KR101029127B1 - Power Supply - Google Patents

Abstract

The present invention relates to a power supply for converting an input power source into a voltage of various sizes to supply power of a voltage required for each part of the system. The present invention includes a plurality of parallel connected switching regulators (20) and series regulators (30) to supply a predetermined DC power (DC) obtained by converting and rectifying the input power into voltages of various magnitudes to each part of the system. The power supply device further includes one or more pressure reducing regulators 40 connected in series with the series regulator 30 to reduce the voltage of the power input to the series regulator 30. According to the present invention, by providing a high efficiency power supply device there is an advantage that can prevent unnecessary power consumption and extend the battery life.

Power Supplies, Regulators, DC / DC Converters, LDO Regulators

Description

Power Supply

1 is a block diagram showing the configuration of a power supply according to the prior art.

Figure 2 is a block diagram showing the configuration of a power supply according to a specific embodiment of the present invention.

3 is a simple circuit diagram showing a basic configuration of a DC / DC converter and an LDO regulator in a power supply according to a specific embodiment of the present invention.

Figure 4 is a block diagram showing the configuration of a power supply according to another embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

10: power supply 20: switching regulator

30: Series Regulator 35: Series Regulator Group

40: pressure reducing regulator 50: switching element

60: switching control means 70: smoothing circuit

The present invention relates to a power supply for converting an input power source into a voltage of various sizes to supply power of a voltage required for each part of the system.

1 is a block diagram showing the configuration of a power supply apparatus according to the prior art. As shown therein, the conventional power supply 10 includes a plurality of switching regulators 20 and a plurality of series regulators to supply power of an appropriate voltage to each module in the system. do.

In the drawing, the switching regulator 20 is a DC / DC converter, and the series regulator 30 is provided with a low voltage drop regulator.

In this case, the series regulator 30 has an advantage of outputting a constant voltage with low ripple, and thus, if there is a sensitive device or module that needs to be supplied with stable power in the system, it should be provided in the power supply device.

However, the series regulator 30 has a high loss power and low efficiency. Therefore, when a plurality of series regulators 30 are provided in the power supply device 10, power consumption increases rapidly.

The series regulator 30 loses power as the difference between the input voltage and the output voltage of the series regulator 30 increases, so that when a high input voltage is directly supplied to the series regulator 30 as in the related art, power loss occurs. This was even bigger.

Recently, the use of portable electronic devices powered by batteries, such as mobile phones, PDAs (Portable Digital Assistants), notebook computers, portable game consoles, digital cameras, MP3 players, and portable multimedia players (PMP) With this rapid increase, battery efficiency of portable electronic devices has become a very important problem.

Although it is desirable to reduce power consumption even in electronic devices that have been used with a conventional AC power source, especially in the case of portable electronic devices, the use of the user is limited when the battery life is exhausted. Therefore, unnecessary power consumption should be further minimized in the portable electronic devices.

Therefore, according to the prior art as described above, there is a problem in that unnecessary power consumption is large in the process of transforming the input voltage by the battery in a portable electronic device driven by the battery.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, an object of the present invention is to provide a power supply device with low power consumption when changing the voltage.

According to a feature of the present invention for achieving the above object, the present invention provides a plurality of DC power supply (DC) obtained by converting and rectifying the input power to a voltage of various magnitudes to supply each part of the system a plurality of A switching regulator and a series regulator connected in parallel; In order to reduce the difference between the input voltage and the output voltage of the series regulator is configured to include one or more pressure reducing regulator in series with the series regulator and for reducing the voltage of the power input to the series regulator.

The series regulator may be classified into one or more series regulator groups including one or more series regulators, and the pressure reducing regulator may be provided for each group.

In addition, the pressure reducing regulator may be a BUCK regulator.

Wherein the pressure reducing regulator comprises a switching element; Switching control means for controlling the switching element; It may be configured to include a smoothing circuit for smoothing the output voltage of the switching device.

On the other hand, the switching control means may be a PWM (Pulse Width Modulation) comparator.

The smoothing circuit includes an inductor and a capacitor; And a diode for regenerating counter electromotive force of the inductor when the switching element is open.

In addition, the power supply device may be configured as an integrated circuit device.

The inductor may be detachably provided to the outside of the integrated circuit device.

The switching device may be a Bipolar Junction Transistor (BJT) or a MOS Field Effect Transistor (MOS-FET).

According to the present invention having the configuration as described above, there is an advantage that it is possible to prevent unnecessary power consumption and extend battery life by providing a high efficiency power supply.

Hereinafter, with reference to the accompanying drawings a specific embodiment of the power supply apparatus according to the present invention as described above will be described in detail.

2 is a block diagram showing the configuration of a power supply according to a specific embodiment of the present invention, Figure 3 is a basic configuration of a DC / DC converter and LDO regulator in a power supply according to a specific embodiment of the present invention 4 is a block diagram showing the configuration of a power supply apparatus according to another embodiment of the present invention.

As shown in FIG. 2, the power supply device 10 according to the present invention includes a plurality of switching regulators 20 and a series regulator 30 that adjust voltages according to voltages required for each part of the system.

At this time, the switching regulator 20 is a regulator of the voltage of the input power source using a switching element such as a transistor or a diode in the form of a pulse, and by using an inductor and a capacitor to smoothly to a substantially constant voltage to transfer to the load. .

The switching regulator 20 may be one of various switching regulator types according to the above-described method, or may be a DC / DC converter. In the present specification, an embodiment in which a DC / DC converter is applied as shown in FIG. 2 will be described.

On the other hand, the series regulator 30 is a regulator in which the power input is passed through and the output side is connected in series. In addition, the series regulator 30 may be one of various series regulators according to the above-described method, or may be an LDO regulator. In the following description, an embodiment to which an LDO regulator is applied will be described.

As shown in the figure, the switching regulator 20 and the series regulator 30 convert a voltage according to a voltage required for each part of a system and serve to supply the same.

In other words, the voltage required for each module, such as a control unit, a storage unit, or an input unit, is different within one electronic device. Therefore, the switching regulator 20 and the series regulator 30 change one input voltage to several voltages in order to supply power by a voltage suitable for each module.

In this case, the series regulator 30 is generally lower in efficiency than the switching regulator 20, but has a feature of less ripple in the output voltage. Therefore, the series regulator 30 is provided with the switching regulator 20 in the power supply device to supply a stable voltage to a more sensitive system module.

Meanwhile, a pressure reducing regulator 40 for reducing the voltage input to the series regulator 30 is provided. The pressure reducing regulator 40 is composed of a series regulator of high efficiency. The DC / DC converter may be configured as shown in the figure among various series regulator types.

As such, the reason why the input voltage of the series regulator 30 is lowered and supplied to the pressure reducing regulator 40 close to the output voltage is because the series regulator 30 reduces the difference between the input voltage and the output voltage of the series regulator 30. To increase the efficiency of.

That is, since the power lost by the series regulator 30 will be (input voltage-output voltage) * current, the smaller the difference between the input voltage and the output voltage, the less power is lost and thus the higher the efficiency.

However, all regulators must have a difference between the input voltage and the output voltage at least greater than the drop-out voltage, wherein the drop-out voltage is the minimum input voltage and output required to maintain the output voltage level at a constant level. The difference in voltage. In the case of an LDO regulator, the dropout voltage is between 0.2V and 0.3V, but in the case of other regulators, it generally has a dropout voltage of 2V or more.

Therefore, the input voltage should be reduced close to the output voltage, but should be reduced in consideration of the dropout voltage.

The decompression regulator 40 may be provided for each series regulator group 35. That is, since the series regulator 30 is provided in the power supply device 10, it can be classified into several groups according to the output voltage level.

The series regulators 30 having similar levels of output voltages are classified into the same group, and the decompression regulator 40 which supplies an appropriate input voltage for each group is connected in series.

For example, as shown in the drawing, the series regulators 30 having output voltage levels of 1.8 V, 1.5 V, and 1.2 V are grouped into one series regulator group 35, and in the series regulator group 35. In the series regulators 30 connected in parallel to each of the series of the pressure-sensitive regulator 40 having an output level of 2V to supply the input voltage of 2V to the series regulator group 35.

As shown in the drawing, the series regulator 30 having an output voltage of 3.25V connects the decompression regulator 40 having an output voltage of 3.4V.

As such, when the series regulator 30 is connected to the series regulator group 35 to connect the decompression regulator 40, the power generated by the series regulator 30 through the minimum number of decompression regulators 40 is connected. The loss can be reduced.

Here, the process of supplying the reduced pressure input voltage by serially connecting the decompression regulator 40 to the series regulator 30 will be described in more detail with reference to the circuit diagram shown in FIG. 3.

In FIG. 3, the pressure reducing regulator 40 is configured as a BUCK regulator. The BUCK regulator is a kind of switching regulator as a switching step-down regulator. In addition, the series regulator 30 will be described as a case consisting of an LDO regulator.

The pressure reducing regulator 40 is composed of a switching element 50, the switching control means 60, and the smoothing circuit (70). The switching device 50 may be provided as a transistor Q1 as shown in the figure. In this case, the transistor Q1 may be a Bipolar Junction Transistor (BJT) or a MOS Field Effect Transistor (MOS-FET).

The switching device 50 receives an input voltage Vin1 of the decompression regulator 40 to generate a pulse voltage such as a square wave through switching.

At this time, the switching element 50 periodically repeats the open and close states in order to convert the input voltage Vin1 into a pulse voltage. The repetition period and the time ratio of the open state and the close state are the switching control means 60. This regulates.

In a specific embodiment of the present invention, the switching control means 60 includes a PWM (Pulse Width Modulation) comparator. The PWM comparator Xcomp divides the output voltage Vout1 of the decompression regulator 40 into a voltage divider by two resistors R1 and R2 and compares it with a reference voltage Vref1 to switch the device 50. To control.

At this time, the reference voltage Vref1 is maintained at a constant voltage by a Zener diode D2, which is compared with the output voltage Vout1 of the decompression regulator 40 by the switching control means 60. Used to adjust the output voltage Vout1.

On the other hand, the voltage modulated to the pulse voltage by the switching element 50 is smoothed to a substantially constant voltage value through the smoothing circuit 70. That is, the inductor L and the capacitor C of the smoothing circuit act as a low pass filter (LPF) to change the pulse voltage to an average value of the pulse voltage.

That is, when the switching element 50 is in the open state, the energy stored in the inductor L and the capacitor C is supplied to the output side while being in the close state, and is maintained at a constant voltage.

The diode D1 in the smoothing circuit 70 serves to regenerate back EMF generated in the inductor L when the switching device 50 is in an open state.

Here, when the switching period of the switching device 50 is T and the time when the switching device 50 is in the close state within one period is Ton, the output voltage (B) by the smoothing circuit 70 Vout1) has the same value as the following equation.

In the above formula Vin1 is the input voltage value of the decompression regulator 40.

Accordingly, the output voltage Vout1 may be adjusted to be close to a desired value by adjusting the Ton and T values. In this case, although the Ton may be fixed and the T value may be adjusted, in general, when the T value is fixed and the Ton value is adjusted, it is easier to smooth the pulse voltage in the smoothing circuit 70.

The Ton / T value is referred to as Duty Ratio.

The PWM comparator Xcomp of the switching control means 60 compares the output voltage Vout1 with the reference voltage Vref1, and when the output voltage Vout1 is lower than a desired voltage, the switching control means 60. ) Increases the Duty Ratio and adjusts the voltage in such a way that the switching control means 60 decreases the Duty Ratio if the output voltage Vout2 is higher than the desired voltage.

The output voltage Vout1 becomes the input voltage Vin2 of the series regulator 30. At this time, the series regulator 30 is an LDO regulator as shown in the figure, and a pass transistor Q2 is provided on an input side. The voltage across the pass transistor Q2 is changed to maintain a constant output voltage. .

On the other hand, the series regulator 30 is provided with operational amplifiers (Op-Amp, X), the reference voltage (Vref2) is connected to the non-inverting terminal of the operational amplifier (X). The reference voltage Vref2 is supplied at a constant value by a zener diode or the like.

The inverting terminal of the operational amplifier X is connected to a voltage obtained by properly dividing the output voltage Vout2 of the series regulator 30 in a voltage divider consisting of resistors R3 and R4.

Accordingly, the operational amplifier X compares the divided voltage values of the reference voltage Vref2 and the output voltage Vout2 connected to the non-inverting terminal and the inverting terminal and calculates an error voltage.

The transistor Q3 is turned on / off so that the error voltage output from the operational amplifier X is close to zero, and the output transistor Vout2 is adjusted as the pass transistor Q2 is turned on / off.

According to the above principle, the voltage supplied from the power supply is reduced twice, thereby increasing the overall efficiency.

The power supply device 10 according to a specific embodiment of the present invention as described above may be configured as an integrated circuit device, the switching regulator according to the type of electronic device to be provided with the power supply device (10). The number or type of the 20 or the series regulator 30 and the pressure reducing regulator 40 may be varied.

In addition, since the circuit shown in FIG. 3 is a simple circuit diagram and is only one example of supplying the first reduced voltage to the series regulator 30, the circuit is designed on the assumption that each device is ideal. The design can be made in consideration of the characteristics of the device, the characteristics of each device, and the economics and safety of the circuit design.

On the other hand, the power supply device according to another embodiment of the present invention, as shown in Figure 4, the overall configuration is the same as the power supply device according to a specific embodiment of the present invention, in particular the smoothing circuit of the pressure reducing regulator 40 There is a difference in that inductors L1 and L2 provided in 70 are provided outside the integrated circuit device and are detachable.

In more detail, when the inductors L1 and L2 of the smoothing circuit 70 are provided in the integrated circuit device, the inductors L1 and L2 are provided as stacked chip inductors.

Since the chip inductor is made compact for an integrated circuit, the cross section of the internal winding is very small. Therefore, the DC resistance value Rdc becomes large and the Q value Q-factor deteriorates.

Therefore, as described above, when the inductors L1 and L2 are provided outside the integrated circuit device, an inductor having a larger internal cross-sectional area, a smaller DC resistance value Rdc, and an excellent Q value can be connected. This can reduce the power lost in the circuit.

When the power loss in the inductors (L1, L2) of the decompression regulator 40 is expressed by a specific equation as follows.

는 상기 감압 레귤레이터(40)의 손실 전력이고, I는 상기 인덕터(L1, L2)에 흐르는 전류값이며,

는 상기 인덕터(L1, L2)에 발생하는 리플 전류, Rdc는 상기 인덕터(L1, L2)의 직류저항값이고, Rac는 상기 인덕터(L1, L2)의 교류저항값이다.here

Is the loss power of the decompression regulator 40, I is the current value flowing through the inductors (L1, L2),

Is a ripple current generated in the inductors L1 and L2, Rdc is a DC resistance value of the inductors L1 and L2, and Rac is an AC resistance value of the inductors L1 and L2.

According to the above equation, since it increases in proportion to the DC resistance value Rdc, the DC resistance values Rdc of the inductors L1 and L2 are decreased to increase the efficiency of the pressure reduction regulator 40.

Meanwhile, in the above equation, the AC resistance values Rac of the inductors L1 and L2 are as follows.

Where f is the frequency, L is the inductance of the inductor, and Q is the Q value of the inductor.

As shown in the equation, the AC resistance value Rac has a larger Q value and a smaller Rdc value. However, since the influence of Rdc is insignificant, in conclusion, the above two equations are summed up. The efficiency of) can be seen.

Therefore, the inductors L1 and L2 are provided outside the integrated circuit device so as to connect an inductor having a small DC resistance value Rdc.

In addition, the inductors L1 and L2 are detachably provided outside the integrated circuit device, so that the inductors L1 and L2 can be appropriately changed into inductors having the necessary inductance and DC resistance value according to the circuit design.

The rights of the present invention are not limited to the embodiments described above, but are defined by the claims, and those skilled in the art can make various modifications and adaptations within the scope of the claims. It is self-evident.

In the power supply device according to the present invention as described above in detail can be expected the following effects.

In other words, by providing a high efficiency power supply, there is an advantage that can prevent unnecessary power consumption and extend the battery life.

In addition, the power supply device according to the present invention has an advantage that an optimal circuit design can be achieved by providing an inductor in a regulator outside the integrated circuit device.

Claims (9)

A plurality of parallel-connected switching regulators and series regulators for supplying a predetermined DC power (DC) obtained by converting and rectifying the input power into voltages of various magnitudes to each part of the system; And at least one pressure reducing regulator connected in series with the series regulator and reducing the voltage of the power input to the series regulator in order to reduce the difference between the input voltage and the output voltage of the series regulator. The method of claim 1, The series regulator, And one or more series regulators including one or more series regulators, wherein the pressure reducing regulator is provided for each group. The method according to claim 1 or 2, The pressure reduction regulator, Power supply characterized by a BUCK regulator. The method of claim 3, wherein The pressure reduction regulator, A switching element; Switching control means for controlling the switching element; And And a smoothing circuit for smoothing the output voltage of the switching element. The method of claim 4, wherein The switching control means, Pulse width modulation (PWM) comparator. The method of claim 4, wherein The smoothing circuit, Inductors and capacitors; And And a diode for regenerating counter electromotive force of the inductor when the switching element is open. The method of claim 6, The power supply device, A power supply comprising an integrated circuit device. The method of claim 7, wherein The inductor is, And a power supply device detachably provided to the outside of the integrated circuit device. The method of claim 4, wherein The switching device, A power supply characterized as a Bipolar Junction Transistor (BJT) or a MOS Field Effect Transistor (MOS-FET).

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