CN100490283C - Unisolated switch DC-DC power supply module, power supply device and communication device - Google Patents

Abstract

The invention relates to the technical field of electronic communication, and discloses a non-isolated switch DC-DC power supply module, including a pulse width modulation PWM generator and a voltage stabilizing conversion circuit, the voltage stabilizing conversion circuit includes a pair of transistors coupled and connected, and the PWM generator outputs a pair of PWM The signal controls the pair of transistors to selectively switch between the on-state and the off-state, so as to step down the input voltage of the power module and output it, wherein, the PWM generator configures each voltage regulation conversion circuit through the corresponding PWM signal The switching frequency of the transistor is the frequency division of the switching frequency of the transistor in the pre-stage pre-stabilization conversion circuit. The invention also discloses a power supply device and a communication device. The embodiments of the present invention can avoid reduction of circuit efficiency when a lower output voltage is provided to the load.

Description

Non-isolated switching DC-DC power modules, power supply units and communication units

technical field

The invention relates to the technical field of electronic communication, in particular to the non-isolated switch DC-DC power supply technology.

Background technique

With the continuous improvement of the integration and processing speed of VLSI such as CPU, how to design a non-isolated low-voltage high-current switching DC-DC (DC-DC) conversion power supply with a wide range of voltage input and high efficiency has become a key issue in the design of power supply circuits. One of the main tasks. Figure 1 shows a structure diagram of a non-isolated low-voltage high-current switching DC-DC conversion power supply circuit in the prior art, which includes a pulse width modulation (Pulse Width Modulation, PWM for short) generator and a multi-phase synchronous rectification step-down Voltage regulator conversion circuit (Buck circuit), the PWM generator outputs a PWM signal to control a pair of metal-oxide-semiconductor field effect transistors (hereinafter referred to as MOS transistors) in each phase of the Buck circuit and selectively conduct and switch between off states to achieve the purpose of stepping down the input voltage; in the above power supply circuit, the average value _U0 of the output voltage is:

$u_0=\frac{t_{\mathrm{on}}}{t_{\mathrm{on}}+t_{\mathrm{off}}}{V}_{\mathrm{DD}}=\frac{t_{\mathrm{on}}}{T}{V}_{\mathrm{DD}}=k{V}_{\mathrm{DD}}$ Formula 1)

Among them, t _on is the time when the MOS tube is in the on state; t _off is the time when the MOS tube is in the off state; V _DD is the input voltage of the power circuit; T=t _on +t _off is the switching period of the MOS tube; k is the conduction duty cycle of the MOS transistor (hereinafter referred to as the duty cycle).

In recent years, the input voltage required by loads such as CPUs has become lower and lower. According to the above formula (1), if a lower output voltage is to be provided in the above power supply circuit, the MOS transistor needs to be reduced when the input voltage is fixed. The duty cycle of the MOS tube is shortened, that is, the conduction time of the MOS tube is shortened, which will increase the switching loss of the MOS tube and reduce the efficiency of the circuit.

In addition, in the prior art, the operating frequency of the MOS transistors in each phase of the Buck circuit is relatively high, resulting in large switching losses and driving losses of the MOS transistors, further reducing the efficiency of the circuit.

Contents of the invention

The technical problem to be solved by the embodiments of the present invention is to provide a non-isolated switch DC-DC power supply module, a power supply device and a communication device, which can avoid the reduction of circuit efficiency when a lower output voltage is provided to the load.

In order to solve the above technical problems, embodiments of the present invention provide the following technical solutions:

A non-isolated switch DC-DC power supply module, including a pulse width modulation PWM generator and a voltage stabilization conversion circuit, the voltage stabilization conversion circuit includes a pair of coupled transistors, and the PWM generator outputs a pair of PWM signals to control the The pair of transistors are selectively switched between the on state and the off state, so as to step down the input voltage of the power module and output it, wherein, the power terminal of the power module and the voltage regulator At least one stage of pre-stage pre-stabilization conversion circuit is connected between the circuits, which is used to perform pre-stage step-down on the input voltage of the power module under the control of the corresponding PWM signal output by the PWM generator, and the pre-stage pre-stabilization The conversion circuit includes a pair of coupled transistors, an inductor and a capacitor, and the pair of transistors are selectively switched between the on state and the off state under the control of the corresponding PWM signal output by the PWM generator, and the One end of the inductor is connected to the capacitor, and the other end is coupled to the transistor pair, the capacitor is connected between the inductor and the ground, the power module includes at least two constant voltage conversion circuits, and the PWM generator passes through the corresponding PWM signal configuration The switching frequency of the transistors in each voltage stabilizing conversion circuit is the frequency division of the switching frequency of the transistors in the pre-stage pre-stabilizing conversion circuit.

A communication device, including a non-isolated switch DC-DC power supply module, the power supply module includes: a pulse width modulation PWM generator and a voltage stabilization conversion circuit, the voltage stabilization conversion circuit includes a pair of coupled transistors, the PWM The generator outputs a pair of PWM signals to control the pair of transistors to selectively switch between the on state and the off state, so as to step down the input voltage of the power module and output it, wherein, in the power module At least one pre-stage pre-stabilization conversion circuit is connected between the power supply terminal of the power supply terminal and the voltage stabilization conversion circuit, which is used to step down the input voltage of the power supply module under the control of the corresponding PWM signal output by the PWM generator. voltage, the pre-stage pre-regulated conversion circuit includes a pair of coupled transistors, an inductor and a capacitor, and the pair of transistors are selectively in the conduction state and under the control of the corresponding PWM signal output by the PWM generator. Switching between off states, one end of the inductor is connected to a capacitor, the other end is coupled to the transistor pair, the capacitor is connected between the inductor and ground, and the power module includes at least two voltage-stabilizing conversion circuits The PWM generator configures the switching frequency of the transistors in each voltage-stabilizing conversion circuit through the corresponding PWM signal to be the frequency division of the switching frequency of the transistors in the pre-stage pre-stabilizing conversion circuit.

A power supply device, including a non-isolated switch DC-DC power supply module, the power supply module includes: a pulse width modulation PWM generator and a voltage stabilization conversion circuit, the voltage stabilization conversion circuit includes a pair of coupled transistors, the PWM The generator outputs a pair of PWM signals to control the pair of transistors to selectively switch between the on state and the off state, so as to step down the input voltage of the power module and output it, wherein, in the power module At least one pre-stage pre-stabilization conversion circuit is connected between the power supply terminal of the power supply terminal and the voltage stabilization conversion circuit, which is used to step down the input voltage of the power supply module under the control of the corresponding PWM signal output by the PWM generator. voltage, the pre-stage pre-regulated conversion circuit includes a pair of coupled transistors, an inductor and a capacitor, and the pair of transistors are selectively in the conduction state and under the control of the corresponding PWM signal output by the PWM generator. Switching between off states, one end of the inductor is connected to a capacitor, the other end is coupled to the transistor pair, the capacitor is connected between the inductor and ground, and the power module includes at least two voltage-stabilizing conversion circuits The PWM generator configures the switching frequency of the transistors in each voltage-stabilizing conversion circuit through the corresponding PWM signal to be the frequency division of the switching frequency of the transistors in the pre-stage pre-stabilizing conversion circuit.

As can be seen from the above technical solutions, the embodiments of the present invention have the following beneficial effects:

By adding a pre-stage pre-stabilization conversion circuit between the power supply terminal of the power module and the voltage stabilization conversion circuit that supplies power to the load, the input voltage of the voltage stabilization conversion circuit is reduced. According to formula (1), when it is necessary to provide a higher voltage to the load When the output voltage is low, since both the input voltage and the output voltage are reduced, the impact on the duty cycle of the transistor in the voltage stabilizing conversion circuit is very small; while in the prior art, a lower output voltage needs to be provided to the load When , since the input voltage is fixed (provided by the power terminal of the power module), it is necessary to reduce the duty cycle of the transistor; therefore, when a lower output voltage is provided to the load, compared with the prior art, the embodiment of the present invention can avoid The reduction of the duty cycle of the transistor in the voltage stabilizing conversion circuit avoids the increase of the switching loss of the transistor and the reduction of the circuit efficiency.

Description of drawings

Fig. 1 is a structural diagram of a non-isolated low-voltage high-current switch DC-DC conversion power supply circuit in the prior art;

2 is a structural diagram of a non-isolated switch DC-DC power supply module according to an embodiment of the present invention;

3 is a schematic diagram of the phase relationship between each phase voltage stabilization conversion circuit and the pre-stage pre-stabilization conversion circuit MOS tube switching frequency in Embodiment 1 of the present invention;

FIG. 4 is a structural diagram of a non-isolated switch DC-DC power supply module according to Embodiment 2 of the present invention;

Fig. 5 is a structural diagram of a non-isolated switch DC-DC power supply module according to Embodiment 3 of the present invention;

Fig. 6 is a structural diagram of a non-isolated switch DC-DC power supply module according to Embodiment 4 of the present invention.

Detailed ways

The invention provides a non-isolated switch DC-DC power supply module, a power supply device and a communication device, and the embodiments of the modules and devices are described in detail below.

Embodiment 1. A non-isolated switch DC-DC power supply module, referring to FIG. 2 , includes a PWM generator 100, a voltage stabilization conversion circuit group 200 and a pre-stage pre-regulation conversion circuit 300;

The pre-stage pre-stabilization conversion circuit 300 includes a pair of MOS tubes 301 and 302, an inductor 310 and a capacitor 320; the drain of the MOS tube 301 is connected to the power terminal V _DD of the power module; the MOS tube 302 The drain is connected to the source of the MOS transistor 301, and its source is connected to the ground; one end of the inductor 310 is connected to the capacitor 320, and the other end is coupled and connected to the source of the MOS transistor 301 and the drain of the MOS transistor 302; The capacitor 320 is connected between the inductor 310 and ground;

The structure of each voltage-stabilizing conversion circuit in the voltage-stabilizing conversion circuit group 200 is the same as that of the pre-stage pre-regulated voltage conversion circuit 300, and also includes a pair of MOS transistors 201 and 202, an inductor 210 and a capacitor 220, each The connection between the elements is similar to the pre-stage pre-stabilization conversion circuit 300, the difference is that the drain of the MOS tube 201 is coupled with the inductor 310 and the capacitor 320 of the pre-stage pre-stabilization conversion circuit 300;

The PWM generator 100 outputs a PWM signal to the gates of the MOS transistors (201, 202, 301 and 302) in the voltage stabilizing conversion circuit 200 and the pre-stage pre-stabilizing conversion circuit 300 to control the conduction of each MOS transistor. To switch between the off state, each pair of MOS transistors in the voltage stabilization conversion circuit 200 and the pre-stage pre-stabilization conversion circuit 300 is set to a different state;

The working principle of the pre-stabilization conversion circuit 300 in this embodiment is the same as that of the voltage stabilization conversion circuit, mainly through the PWM signal output by the PWM generator to control the MOS transistor pairs 301 and 302 in the circuit selectively. switch between the on and off states to achieve the purpose of stepping down the input voltage of the circuit; specifically, when the MOS transistor 301 is turned on, the MOS transistor 302 is turned off, and the current flows from V _DD through the MOS transistor 301 and the inductor 310 to charge the capacitor 320; when the MOS tube 301 is turned off, the MOS tube 302 is turned on to provide a freewheeling path for the current to discharge the capacitor 320;

In this embodiment, the capacitors of the voltage stabilization conversion circuits in the voltage stabilization conversion circuit group 200 are connected in parallel to each other to supply power to the load to form a multi-phase voltage stabilization conversion circuit, which can generate a larger output current with higher efficiency. ; Wherein, the PWM generator configures the voltage-stabilizing transformation circuits of each phase to work in different phases with each other through the corresponding PWM signal, and can configure the switching frequency of the MOS tube in the voltage-stabilizing transformation circuit of each phase to be the pre-stage pre-stabilizing transformation circuit The N frequency division of the switching frequency of the MOS tube in the middle, and the conduction state of the MOS tube in the voltage stabilization conversion circuit of each phase is alternately synchronized with the conduction state of the MOS tube in the pre-stage pre-regulation conversion circuit, where N is equal to the stability The sum of the number of voltage conversion circuits; for example, if the voltage stabilization conversion circuit group 200 forms a 4-phase voltage stabilization conversion circuit, if the switching frequency of the MOS tube in the pre-stage pre-stabilization conversion circuit is f, then each phase voltage stabilization conversion The switching frequency of the MOS tube in the circuit is divided by 4 of f, that is, f/4. The voltage stabilization and conversion circuits of each phase work in different phases, and the conduction state of the MOS tube in each phase circuit is alternately with the pre-stabilized state of the previous stage. The conduction state of the MOS transistors in the voltage conversion circuit is synchronized, and the phase relationship between the voltage stabilization conversion circuit of each phase and the switching frequency of the MOS transistors of the pre-stage pre-regulation conversion circuit can be referred to in FIG. 3 .

Embodiment 2. A non-isolated switch DC-DC power supply module. Referring to FIG. 4, this embodiment is basically the same as Embodiment 1, the main difference is that in this embodiment, each voltage regulator in the voltage stabilization conversion circuit group The conversion circuit outputs separately to form a multi-channel voltage-stabilizing conversion circuit, which can supply power to multiple loads respectively; similar to Embodiment 1, the PWM generator can also configure each voltage-stabilizing conversion circuit to work in different phases with each other through the corresponding PWM signal , and can configure the switching frequency of the MOS tube in each voltage-stabilizing conversion circuit to be N divided by the switching frequency of the MOS tube in the pre-stage pre-stabilizing conversion circuit, and make the conduction state of the MOS tube in each voltage-stabilizing conversion circuit Alternately synchronizing with the conduction state of the MOS transistor in the pre-stage pre-stabilization conversion circuit, wherein, N is equal to the sum of the number of voltage stabilization conversion circuits.

Embodiment 3. A non-isolated switch DC-DC power supply module. Referring to FIG. 5, this embodiment is basically the same as Embodiment 1, the main difference is: in this embodiment, there are some stabilizing The voltage conversion circuit forms a multi-phase voltage stabilization conversion circuit and then outputs, thus forming a multi-phase multi-channel voltage stabilization conversion circuit; similar to Embodiment 1, the PWM generator can also configure each voltage stabilization conversion circuit in different phases through the corresponding PWM signal. It works under the following conditions, and can configure the switching frequency of the MOS transistors in each circuit to be the N frequency division of the switching frequency of the MOS transistors in the pre-stage pre-stabilization conversion circuit, and make the conduction state of the MOS transistors in each voltage stabilization conversion circuit Alternately synchronizing with the conduction state of the MOS transistor in the pre-stage pre-stabilization conversion circuit, wherein, N is equal to the sum of the number of voltage stabilization conversion circuits.

In the above embodiments of the present invention, the PWM generator can output a PWM signal with a fixed duty ratio to the voltage stabilizing conversion circuit or the pre-stage pre-stabilizing conversion circuit according to the needs of the actual situation, and can also output the PWM signal to the stable voltage The output voltage of the voltage conversion circuit or the pre-stage pre-stabilization conversion circuit is detected, and the duty cycle of the PWM signal output to the voltage stabilization conversion circuit or the previous-stage pre-stabilization conversion circuit is adjusted according to the detection result, so as to The output voltage of the voltage stabilizing transformation circuit or the pre-stage pre-stabilizing transformation circuit is adjusted.

In more embodiments of the power module of the present invention, at least one path of the electrical signal that has been stepped down by the pre-stage pre-stabilization conversion circuit can also be divided and output directly to supply power to other power modules.

In the above embodiments of the present invention, a one-stage pre-stage pre-stabilization conversion circuit is used for illustration. In more embodiments of the power module of the present invention, it is also possible to consider the need to use two or more stages of multi-stage pre-voltage conversion circuits according to actual conditions. Stage pre-regulation conversion circuit.

Embodiment 4. A non-isolated switch DC-DC power supply module. Referring to FIG. 6, this embodiment is similar to Embodiment 1, the main difference is that in this embodiment, two stages of pre-stage pre-stabilization conversion circuits are used, each The structure of the pre-stage pre-stabilization transformation circuit is basically the same as that of the pre-stage pre-stabilization transformation circuit described in the above embodiment, the difference is:

The drain of the MOS transistor 401 of the pre-stage pre-stabilization conversion circuit 400 is connected to the power supply terminal V _DD of the power module; The inductor 410 and the capacitor 420 of 400 are coupled and connected, that is, the voltage output by the pre-stage pre-stabilization conversion circuit of the previous stage is used as the input voltage of the pre-stage pre-stabilization conversion circuit of the subsequent stage;

The PWM generator 600 outputs PWM signals to the gates of the MOS transistors in the pre-stage pre-regulated voltage conversion circuit 400 and the pre-stage pre-regulated voltage conversion circuit 500 to control each MOS transistor to switch between on and off states, and configure The conduction state of the MOS transistor in the pre-stage pre-stabilization conversion circuit 400 is synchronized with the conduction state of the MOS transistor in the pre-stage pre-regulation conversion circuit 500 .

In more embodiments of the power module of the present invention, other switching transistors other than MOS tubes, such as bipolar transistors (BJT) or Insulated Gate Bipolar Transistor (IGBT), etc.

An embodiment of the present invention also provides a communication device, which may include the non-isolated switch DC-DC power module described in any of the power module embodiments above.

An embodiment of the present invention also provides a power supply device, which may include the non-isolated switch DC-DC power supply module described in any of the above power module embodiments.

In the above-mentioned embodiments of the present invention, the input voltage of the voltage-stabilizing conversion circuit is reduced by adding a pre-stage pre-stabilizing conversion circuit between the power supply terminal of the power supply module and the voltage-stabilizing conversion circuit supplying power to the load, according to the formula (1 ), when it is necessary to provide a lower output voltage to the load, since both the input voltage and the output voltage are reduced, the impact on the duty cycle of the transistor in the voltage stabilizing conversion circuit is very small; and in the prior art, it is necessary to provide When the load provides a lower output voltage, since the input voltage is fixed (provided by the power terminal of the power module), it is necessary to reduce the duty cycle of the transistor; therefore, when providing a lower output voltage to the load, compared with the existing technology , the embodiment of the present invention can avoid the reduction of the duty cycle of the transistor in the voltage stabilizing conversion circuit, thereby avoiding the increase of the switching loss of the transistor and the reduction of the circuit efficiency;

In addition, adding a pre-stage pre-stabilization conversion circuit between the power supply terminal of the power module and the voltage stabilization conversion circuit can also achieve the effect of increasing the input voltage range of the power module; taking the supply voltage of 1V to the load as an example, if the transistor The working duty cycle range is 20%-50%. According to the formula (1), when there is no pre-stage pre-regulation conversion circuit, the input voltage range of the power module is 2V-5V; and the pre-stage pre-regulation conversion circuit is added Finally, the input voltage range of the power module can reach 4V-25V.

The non-isolated switch DC-DC power supply module, power supply device and communication device provided by the present invention have been introduced in detail above. In this paper, specific examples are used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only used To help understand the method and its ideas of the present invention; at the same time, for those of ordinary skill in the art, according to the ideas of the present invention, there will be changes in the specific implementation and scope of application. In summary, the content of this specification It should not be construed as limiting the invention.

Claims (6)

1, a kind of Unisolated switch DC-DC power supply module, comprise pulse-width modulation PWM generator and voltage stabilizing translation circuit, described voltage stabilizing translation circuit comprises a pair of transistor that is of coupled connections, described PWM generator is exported a pair of pwm signal and is controlled this transistor is optionally switched between conducting state and off state, carry out exporting after the step-down with input voltage to described power module, it is characterized in that, between the power supply terminal of described power module and described voltage stabilizing translation circuit, connect the pre-voltage stabilizing translation circuit of one-level prime at least, be used for that the input voltage to described power module carries out the prime step-down under the control of the corresponding pwm signal of PWM generator output, the pre-voltage stabilizing translation circuit of described prime comprises a pair of transistor that is of coupled connections, one inductor and a capacitor, this optionally switches between conducting state and off state under the corresponding pwm signal control of described PWM generator output transistor, described inductor one end is connected with capacitor, the other end and described transistor are to being of coupled connections, described capacitor is connected between inductor and the ground, described power module comprises at least two voltage stabilizing translation circuits, and the pwm signal of described PWM generator by correspondence disposes that transistorized switching frequency is the frequency division of transistorized switching frequency in the pre-voltage stabilizing translation circuit of prime in each voltage stabilizing translation circuit.

2, Unisolated switch DC-DC power supply module as claimed in claim 1, it is characterized in that, described PWM generator, be used for by correspondence the transistorized conducting state of pwm signal described each the voltage stabilizing translation circuit of configuration alternately with the pre-voltage stabilizing translation circuit of prime in transistorized conducting state synchronous.

3, Unisolated switch DC-DC power supply module as claimed in claim 1 or 2 is characterized in that, the pwm signal that described PWM generator outputs to the pre-voltage stabilizing translation circuit of prime is the fixing pwm signal of duty ratio.

4, as claim 1 or 2 each described Unisolated switch DC-DC power supply modules, it is characterized in that, described PWM generator, be further used for the duty ratio of the pwm signal that outputs to the pre-voltage stabilizing translation circuit of prime is adjusted, described adjustment is to carry out according to the testing result of the voltage that is obtained after the step-down of the pre-voltage stabilizing translation circuit of prime.

5, a kind of communicator, comprise Unisolated switch DC-DC power supply module, described power module comprises: pulse-width modulation PWM generator and voltage stabilizing translation circuit, described voltage stabilizing translation circuit comprises a pair of transistor that is of coupled connections, described PWM generator is exported a pair of pwm signal and is controlled this transistor is optionally switched between conducting state and off state, carry out exporting after the step-down with input voltage to described power module, it is characterized in that, between the power supply terminal of described power module and described voltage stabilizing translation circuit, connect the pre-voltage stabilizing translation circuit of one-level prime at least, be used for that the input voltage to described power module carries out the prime step-down under the control of the corresponding pwm signal of PWM generator output, the pre-voltage stabilizing translation circuit of described prime comprises a pair of transistor that is of coupled connections, one inductor and a capacitor, this optionally switches between conducting state and off state under the corresponding pwm signal control of described PWM generator output transistor, described inductor one end is connected with capacitor, the other end and described transistor are to being of coupled connections, described capacitor is connected between inductor and the ground, and described power module comprises at least two voltage stabilizing translation circuits; The pwm signal of described PWM generator by correspondence disposes that transistorized switching frequency is the frequency division of transistorized switching frequency in the pre-voltage stabilizing translation circuit of prime in each voltage stabilizing translation circuit.

6, a kind of supply unit, comprise Unisolated switch DC-DC power supply module, described power module comprises: pulse-width modulation PWM generator and voltage stabilizing translation circuit, described voltage stabilizing translation circuit comprises a pair of transistor that is of coupled connections, described PWM generator is exported a pair of pwm signal and is controlled this transistor is optionally switched between conducting state and off state, carry out exporting after the step-down with input voltage to described power module, it is characterized in that, between the power supply terminal of described power module and described voltage stabilizing translation circuit, connect the pre-voltage stabilizing translation circuit of one-level prime at least, be used for that the input voltage to described power module carries out the prime step-down under the control of the corresponding pwm signal of PWM generator output, the pre-voltage stabilizing translation circuit of described prime comprises a pair of transistor that is of coupled connections, one inductor and a capacitor, this optionally switches between conducting state and off state under the corresponding pwm signal control of described PWM generator output transistor, described inductor one end is connected with capacitor, the other end and described transistor are to being of coupled connections, described capacitor is connected between inductor and the ground, and described power module comprises at least two voltage stabilizing translation circuits; The pwm signal of described PWM generator by correspondence disposes that transistorized switching frequency is the frequency division of transistorized switching frequency in the pre-voltage stabilizing translation circuit of prime in each voltage stabilizing translation circuit.

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