WO2002099947A1

WO2002099947A1 - Power unit and method for power supply of power unit

Info

Publication number: WO2002099947A1
Application number: PCT/JP2001/004614
Authority: WO
Inventors: Kouji Furuuchi
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 2001-05-31
Filing date: 2001-05-31
Publication date: 2002-12-12
Also published as: JPWO2002099947A1

Abstract

A step-up/down power unit capable of efficiently utilizing a battery (1), characterized by comprising the battery (1) driving an electronic circuit (4), a step-up converter (2) building up the output voltage of the battery (1) connected between the battery (1) and the electronic circuit (4), a diode (5) connected parallel with the step-up converter (2) and bypassing a current discharged from the battery (1), a linear regulator (3) building down the voltage built up by the step-up converter (2), and an auxiliary power supply circuit (6) connected parallel with the step-up converter (2).

Description

Description Power supply device and power supply method for power supply device

The present invention relates to a power supply device and a power supply method of the power supply device, for example, a portable electronic device driven by a battery and having an internal circuit operating within an operating voltage range of the battery. For example, the operating voltage range of a lithium-ion battery is 2.75 V to 4.2 V, and the drive voltage (V cc) of an electronic circuit required for an LSI or the like for realizing the functions of a portable electronic device is The present invention relates to a power supply and a power supply method for the power supply when the voltage is 3 V or the like. Background art

Conventional example 1.

FIG. 6 shows a configuration of a conventional power supply device.

Here, the battery 1 is a power source of the portable electronic device. The step-up converter 2 converts the voltage of the battery 1 to a more stable high voltage. The linear regulator 3 gradually reduces the output voltage of the step-up comparator 2 to the drive voltage of the electronic circuit 4. The electronic circuit 4 indicates a main circuit of the portable electronic device.

The step-up comparator 2 is composed of a control circuit section 50, a switching transistor 51, a choke coil 52, a diode 53, and a capacitor 54. The output voltage of the step-up comparator 2 is fed back to the control circuit 50. The emitter terminal of the transistor 51 and one terminal of the capacitor 54 are connected to the reference voltage (ground) 55 of the circuit. Where the reference voltage of the circuit is This is the negative electrode voltage of the power supply 101 inside the battery 1. The negative electrode of the power supply 101 is connected to the grounds 102, 55, 57, 59, 301, 401, and the grounds 102, 55, 57, 59, 301, 401 maintain the reference voltage of the circuit. A capacitor 56 is connected to the output side of the battery 1. Capacitor 56 is connected to ground 57. A capacitor 58 for stabilizing the output is connected to the output side of the linear regulator. The capacitor 58 is connected to the ground 59. Next, the operation will be described. The voltage of battery 1 is boosted to a voltage higher than the output voltage range of battery 1 by step-up comparator 2. By this operation, a constant voltage is generated irrespective of the state of the voltage of the battery 1.Next, the constant voltage boosted by the step-up converter 2 is input and the linear regulator 3 Step down the voltage. As a result, a constant and stable voltage for the electronic circuit 4 is generated. The electronic circuit 4, which is the main circuit of the portable electronic device, operates based on the voltage stepped down by the linear regulator 3. As described above, according to the step-up / down power supply device in which the step-up compa- nator 2 is configured as a preceding circuit and the linear regulator circuit 3 is configured as a subsequent circuit, the voltage of the battery 1 is higher than the voltage required by the electronic circuit 4. Even if the output is low, a stable output can be obtained. In the conventional technology, it is also possible to configure the subsequent linear regulator 3 as a step-down converter (chopper-type switching regulator).

In addition, as a switching regulator system that performs the same function as the linear regulator system 3, there is a SEP IC (Single End PRIMary Ind ance ann tance Control) circuit system or a trans system. Here, in the step-up / down power supply device of the conventional portable terminal, the step-up compa- nator 2 always operates. However, when operating constantly, such switching type power supply circuits usually have the characteristic that the efficiency becomes extremely poor when the output power is reduced. Therefore, when the power consumption of the portable electronic device decreases, for example, when the mobile phone is in a standby state, or when a PDA (Persona 1 Digit 1 Assistance) or PC (Personal Computer) In the low power consumption mode such as the power saving mode (used by the names of suspend, stamp-pay, sleep, etc.), the loss of the step-up converter 2 is the main factor that shortens the operation time of the device. There was a problem.

Therefore, depending on the operating conditions of the equipment, only the linear regulator 3 is installed without the step-up / down power supply, and the battery 1 is used only in the voltage range of the battery 1 that is higher than the operating voltage of the electronic circuit 4. In some cases . For example, when the operating voltage of the electronic circuit 4 is 3.3 V, only the voltage between 4.2 V and 3.5 V is used in consideration of the saturation voltage of the linear regulator 3.

, 3.4 V or less is not used.

As described above, depending on the power consumption of the device, to use the entire voltage range of battery 1, rather than installing step-up converter overnight 2, battery 1 without 4.2-volt converter above 4.2 V Using up to 3.5 V may result in a longer operating time because there is no loss in step-up converter 2.

However, during the period during which the operation of the step-up compa- nator 2 is originally required, when the voltage of the battery 1 becomes smaller than the input voltage of the linear regulator 3 required to generate the operating voltage of the electronic device 4. Only. For this reason, while the battery 1 voltage is high, a step-up 2 Stop or pause (for example, if the step-up converter 2 is a PWM (pulse width modulation) switching type switching converter, the switching-on duty is 0% or close to it. The power loss of the step-up comparator 2 can be suppressed.

However, when simply stopping and pausing, the battery 1 voltage drops when the output current increases due to load fluctuations. As a result, the voltage of the battery 1 falls below the voltage required by the linear regulator 3. Therefore, the power supply to the electronic device 4 becomes unstable, causing the electronic device 4 to malfunction.

Therefore, usually to prevent this problem, a step-up converter

2 sets the output voltage higher than the maximum voltage of the battery 1 and keeps it operating at all times in order to obtain high-speed response performance. However, this leads, as described above, to always generate power loss due to the step-up compa- nator 2.

The step-down power supply represented by the linear regulator 3 in the latter stage may use a switching-type step-down comparator depending on the situation.

Thus, in the above-described step-up / down power supply device, it is difficult to use the battery 1 over the entire range of the battery voltage range while suppressing the power supply device.

An object of the present invention is to provide a step-up / down power supply device capable of suppressing power loss.

Another object of the present invention is to eliminate the instability of power supply to electronic devices due to load fluctuations and to obtain a step-up / down power supply that can supply power stably. It is another object of the present invention to obtain a step-up / down power supply that can efficiently use a battery. Conventional example 2.

Japanese Unexamined Patent Publication No. 57-2063231 discloses that when a vehicle's engine is stopped, the battery cannot be started due to the discharge of the battery due to the operation of a DC-DC (direct current-direct current) comparator. To avoid this, a battery, a DC-DC converter that boosts the voltage of this battery, an identification switch that also operates the DC_DC converter, and a constant-voltage circuit that receives the output of the booster A vehicle electronic device to which the output of the constant voltage circuit is input; and a circuit in which power is directly supplied from the battery to the vehicle electronic device via a diode when the DC-DC converter is off. A power supply device for a vehicle electronic device provided with a power supply is described.

Although not shown in the figure, in the above configuration, when the above-mentioned identification switch is off, the above-mentioned DC-DC converter is not driven, and the battery is supplied to the constant voltage circuit through the above-mentioned diode. Further, it is supplied to the above-mentioned vehicle electronic device. When the above-mentioned identification switch is on, the battery is charged because the engine is running most of the time when the ignition switch is on. As a result, the battery does not discharge even if the power consumption increases due to the operation of the DC-DC converter. Also, when the vehicle's engine star starts, the DC-DC converter operates in the same way, and the battery voltage drops. In spite of this, it is stated that the voltage is boosted by the DC-DC converter and can be supplied to the above-mentioned vehicle electronic device with a normal voltage power supply.

However, in the above power supply device, the battery is assumed to be normally charged by the engine, and However, this does not solve the problem of effectively using the voltage within the unusable voltage range. Conventional example 3.

Japanese Patent Application Laid-Open No. Hei 4-2590917 discloses that as a DC power supply device for driving electrical components having different operating voltages between a high-voltage drive system and a low-voltage drive system, there are two types of DC power supply devices: Switchin Gregiyure and Linear Regyure. It describes a DC power supply device provided with target voltage switching means for switching a target voltage of the switching power supply.

Although not shown, the switching regulator converts a DC voltage to a target voltage specified from the outside and outputs the target voltage to drive a high-voltage drive system. Further, the linear regulator circuit branches and inputs the output voltage from the switching regulator circuit, converts the output voltage to a predetermined voltage lower than the output voltage, and outputs the predetermined voltage, thereby driving a low voltage drive system. Further, when the output voltage from the switching regulator is supplied to the high-voltage drive system, the target voltage switching means is configured so that the switching voltage is higher than a target voltage that is not supplied. Change the target voltage for one night.

This suppresses power loss in the linear regulator when no power is supplied to the high-voltage drive system.

However, the DC power supply is intended to reduce the power loss caused by boosting the voltage required to drive the high-voltage drive system electrical components when driving the low-voltage drive system electrical components. However, this does not solve the problem of effectively using the power supply to an unusable voltage range. Disclosure of the invention

The power supply device of the present invention includes: a first power supply unit that drives a load unit; A booster for boosting an output voltage of the first power supply connected between the first power supply and the load;

A bypass circuit unit connected in parallel with the booster unit and bypassing a current discharged from the first power supply unit;

A step-down unit that steps down the voltage boosted by the step-up unit,

A booster section and a second power supply section connected in parallel.

The booster has a switch for driving the booster, feeds the output voltage of the booster, controls the switch based on the feedback result, and keeps the output voltage constant. It is a stable non-isolated converter.

Further, the bypass circuit unit includes a diode through which a current flows only when an input voltage of the boosting unit is higher than an output voltage of the boosting unit.

Further, the second power supply unit includes a power storage unit that is charged by an output current of the boosting unit.

Also, the second power supply unit includes a first time setting circuit unit that sets a time period for discharging power from the second power supply unit;

The output voltage of the booster is changed in synchronization with the start of the time for discharging power from the second power supply set by the first time setting circuit. A second time setting circuit for setting the time to

The power supply device includes a voltage variable circuit unit that changes an output voltage of the boosting unit during a time set in the second time setting circuit unit.

Further, the power supply device sets the output voltage of the boosting unit to a voltage value higher than the output voltage of the second power supply unit while the second time setting circuit unit is operating. .

Further, in the power supply method of the power supply device according to the present invention, the load unit is driven by the first power supply unit,

When the output voltage of the first power supply unit is lower than the voltage required to drive the load unit, the output voltage of the first power supply unit is boosted;

Bypassing the current discharged from the first power supply unit until the output voltage of the first power supply unit becomes lower than the voltage required to drive the load unit, and boosting the output of the first power supply unit. And boosting the bypassed voltage by the second power supply when the voltage is lower than the voltage required to drive the load;

Reducing at least one of the output voltage of the first power supply unit, the boosted output voltage of the first power supply unit, and the output voltage of the second power supply unit to a voltage for driving a load unit; It is characterized by.

Further, the power supply method of the power supply device further includes charging the second power supply unit with a boosted output voltage of the first power supply unit. The power supply method of the power supply device further includes setting a first time for discharging power from the second power supply unit,

Discharging power from the second power supply unit during the set first time, and changing the output voltage of the first power supply unit in synchronization with the start of discharge from the second power supply unit. Set a time of 2,

The output voltage of the first power supply unit is changed during the second time. Further, the power supply method of the power supply device is further characterized in that, when the boosting of the output voltage of the first power supply unit is started, the boosted voltage is set higher than the output voltage of the second power supply unit. I do. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a configuration diagram of a step-up / down power supply device according to Embodiment 1. FIG. 2 is a time chart illustrating an example of an operation of the auxiliary power supply circuit and an operation of charging the auxiliary power supply circuit according to Embodiment 1.

Fig. 3 shows the difference in operating state between the conventional step-up comparator and the step-up comparator according to the first embodiment according to the battery voltage. Fig. 4 shows the voltage detection of the auxiliary power supply circuit according to the second embodiment. FIG. FIG. 5 is a configuration diagram of a step-up / down power supply device according to the third embodiment. Figure 6 is a block diagram of a conventional step-up / down power supply. BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1.

Hereinafter, Embodiment 1 will be described with reference to the drawings.

In FIG. 1, a battery 1 is an example of a first power supply unit and is a main power source of a portable electronic device. The step-up converter 2 is an example of a booster, and is a non-insulating type converter that converts the voltage of the battery 1 to a more stable high voltage. The linear regulator 3 is an example of a step-down unit, and stably steps down the output voltage of the step-up converter 2 to the drive voltage of the electronic circuit 4. The electronic circuit 4 is an example of a load unit, and shows a main circuit of a portable electronic device.

The step-up converter 2 includes a control circuit section 50, a switching transistor 51, a choke coil 52, a diode 53, a capacitor 54, and a voltage variable circuit 13 (an example of a voltage variable circuit section). The output voltage of the step-up comparator 2 is fed back to the control circuit 50 via the voltage variable circuit 13. The emitter terminal of the transistor 51 and one terminal of the capacitor 54 are connected to a reference voltage (ground) 55 of the circuit. Here, the reference voltage of the circuit is the negative voltage of the power supply 101 inside the battery 1. The negative pole of the power supply 101 is connected to the grounds 102, 55, 57, 59, 301, 401, 64, 66, and the grounds 102, 55, 57, 59, 301, Reference numerals 40 1, 64, and 66 maintain the reference voltage of the circuit.

A capacitor 56 is connected to the output side of the battery 1. Capacitor 56 is connected to ground 57. The output side of the linear regulator 3 is connected to a capacitor 58 for stabilizing the output. Capacitor 58 is connected to ground 59.

The voltage of the step-up comparator 2 is controlled by the voltage variable circuit 13. Has a variable function. The bypass diode 5 is connected in parallel with the above-described step-up comparator 2 (an example of a bypass circuit). Further, the step-up comparator 2 can be started or stopped externally by inputting a 〇N / OFF (on / off) signal to the control circuit unit 50 from outside. The auxiliary power supply circuit 6 is an example of a second power supply unit, and is connected to the output of the step-up converter 2 and the power source side of the bypass diode 5 to supplement the power. The voltage detection circuit 7 connects one of the two terminals of the input to the positive terminal of the DC power supply 65 constituting the reference voltage, and the other to the output of the step-up converter 2 and the power source of the bypass diode 5. The negative side of DC power supply 65 is connected to ground 66. The voltage detection circuit 7 determines whether the auxiliary power supply circuit 6 supplies power. The timer 8 is an example of a first time setting circuit section. The input is connected to the output of the voltage detection circuit 7, and the output is input to and controlled by the timer 9, the semiconductor switch 10, and the comparator 60. The timer 8 operates the auxiliary power supply circuit 6 for an arbitrary time by the output of the voltage detection circuit 7. The timer 9 is an example of a second time setting circuit unit. The input is connected to the output of the timer 8, and the output of the timer 9 is connected to the voltage variable circuit 13. The timer 9 operates the voltage variable circuit 13 so that the output voltage setting of the step-up comparator 2 is set higher than the normal operation state for an arbitrary time in synchronization with the start of the operation of the auxiliary power supply circuit 6. The semiconductor switch 10 is a switch typified by a FET (Field Effect Transistor) or a bipolar transistor. The semiconductor switch 10 turns on / off the auxiliary power supply by the output of the timer 8. Like the semiconductor switch 10, the semiconductor switch 11 is a switch represented by a FET (Field Effect Transistor) or a bipolar transistor. Semiconductor switch 11 is driven by the output of comparator 60. Turns on / off the circuit for charging the auxiliary power energy. The capacitor 12 is an example of a power storage means. One of the two terminals is connected to the ground 64, and the other is connected to the cathode of the diode 61 and the anode of the diode 62. Capacitor 12 stores auxiliary power energy. The diode 61 has its anode connected to the output of the step-up converter 2 and the output side of the bypass diode 5 via the resistor 63 and the semiconductor switch 11. The diode 62 has its cathode side connected to the output of the step-up comparator 2 and the cathode side of the bypass diode 5 via the semiconductor switch 10.

Next, the operation of the power supply device will be described. Step-up converter 2 sets the output voltage so as to output the minimum voltage required for operation of linear regulator 3. Therefore, when the voltage of the battery 1 is higher than the output voltage set value of the step-up converter 2, the output feedback control circuit 50 of the step-up converter 2 operates to stop the switching operation of the transistor 51. However, the step-up comparator 2 is actually in a resting state or intermittently oscillating. In any case, the power loss is suppressed. The bypass diode 5 reduces the voltage loss due to the input / output resistance of the step-up comparator 2 so that the output voltage of the step-up comparator 2 becomes as close to the battery 1 voltage as possible, and the step-up diode 5 Upcomer 2 works to keep the dormant state. The auxiliary power supply circuit 6 detects the input voltage of the linear regulator 3 when the voltage of the battery 1 decreases due to a sudden increase in the load of the electronic circuit 4 or when the operation delay of the step-up comparator 2 occurs. When the voltage falls below the normal operating range, supplementary energy supplementation is performed rapidly, and the voltage is increased.

Also, when starting up this power supply circuit, The initial set value of the output voltage setting of the up-converter 2 is set to a high voltage for charging the capacitor 12 in the auxiliary power supply circuit 6. Here, in the voltage variable circuit 13, the output voltage of the step-up comparator 2 is set by varying the resistance value ratio of the portion for detecting the output voltage of the step-up comparator 2. The above initial setting value operates only for a certain period of time, and the time setting is generated by a reset IC (Integrated Circuit) (not shown) because it is different from the setting time of the timer 9. However, since the setting time of the timer 9 is longer than the charging time of the capacitor 12 as described later, the time setting of the above initial setting value may be generated by the timer 9.

Next, the operation of the auxiliary power supply circuit 6 will be described. The voltage detection circuit 7 is a comparator that detects the voltage of the step-up comparator 2 and uses the minimum required operating voltage of the linear regulator 3 as a comparison reference value. When the voltage drops, the output signal of the voltage detection circuit 7 as a comparator is inverted. In practice, the power supply operation of the auxiliary power supply circuit 6 also has a time lag element, so the voltage that is slightly higher than the minimum required operating voltage of the linear regulator 3 is used as the comparison reference value of the voltage detection circuit 7. . The one-shot timer 8 and the timer 9 operate with the output signal of the voltage detection circuit 7 being inverted as a trigger. By the output of the timer 8, the semiconductor switch 10 as an auxiliary power supply ON switch conducts for an arbitrary fixed time, and the electric charge accumulated in the capacitor 12 is converted into voltage energy through the diode 62 and the semiconductor switch 10 as voltage energy. Supply to the input of evening 3. In addition, the voltage variable circuit 13 changes the output voltage of the step-up comparator 2 to about 0.5 V from the maximum voltage of the capacitor 12 of the auxiliary power supply circuit 6 for an arbitrarily set time by the output of the timer 9. Set to a high value. As a result, the output voltage of step-up converter 2 rises to the set value. You. When the set time of the timer 8 is reached, the semiconductor switch 10 which is the auxiliary power supply ON switch is turned off and the semiconductor switch 11 which is the auxiliary power supply charge ON switch is turned ON. Then, the auxiliary power supply circuit 6 rapidly charges the capacitor 12 with the increased output voltage of the step-up converter 2, and makes the capacitor 12 transition to the next auxiliary power supply operation preparation state. The time of timer 9 is set to the sum of the time of timer 8 and the time of charging capacitor 12. However, considering some margin, it is desirable to set the time to be longer than the above sum.

FIG. 2 is a time chart showing an example of the operation of the auxiliary power supply circuit 6 and the operation of charging the auxiliary power supply circuit 6 according to the first embodiment.

In FIG. 2, the voltage of the battery 1 is higher (H) than the minimum operating voltage of the linear regulator 3. The load of the electronic circuit 4 is in a small (L) state. The output voltage of the step-up comparator 2 is higher (H) than the minimum operating voltage of the linear regulator 3. The output signal of the voltage detection circuit 7 is in the Low (L) state. The output of timer 8 is off (OFF). The output of evening camera 9 is OFFF. The output setting of the voltage variable circuit 13 is the minimum operating voltage (normal setting: N) of the linear regulator. The semiconductor switch 10, which is the auxiliary power supply switch, is an off-switch. The semiconductor switch 11, which is the auxiliary power charging switch, is on (ON). This is normal operation.

Here, when the load of the electronic circuit 4 becomes large (H), the voltage of the battery 1 decreases. In addition, the output voltage of the step-up comparator 2 also decreases.

Further, the output signal of the voltage detection circuit 7 is in a High (H) state.

As a result, the output of timer 8 turns ON. As a result, the semiconductor switch 10 is turned on. Also, the semiconductor switch 11 is turned off. This As a result, power is supplied from the capacitor 12 of the auxiliary power supply circuit 6 to the input of the linear regulator 3.

In addition, the output of image 9 becomes ON. As a result, the output setting of the voltage variable circuit 13 becomes a value higher than the maximum voltage of the capacitor 12 of the auxiliary power supply circuit 6 (high voltage setting: H H). As a result, Step-up Comparator 2 starts operating. Here, when power is not supplied from the capacitor 12, the output voltage of the step-up converter 2 must be lower than the minimum operating voltage (M in) of the linear regulator 3 as shown by the dotted line in Fig. 2. become.

Next, when the output voltage of the step-up comparator 2 goes high, the output signal of the voltage detection circuit 7 goes low.

Next, when the output of the timer 8 becomes OFF, the semiconductor switch 10 turns OFF.

F. Further, the semiconductor switch 11 becomes ON. As a result, the capacitor 12 is rapidly charged from the increased output voltage of the step-up converter 2, and the capacitor 12 is shifted to the next auxiliary power supply operation preparation state.

Next, when the output of the timer 9 becomes OFF, the output setting of the voltage variable circuit 13 becomes N state. As a result, the operation of the step-up comparator 2 stops.

Thus, a series of operations of the auxiliary power supply circuit 6 and an operation of charging the auxiliary power supply circuit 6 are completed.

By operating as described above, it is possible to extend the driving time of one battery while supplying more stable power.

Here, for example, FIG. 3 is a diagram showing, as an example, a difference between an operation state of a step-up downcomer which is a conventional power supply and an operation state of the power supply according to the first embodiment in accordance with the voltage of the battery 1. Where the operation of the electronic circuit 4 The voltage is 3.3 V, and the saturation voltage of the linear regulator is 0.3 V. Therefore, the minimum operating voltage of the linear regulator 3 is 3.6 V.

In the case of FIG. 3, according to the first embodiment, the operation of the step-up comparator 2 is in a halt state when the battery 1 voltage is between 4.2 V and 3.61 V. The power loss in this portion can be suppressed as compared with the conventional power supply device, which is a continuous operation of the step-up comparator.

As described above, in the step-up / down power supply of the first embodiment, the output voltage of the step-up converter 2 is set as low as possible within the voltage range in which the subsequent linear regulator 3 can operate. I do. Further, the diode 5 having a low forward voltage is connected in parallel with the step-up converter 2 as a bypass diode. As a result, the voltage variable circuit 13 is set so that the operation of the step-up comparator 2 is at a maximum in the battery 1 voltage range, the power loss of the power supply unit is reduced, and the battery-powered portable The driving time of the electronic device can be extended.

In addition, in order to provide stable power supply against load fluctuations, it is necessary to wait until the two circuits of the step-up converter suddenly change (for example, at startup) until the two circuits of the step-up converter operate normally. In other words, while the voltage is lower than the voltage range at which the linear regulator 3 can operate, the auxiliary power supply becomes an electric power tank circuit to supply power to the linear regulator 3 instead of the step-up comparator 2. Construct circuit 6. Then, when the load suddenly changes, the semiconductor switches 10 and 11 supply auxiliary power to the linear power supply 3 from the auxiliary power supply circuit 6 for a fixed time so that the power supply to the electronic circuit 4 can be stably performed. . In addition, at this time, the output voltage setting of the step-up converter 2 is changed to a higher value by the voltage variable circuit 13 so that the state of the step-up converter 2 can be simultaneously changed to the normal switching operation state. The time to increase the output voltage setting is from the auxiliary power supply circuit 6. Power supply time and auxiliary power supply circuit 6

It is the sum of the time to recharge to 1 and 2. This is the necessary operation to prepare for the next sudden load change. The time during which power is supplied from the auxiliary power supply circuit 6 is the time required for the step-up converter 2 to return to the normal switching state.

Also, at the time of starting the power supply circuit, the auxiliary power supply circuit 6 is charged, so that the output voltage setting is similarly increased.

By incorporating the step-up / down power supply device incorporating the auxiliary power supply circuit 6 according to the first embodiment into a battery-driven electronic device, it is possible to extend the driving time of one battery while supplying more stable power. Embodiment 2

In Embodiment 1 described above, an embodiment using a timer circuit to create an arbitrary time is shown. However, instead of the timers 8 and 9, a CR circuit using a simple capacitor (C) and a resistor (R) is used. Similar effects can be obtained with a constant circuit. Hereinafter, the second embodiment will be described with reference to FIG. 4 focusing on the differences from the first embodiment.

The drive circuit 14 includes a semiconductor switch 81, a capacitor 82, a resistor 83, and a diode 84. The output of the voltage detection circuit 7 is connected to the anode side of the diode 84, and the switch input terminal of the semiconductor switch 81, one terminal of the capacitor 82 and the resistor 8 are connected to the output side of the diode 84. 3 is connected to one terminal. The other terminal of each of the capacitor 82 and the resistor 83 is connected to the switch input terminal of the semiconductor switch 10 via the semiconductor switch 81 and to the ground 86. The drive circuit 14 is a circuit for driving the semiconductor switch 10 which is an auxiliary power supply ON switch, and the semiconductor switch 10 is turned on by the CR time constant. Delays the transition from on to off.

The drive circuit 15 includes a semiconductor switch 71, a capacitor 72, resistors 73 and 75, and a diode 74. The output of the voltage detection circuit 7 is connected to the node side of the diode 74, and the switch input terminal of the semiconductor switch 71, one terminal of the capacitor 72, and the resistor 73 are connected to the cathode side. Are connected to one terminal. The other terminal of each of the capacitor 72 and the resistor 73 is connected to the signal input terminal of the voltage variable circuit 13 and the resistor 75 via the semiconductor switch 71, and to the ground 76. ing. The drive circuit 15 is a circuit that drives the voltage variable circuit 13 and uses the CR time constant to set the voltage of the step-up converter 2 to a high voltage for a period determined by the CR time constant. 3 can be driven. The grounds 76 and 86 are connected to the negative electrode of the power supply 101, and the ground grounds 76 and 86 maintain the reference voltage of the circuit.

In the second embodiment, there is obtained an effect that a timer portion can be configured by configuring a cheaper component than in the first embodiment. Embodiment 3.

In the first and second embodiments, the embodiment using the dedicated auxiliary power supply circuit 6 has been described.However, for example, a portable electronic device may use a plurality of power supply types, and these power supply outputs may be supplemented. Similar effects can be obtained as an energy supply source of the power supply circuit 6. Hereinafter, the third embodiment will be described with reference to FIG.

The output of the other power supply 16 is connected to the anode of the diode 62. In addition, the output of the other power supply 16 is connected to the electronic circuit 4 and can directly drive the electronic circuit 4. The output of the other power supply 16 is The other power supply 16 that is connected to the output of the battery 1 and can substitute for the output of the battery 1 is an example of the second power supply unit, and the output voltage of the normal setting of the step-up comparator 2 The output capacity is higher than that of the linear regulator, and the power capacity is several times larger than the load capacity of the linear regulator. By turning on the semiconductor switch 10 which is an auxiliary power supply switch, energy is supplied from the output of the other power supply 16 to the input of the linear regulator 3 via the semiconductor switch 10. In the third embodiment, since the auxiliary power supply circuit 6 does not need to store energy, the semiconductor switch 11 as the auxiliary power supply circuit charging on switch and the capacitor 12 for storing energy are unnecessary. Further, since the time during which the semiconductor switch 10 as the auxiliary power supply on switch is on and the time during which the voltage setting of the step-up comparator 2 is increased may be the same, the timer 9 is also unnecessary.

According to the third embodiment, the configuration can be further reduced than in the second embodiment. However, the effect on power saving is small since the other power supply 16 outputs are operating. Lithium-based secondary batteries are generally used in portable electronic devices, but when they are used in one cell, the operating voltage is generally 2.75 V to 4.2 V. In order to create a general operating voltage of 3 V or 3.3 V for electronic equipment within this usable voltage range, for example, the power supply must increase the voltage by using one battery voltage in the above-mentioned usable voltage range. The first, second, and third embodiments relate to a method for improving the voltage conversion efficiency of this step-up / down power supply circuit.

The above-mentioned step-up / down power supply circuit is a step-up / down power supply that aims to increase the usable voltage range and minimizes power loss. In order to suppress this, the output voltage of the step-up converter is set as low as possible at the lower end of the input range of the linear regulator 3 at the subsequent stage, and the boosted voltage is a constant voltage required by the electronic circuit 4. (Eg 3 V) to reduce the voltage to keep it constant at

Input voltage battery 1 Bypass diode 5 that bypasses when the voltage is higher than Linear Regula 3

An auxiliary power supply circuit 6 for compensating for a drop in the voltage of the battery 1 due to a sudden load change when the booster type converter is stopped,

A high-efficiency step-up power supply device comprising a voltage variable circuit 13 for temporarily setting the output voltage setting of the booster circuit higher than usual in synchronization with the operation of the auxiliary power supply circuit 6.

In addition, the step-up / down power supply circuit obtains the power supply of the auxiliary power supply circuit 6 for the purpose of obtaining the power supply of the auxiliary power supply circuit 6 by self-excitation as described above. A voltage variable circuit 13 for setting the output voltage of the step-up converter 2 higher than usual for a predetermined period;

A high-efficiency step-up power supply device comprising: an auxiliary power supply circuit 6 equipped with a battery or a capacitor 12 that stores power at a voltage set higher than usual. Industrial applicability

According to the preferred embodiment of the present invention, unnecessary boosting operation in the state where the first power supply section voltage is high and the power supply capacity is sufficient is stopped, high efficiency is maintained, and the use range of the battery is further reduced. Since the operation can be performed to the end, there is an effect that the power supply capacity can be used to the maximum.

As described above, for example, the operation mode of the battery-powered portable electronic device is Suppress power loss in power supply devices in standby mode on mobile phones and low power consumption operation modes (called suspend mode, stamp mode, sleep mode) on PDAs and PCs, and further reduce power consumption There is an effect that can be realized.

Therefore, there is an effect that a battery-driven portable electronic device having a longer power supply driving time can be obtained.

Further, even if the second power supply unit is not a multi-output power supply, it is possible to obtain an effect that stable power supply to the load unit can be realized. That is, even in a single power supply device, it is possible to obtain the effect of realizing stable power supply to the load unit. According to the preferred embodiment of the present invention, the input voltage of the step-down unit is not packed and controlled. Providing the insulation type converter has the effect that the boosting operation can be automatically performed as needed when necessary.

According to the preferred embodiment of the present invention, there is an effect that the diode does not supply power without passing through the booster circuit at the time of boosting, and the loss of boosted power can be reduced. .

According to the preferred embodiment of the present invention, since the second power supply unit is charged, there is no need for a disposable auxiliary power supply, and there is an effect that a power supply device can be realized by the first power supply unit alone.

According to the preferred embodiment of the present invention, the power supply time from the second power supply unit can be set arbitrarily. Also, there is an effect that the output voltage of the booster can be arbitrarily varied for a certain period of time. As a result, the booster can smoothly transition to a normal operating state, and the power consumption can be further reduced.

According to the preferred embodiment of the present invention, it is possible to obtain an effect that a time setting circuit can be configured by configuring inexpensive components. According to the preferred embodiment of the present invention, it is possible to smoothly transition the state of the booster to a normal operation state, and further achieve an effect of further reducing power consumption. Also, there is an effect that the second power supply unit can be sufficiently charged.

Claims

The scope of the claims

1. a first power supply unit for driving a load unit;

A booster for boosting an output voltage of the first power supply connected between the first power supply and the load;

A step-down unit that steps down the voltage boosted by the step-up unit,

A power supply device comprising the booster and a second power supply connected in parallel.

2. The booster has a switch for driving the booster and feeds back the output voltage of the booster, controls the switch based on the feedback result, and stabilizes the output voltage to a constant value. 2. The power supply according to claim 1, wherein the power supply is a non-insulated converter.

3. The power supply device according to claim 1, wherein the bypass circuit unit includes a diode through which a current flows only when an input voltage of the boosting unit is higher than an output voltage of the boosting unit.

4. The power supply device according to claim 1, wherein the second power supply unit includes a power storage unit that is charged by an output current of the boosting unit.

5. The second power supply unit includes: a first time setting circuit unit that sets a time period for discharging power from the second power supply unit;

2. The power supply device according to claim 1, wherein the power supply device includes a voltage variable circuit unit that changes an output voltage of the boosting unit during a time set in the second time setting circuit unit.

6. The power supply device sets the output voltage of the boosting unit to a voltage value higher than the output voltage of the second power supply unit while the second time setting circuit unit is operating. The power supply device according to claim 5.

7. The load is driven by the first power supply,

Reducing at least one of the output voltage of the first power supply unit, the boosted output voltage of the first power supply unit, and the output voltage of the second power supply unit to a voltage for driving a load unit; A power supply method for a power supply device, comprising:

8. The power supply method for a power supply device according to claim 7, further comprising charging the second power supply unit with a boosted output voltage of the first power supply unit.

9. The power supply method of the power supply device further includes setting a first time for discharging power from the second power supply unit,

Discharging power from the second power supply unit during the set first time; Setting a second time for changing the output voltage of the first power supply unit in synchronization with the start of discharge from the second power supply unit;

The power supply method for a power supply device according to claim 7, wherein the output voltage of the first power supply unit is changed during the second time.

10. The power supply method of the power supply device further includes, when starting to boost the output voltage of the first power supply unit, setting the boosted voltage to be higher than the output voltage of the second power supply unit. The power supply method for a power supply device according to claim 7, wherein