JP3939767B2 - Voltage supply device for processor unit - Google Patents

Description

[0001]
[Industrial application fields]
The present invention includes a battery and one or more voltage controllers connected to the battery, the voltage controller having at least two output sides connectable to a processor unit, from the output side The present invention relates to a voltage supply device for a processor unit, in which mutually independent voltages appear, one of the voltages being a persistent voltage and the other being a switchable voltage.
[0002]
[Prior art]
The processor unit is usually combined with a central processor unit CPU and at least one RAM memory. In some cases, this memory stores data that should not be erased even when the CPU and other peripheral devices are shut off. Therefore, the RAM data memory should be continuously supplied with a voltage even when the CPU is cut off.
[0003]
Known processors, such as those provided in automotive control systems, have either a common voltage supply terminal or a separate voltage supply terminal for the CPU and RAM memory. In the case of only one common voltage supply terminal, the CPU is activated or deactivated by a control input provided specially for this. In this case, a supply voltage is continuously applied to the voltage supply terminal.
[0004]
Such a voltage supply device is known from German Offenlegungsschrift DE 404 162 in connection with the voltage supply of the control device. In this known device, a voltage controller is provided, which is supplied with a voltage from the vehicle battery, and this controller itself also sends out a controlled sustained voltage (standby voltage) or a switched voltage. To do. Two voltages are optionally obtained from the controller. The document does not mention details on the configuration of the main controller or the configuration of the auxiliary or standby controller, however, the persistent voltage supply cannot supply a large current. Otherwise, the battery discharge when the CPU is shut off becomes excessively large.
[0005]
Since the power supply current of recent integrated circuits is very small, a voltage power supply stage with a small current capacity can be used for continuous power supply. Such a stage can be manufactured relatively inexpensively and has a small number of elements. In addition, there are no temperature problems. This is because the device delivers only a small output. Of course, even in such a circuit, a small current consumption based on a small reactive current in the voltage controller is required in the standby operation state. Therefore, normally a continuous voltage controller with a small current capacity is used in the control device.
[0006]
The central processor unit CPU and RAM memory are usually part of the controller circuit. This controller device circuit can be generally large in capacity. The total current consumption of the CPU, RAM and peripheral devices is significantly larger than that of the CPU and RAM itself in the case of a normal control device. Therefore, a high voltage controller is necessary for this. This voltage controller is turned on during normal operation and disconnected during standby operation. The connection or disconnection is controlled through, for example, an ignition lock switch. Therefore, the switching voltage controller must be able to supply a large current.
[0007]
When a battery voltage is applied to the control device, the ignition lock switch is generally not turned on. Therefore, only the low current voltage controller for CPU / RAM is activated, and the high current voltage controller is not activated. In this case, the following problems occur. :
That is, when the voltage is raised from 0 V to the target value VDD, the capacity of the continuous voltage controller having only a small current capacity is greatly exceeded. Such an increase in current consumption is due to the current flowing from the CPU / RAM to the peripheral device (which itself has not yet been supplied with voltage) via the corresponding terminals. Transistors included in the push-pull circuit of the internal CPU / RAM, for example _0. An indeterminate state of the transistor longitudinal current under voltage between the target value VDD of 2～0.8V. Such currents can add up in a complex CPU / RAM.
[0008]
This increased current demand puts the persistent voltage controller with only a small current capacity into a current limiting state. The voltage stays at a target value VDD of 0.6V, thereby causing an uncertain state to the CPU in some cases. For example, the initial reset is not performed, causing a load problem for the voltage controller concerned. At the same time, the current consumption of the control device is significantly increased and there is a risk of the battery being discharged early.
[0009]
In this case, when two voltage controllers are integrated and combined, an even greater disadvantage may occur. That is, the voltage of the CPU / RAM voltage controller is used to demonstrate the operation capability at the time of switching of the voltage controller having a large current capacity or in some cases, for example, for power-on-reset or other functions included therein. Is diverted. This sometimes leads to a loss of the function of the entire controller unit and the function of the entire control device.
[0010]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to make improvements in order to eliminate the disadvantages of the conventional processor as described above.
[0011]
[Means for Solving the Problems]
According to the present invention, the problem is that a small current can be taken out from the output side where the sustaining voltage appears, and a relatively high current can be taken out from the other output side. Circuit means are provided between the two output sides and the processor unit between the two sides, so that the circuit means has little power consumption persistence during the switching phase. It is constructed and solved so that a switchable voltage with high power consumption can be taken out.
[0012]
The advantage obtained by the voltage supply device for a processor unit according to the present invention is that a continuous voltage controller with a small current capacity can be used for powering a RAM memory, and a switching voltage controller with a larger current capacity can be used. The controller can take over voltage supply to other controllers or peripherals after ignition switch closure without causing the problem of persistent voltage controller overload that can occur during the input connection. It can be done. The switching voltage controller at that time is the original main voltage controller.
[0013]
This advantage is obtained by the following configuration. That is, an additional circuit means is provided between the two output sides, and a sustaining voltage with a small current capacity or a switching voltage with a large current capacity can be taken out from the output side of the voltage controller. Obtained by a configuration which supports the low voltage capacity persistent voltage controller correspondingly during the switching phase and supplies the controller with the required high voltage or current after the input connection from the large current capacity voltage controller. .
[0014]
Further advantageous embodiments of the invention are described in the dependent claims. In this case, the circuit means between the output sides of the voltage controller is advantageously configured as a switch which is directly controlled by a CPU or ignition lock. However, this switch may be replaced by a suitably circuited diode or transistor.
[0015]
Particularly advantageously, this circuit means itself maintains the desired switching position.
[0016]
If the circuit means between the two control outputs has a DMOS structure, very good synchronization of the two control voltages can be obtained. According to the DMOS structure, when the voltage in the persistent voltage controller exceeds the voltage in the main voltage controller, an automatic shutoff is performed immediately. In other words, feedback from the sustaining voltage section to the main controller output is advantageously avoided.
[0017]
【Example】
Next, embodiments of the present invention will be described in detail with reference to the drawings.
[0018]
FIG. 1 is a block circuit diagram showing a first embodiment of the present invention. What is indicated by reference numeral 10 in the figure is a battery. The battery 10 supplies voltage to all the devices. The positive electrode of the battery 10 is directly connected to the first input side IN of the voltage controller 11, and the second input side ON of the voltage controller 11 is connected via the ignition lock 12.
[0019]
The voltage controller 11 has two output sides SH and CL. A detailed description of the internal connection configuration of the voltage controller is not necessary here and will be omitted. In any case, the voltage controller is configured as follows. In other words, a high current switching voltage is generated on the output side SH of the voltage controller 11, while a slight current sustaining voltage is generated on the output side CL. In the block circuit portion of the voltage controller 11, a block 11a is shown as a low current continuous voltage controller, and a block 11b is shown as a high current switching voltage controller. This block 11b represents the original main voltage controller. These may be used with two separate voltage controllers.
[0020]
A line is led to the positive terminal of the block 13 from the output side SH of the voltage controllers 11 to 11a. This block 13 is a peripheral circuit device, an output stage, EPROMS, and the like. The other side of the block 13 is connected to ground. The output side CL of the voltage controller 11 is connected to the switch S1. The other side of this switch is connected to the central processor 14. In this case, the central processor 14 has a CPU and a RAM memory. The CPU and RAM memory must be continuously supplied with voltage.
[0021]
Another switch H <b> 1 is connected to the connection line between the switch S <b> 1 and the processor 14. The other side of the switch H1 is connected to the output side SH of the voltage controller 11 and the peripheral device 13. This switch H1 may be realized in the form of a diode or a transistor.
[0022]
The switch S1 is controlled or switched via the logic element 15. This logic element 15 triggers switching depending on the switching state of the two switching stages 16, 17 (which are connected to the two inputs of the logic element 15). One of the other two terminals of the two switching stages 16 and 17 is connected to the ignition lock 12 or the second input ON of the voltage controller 11, and the other is connected to the positive input of the central processor 14. . The central processor 14 includes a CPU 14a and a memory (RAM) 14b. The input side of the switching stage 16 is directly connected to the ignition lock 12, but is indirectly related to the ignition lock 12. For example, the input side of the switching stage 16 may be connected to the output side SH of the voltage controller 11.
[0023]
The embodiment shown in FIG. 1 can be realized by using, for example, the circuit portion shown in FIG. 2 are denoted by the same reference numerals as those shown in FIG.
[0024]
In the embodiment shown in FIG. 2, a series circuit comprising a diode D1 and a collector-emitter section of the transistor T1 is provided between the output side SH of the voltage controller 11 and the output side CL of the voltage controller 11. . The diode D1 and the transistor T1 inherit the function of the switches H1 to S1 of the embodiment according to FIG.
[0025]
The transistor T1 is maintained in a conductive state or a cut-off state by controlling the base potential. For the control of the base potential, a series circuit including a resistor R1, a diode D2, and a relay control unit (for example, the main relay control unit 18) is used. A series circuit including the resistor R1, the diode D2, and the relay control unit (for example, the main relay control unit 18) is connected to the base of the transistor T1. In this case, the other side of the main relay control unit 18 is connected to the ignition lock 12. Further, a resistor R2 is connected to the base of the transistor T1. The resistor R2 is connected to the ground through the collector-emitter section of the transistor T2. The base of the transistor T2 is connected to the processor 14 through the resistors R3 and R4, and is further connected to the ground through another resistor R5.
[0026]
The transistor T1 is used on the one hand as a switch and on the other hand for the current amplification of the transistor T1. Adjustment of the amplification of the transistor T1 is made by appropriate selection of circuit elements in the current path including the resistor R1, the diode D2, the main relay control unit 18, and the ignition lock 12, or the resistor R2, the transistor T2, the resistors R3, R4, R4, and R5. This is done by appropriate selection of circuit elements in the current path. Depending on whether the main relay control 18 is switched off or switched on, current flows in one of the two current paths, causing a corresponding control of the amplification of the transistor T1. The maximum short circuit current is set by the resistance ratio. This provides a current limit that is switched between two values of the overall voltage controller. As an example for the standby current limitation, for example, 1 mA is selected when the ignition is interrupted or after-running period, and 100 mA is selected during normal operation.
[0027]
Next, functions of the embodiment of the present invention will be described.
[0028]
After the first application of the battery sustaining voltage, the sustaining voltage controller is activated with a small current 11b and a voltage appears at the output CL. However, the required power supply output for CPU / RAM of processor 14 is blocked by electrical switch S1 or transistor T1. That is, the output side CL is activated and the pull-up control to the target value VDD is performed. However, the CPU or RAM is not yet powered. At this stage, data cannot be stored yet. The output side SH is not yet activated at this point. The voltage controller 11a is activated by a switch signal generated following the operation of the ignition switch 12 or the operation of the ignition switch. This activation acts to raise the target value VDD for the CPU / RAM-peripheral device. This avoids the problem of current outflow through the CPU / RAM-terminal, so-called port.
[0029]
There are two switching passing transmissions for supplying voltage from the output side CL to the CPU / RAM terminal via the switch S1, as described below.
[0030]
Example of change 1:
The CPU / RAM and the peripheral device together with the peripheral device via the auxiliary current path H1 (for example, from the high current voltage controller SH to the CPU / RAM power supply terminal via the diode D1) that operates temporarily is synchronously set to the target value. Brought to the level. By increasing the power supply voltage of the CPU / RAM via the auxiliary current path H1 simultaneously with the increase of the target value VDD for the peripheral device of the CPU / RAM, the faulty terminal current or port current is reduced to the minimum. The voltage controller SH can generate an extra current provided by the longitudinal current in the push-pull stage within the CPU / RAM. If the power supply voltage is smoothly raised, a clear relationship to the subsequent operation can be obtained by the power-on-reset that controls the internal flip-flop.
[0031]
Change Example 2:
A switching stage that is driven and controlled by the ignition lock switch 12 is used instead of the auxiliary current path H1. This switching stage is OR-coupled with another self-holding stage described below and acts on the switch S1. By increasing the voltage to the CPU / RAM-peripheral device, the port outflow current described in the first variation is reduced to a minimum. As a result, only the current due to the push-pull stage of the control device is left for raising the power supply of the CPU / RAM.
[0032]
If this appearing current is within the capacity range of the voltage controller CL, the auxiliary current path H1 can be omitted. The first closing connection of the switch S1 is made via a switching stage 16 controlled by the ignition lock switch 12. In this case, the switching stage 16 (which already exists for another purpose) is used together, for example, as an output stage for the main relay controller or as a switching stage for a similar ignition lock switch. An additional positive effect is the additional base current for switch S1, which is possible in the active state of the CPU / RAM. This additional base current is meaningful when the switch S1 is a bipolar transistor. Thereby, the voltage drop across the switch S1 is minimized.
[0033]
The power supply voltage in the CPU / RAM that is raised to the target value VDD is a control voltage from the voltage controller CL for activating the electrical switch to the CPU / RAM. The circuit connection configuration for activating the switch S1 is configured as follows. That is, the switch S1 and the target value VDD when the switch S1 itself is electrically connected to the output side and the CPU / RAM power supply terminal are configured to be always kept in an activated state from this point. This corresponds to a self-holding circuit.
[0034]
The voltage dropping in the activated electrical switch S1 can be less than the voltage drop in the auxiliary switch H1 from the main voltage feed to the CPU-feed terminal. This allows the continuous voltage feed controller to take over the current supply completely or partially. A persistent voltage controller is configured for the CPU / RAM-current provided here.
[0035]
Shutting down the ignition lock switch 12 causes the main voltage controller to shut down directly or indirectly or with a time delay. The CPU / RAM is replaced with a standby mode with relatively little power consumption by a signal derived from the CPU / RAM control input side. The switch S1 is continuously activated by the feedback to the electric switch S1 between the CPU and the power supply terminal, and the RAM memory is supplied with power. As a result, the data filed in the RAM continues to be stored.
[0036]
Possible port outflow currents are avoided by placing the port in a predetermined high resistance state. Irregular longitudinal current in the push-pull stage no longer occurs. The standby current is very small. The constituent elements provided between the two voltage control units 11a and 11b or CL and SH may be constituted by a separated structure or an integrated structure.
[0037]
A DMOS structure can be formed between the main controller output side and the standby-output side. In particular, a DMOS diode D1 is possible. The DMOS structure between the main controller output side SH and the standby-output side CL supports the standby output when the demand for current increases instantaneously. Due to this DMOS structure, the main controller and the standby voltage are synchronized via the resistor RDSon. The DMOS structure is immediately shut off when the standby voltage exceeds the main controller voltage. That is, feedback from the continuous voltage controller 11b to the main voltage controller 11a or its output side is impossible.
[0038]
【The invention's effect】
According to the present invention, a continuous voltage controller having a small current capacity can be used for power supply of the RAM memory, and a switching voltage controller having a larger current capacity can be used. The voltage supply to other control devices or peripheral devices after the ignition switch is closed can be performed without causing the problem of the overload of the continuous voltage controller that may occur therein.
[Brief description of the drawings]
FIG. 1 shows a first embodiment according to the present invention.
FIG. 2 is a diagram showing a second embodiment according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Battery 11 Voltage controller 12 Ignition lock 13 Block 14 Central processor 15 Logic element 16 Circuit stage 17 Circuit stage

Claims (8)

A battery and one or more voltage controllers connected to the battery, the voltage controller having at least two outputs connectable to the processor unit and independent from the outputs; In a voltage supply for a processor unit, where a voltage appears, one of said voltages being a persistent voltage and the other being a switchable voltage,
A small current can be extracted from the output side where the sustain voltage appears, and a relatively high current can be extracted from the other output side, and the two output sides between the two output sides of the voltage controller. Circuit means for temporarily forming a connection between the processor unit and the processor unit;
For the processor unit, whereby the circuit means is adapted to support a low voltage consumption sustaining voltage during the switching phase and also to extract a high power consumption switching voltage Voltage feeder.   The said battery is always connected with the 1st input side of the said voltage controller, Furthermore, the said battery can be connected with the 2nd input side of the said voltage controller via a switch means. Voltage supply device for processor unit.   3. The voltage supply device for a processor unit according to claim 2, wherein the processor unit is a control device having a central processor unit (CPU) and at least one RAM memory, and the switch means is an ignition switch of an automobile. 2. The circuit means between two output sides of the voltage controller is two switches, and the switch is switched according to the switching position of the switch means connected to the input side of the voltage controller. The voltage power supply device for a processor unit according to any one of? 3. The circuit means between the two output sides of the voltage controller is a diode (D1) or a transistor and a transistor (T1), and the potential at the base of the transistor (T1) is connected to the input side of the voltage controller. The voltage supply device for a processor unit according to any one of claims 1 to 3, which can be controlled in accordance with a switching position of the switch means.   6. The voltage supply device for a processor unit according to claim 5, wherein a series circuit including a collector-emitter section of the diode (D1) and the transistor (T1) is provided between two output sides of the voltage controller.   The voltage for the processor unit according to any one of claims 1 to 6, wherein another load, for example, a peripheral device, an output stage, an EPROM memory, or the like is connected to an output side of the voltage controller capable of extracting a high current. Power supply device.   In parallel with the voltage controller, a main relay control unit or another circuit controlled depending on a signal from the ignition lock (12) is provided, and the main relay control unit or the other circuit is provided. Is connected to the base of the transistor (T1) via another switching element, and is further connected to a connection point between the collector of the transistor (T1) and the cathode of the diode (D1). The voltage power supply device for a processor unit according to any one of the preceding claims.

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