 is a peak-and-hold drive control in the apparatus for diagnosing an overcurrent of a peak-and-hold injector driver according to an embodiment of the present invention A timing diagram illustrating a process in which is performed, FIG. 3 is a timing diagram illustrating a case in which overcurrent occurs in the hold phase according to an embodiment of the present invention, and FIG. 4 is an overcurrent diagnosis method according to an embodiment of the present invention It is a timing diagram for explanation.

Referring to FIG. 1 , an apparatus for diagnosing overcurrent of a peak-and-hold injector driver according to an embodiment of the present invention includes a driving unit 100 , a current sensing unit 200 , a comparator 300 , and a control unit 400 . .

The driving unit 100 is configured to switch power to a load, and may be, for example, a low-side switch implemented as an FET. In this case, the control unit 400 may be connected to the gate of the driving unit 100 , the load may be connected to the drain, and a shunt resistor may be connected to the source. Here, the load may be various vehicle actuators such as a solenoid for driving the injector, a motor, and a variable solenoid valve, and the driving unit 100 may be connected to the actuator to control the driving current flowing through the actuator.

The current sensing unit 200 may sense a driving current flowing through the load.

That is, the current sensing unit 200 may sense a current flowing through the shunt resistor at the lower end of the low-side driving switch 100 . The current sensing unit 200 may be implemented as, for example, an operational amplifier.

The comparator 300 may compare the driving current sensed by the current sensing unit 200 with one or more threshold levels preset for peak and hold driving control of the load, respectively. For example, in a peak phase, the comparator 300 may compare the driving current with a peak threshold level. Also, in the hold phase, the comparator 300 may compare the driving current with the hold threshold level.

The controller 400 may perform peak-and-hold current control, and may diagnose overcurrent during peak-and-hold current control. In this case, the controller 400 may diagnose the overcurrent in at least one of a peak phase and a hold phase.

As shown in FIG. 2 , the controller 400 may perform peak-and-hold driving control of the injector through first to fourth phases.

In the first phase, the control unit 400 may turn on the driving unit 100 until the driving current (Load Current) reaches a preset peak threshold level (PEAK_th). That is, the control unit 400 turns on the driving unit 100 in the first phase, and accordingly, the driving current flowing through the load increases. When it is determined that the driving current has reached the peak threshold level through the comparator 300 , Next, the second phase proceeds. 'Charging' shown in FIG. 2 corresponds to the first phase.

In the second phase, the controller 400 may PWM (Pulse Width Modulation) control the driving unit 100 so that the driving current is maintained at the peak threshold level PEAK_th according to the preset base frequency during the preset peak hold time. . The 'PEAK pahse' shown in FIG. 2 corresponds to the second phase.

Specifically, in the second phase, the control unit 400 turns off the driving unit 100, and at a time synchronized with the rising edge of the clock signal (CLK_HOLD, hereinafter referred to as a hold clock signal) reflecting the base frequency. By repeatedly performing the operation of turning on the driving unit 100 during the peak hold time, the driving unit 100 may be PWM controlled. That is, when it is determined through the comparison unit 300 that the driving current exceeds the peak threshold level (Peak_th), the control unit 400 turns off the driving unit 100 and synchronizes with the rising edge of the hold clock signal CLK_HOLD. The operation of turning on the driving unit 100 again at a point in time may be repeatedly performed during the peak hold time. Accordingly, the driving current can be maintained at the peak threshold level (Peak_th) according to the base frequency, that is, the driving current that rises or falls in one cycle of the hold clock signal as shown in 'Peak Phase' of FIG. 2 is the peak threshold level. (Peak_th) may be maintained. When the peak hold time elapses from the time when the second phase is started, the controller 400 proceeds to the next third phase.

In the third phase, the control unit 400 may turn off the driving unit 100 for a preset peak-off time to reduce the driving current. That is, in the third phase, the control unit 400 turns off the driving unit 100 during the peak-off time to reduce the driving current, and when the peak-off time elapses, the following fourth phase is performed. 'Discharging' shown in FIG. 2 corresponds to the third phase.

In the fourth phase, the controller 400 may PWM control the driver 100 so that the driving current is maintained at the hold threshold level HOLD_th set in advance to a value smaller than the peak threshold level PEAK_th according to the base frequency.

Specifically, in the fourth phase, the control unit 400 turns on the driving unit 100 at a point in time synchronized with the rising edge of the hold clock signal, and the driving current exceeds the hold threshold level (Hold_th) through the comparator 300 . If it is determined that the driving unit 100 is turned off, the driving unit 100 may be PWM controlled. Accordingly, the driving current may be maintained at the hold threshold level Hold_th according to the base frequency, that is, one of the hold clock signals CLK_HOLD as shown in 'Hold Phase' (corresponding to the fourth phase) of FIG. 2 . The upper limit of the driving current that rises and falls in the cycle may be maintained at the hold threshold level Hold_th.

As described above, in the first phase of turning on the driving unit 100 until the driving current reaches a preset peak threshold level, the control unit 400, during the preset peak hold time, the driving current peaks according to the preset base frequency. A second phase in which the driving unit 100 is PWM controlled to be maintained at a threshold level, a third phase in which the driving unit 100 is turned off during a preset peak off time to decrease the driving current, and the driving current is set to a peak threshold according to the base frequency The peak-and-hold driving control of the injector is performed through the fourth phase of PWM-controlling the driving unit 100 so as to be maintained at a preset hold threshold level with a value smaller than the level.

Meanwhile, overcurrent may occur in peak-and-hold current control. When an overcurrent (SCB) occurs in the peak-and-hold control, the peak threshold level is first reached in the peak phase before the driving current reaches the overcurrent threshold level, and the hold threshold level is first reached in the hold phase and the driving unit ( 100) is turned off, so overcurrent detection is impossible.

For example, as shown in FIG. 3 , when an overcurrent (SCB) occurs in the hold phase, the overcurrent threshold level (SCB_th) is set because the driving current exceeds the hold threshold level (Hold_th) within a short time. Since the driving unit 100 is turned off without being exceeded, overcurrent detection is impossible.

Accordingly, in the exemplary embodiment of the present invention, the overcurrent may be diagnosed by measuring the ON time, which is a time required for the driving current to reach a preset threshold level for peak-and-hold driving control.

The driving current is changed according to the ON time and OFF time of the driving unit 100 (or the load), and the OFF time is periodically fixed. However, in the case of the on-state time, since the time it takes for the driving unit 100 (or the load) to change from the off-state to the on-state and the driving current reaches the threshold level, it may be variable. If an overcurrent (SCB) occurs, the slew rate of the driving current increases, and the time it takes to reach the peak threshold level or the hold threshold level becomes shorter than in normal operation. Accordingly, the on-state time of the overcurrent (SCB) state is shorter than the on-state time of the normal operation. Using this, the controller 400 may diagnose the overcurrent using the on-state time.

The control unit 400 measures the on-state time, which is the time it takes for the driving current to reach the threshold level, through the comparison unit 300, and compares the on-state time with a preset reference on-state time. Based on this, overcurrent can be diagnosed. Here, the reference on-state time is a time taken until the driving current reaches a threshold level during normal operation, and may be a value stored in advance. For example, referring to FIG. 4 , the controller 400 may set an ON time, which is a time required for the driving current to reach a threshold level during normal operation, as a reference ON state time.

Specifically, the controller 400 may measure the on-state time in the peak phase or the hold phase, compare the on-state time with the reference on-state time, and determine whether the on-state time is equal to or less than the reference on-state time. Then, the control unit 400 counts the number of times the on-state time is equal to or less than the reference on-state time in the peak phase or the hold phase, and when the counted number is equal to or greater than the preset reference number, the control unit 400 has overcurrent occurrence can do.

When the generation of overcurrent occurs, the control unit 400 turns on the driving unit 100 for a preset maximum on-state time, determines whether the overcurrent threshold level of the driving current is exceeded during the maximum on-state time, and based on the determination result Overcurrent can be diagnosed. Here, the maximum on-state time may be a time arbitrarily set to forcibly turn on the driving unit 100 , and the overcurrent threshold level may be a value arbitrarily set for overcurrent diagnosis.

Specifically, the controller 400 may determine whether the driving current exceeds an overcurrent threshold level during the maximum on-state time.

When the driving current exceeds the overcurrent threshold level, the controller 400 may measure an excess time during which the driving current exceeds the overcurrent threshold level, and determine whether the excess time exceeds a preset overcurrent detection reference time. Here, the overcurrent detection reference time may be set to a value less than the maximum on-state time. When the excess time exceeds the overcurrent detection reference time, the controller 400 may finally diagnose the occurrence of the overcurrent. When the overcurrent is finally diagnosed, the control unit 400 may turn off the driving unit 100 .

If the driving current does not exceed the overcurrent threshold level during the maximum on-state time, the controller 400 may determine that the overcurrent excitation stage is not an overcurrent occurrence.

For example, referring to FIG. 4 , since the number of times that the on-state time (B) is less than the reference on-state time (A) in the SCB excitation end region is '3', the control unit 400 may determine that an overcurrent has occurred. have. In order to determine such an overcurrent excitation stage, the control unit 400 turns on the driving unit 100 for the maximum on-state time, and measures the time during which the driving current exceeds the overcurrent threshold level during the maximum on-state time to determine whether the overcurrent have. When the time C for which the driving current exceeds the overcurrent threshold level as in the SCB diagnosis area is equal to or longer than the overcurrent detection reference time SCB_FILTER_TIME, the controller 400 may determine that the overcurrent excitation stage is an overcurrent.

5 is a flowchart illustrating a method for diagnosing overcurrent of a peak-and-hold injector driver according to an embodiment of the present invention.

Referring to FIG. 5 , the control unit 400 performs peak-and-hold current control (S500), measures the reference on-state time (S501), and initializes the number of times (S502). In this case, the controller 400 may store the reference on-state time and number of times.

When step S502 is performed, the controller 400 measures the on-state time, which is the time it takes for the driving current to reach the threshold level (S504), and determines whether the on-state time is less than or equal to a preset reference on-state time (S504). S506). In this case, the controller 400 may measure an on-state time, which is a time taken for the driving current to reach a peak threshold level in a peak phase. Also, in the hold phase, the controller 400 may measure the on-state time, which is the time it takes for the driving current to reach the hold threshold level.

As a result of the determination in step S506, if the on-state time is less than or equal to the reference on-state time, the control unit 400 counts the number of times the on-state time is less than the reference on-state time during the peak phase or the hold phase (S508), and the counted number of times is It is determined whether the number of times is equal to or greater than a preset reference number (S510).

As a result of the determination of step S510, if the counted number is greater than or equal to the reference number, the control unit 400 turns on the driving unit 100 for the maximum on-state time (S512), and determines whether the driving current exceeds the overcurrent threshold level during the maximum on-state time (S512). It is determined (S514).

As a result of the determination in step S514, if the driving current exceeds the overcurrent threshold level, the controller 400 measures an excess time for which the driving current exceeds the overcurrent threshold level, and determines whether the excess time is equal to or greater than a preset overcurrent detection reference time do (S516).

As a result of the determination in step S516, if the excess time exceeds the overcurrent detection reference time, the controller 400 finally diagnoses the overcurrent prediction as overcurrent (S518). When the overcurrent is finally diagnosed, the control unit 400 may turn off the driving unit 100 .

If, as a result of the determination in step S514, the driving current does not exceed the overcurrent threshold level during the maximum on-state time, the controller 400 determines that the overcurrent has not occurred, and determines whether the maximum on-state time ends (S520). ).

As a result of the determination in step S520, when the maximum on-state time is over, the control unit 400 performs step S501. If, as a result of the determination in step S520, the maximum on-state time does not end, the controller 400 performs step S512.

As a result of the determination in step S516, if the excess time does not exceed the overcurrent detection reference time, the controller 400 performs step S512.

As a result of the determination in step S510, if the count is not equal to or greater than the reference number, the controller 400 performs step S504.

As a result of the determination in step S506, if the on-state time is not equal to or less than the reference on-state time, the controller 400 performs step S502.

As described above, in the apparatus and method for diagnosing overcurrent of a peak-and-hold injector driver according to an embodiment of the present invention, it takes until the driving current reaches a preset threshold level for peak-and-hold driving control. By diagnosing overcurrent by measuring the ON time, which is the time, when an overcurrent occurs in peak-and-hold current control, it can be detected quickly and accurately to turn off the injector driver to prevent circuit burnout. .

Although the present invention has been described with reference to the embodiment shown in the drawings, this is merely an example, and those skilled in the art to which various modifications and equivalent other embodiments are possible. will understand

Accordingly, the true technical protection scope of the present invention should be defined by the following claims.

100: drive unit
200: current sensing unit
300: comparison unit
400: control unit

Claims (15)

a driving unit for driving an external load;
a current sensing unit sensing a driving current flowing through the load;
a comparator for comparing the driving current sensed by the current sensing unit with one or more threshold levels preset for peak and hold driving control of the load; and
An on-state time, which is a time required for the driving current to reach the threshold level, is measured through the comparator, the on-state time is compared with a preset reference on-state time, and the overcurrent is diagnosed based on the comparison result control unit
Peak-and-hold injector driver overcurrent diagnosis device comprising a.
According to claim 1,
The control unit is
It is determined whether the on-state time is equal to or less than the reference on-state time, the number of times the on-state time becomes equal to or less than the reference on-state time is continuously counted, and when the counted number is equal to or greater than a preset reference number, overcurrent occurs An overcurrent diagnostic device of the peak-and-hold injector driver, characterized in that the excitation stage.
3. The method of claim 2,
The control unit is
When the generation of the overcurrent is terminated, the driving unit is turned on for a preset maximum on state time, and it is determined whether the driving current exceeds a preset overcurrent threshold level during the maximum on state time, and the overcurrent based on the determination result An overcurrent diagnosis device for a peak-and-hold injector driver, characterized in that the final diagnosis is made.
4. The method of claim 3,
The control unit is
When the driving current exceeds the overcurrent threshold level, the excess time is measured, and when the excess time exceeds a preset overcurrent detection reference time, a final diagnosis is made as overcurrent. Overcurrent diagnostic device.
5. The method of claim 4,
The overcurrent detection reference time is less than the maximum on-state time.
4. The method of claim 3,
The control unit is
An apparatus for diagnosing overcurrent of a peak and hold injector driver, characterized in that when the overcurrent is diagnosed, the driving unit is turned off.
According to claim 1,
The driving unit,
and a low-side switch connected to the load to control the driving current flowing through the load.
According to claim 1,
The control unit is
During a preset peak hold time, a peak phase for controlling the driving unit PWM (Pulse Width Modulation) so that the driving current is maintained at a peak threshold level according to a preset base frequency, and the driving current according to the base frequency The overcurrent diagnosis apparatus of a peak-and-hold injector driver, characterized in that the overcurrent is diagnosed in at least one of a hold phase for controlling the PWM control of the driving unit such that is maintained at a preset hold threshold level with a value smaller than the peak threshold level. .
detecting, by a sensing unit, a driving current flowing through a load;
comparing the sensed driving current with one or more threshold levels preset for peak and hold driving control of the load, respectively, by a comparator;
measuring, by a controller, an on-state time, which is a time taken for the driving current to reach the threshold level; and
comparing, by the controller, the on-state time with a preset reference on-state time, and diagnosing the overcurrent based on the comparison result
A method for diagnosing overcurrent of a peak-and-hold injector driver, comprising:
10. The method of claim 9,
In the step of diagnosing the overcurrent,
The control unit determines whether the on-state time is equal to or less than the reference on-state time, counts the number of times the on-state time becomes equal to or less than the reference on-state time continuously, and the counted number is equal to or greater than a preset reference number In a case, the overcurrent diagnosis method of the peak-and-hold injector driver, characterized in that the excitation is terminated.
11. The method of claim 10,
In the step of diagnosing the overcurrent,
The control unit turns on the driving unit for a preset maximum on-state time when the occurrence of the overcurrent is terminated, and determines whether the driving current exceeds a preset overcurrent threshold level during the maximum on-state time, and the determination result An overcurrent diagnosis method of a peak-and-hold injector driver, characterized in that the final diagnosis is made based on the
12. The method of claim 11,
In the step of diagnosing the overcurrent,
The control unit, when the driving current exceeds the overcurrent threshold level, measures the excess time, and when the excess time exceeds a preset overcurrent detection reference time, finally diagnoses it as overcurrent. How to diagnose overcurrent of hold injector driver.
13. The method of claim 12,
The overcurrent detection reference time is less than the maximum on-state time.
10. The method of claim 9,
After diagnosing the overcurrent,
The method for diagnosing overcurrent of a peak-and-hold injector driver, further comprising the step of the controller turning off the driving unit.
10. The method of claim 9,
In the step of diagnosing the overcurrent,
The control unit includes a peak phase for controlling the driving unit PWM (Pulse Width Modulation) so that the driving current is maintained at a peak threshold level according to a preset base frequency during a preset peak hold time, and at the base frequency. Accordingly, the peak-and-hold injector driver, characterized in that the overcurrent is diagnosed in at least one of a hold phase for PWM controlling the driving unit so that the driving current is maintained at a preset hold threshold level with a value smaller than the peak threshold level. of overcurrent diagnosis method.

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