TWI411210B - Freewheel charge-pump controlled single-inductor multiple-output dc-dc converter - Google Patents

Abstract

This present invention disclose a freewheel charge-pump controlled single-inductor multiple-output DC-DC converter. The single-inductor multiple-output (SIMO) DC-DC converter is comprising a single-inductor multiple-output (SIMO) converting circuit and a controlling circuit. The SIMO converting circuit is further including at least one charge-pump where a charge storage device is included. By means of the charge storage function, in the state of pulse-frequency width modulation (PWM) switching, an added DC-DC output can be derived. The present invention provides the freewheel charge-pump control technique (FCPC) that leads the SIMO DC-DC converter to operate in the pseudo-continuous conduction mode (PCCM) and discontinuous conduction mode (DCM) by time-multiplexing control. A better crossover regulation and higher output current can be achieved.

Description

Single Inductor Multiple Output DC Converter with Charge Pump Control

The present invention relates to a single inductor multiple output DC converter with charge pump control, and more particularly to a DC to DC converter using a forward conduction charge pump to control multiple outputs.

With the rapid development of consumer electronic products, especially in the demand for portable small devices, such as personal digital assistants (PDAs), mobile phones, digital cameras, etc., for the circuit design of electronic devices, the orientation High-density system layout has become a necessary trend, and reducing the number of electronic components as much as possible has become one of the goals pursued by wafer design. High-efficiency DC-to-DC converters have always played an important role in improving the power management of portable devices and how to increase battery usage. Therefore, how to design a power converter with small size, high efficiency and low input voltage has become a major challenge in the design.

In the DC-to-DC conversion circuit, the phenomenon of crossover distortion persists. Many of the literatures published in previous research, papers, products, or patents are often devoted to reducing the phenomenon of crossover distortion, or using various methods to reduce The effect of crossover distortion; especially in the DC-to-DC voltage converter circuit, since the relationship between voltage and current is not linear, when the input voltage is low, the output voltage has a dead zone, and the output voltage of this section is The input voltage forms a nonlinear relationship, creating a problem of crossover regulation.

For DC voltage conversion circuits, single-inductor multiple-output architectures continue to receive attention due to their high conversion efficiency; single-inductor and multi-output DC voltage conversion circuits can be divided into two major categories, which are divided into single The single energizing cycle per swing period and the multiple energizing cycle per swing period, the former such as Taiwan patent TW508869, US patent US 6075295, under this circuit architecture. In order to meet the demand that the load can change with the demand, complex control circuits composed of complex control theory are often needed to control, so it is difficult to reduce the cost. For a single-cycle multiple charge and discharge mode, for example, US Pat. No. 7,224,085 discloses a single-inductor dual-output (SIDO) voltage conversion circuit, and US Patent No. 7,256,568, US Pat. No. 7,432,614, and Chinese Patent Publication No. CN101083432 disclose a single inductor multiple output. (Single-inductor multiple-output, SIMO) voltage conversion circuit, although the problem of crossover voltage has been reduced, a less complicated control architecture can be used, and the circuit topology is as shown in Fig. 1; in Fig. 1, it is known single inductor multiple-output voltage converter circuit 10, cis-conducting switches S _FW (Freewheel switch), the switch S _O1 is turned on, when the S _i1 on power source V _g1 the inductor L is charged (when S _i2 on power source V _g2 is to Inductor L is charged, ..., when the S _{im is} turned on, the power supply V _gm charges the inductor L); in the next stage, the switch S _{n is} turned on, and the output switch S _{O1 is} turned on to discharge the inductor L, generating a voltage V _O1 output, in the next phase and the output switch S _O2 turned discharge inductor L generates a voltage output V _O2, ..., in the next phase, the output switch S _on the inductance L is turned on so that discharge, a voltage V _on output; up to The purpose of multiple outputs. However, although such a circuit can reduce the problem of crossover regulation, there is a problem that the conversion efficiency is not high and the output voltage has a large ripple.

In order to improve the conversion efficiency of the conversion circuit of the SIMO architecture, Dongsheng MA published "A Pseudo-CCM/DCM SIMO Switching Converter With" in IEEE J. Solid-State Circuits, Vol. 38, No. 1, Jan. 2003. Freewheel Switching", the circuit diagram is shown in Figure 2, allowing the voltage conversion circuit to operate in a pseudo-continuous conduction mode (PCCM) and a discontinuous conduction mode (DCM) with a time-multiplexing control. ) for voltage conversion; in FIG. 2, the voltage conversion circuit also cis-conducting switches S _f to form a continuous conduction mode virtual single inductor multiple-output (PCCM SIMO). After the charging of the inductor L is completed, in the first phase ψ _a , the switch S _{1 is} not turned on, and the output switch S _{a is} turned on to discharge the inductor L to generate a voltage V _oa output. When the inductor L is charged, the next phase ψ _b , the output switch S _{b is} turned on to discharge the inductor L, and the voltage V _{ob is} generated; please refer to FIG. 3 , through the phase and output of the circuit, the voltage I _{L of the} voltage conversion is relatively stable, and the DC current Idc is relatively Higher, that is, the voltage converted by this circuit can reduce the problem of crossover regulation and provide higher output current; but during the forward conduction switch, the circuit does not perform voltage conversion, which wastes time and power. And the virtual continuous conduction mode single inductor multiple output (PCCM SIMO) circuit must lengthen the operation cycle to increase the number of outputs, and the longer the operation cycle will make the output voltage ripple larger, this problem still needs to be solved.

In view of the above-mentioned problems of the prior art, it is an object of the present invention to provide a single-inductor multiple-output DC converter with charge pump control to solve the conventional single-inductor multiple-output DC converter during the forward-conducting switch. The circuit does not perform voltage conversion, which wastes time and power. The single-inductor multi-output DC converter with charge pump control is composed of a single-inductor multi-output DC conversion circuit and a control circuit, and the single-inductance multi-output DC conversion circuit controls the voltage (V _IN ) of the input DC terminal through the control. The circuit is controlled by pulse width modulation to convert the voltages of the output DC terminals of the two groups into a voltage of the first output DC terminal (V _O1 ) and a voltage of the second output DC terminal (V _O2 ); The output DC conversion circuit includes:

(1) A single inductance component, connected to the input DC terminal, is composed of a conduction switch (S _f ) and an inductor (L), and the conduction switch (S _f ) and the inductor (L) are connected in parallel The turn-on switch is configured to control a frequency at which the input DC terminal is connected to the inductor, and is used to maintain a current flowing through the inductor; and the single-inductor multi-output DC conversion circuit is operated in a virtual state by a turn-on switch (S _f ) The continuous-continuous conduction mode (PCCM) and the discontinuous conduction mode (DCM), that is, when the output load current is heavy, the single-inductor multi-output DC conversion circuit operates in a virtual continuous conduction mode. (PCCM); The single-inductor multi-output DC conversion circuit operates in discontinuous conduction mode (DCM) at light loads.

(2) a reference voltage switching switch (S _n ) connected in series between the single inductor element and a reference voltage for charging the inductor (L) with the voltage of the input DC terminal. For some applications, The reference voltage may be a ground voltage or a reference voltage higher than the ground voltage; (3) an output control module connected to the single inductor element and the reference voltage switch (S _n ) for inputting a DC voltage of the DC terminal Performing voltage conversion and outputting to the first output DC terminal and the second output DC terminal; the output control module further includes a first pulse width modulation device (PWM1), a charge pump (charge-pump), and a first two PWM means (the PWM2); wherein: the first pulse width modulation means (PWM1), comprising a first switch (S ₁₎ and a second switch (S _2), the control circuit via the phase control of the The first switch (S ₁ ) and the second switch (S ₂ ) output the voltage of the input DC terminal to the first output DC terminal; the charge pump includes a charge storage device, and the charge storage device can be a single a capacitor or a plurality of capacitors connected to the first a pulse width modulation device (PWM1), the second output DC terminal and the second pulse width modulation device (PWM2), when the charge storage device is discharged, for outputting a voltage to the second output DC terminal; further The charge pump can further include a diode disposed between the charge storage device and the second output DC terminal to prevent current backlash.

The second pulse width modulation device (PWM2) includes a third switch (S ₃ ) and a fourth switch (S ₄ ), and the phase of the signal is sent via the control circuit to control the third switch (S ₃ ) and the a fourth switch (S ₄ ); when the inductor (L) discharges the first output DC terminal, simultaneously charging the charge pump; when the conduction switch (S _f ) is turned on, the voltage of the input DC terminal Output to the second output DC terminal. Further, the first pulse width modulation device (PWM1) and the second pulse width modulation device (PWM2) may be composed of a gold oxide half field effect transistor MSOFET.

The single-inductor multi-output DC converter with charge pump control of the present invention uses a freewheel charge-pump control technique (FCPC) to increase the output without lengthening the operation cycle, and solves the prior art. Use the waste of the pass-through switching time.

According to another object of the present invention, a single inductor multiple output DC converter with charge pump control is proposed, similar to the foregoing, but wherein the charge pump is two, and for the second charge pump, a corresponding third pulse width is provided. Modulation device (PWM3) for controlling the DC output of the other; similarly, a third charge pump can be added, and a corresponding fourth pulse width modulation device (PWM4) is provided for controlling the increased DC Output.

According to still another object of the present invention, a single inductor multiple output DC converter with charge pump control is provided, comprising a single inductor multi-output DC conversion circuit and a control circuit, the single inductor multi-output DC conversion circuit is an input The voltage at the DC terminal (V _IN ) is controlled by the pulse width modulation of the control circuit to be converted into voltages of the N output DC terminals (V _O1 , V _O2 , . . . V _ON ), where N is an even number and is greater than or equal to 4, The single-inductor multi-output DC conversion circuit comprises: (1) a single inductor component connected to the input DC terminal, comprising a conduction switch (S _f ) and an inductor (L), the conduction switch (S _f ) and The inductor (L) is connected in parallel; its function is as described above; (2) a reference voltage switching switch (S _n ) is connected in series between the single inductor element and a reference voltage for making the input DC The voltage of the terminal charges the inductor (L). For some applications, the reference voltage may be a ground voltage or a reference voltage higher than the ground voltage; (3) a plurality of output control modules, usually N/2 Connected to the single inductive component and the reference a voltage switching switch (S _n ), wherein each of the output control modules is configured to convert the DC voltage of the input DC terminal to a voltage output of the DC output, and output the output voltage to the two output DC terminals; each of the output control modules further includes a first pulse width modulation varying means (PWM1), a charge pump and a second pulse width modulation means (the PWM2); wherein: the first pulse width modulation means (PWM1), comprising a first switch (S ₁₎ and a second switch (S ₂ ), the first switch (S ₁ ) and the second switch (S ₂ ) are controlled by the phase of the signal sent by the control circuit, and the voltage of the input DC terminal is output to the first output DC terminal (V _{O1 )} The charge pump includes a charge storage device, and the charge storage device may be a single capacitor or a plurality of capacitors connected to the first pulse width modulation device (PWM1), the second output DC terminal, and the first a second pulse width modulation device (PWM2) for outputting a voltage (V _O2 ) to the second output DC terminal when the charge storage device is discharged; further, the charge pump may further comprise a diode, the system is configured The charge storage device and the second output are straight Between the terminal for preventing current thrust; the second pulse width modulation means (the PWM2), comprising a third switch (S ₃₎ with a fourth switch (S _4), of the signal issued by the phase control circuit Controlling the third switch (S ₃ ) and the fourth switch (S ₄ ); when the inductor (L) discharges the first output DC terminal, simultaneously charging the charge pump; when the conduction switch (S _f When conducting, the voltage of the input DC terminal is output to the second output DC terminal. Further, the first pulse width modulation device (PWM1) and the second pulse width modulation device (PWM2) may be composed of a gold oxide half field effect transistor MSOFET.

According to still another object of the present invention, a single inductor multiple output DC converter with charge pump control is provided, similar to the foregoing, but each of the output control modules of the plurality of output control modules may have two charge pumps. Or more than two, for the second charge pump, there is a corresponding third pulse Width modulation device (PWM3) for controlling the DC output of the other; similarly, a third charge pump can be added, and a corresponding fourth pulse width modulation device (PWM4) is provided for controlling the increased DC output.

According to the present invention, a single-inductor multiple output DC converter with charge pump control according to the present invention may have one or more of the following advantages:

(1) The single-inductor multi-output DC converter with charge pump control of the present invention can increase the amount of DC stored by the charge storage device during the pulse width modulation of the forward-conducting switch by the charge pump of the output control module. The output can be used to solve the problem that the single-inductance multi-output DC converter does not perform voltage conversion during the forward conduction switch, which wastes time and power.

(2) The single-inductor multi-output DC converter of the present invention can increase the DC output by the charge storage device during the pulse width modulation of the forward conduction switch by the charge pump of the output control module. To solve the single-inductance DC converter of the prior art, in the pseudo-continuous conduction mode (PCCM), the conversion circuit must increase the output number to lengthen the operation cycle, and the operation cycle becomes longer to make the output voltage The obvious defects of the ripples become larger.

1‧‧‧Single-inductor multi-output DC conversion circuit

2‧‧‧Input DC terminal

3‧‧‧Control circuit

10‧‧‧ 知 single inductor multiple output voltage conversion circuit

11‧‧‧Output control module

111‧‧‧First Output Control Module

112‧‧‧Second output control module

12‧‧‧reference voltage switch

13‧‧‧Single Inductive Components

141‧‧‧First pulse width modulation device

142‧‧‧Second pulse width modulation device

143‧‧‧Three pulse width modulation device

144‧‧‧fourth pulse width modulation device

151‧‧‧First output DC terminal

152‧‧‧second output DC terminal

153‧‧‧3rd output DC terminal

154‧‧‧four output DC terminal

161‧‧‧First voltage divider

162‧‧‧Second voltage divider

163‧‧‧ Third voltage divider

164‧‧‧4th voltage divider

17‧‧‧Charge pump

171‧‧‧First charge pump

173‧‧‧third charge pump

1 is a schematic diagram of a single inductor multiple output voltage conversion circuit of the prior art; FIG. 2 is a schematic diagram of another prior art single inductor multiple output voltage conversion circuit; FIG. 3 is a switch control signal and output of FIG. Phase diagram of the current; FIG. 4 is a schematic diagram of the circuit of the first embodiment of the single-inductor multi-output DC converter with charge pump control of the present invention; FIG. 5 is a single inductor with charge pump control of the present invention. Schematic diagram of the relationship between the pulse width modulation time section and the output current of the first embodiment of the multiple output DC converter; 6 is a schematic diagram of a circuit of a second embodiment of a single-inductor multi-output DC converter with charge pump control according to the present invention; FIG. 7 is a single-inductor multi-output DC converter with charge pump control according to the present invention; The phase diagram of the switch control signal and the output current of the second embodiment; FIG. 8 is the pulse width modulation time section and the output current of the second embodiment of the single-inductor multi-output DC converter with charge pump control of the present invention. Schematic diagram of the relationship; FIG. 9 is a schematic diagram of the control process of the phase of the pulse width modulation switches of the second embodiment of the single-inductor multiple-output DC converter with charge pump control of the present invention; and FIG. The circuit topology diagram of the third embodiment of the single-inductor multi-output DC converter with charge pump control of the present invention.

Please refer to FIG. 4, which is a schematic diagram of the circuit of the first embodiment of the single-inductor multi-output DC converter with charge pump control according to the present invention. As shown in the figure, the single-inductor multi-output DC converter with charge pump control of the present invention is composed of a single-inductor multi-output DC conversion circuit 1 and a control circuit 3, and the voltage (V _IN ) of the input DC terminal 2 is passed through the The control circuit 3 is controlled by pulse width modulation and converted into voltages of the output DC terminals of the two groups, which are respectively the voltage of the first output DC terminal 151 (V _O1 ) and the voltage of the second output DC terminal 152 (V _O2 ), The voltage of the output DC terminal 151 (V _O1 ) and the voltage of the second output DC terminal 152 (V _O2 ); through this conversion, the voltage (V _IN ) of the input DC terminal 2 can be down-boosted or boosted-boosted. the way to convert a first DC output terminal 151 of the voltage (V _O1) 152 of the voltage (V _O2) and a second DC output terminal.

The single inductor multi-output DC conversion circuit 1 includes a single inductor component 13, a reference voltage switch (S _n ) 12 and an output control module 11 for converting the voltage (V _IN ) of the input DC terminal 2 into DC-DC ( The voltage of the first output DC terminal 151 (V _O1 ) of the DC-DC) and the voltage (V _O2 ) of the second output DC terminal 152:

(1) A single inductance element 13 is connected to the input DC terminal 2 and is composed of a conduction switch (S _f ) and an inductor (L). The conduction switch (S _f ) and the inductor (L) are connected in parallel. The phase ψ _f of the signal sent by the receiving control circuit 3 is the control conduction switch (S _f ) being turned on and off, and the conduction switch (S _f ) is used to control the frequency at which the input DC terminal 2 is connected to the inductor (L). And for maintaining the current flowing through the inductor (L) so that the current flowing through the inductor (L) is within a range of zero to a certain magnitude; the single inductor multi-output DC is made by the conduction switch (S _f ) The conversion circuit 1 operates in a virtual continuous conduction mode (PCCM) and a discontinuous conduction mode (DCM), that is, when the output load current is a heavy load, the single-inductance multi-output DC conversion circuit 1 operates in a virtual continuous conduction mode (PCCM); The single-inductor multi-output DC conversion circuit 1 operates in discontinuous conduction mode (DCM) at light loads.

(2) a reference voltage switching switch (S _n ) 12 connected in series between the single inductance element 13 and a reference voltage for charging the inductor (L) with the voltage of the input DC terminal 2; for some applications The reference voltage may be a ground voltage or a reference voltage higher than the ground voltage; the reference voltage switch (S _n ) 12 is in a pulse-frequency width modulation (PWM) mode of operation, and is sent via the control circuit 3 The phase of the signal ψ _n is signaled to turn the control on (S _f ) on and off.

(3) an output control module 11 connected to the single inductor component and the reference voltage switch (S _n ) for voltage conversion of a DC voltage (V _IN ) input to the DC terminal 2; the output control module 11 further includes a first pulse width modulation device (PWM1) 141, a charge pump 17 and a second pulse width modulation device (PWM2) 142, and an output control module 11; wherein the output control module 11 is also modulated by pulse width In the operation mode, the signals of the phases ψ _f and ψ ₁ are sent via the control circuit 3 to control the first pulse width modulation device (PWM1) 141 and the second pulse width modulation device (PWM2) 142, respectively.

The first pulse width modulation device (PWM1) 141 is composed of a first switch (S ₁ ) and a second switch (S ₂ ), and the first switch (S) is controlled by the signal circuit ψ ₁ via the control circuit 3 ₁ ) opening and closing the second switch (S ₂ ) to output the input DC terminal 2 via the voltage of the single inductor element 13 to the first output DC terminal 151; the first output DC terminal 151 is configured by the capacitor C ₁ and the load The capacitor R _{1 is} represented by a charge storage device (C _X ), and the output voltage is V _O1 , and the DC output terminals 152 and the like are identical. The charge storage device (C _X ) may be a single capacitor or a plurality of capacitors, and is connected to the first pulse width modulation device (PWM1) 141, the second output DC terminal 152 and the second pulse width modulation device. (PWM2) 142, when the charge storage device (C _X ) is discharged, for outputting a voltage (V _O2 ) to the second output DC terminal 152; further, the charge pump 17 may further comprise a diode Provided between the charge storage device (C _X ) and the second output DC terminal 152 to prevent current backflush .

The second pulse width modulation device (PWM2) 142 includes a third switch (S ₃ ) and a fourth switch (S ₄ ). The phase ψ _f and ψ _{1 of the} signal sent by the control circuit 3 respectively control the first a three switch (S ₃ ) and the fourth switch (S ₄ ); when the inductor (L) discharges the first output DC terminal 151, simultaneously charging the charge pump 17; when the conduction switch (S _f ) When turned on, the voltage of the input DC terminal 2 is output to the voltage (V _O2 ) of the second output DC terminal 152 via the single inductance element 13 . Moreover, the first pulse width modulation device (PWM1) 141 and the second pulse width modulation device (PWM2) 142 may be composed of a gold oxide half field effect transistor MSOFET or other semiconductor elements, and are not limited thereto. The circuit diagram of Fig. 4 is only a schematic diagram of the circuit topology of the present embodiment, and the actual circuit configuration is not limited to the combination of the illustrated electronic components.

Please refer to FIG. 5, which is a schematic diagram showing the relationship between the pulse width modulation time section and the output current in the present embodiment. The control circuit 3 emits ψ _n , ψ ₁ and ψ _f phases in one cycle time T _S . The signal, the control reference voltage switch 12, the first pulse width modulation device (PWM1) 141, the second pulse width modulation device (PWM2) 142 and the switch corresponding to the single inductance element 13 will input the voltage of the DC terminal 2 ( V _IN ) is converted to a voltage (V _O1 ) of the first output DC terminal 151 of the DC-DC (DC-DC) and a voltage (V _O2 ) of the DC terminal 152 of the second output; in FIG. 5, through the inductor ( The current I _L (output current) of _L ) maintains a higher DC current I _dc than the prior art. In this embodiment, the single-inductor multi-output DC converter with charge pump control uses a freewheel charge-pump control technique (FCPC) to increase the output but does not lengthen the operation cycle. Previous techniques used a pass-through switch to waste time and power.

For different applications, as in this embodiment, the output control module 11 includes two or two groups in addition to the first pulse width modulation device (PWM1) 141 and the second pulse bandwidth modulation device (PWM2) 142. Above the group of charge pumps 17, for the second charge pump 17, there is a corresponding third pulse width modulation device (PWM3) for controlling the output voltage of the third DC output terminal; similarly, a third may be added. A charge pump is provided with a corresponding fourth pulse width modulation device (PWM4) for controlling the voltage of the fourth DC output terminal; thereby further saving the forward switching time.

Please refer to FIG. 6 which is a circuit topology diagram of a second embodiment of a single-inductor multi-output DC converter with charge pump control according to the present invention. As shown in the figure, compared with the first embodiment, in the single-inductor multi-output DC conversion circuit 1, a second output control module 112 is added to the first output control module 111, and the first output control module is used. The group 111 converts the voltage (V _IN ) of the input DC terminal 2 into a voltage (V _O1 ) of the first output DC terminal 151 of the DC-DC (DC-DC) and a voltage (V _O2 ) of the DC terminal 152 of the second output, The voltage (V _IN ) of the input DC terminal 2 is converted by the second output control module 112 into a voltage (V _O3 ) of the DC-DC (the DC-DC) output DC terminal 153 and the fourth output DC terminal 154 Voltage (V _O4 ).

In this embodiment, the single-inductor multi-output DC converter with charge pump control includes a single-inductor multi-output DC conversion circuit 1 and a control circuit 3. The single-inductor multi-output DC conversion circuit 1 is an input DC terminal. The voltage of 2 (V _IN ) sends signals of ψ _n , ψ ₁ , ψ ₂ , ... and ψ _f phase via the control circuit 3, and is controlled by pulse width modulation, and the output is converted into voltages of N output DC terminals (V _O1 , V _O2 , ... V _ON ), where N is an even number and greater than or equal to 4, and only a single inductance multi-output DC converter circuit topology diagram of N=4 is shown in FIG. The following is only a description of N=4, but not limited to this. The single inductor multi-output DC conversion circuit 1 comprises:

(1) A single inductor element 13 is connected to the input DC terminal 2 and includes a conduction switch (S _f ) and an inductor (L). The conduction switch (S _f ) and the inductor (L) are connected in parallel. The function is as described in the first embodiment, and details are not described herein again.

(2) a reference voltage switching switch (S _n ) 12 connected in series between the single inductance element 13 and a reference voltage for charging the inductor (L) with the voltage (V _IN ) of the input DC terminal 2, For some applications, the reference voltage can be a ground voltage or a reference voltage that is higher than the ground voltage.

(3) The plurality of output control modules are generally N/2. In the sixth embodiment of the embodiment, two output control modules are shown, which are the first output control module 111 and the second output control module 112. a plurality of output control modules are respectively connected to the single inductor component 13 and the reference voltage switch (S _n ) 12, wherein each of the output control modules is configured to apply a voltage to the DC voltage (V _IN ) of the input DC terminal 2 After being converted, the output is output to the two output DC terminals, the first output DC terminal and the second output DC terminal; each of the output control modules further includes a first pulse width modulation device (PWM1), a charge pump and a The second pulse width modulation device (PWM2), as shown in FIG. 6, the first output control module 111 controls the output voltage (V _O1 ) of the first output DC terminal 151 and the output voltage of the second output DC terminal 152 ( V _O2 ); each of the output control modules further includes two pulse width modulation devices (a first pulse width modulation device (PWM1) and a second pulse width modulation device (PWM2)) and a charge pump; As shown in FIG. 6, the first output control module 111 includes a first pulse width modulation The variable device (PWM1) 141, the second pulse width modulation device (PWM2) 142 and a first charge pump 171, and the second output control module 112 also includes a first pulse width modulation device (here, for convenience of explanation, A pulse width modulation device is labeled as a third pulse width modulation device (PWM3) 143), and a second pulse width modulation device (for convenience of explanation, the second pulse width modulation device is labeled as a fourth pulse width) The modulation device (PWM4) 144) is coupled to a third charge pump 173.

The first pulse width modulation device (PWM1) 141 includes a first switch (S ₁ ) and a second switch (S ₂ ), and the signal of the phase ψ ₁ is sent via the control circuit 3 to control the first switch (S ₁ And the second switch (S ₂ ), the voltage (V _IN ) of the input DC terminal 2 is output to the output voltage (V _O1 ) of the first output DC terminal 151.

The first charge pump 171 includes a charge storage device (C _X ). The charge storage device can be a single capacitor or a plurality of capacitors, and is connected to the first pulse width modulation device (PWM1) 141 and the second output DC. And the second pulse width modulation device (PWM2) 142 is configured to output a voltage (V _O2 ) to the second output DC terminal 152 when the charge storage device (C _X ) is discharged; further, the first The charge pump can further include a diode disposed between the charge storage device (C _X ) and the second output DC terminal 152 to prevent current backlash.

The second pulse width modulation device (PWM2) 142 includes a third switch (S ₃ ) and a fourth switch (S ₄ ), and the signal of the phase ψ _f1 and ψ ₁ is sent via the control circuit 3 to control the third a switch (S ₃ ) and the fourth switch (S ₄ ); when the inductor (L) discharges the first output DC terminal 151, simultaneously charging the first charge pump 171; when the conduction switch (S _f When 12 is turned on, the voltage of the input DC terminal 2 is output to the second output DC terminal 152. Further, the first pulse width modulation device (PWM1) 141 and the second pulse width modulation device (PWM2) 142 may be composed of a gold oxide half field effect transistor MSOFET.

The second output control module 112 includes a third pulse width modulation device (PWM3) 143, a fourth pulse width modulation device (PWM4) 144, and a third charge pump 173. The third pulse width modulation device (PWM3) 143 includes a fifth switch (S ₅ ) and a sixth switch (S ₆ ), and the signal of the phase ψ ₂ is sent via the control circuit 3 to control the fifth switch (S ₅ And the sixth switch (S ₆ ), the voltage (V _IN ) of the input DC terminal 2 is output to the output voltage (V _O3 ) of the third output DC terminal 153.

The third charge pump 173 includes a charge storage device (C _y ) connected to the third pulse width modulation device (PWM3) 143, the fourth output DC terminal, and the fourth pulse width modulation device (PWM4) 144. And discharging the voltage (V _O4 ) to the fourth output DC terminal 154 when the charge storage device (C _y ) is discharged.

The fourth pulse width modulation device (PWM4) 144 includes a seventh switch (S ₇ ) and an eighth switch (S ₈ ), and sends a signal of phase ψ ₂ and ψ _f2 via the control circuit 3 to control the seventh a switch (S ₇ ) and the eighth switch (S ₈ ); when the inductor (L) discharges the third output DC terminal 153, simultaneously charging the third charge pump 173; when the conduction switch (S _f When 12 is turned on, the voltage of the input DC terminal 2 is output to the fourth output DC terminal 154.

(4) N/2 voltage dividers, in this embodiment, two voltage dividers, respectively a first voltage divider 161 and a third voltage divider 163, the first voltage divider 161 is used to output the first output The output voltage (V _O1 ) of the DC terminal 151 is divided and outputted to the control circuit 3, and the third voltage divider 163 is configured to divide the output voltage (V _O3 ) of the third output DC terminal 153 by the output voltage. The control circuit 3 can be controlled by the output voltage (V _O1 ) of the first output DC terminal 151 and the output voltage (V _O3 ) of the third output DC terminal 153.

Please refer to FIGS. 7 and 8. FIG. 7 is a phase diagram of the switching control signal and output current of the single-inductor multiple-output DC converter with charge pump control according to the embodiment, and FIG. 8 is a pulse width modulation time zone. Schematic diagram of the relationship between the segment and the output current; in Fig. 7, in the period T _S , in the phase I, the control circuit 3 outputs a high potential of the signal phase ψ _n to turn on the reference voltage switching switch (S _n ); The control circuit 3 outputs a low signal potential of the phase ψ _n to turn off the reference voltage switching switch (S _n ), and the output signal phase has a high potential of ψ ₁ to turn the first switch (S ₁ ) and the second switch (S) ₂ ) conducting with the fourth switch (S ₄ )

In phase III, the control circuit 3 outputs a high potential of the signal phase ψ _f , ψ _f1 , and turns on the conduction switch (S _f ) of the single inductance element and the third switch (S ₃ ). For the control of the second output control module 112, in the second half of the period T _S , in the phase IV, the control circuit 3 outputs a high potential of the signal phase ψ _n to turn on the reference voltage switching switch (S _n ); V, the output circuit 3 outputs a signal phase with a low potential of ψ _n to turn the reference voltage switching switch (S _n ) non-conducting, and the output signal phase is 高₂ high potential to turn the fifth switch (S ₅ ) and the sixth switch ( S ₆ ) is turned on with the eighth switch (S ₈ ). Then, in phase VI, the control circuit 3 outputs a high potential of the signal phase ψ _f , ψ _{f2 to} turn on the conduction switch (S _f ) and the seventh switch (S ₇ ); thus completing one cycle of control to make the input DC terminal 2 The voltage (V _IN ) is output to the first output DC terminal 151, the second output DC terminal 152, the third output DC terminal 153, and the fourth output DC terminal 154. Referring to Figure 8, in a period T _S , the current I _L (output current) through the inductor (L) maintains a higher DC current I _dc than the prior art.

The operation sequence of each switch of the single-inductor multi-output DC conversion circuit 1 is as shown in FIG. 9. In the period T _S , in the phase I, the control circuit 3 outputs a high potential of the signal phase ψ _n to switch the reference voltage ( S _n ) is turned on, at which time the input DC terminal 2 charges the inductor (L) of the single inductance element 13. In phase II, the control circuit 3 outputs a low potential of the signal phase ψ _n to turn the reference voltage switching switch (S _n ) non-conducting, and the output signal phase has a high potential of ψ ₁ to turn the first switch (S ₁ ), the second The switch (S ₂ ) and the fourth switch (S ₄ ) are turned on, at which time the inductor (L) is discharged, generating a boost voltage at the output voltage (V _O1 ) of the first output DC terminal 151, and simultaneously for the charge storage device (C _X ) Charging. In phase III, the control circuit 3 outputs a high potential of the signal phase ψ _f , ψ _f1 , and turns on the conduction switch (S _f ) of the single inductance component and the third switch (S ₃ ), at this time, because of the third switch ( S ₃ ) is turned on, and the lower plate voltage of the charge storage device (C _x ) is changed from 0 (0 is the ground voltage, and the reference voltage is used for different applications) to V _IN , so the upper plate voltage is boosted from V _O1 to V _IN + V _O1 , generating a boost output to the voltage (V _O2 ) of the second output DC terminal 152. In phase IV, the control circuit 3 outputs a high potential of the signal phase ψ _n to turn on the reference voltage switching switch (S _n ), at which time the input DC terminal 2 charges the inductor (L) of the single inductance element 13. In phase V, the control circuit 3 outputs a low potential of the signal phase ψ _n to turn off the reference voltage switching switch (S _n ), and the output signal phase is 高₂ high potential to turn the fifth switch (S ₅ ), sixth The switch (S ₆ ) is turned on with the eighth switch (S ₈ ) to discharge the energy of the inductor (L) to the voltage (V _O3 ) of the third output DC terminal 153 and the charge storage device (C _Y ). Then, in phase VI, the control circuit 3 outputs a high potential of the signal phase ψ _f , ψ _{f2 to} turn on the conduction switch (S _f ) and the seventh switch (S ₇ ), and the seventh switch (S ₇ ) is turned on. The lower plate voltage of the charge storage device (C _Y ) is boosted from 0 (0 is the ground voltage, the reference voltage for different applications) to V _IN , and the upper plate voltage is boosted from V _O3 to V _IN +V _O3 , An output voltage (V _O4 ) of the boosted fourth output DC terminal 154 is generated. Repeating the above six stages, the single-inductor multi-output DC conversion circuit 1 can generate four sets of output voltages. Thus, in the present embodiment, the single inductor multiple output DC converter uses a freewheel charge-pump control technique (FCPC) in a virtual continuous conduction mode (PCCM) and a discontinuous conduction mode (DCM). The voltage conversion by time-multiplexing control not only has better crossover voltage regulation and the ability to provide larger load current, but also increases the number of outputs and reduces the energy consumption, and solves the prior art use direction. Turning on the switching time.

In this embodiment, if the output of the output DC terminal is to be further increased, two or more charge pumps may be disposed in the first output control module 111, such as adding a second charge pump 172 (not shown on the figure). And a corresponding fifth pulse width modulation device (PWM5) is provided for controlling the fifth output DC terminal (not shown); similarly, the second output control module 112 can be additionally added. The fourth charge pump 174 (not shown) is provided with a corresponding sixth pulse width modulation device (PWM6) for controlling the sixth output DC terminal (not shown).

Please refer to FIG. 10, which is a circuit topology diagram of a third embodiment of a single-inductance multi-output DC converter with charge pump control according to the present invention. The architecture and operation mode are the same as the second embodiment. Let me repeat. However, the voltage divider of the single-inductor multi-output DC conversion circuit 1 is as follows:

(4) N voltage dividers, in this embodiment are four voltage dividers, respectively a first voltage divider 161, a second voltage divider 162, a third voltage divider 163 and a fourth voltage divider 164; The first voltage divider 161 is configured to divide the output voltage (V _O1 ) of the first output DC terminal 151 and output the voltage to the control circuit 3; the second voltage divider 162 is configured to use the second output DC terminal 152. The output voltage (V _O2 ) is divided and outputted to the control circuit 3; the third voltage divider 163 is configured to divide the output voltage of the third output DC terminal 153 and output the voltage to the control circuit. The fourth voltage divider 164 is configured to divide the output voltage (V _O4 ) of the fourth output DC terminal 154 into a voltage and output the voltage to the control circuit 3; the control circuit 3 can output according to the first output DC terminal 151. The voltage (V _O1 ), the output voltage (V _O2 ) of the second output DC terminal 152, the output voltage (V _O3 ) of the third output DC terminal 153, and the output voltage (V _O4 ) of the fourth output DC terminal 154 are controlled. Calculation.

The above is intended to be illustrative only and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the scope of the appended claims.

1‧‧‧Single-inductor multi-output DC conversion circuit

2‧‧‧Input DC terminal

3‧‧‧Control circuit

111‧‧‧First Output Control Module

112‧‧‧Second output control module

12‧‧‧reference voltage switch

13‧‧‧Single Inductive Components

141‧‧‧First pulse width modulation device

142‧‧‧Second pulse width modulation device

143‧‧‧Three pulse width modulation device

144‧‧‧fourth pulse width modulation device

151‧‧‧First output DC terminal

152‧‧‧second output DC terminal

153‧‧‧3rd output DC terminal

154‧‧‧four output DC terminal

161‧‧‧First voltage divider

163‧‧‧ Third voltage divider

171‧‧‧First charge pump

173‧‧‧third charge pump

Claims (8)

A single-inductor multiple-output DC converter with charge pump control includes a single-inductor multi-output DC conversion circuit and a control circuit. The single-inductor multi-output DC conversion circuit passes a voltage of an input DC terminal through the control circuit. The pulse width modulation control is converted into voltages of the N output DC terminals, wherein N is an even number and greater than or equal to 4, wherein the single inductor multi-output DC conversion circuit comprises: a single inductance component connected to the input DC terminal, including a turn-on switch and an inductor, the turn-on switch and the inductor are connected in parallel; the turn-on switch is configured to control a frequency at which the input DC terminal is connected to the inductor, and is used to maintain a current flowing through the inductor; a reference voltage switching switch connected in series between the single inductor component and a reference voltage for charging the inductor with the voltage of the input DC terminal; a plurality of output control modules connected to the single inductor component and the reference voltage a switch, wherein each output control module is configured to perform voltage conversion on the DC voltage of the input DC terminal and output the output to the second The output DC terminal is a first output DC terminal and a second output DC terminal; each of the output control modules further includes a first pulse width modulation device, a charge pump and a second a pulse width modulation device, wherein: the first pulse width modulation device comprises a first switch and a second switch, and the phase of the signal is sent via the control circuit to control the first switch and the second switch, the input is The voltage of the DC terminal is output to the first output DC terminal; the charge pump includes a charge storage device connected to the first pulse width modulation device, the second output DC terminal and the second pulse width modulation device And outputting a voltage to the second output DC terminal when the charge storage device is discharged; the second pulse width modulation device includes a third switch and a fourth switch, via the control The phase of the signal from the circuit controls the third switch and the fourth switch; when the inductor discharges the first output DC terminal, simultaneously charges the charge pump; when the conduction switch is turned on, the input DC terminal The voltage is output to the second output DC terminal. The single-inductor multiple-output DC converter with charge pump control according to claim 1, wherein the reference voltage switching switch is connected in series between the single inductor element and the ground. The single-inductor multi-output DC converter with charge pump control according to claim 1, wherein the charge pump further comprises a diode disposed between the charge storage device and the corresponding output DC terminal. It is used to prevent the current backlash of the output DC terminal. The single-inductor multiple-output DC converter with charge pump control according to claim 1, wherein the charge pump is two or more, and is provided with a pulse width modulation device corresponding to the charge pump. The single-inductor multiple-output DC converter with charge pump control according to claim 1, wherein the single-inductor multiple-output DC converter further comprises N/2 voltage dividers, and the voltage divider is connected to the corresponding The output DC end is used for shunting the output voltage of the corresponding output DC terminal and feeding it back to the control circuit. A single-inductor multiple-output DC converter with charge pump control as described in claim 1, wherein the single-inductor multiple-output DC converter further includes N voltage dividers connected to each of the output DCs The terminal is configured to feed back the corresponding output DC end shunt output voltage to the control circuit. The single-inductor multi-output DC converter with charge pump control according to claim 1, wherein the charge storage device of the charge pump is formed by a capacitor. The single-inductor multi-output DC converter with charge pump control according to claim 1, wherein the first pulse width modulation device and the second pulse width modulation device are composed of one or more gold oxides. Half field effect transistor.