JP6730726B2 - DC current control device and electronic equipment - Google Patents

Description

The present invention relates to a direct current control device and electronic equipment.

2. Description of the Related Art Lighting products using light emitting diodes (hereinafter, referred to as LEDs) require accurate dimming even in a very dark place. Therefore, there is already known a PWM output variable current circuit with relatively high low-luminance accuracy (referred to as current accuracy in setting to emit light at low current setting) (for example, refer to Patent Document 1).

The LED dimming device including the output variable current circuit according to the known conventional example is less likely to cause noise even when the LED current is large, and LED brightness is less likely to vary even if the dimming is deepened. In order to provide the device, it has the following configuration. The LED dimming device includes a constant current circuit that variably controls the magnitude of the current flowing through the LED load, a transistor that intermittently controls the current flowing through the LED load, and a constant current circuit that receives a dimming signal output from the dimmer. A circuit and a dimming control circuit for controlling the transistor. When the dimming signal output from the dimmer is on the higher brightness side than a predetermined level, the dimming control circuit sets the current flowing through the LED load as a continuous current and dims the LED load according to the magnitude of the flowing current. Further, the dimming control circuit changes the duty ratio of a pulsed waveform in which the current flowing through the LED load is pulsed when the dimming signal output from the dimmer is on the lower brightness side than a predetermined level. This dims the LED load.

However, the EMI problem occurs in the output variable current circuit according to the conventional example, and flicker occurs in the LED lighting. On the other hand, in the DC current control circuit, it is difficult to improve the low luminance accuracy due to the offset of the control circuit when the luminance is low.

Even in a general DC current control circuit, there is a problem that the current control accuracy at a low current cannot be increased.

An object of the present invention is to solve the above problems and to provide a direct current control device capable of improving the current control accuracy at a low current as compared with the prior art.

A direct current control device according to one aspect of the present invention,
A plurality of direct current control circuits connected in parallel to a load, each of which continuously supplies a current flowing through each of the direct current control circuits in a predetermined current setting period based on a current control signal indicating a current setting value. A DC current control device comprising a plurality of DC current control circuits for controlling, wherein the DC current control device continuously controls an output current flowing through the load,
A plurality of current setting periods in which the plurality of direct current control circuits respectively control the currents flowing in the respective direct current control circuits are different from each other or partially set to overlap each other.

Therefore, according to the DC current control device of the present invention, it is possible to improve the current control accuracy at a low current as compared with the prior art.

1 is a block diagram showing a configuration example of a DC current control device 10 and its peripheral circuits according to Embodiment 1 of the present invention. 3 is a graph showing an output current control characteristic PR required in the DC current control device 10 of FIG. 1. It is a graph which shows the output current control characteristic P11 of the 1st control pattern which concerns on the direct current control circuit 11-1 of FIG. 11 is a graph showing an output current control characteristic P12 of the first control pattern according to the DC current control circuit 11-2 of FIG. 1. 3 is a graph showing an output current control characteristic P1T of a first control pattern according to the DC current control device 10 of FIG. 1. It is a graph which shows the output current control characteristic P21 of the 2nd control pattern which concerns on the direct current control circuit 11-1 of FIG. It is a graph which shows the output current control characteristic P22 of the 2nd control pattern which concerns on the direct current control circuit 11-2 of FIG. 6 is a graph showing an output current control characteristic P2T of a second control pattern according to the DC current control device 10 of FIG. 1. It is a graph which shows the output current control characteristic P31 of the 3rd control pattern which concerns on the direct current control circuit 11-1 of FIG. It is a graph which shows the output current control characteristic P32 of the 3rd control pattern which concerns on the direct current control circuit 11-2 of FIG. 7 is a graph showing an output current control characteristic P3T of a third control pattern according to the DC current control device 10 of FIG. 1. 11 is a graph showing an output current control characteristic P41 of a fourth control pattern used when there is current variation in the DC current control circuit 11-1 of FIG. 11 is a graph showing an output current control characteristic P42 of a fourth control pattern used when there is current variation in the DC current control circuit 11-2 of FIG. 1. 7 is a graph showing an output current control characteristic P4T of a fourth control pattern according to the DC current control device 10 used when there is current variation in the DC current control circuits 11-1 and 11-2 of FIG. 1. It is an enlarged view of a part 101 of the output current control characteristic P4T of FIG. 6C. 11 is a graph showing an output current control characteristic P51 of a fifth control pattern used when there is current variation in the DC current control circuit 11-1 of FIG. 1. 11 is a graph showing an output current control characteristic P51 of a fifth control pattern used when there is current variation in the DC current control circuit 11-1 of FIG. 1. 9 is a graph showing an output current control characteristic P5T of a fifth control pattern according to the DC current control device 10 used when there is current variation in the DC current control circuits 11-1 and 11-2 of FIG. 1. It is a graph which shows the output current control characteristic P6T of the 6th control pattern which is a modification of Drawing 7C. FIG. 8B is an enlarged view of a portion 102 of the output current control characteristic P6T of FIG. 8A. FIG. 6 is a block diagram showing a configuration example of a DC current control device 10A and its peripheral circuits according to a second embodiment of the present invention.

Embodiments according to the present invention will be described below with reference to the drawings. In addition, in each of the following embodiments, the same components are denoted by the same reference numerals.

Embodiment 1.
FIG. 1 is a block diagram showing a configuration example of a DC current control device 10 and its peripheral circuits according to a first embodiment of the present invention. In FIG. 1, the circuit device according to the first embodiment is a dimming control device for dimming by controlling the current of an LED D1 which is a light source load, for example, power supplies 1 and 2, and a device control circuit 3 And a DC current control device 10. Here, the DC current control device 10 is configured to include a plurality of DC current control circuits 11-1 and 11-2, and an offset resistor 4 having a resistance value Roffset, which is optionally provided. Here, the offset resistor 4 is used in all control patterns except a third control pattern described later. The offset resistor 4 can adjust the output current control characteristic of the DC current control circuit 11-1 so as to lower the output current ILED1 as a whole in the output current ILED1 characteristic with respect to the brightness setting rate described later.

The direct current control circuit 11-1 includes an output current control circuit 12-1, a MOS field effect transistor (hereinafter, referred to as a MOS transistor) Q1, and a sense resistor 13-1 having a resistance value R1. The DC current control circuit 11-2 includes an output current control circuit 12-2, a MOS transistor Q2, and a sense resistor 13-2 having a resistance value R2.

In FIG. 1, the power supply 1 supplies a power supply current or a power supply voltage to the output current control circuits 12-1 and 12-2, and also supplies it to the sense resistor 13-1 via the offset resistor 4. Further, the power supply 2 supplies a power supply current or a power supply voltage to the anode of the LED D1, the cathode of the LED D1 is grounded via the MOS transistor Q1 and the sense resistor 13-1, and the MOS transistor Q2 and the sense resistor 13-2 are connected. Grounded through. The output current flowing from the power supply 2 through the LED D1, the MOS transistor Q1 and the sense resistor 13-1 is ILED1. The output current flowing from the power supply 2 through the LED D1, the MOS transistor Q2 and the sense resistor 13-2 is ILED2.

Each of the output current control circuits 12-1 and 12-2 is configured by using an operational amplifier and a resistor as disclosed in, for example, Patent Document 2. The output current control circuit 12-1 outputs the output current ILED1 based on the voltage VLED1 of the sense resistor 13-1 and the sense control circuit 13-1, which is a dimming signal indicating the brightness setting rate, which is input from the device control circuit 3. The output current ILED1 is controlled so that the output current corresponds to The output current control circuit 12-2 outputs the output current ILED2 based on the voltage VLED2 of the sense resistor 13-2 and the current control signal, which is a dimming signal indicating the brightness setting rate, which is input from the device control circuit 3. The output current ILED2 is controlled so that the output current corresponds to The DC current control circuits 11-1 and 11-2 control the gate voltages of the MOS transistors Q1 and Q2 to control the output currents ILED1 and ILED2 flowing therein.

Various control patterns of the output current ILED in the DC current control device 10 configured as described above will be described below.

FIG. 2 is a graph showing an example of the output current control characteristic PR required in the DC current control device 10 of FIG. In FIG. 2, the following is required as the output current control characteristic PR.
(1) When the brightness setting rate is 0.025%, the output current ILED of 0.1 mA flows.
(2) Thereafter, as the brightness setting rate is increased, the output current ILED is continuously (analogically, not discretely or digitally) increased substantially in proportion to the brightness setting rate.
(3) When the brightness setting rate is 100%, the output current ILED of 400 mA flows.

FIG. 3A is a graph showing an output current control characteristic P11 of the first control pattern according to the DC current control circuit 11-1 of FIG. FIG. 3B is a graph showing the output current control characteristic P12 of the first control pattern relating to the DC current control circuit 11-2 of FIG. Further, FIG. 3C is a graph showing the output current control characteristic P1T of the first control pattern according to the DC current control device 10 of FIG.

In the case where the lower limit value of the brightness setting rate at which the DC current control circuits 11-1 and 11-2 can output the current accuracy equal to or higher than a predetermined value is 0.5%, and a request for an LED lighting product is as shown in FIG. explain. Here, the current value at the maximum brightness setting rate (100%) is 400 mA, and the current value at the minimum brightness setting rate is 0.025% is 0.1 mA.

In the direct current control circuit 11-1, the resistance value R1 of the sense resistor 13-1 is set so that the current value at the maximum brightness setting rate is 400 mA, and the reference output current control characteristic P11R of FIG. 3A is obtained. .. Next, the resistance value Roffset of the offset resistor 4 is adjusted to obtain the output current control characteristic P11 in which the current value becomes 0 A when the brightness setting ratio is 0.5%, as shown in FIG. 3A. Further, in the DC current control circuit 11-2, the sense resistor 13-2 is set so that the output current ILED2 becomes 0.1 mA when the minimum luminance setting ratio within the adjustment range that can provide a predetermined current accuracy is 0.5%. The resistor R2 is set. Here, the total output current ILED is expressed by the following equation.

ILED=ILED1+ILED2 (1)

Therefore, in the low brightness setting rate period T2, the DC current control circuits 11-1 and 11-2 are turned on to control the output current ILED2. After that, in the high brightness setting rate period T3 which is higher than the low brightness setting rate period T2, the direct current control circuits 11-1 and 11-2 are turned on and only the direct current control circuit 11-1 controls the output current ILED1. The control pattern of 1 is used. At this time, the setting range of the entire output current ILED is 0.1 mA to 418 mA as shown in FIG. 3C.

In the first control pattern described above, as shown in FIG. 3C, the output current ILED is controlled even in the period in which the brightness setting rate exceeds 100%, and a useless control current period occurs, so that the first control is performed. Consider the following second control pattern in which the pattern is modified. In the second control pattern, similarly to the first control pattern, the output current control characteristic of the DC current control circuit 11-1 is changed from P21R to P21. Here, the output current control characteristic P21 is similar to the output current control characteristic P11.

Although the DC current control circuit 11-1 is turned on in the low brightness setting rate period T2 of the first control pattern described above, the present invention is not limited to this, and the DC current control circuit 11 is not used. -1 may be turned off.

FIG. 4A is a graph showing an output current control characteristic P21 of the second control pattern according to the DC current control circuit 11-1 of FIG. FIG. 4B is a graph showing the output current control characteristic P22 of the second control pattern relating to the DC current control circuit 11-2 of FIG. Further, FIG. 4C is a graph showing the output current control characteristic P2T of the second control pattern according to the DC current control device 10 of FIG.

Also in this second control pattern, as in the first control pattern, the DC current control circuits 11-1 and 11-2 are turned on to control the output current ILED2 in the low brightness setting rate period T2. After that, in the high brightness setting rate period T3 which is higher than the low brightness setting rate period T2, the DC current control circuits 11-1 and 11-2 are turned on, and only the DC current control circuit 11-1 controls the output current ILED1.

In this case, the output current control characteristic P21 of the DC current control circuit 11-1 of FIG. 4A is similar to the output current control characteristic P11 as described above. On the other hand, the output current control characteristic P22 of the DC current control circuit 11-2 of FIG. 4B is the same as the output current control characteristic P12 of FIG. It is controlled to be constant at 2 mA in the range of 100% to 100%. The overall output current ILED at this time can be changed in the range of 0.1 mA to 400 mA in the range of 0.025% to 100% of the brightness setting rate as in the output current control characteristic P2T of FIG. 4C. It can be seen that the output current control characteristic P2T thus obtained is similar to the required output current control characteristic PR in FIG. 2 and the output current control characteristic PR can be set.

According to the second control pattern, the brightness setting rate is improved to 0.025% within the adjustment range where the DC current control circuits 11-1 and 11-2 can provide a current accuracy of 0.5%, and flicker and/or It is possible to realize the DC current control device 10 for the LED drive circuit that does not generate EMI.

The DC current control circuit 11-1 is turned on during the low brightness setting rate period T2 of the above second control pattern, but the present invention is not limited to this, and the DC current control circuit 11 is not used. -1 may be turned off.

FIG. 5A is a graph showing the output current control characteristic P31 of the third control pattern relating to the DC current control circuit 11-1 of FIG. FIG. 5B is a graph showing the output current control characteristic P32 of the third control pattern relating to the DC current control circuit 11-2 of FIG. Further, FIG. 5C is a graph showing the output current control characteristic P3T of the third control pattern according to the DC current control device 10 of FIG.

In the third control pattern, the DC current control circuit 11-2 is turned on to control the output current ILED2 in the low brightness setting rate period T2A. After that, in the high brightness setting rate period T1 which is higher than the low brightness setting rate period T2A, only the DC current control circuit 11-1 is turned on and only the DC current control circuit 11-1 controls the output current ILED1. That is, the DC current control circuit 11-2 is turned off in the high brightness setting rate period T1.

In this case, the DC current control circuit 11-1 sets the resistance value R1 of the sense resistor 13-1 so that the maximum output current ILED1 of the maximum brightness setting rate is 400 mA, and the output current of the brightness setting rate of 5% or less. The DC current control circuit 11-1 is turned off at ILED1=20 mA or less. Further, at the minimum brightness setting rate, the sense resistor 13- is set so that the output current ILED2 within the adjustment range where the DC current control circuit 11-2 can give a predetermined current accuracy becomes 0.1 mA at the brightness setting rate of 0.5%. A resistance value R2 of 2 is set.

Therefore, in the third control pattern, as shown in FIG. 5C, the current range of the output current ILED can be controlled in the range of 0.125 to 400 mA when the brightness setting rate is in the range of 0.025% to 100%. According to the third control pattern, the brightness setting rate is improved to 0.025% within the adjustment range where the DC current control circuits 11-1 and 11-2 can provide a current accuracy of 0.5%, and flicker and It is possible to realize the DC current control device 10 for the LED driving circuit, which does not generate EMI.

Next, the fourth to sixth control patterns in the case where there are current variations (±α and ±β in FIGS. 6A to 8B) due to control or output offset in the DC current control device 10 will be described below.

FIG. 6A is a graph showing an output current control characteristic P41 of a fourth control pattern used when the DC current control circuit 11-1 in FIG. 1 has current variations. FIG. 6B is a graph showing the output current control characteristic P42 of the fourth control pattern used when there is current variation in the DC current control circuit 11-2 of FIG. FIG. 6C is a graph showing the output current control characteristic P4T of the fourth control pattern according to the DC current control device 10 used when there is current variation in the DC current control circuits 11-1 and 11-2 of FIG. .. FIG. 6D is an enlarged view of a portion 101 of the output current control characteristic P4T of FIG. 6C.

The brightness setting rate of the DC current control circuit 11-2 of FIG. 6B is (20+0.1) mA when the brightness setting rate is 100%, and the brightness setting rate of the DC current control circuit 11-1 of FIG. 6A is (20+0.1) mA. Think of the case. Here, in FIG. 6C showing the overall output current control characteristic, the luminance setting rate is 5%, (20+0.2) mA (γ=0.2), and the luminance setting rate is 0.025% and +0.05%. Of the output current ILED, the current accuracy is significantly deteriorated. In order to solve this problem, adjustment of the resistance value Roffset of the offset resistor 4 is used.

The output current ILED1 is set to a current value close to 0 A by adjusting the resistance value Roffset of the offset resistor 4 in the setting of the low luminance setting rate period (0.025% to 5%) of the DC current control circuit 11-1. You can leave it. As shown in FIG. 6A, similarly to the output current control characteristics P11 and P21 of the first and second control patterns of FIGS. 3A and 4A, the output current control characteristic P41 is obtained in the DC current control circuit 11-1. On the other hand, in the direct current control circuit 11-2, the output current control characteristic P42 is obtained in the direct current control circuit 11-2 similarly to the output current control characteristic P22 of the first control pattern in FIG. 3B.

The overall output current control characteristic P4T obtained at this time is shown in FIG. 6C and an enlarged view of FIG. 6D. The control method at this time is the same as that of the first and second control patterns. As is clear from FIGS. 6C and 6D, the overall output current control characteristic P4T extends linearly over the two periods T2 and T3 at a brightness setting rate of 5% when there is no current variation. However, when there is a variation in current, there is a problem that a discontinuous portion such as the characteristic P4TB in FIG. 6D occurs.

Fifth and sixth control patterns for solving this problem will be described below with reference to FIGS. 7A to 8B.

7A and 7B are graphs showing the output current control characteristic P51 of the fifth control pattern used when there is current variation in the DC current control circuit 11-1 of FIG. FIG. 7C is a graph showing the output current control characteristic P5T of the fifth control pattern according to the DC current control device 10 used when there is current variation in the DC current control circuits 11-1 and 11-2 of FIG. ..

In the fifth control pattern, as shown in FIG. 7A, by adjusting the reference output current control characteristic P51R of the direct current control circuit 11-1 and the resistance value Roffset of the offset resistor 4, the output current ILED1 is adjusted to the brightness setting rate 0. If it exceeds 0.5%, adjust to 0A. As a result, the output current control characteristic P51 of FIG. 7B is obtained. The output current control characteristic P51 and the output current control characteristic P42 (FIG. 6B) relating to the direct current control circuit 11-2 are used to perform control using the control method of the fourth control pattern. As a result, the overall output current control characteristic P5T of FIG. 7C is obtained. Therefore, in the overall output current control characteristic P5T of FIG. 7C, the output current ILED changes more smoothly with respect to the brightness setting ratio method than in the overall output current control characteristic P4T of FIG. 6D.

Next, a sixth control pattern according to a modified example in which the output current ILED can be changed more smoothly than the fifth control pattern will be described below.

FIG. 8A is a graph showing an output current control characteristic P6T of a sixth control pattern which is a modified example of FIG. 7C. 8B is an enlarged view of a portion 102 of the output current control characteristic P6T of FIG. 8A.

In this case, as shown in FIGS. 8A and 8B, the period of the brightness setting rate controlled by the direct current control circuit 11-2 is moved to the left in the figure so as to overlap with the period T2, and the overlapping period is increased. Is T4, and a period excluding the period T4 from the period T2 is a period T2a. Here, in the period T2a, only the DC current control circuit 11-2 is turned on and only the DC current control circuit 11-2 controls. Next, in the period T4, both the DC current control circuits 11-1 and 11-2 are turned on and both the DC current control circuits 11-1 and 11-2 control both. Further, in the period T3, both the DC current control circuits 11-1 and 11-2 are turned on, but only the DC current control circuit 11-1 is controlled.

The output current ILED of the output current control characteristic P6T of the sixth control pattern obtained as described above is smaller than that of the output current control characteristic P5T of the fifth control pattern in both the brightness setting rate and the output current ILED. It changes smoothly in the increasing/decreasing direction. The output current ILED can be changed continuously and substantially in proportion to the brightness setting rate.

The direct current control circuit 11-1 is turned on in the low brightness setting rate period T2 of the fourth to fifth control patterns and the low brightness setting rate period T2a of the sixth control pattern described above. However, the DC resistance control circuit 11-1 may be turned off without using the offset resistor 4.

Table 1 below summarizes the first to sixth control patterns described above. In Table 1, turning on the circuits 11-1 and 11-2 means operating the circuits 11-1 and 11-2. Further, the control by the circuits 11-1 and 11-2 means that the output current is changed and controlled according to the current control signal.

As described above, according to the first embodiment, since the influences of the output offsets of the DC current control circuits 11-1 and 11-2 are the same, the lower limit of the brightness setting rate is maintained while maintaining a predetermined current accuracy. It is characterized in that the value can be reduced to less than 0.5%. As a result, it is possible to improve the brightness setting rate to 0.025% within the adjustment range in which the DC current control circuits 11-1 and 11-2 can provide a current accuracy of 0.5%. Therefore, it is possible to realize the DC current control device 10 for the LED drive circuit in which flicker and/or EMI do not occur. Further, even when the output current control characteristic has a current variation, the output current ILED1 can be set to a current value close to 0 A by using the offset resistor 4, whereby a low brightness setting rate is obtained. The current setting accuracy in can be improved.

Therefore, by using the DC current control device 10 according to the present embodiment in the LED drive circuit, it is possible to accurately perform dimming even in a very dark place of the LED lighting, as compared with the conventional technique, and to achieve EMI or Flicker can be prevented.

In the first embodiment described above, the output current is controlled by the brightness setting rate (%), but the present invention is not limited to this, and the output current may be controlled by the brightness setting value or the output current setting value.

Embodiment 2.
FIG. 9 is a block diagram showing a configuration example of the DC current control device 10A and its peripheral circuits according to the second embodiment of the present invention. The direct current control device 10A according to the second embodiment includes a plurality of N direct current control circuits 11-1 to 11-N as compared with the direct current control device 10 according to the first embodiment of FIG. Characterize.

9, the DC current control circuit 11-1 includes an output current control circuit 12-1, a MOS transistor Q1, and a sense resistor 13-1 having a resistance value R1. The DC current control circuit 11-2 includes an output current control circuit 12-2, a MOS transistor Q2, and a sense resistor 13-2 having a resistance value R2. Similarly, the DC current control circuit 11-N includes an output current control circuit 12-N, a MOS transistor QN, and a sense resistor 13-N having a resistance value RN. The output current ILEDN flows through the MOS transistor QN and the sense resistor 13-N.

In the second embodiment, by using a plurality of direct current control circuits 11-1 to 11-N to set three or more brightness setting rate periods and a plurality of intermediate brightness setting rate periods, the first embodiment can be realized. The output current ILED can be controlled with higher accuracy as compared with the above.

Modified example.
Although the DC current control devices 10 and 10A used as the LED drive device have been described in the above embodiments, the present invention is not limited to this, and is applicable to general applications having a predetermined load such as a motor and a rechargeable battery. It can also be applied to such a DC current control device. The DC current control device is not limited to the lighting device including the LED drive device, but can be widely applied to a control device that controls a current of a motor or a rechargeable battery and an electronic device including the control device.

In the embodiment, as shown in FIG. 2 and the like, the output current ILED is continuously controlled so as to change substantially in proportion to the brightness setting rate. On the other hand, in a DC current control device for general predetermined applications, "brightness setting rate" can be read as "current setting rate", and "brightness setting rate period" can be read as "current setting rate period". You can Further, the current control signal may be a control signal indicating a current setting rate or a current setting value. Further, the "current setting rate period" may be represented by a current setting value and may be referred to as a "current setting period".

Although the MOS transistors Q1 to QN are used in the above embodiments, the present invention is not limited to this, and is a current control element (transistor element) such as a bipolar transistor capable of controlling a current according to a control voltage. May be.

In the above embodiment, the sense resistors 13-1 to 13-N for detecting the voltage corresponding to the output current are provided, but the present invention is not limited to this, and the output current or the voltage corresponding to the output current can be detected. Any detection element may be used.

Summary of the embodiment.
The direct current control device according to the first aspect is
A plurality of direct current control circuits connected in parallel to a load, each of which continuously supplies a current flowing through each of the direct current control circuits in a predetermined current setting period based on a current control signal indicating a current setting value. Equipped with multiple direct current control circuits to control,
A direct current control device for continuously controlling an output current flowing through the load,
A plurality of current setting periods in which the plurality of direct current control circuits respectively control the currents flowing in the respective direct current control circuits are different from each other or partially set to overlap each other.

A direct current control device according to a second aspect is the direct current control device according to the first aspect,
The plurality of direct current control circuits,
A first direct current control circuit for controlling a current flowing through the first direct current control circuit in a first current setting period;
A second direct current control circuit for controlling a current flowing through the second direct current control circuit in a second current setting period including at least a current setting value larger than the first current setting period. And

A DC current control device according to a third aspect is the DC current control device according to the second aspect,
The first direct current control circuit is operated in the first and second current setting periods, and a current flowing through the first direct current control circuit is supplied to the first direct current control circuit in response to the current control signal in the first current setting period. Change and control,
The second DC current control circuit is operated during the second current setting period, and changes the current flowing through the second DC current control circuit according to the current control signal during the second current setting period. It is characterized by controlling.

A DC current control device according to a fourth aspect is the DC current control device according to the second aspect,
The first direct current control circuit is operated during the first current setting period, and changes the current flowing through the first direct current control circuit according to the current control signal during the first current setting period. Control and
The second DC current control circuit is operated during the second current setting period, and changes the current flowing through the second DC current control circuit according to the current control signal during the second current setting period. It is characterized by controlling.

A direct current control device according to a fifth aspect is the direct current control device according to the second aspect,
The first direct current control circuit is operated in the first and second current setting periods, and a current flowing through the first direct current control circuit is supplied to the first direct current control circuit in response to the current control signal in the first current setting period. Change and control,
The second DC current control circuit is operated in the first and second current setting periods, and controls the current flowing through the second DC current control circuit in the second current setting period according to the current control signal. It is characterized by changing and controlling.

A direct current control device according to a sixth aspect is the direct current control device according to any one of the second to fifth aspects,
Each DC current control circuit,
A current control element connected from a predetermined first power supply via the load;
A detection element that is connected to the current control element and detects a current or a voltage corresponding to the current flowing in each of the DC current control circuits,
An output current control circuit that controls the current control element so that the current becomes the current setting value of the current control signal based on the current control signal and the current detected by the detection element or the voltage corresponding to the current. It is characterized by having and.

A direct current control device according to a seventh aspect is the direct current control device according to the sixth aspect, wherein the current control element is a transistor.

A DC current control device according to an eighth aspect is the DC current control device according to the sixth or seventh aspect, wherein the detection element is a sense resistor that detects a voltage corresponding to the current. ..

A direct current control device according to a ninth aspect is the direct current control device according to any one of the sixth to eighth aspects,
The value of the detection element of the second DC current control circuit is set based on the maximum current setting value of the second current setting period,
The value of the detection element of the first DC current control circuit is set based on the minimum current setting value in the first current setting period.

A direct current control device according to a tenth aspect is the direct current control device according to any one of the sixth to ninth aspects,
The second DC current control circuit further includes an offset connected between a connection point between the current control element and the detection element of the second DC current control circuit and a predetermined second power supply. With resistance,
A third current setting period in which the first current setting period and the second current setting period overlap with each other,
The first and second direct current control circuits are respectively operated in the third current setting period, and the first and second direct current control circuits are respectively operated in response to the current control signal in the third current setting period. It is characterized in that the current flowing in the circuit is changed and controlled.

An electronic device according to an eleventh aspect is characterized by including the direct current control device according to any one of the first to tenth aspects.

1, 2... power supply,
3... Device control circuit
4... Offset resistance,
10, 10A... DC current control device,
11-1 to 11-N... DC current control circuit,
12-1 to 12-N... Output current control circuit,
13-1 to 13-N... sense resistor,
D1... Light emitting diode (LED),
Q1 to QN... MOS transistors.

JP, 2011-108669, A JP, 2010-066984, A

Claims (8)

A plurality of direct current control circuits connected in parallel to a load, each of which continuously supplies a current flowing through each of the direct current control circuits in a predetermined current setting period based on a current control signal indicating a current setting value. A DC current control device comprising a plurality of DC current control circuits for controlling, wherein the DC current control device continuously controls an output current flowing through the load,
A plurality of current setting periods in which the plurality of direct current control circuits respectively control the currents flowing in the respective direct current control circuits are different from each other, or set so as to partially overlap each other ,
The plurality of direct current control circuits,
A first direct current control circuit for controlling a current flowing through the first direct current control circuit in a first current setting period;
A second direct current control circuit for controlling a current flowing through the second direct current control circuit in a second current setting period including at least a current setting value larger than the first current setting period;
Each DC current control circuit,
A current control element connected from a predetermined first power supply via the load;
A detection element that is connected to the current control element and detects a current or a voltage corresponding to the current flowing in each of the DC current control circuits,
An output current control circuit that controls the current control element so that the current becomes the current setting value of the current control signal based on the current control signal and the current detected by the detection element or the voltage corresponding to the current. With and
The second DC current control circuit further includes an offset connected between a connection point between the current control element and the detection element of the second DC current control circuit and a predetermined second power supply. With resistance,
A third current setting period in which the first current setting period and the second current setting period overlap with each other,
The first and second direct current control circuits are respectively operated in the third current setting period, and the first and second direct current control circuits are respectively operated in response to the current control signal in the third current setting period. A direct current control device characterized by changing and controlling a current flowing through a circuit . The first direct current control circuit is operated in the first and second current setting periods, and a current flowing through the first direct current control circuit is supplied to the first direct current control circuit in response to the current control signal in the first current setting period. Change and control,
The second DC current control circuit is operated during the second current setting period, and changes the current flowing through the second DC current control circuit according to the current control signal during the second current setting period. The direct current control device according to claim 1, which is controlled. The first direct current control circuit is operated during the first current setting period, and changes the current flowing through the first direct current control circuit according to the current control signal during the first current setting period. Control and
The second DC current control circuit is operated during the second current setting period, and changes the current flowing through the second DC current control circuit according to the current control signal during the second current setting period. The direct current control device according to claim 1, which is controlled. The first direct current control circuit is operated in the first and second current setting periods, and a current flowing through the first direct current control circuit is supplied to the first direct current control circuit in response to the current control signal in the first current setting period. Change and control,
The second DC current control circuit is operated in the first and second current setting periods, and controls the current flowing through the second DC current control circuit in the second current setting period according to the current control signal. The DC current controller according to claim 1 , wherein the DC current controller is controlled by changing it. The DC current control device according to claim 1, wherein the current control element is a transistor. The detecting element, a direct current control device according to any one of claims 1 to 5 is the sense resistor for detecting a voltage corresponding to the current. The value of the detection element of the second DC current control circuit is set based on the maximum current setting value of the second current setting period,
The value of the detection element of the said 1st direct current control circuit is set based on the minimum electric current setting value of the said 1st electric current setting period, The direct current as described in any one of Claims 1-6. Current control device. An electronic apparatus comprising the direct current control device according to any one of claims 1-7.

Images