TW201220659A - applicable in an electronic device requiring a regulated output of positive and negative voltage supply sources - Google Patents

Abstract

A buck-boost converter with positive and negative output ends includes a switch component, an inductor, a positive voltage output circuit, and a negative voltage output circuit. The positive voltage output circuit and the negative voltage output circuit are respectively electrically connected to a positive output end and a negative output end, and each includes two capacitors and two conduction components. The present invention is characterized in that: whether the switch component is conducted or not, and the positive voltage output circuit and the negative voltage output circuit both supply current to the inductor, which excites the inductor and boosts the positive and negative ends. Therefore, the present invention can be utilized in an electronic device requiring a regulated output of positive and negative voltage supply sources.

Description

201220659 VI. Description of the Invention: [Technical Field] The present invention relates to a buck-boost type converter, and more particularly to a buck-boost converter having positive and negative output terminals. [Prior Art] It is known that a vehicle power source is a vehicle engine that drives a generator to generate electricity after charging a lead-acid battery, thereby providing in-vehicle electronic equipment such as an engine control system, an audio, and an in-car entertainment device as a power source. However, electronic devices using the aforementioned vehicle power supply are subject to a large change in input voltage, such as a small car such as a car, which mainly uses a 丨2V battery, and a 12V battery has a voltage range of 1 〇 8 volts (discharged) to U8 VR ( Between the full charge, the audio amplifier with a 12 V power supply and a half-bridge drive architecture can only get about 4.5 W of output power from the commonly used 4 ohm speaker load, which is obviously insufficient. In addition, in order to provide a better low-frequency response output, it is preferable to use a positive and negative voltage supply. For a circuit structure in which a single power supply is converted into a positive and negative output, although many studies have been proposed, the circuit structure is complicated and the number of components is large, so it is not practical. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a buck-boost converter having positive and negative output terminals that are easy to implement with a circuit. Thus, the buck-boost converter having positive and negative outputs includes a switching element, a first inductor, a positive voltage output circuit and a negative voltage output circuit. The switching element has a first end and a second end for obtaining an input voltage; the first inductor has a grounded first end and a second end electrically connected to the second end of the switching element 201220659. The positive voltage output circuit is electrically connected between the first inductor and the positive output terminal: having a first capacitor, a first conductive component, a second inductor, and a second capacitor; the first capacitor has an electrical connection a first end of the second end of the first inductor and a second end; the first conductive element has a first end electrically connected to the second end of the first capacitor and a second end connected to the ground; The second inductor has a first end electrically connected to the first end of the first conductive device and a second end electrically connected to the positive output; the third capacitor has a second electrical connection to the second inductor a first end between the end and the positive output and a second end connected to the ground. "Hai negative voltage output circuit is electrically connected between the first inductor and the negative output terminal, has a second conducting component and a second capacitor, the second conducting component has a second end electrically connected to the first inductor The first end and a second end electrically connected to the negative output end; the second capacitor has a first end electrically connected to the negative output end and a second end connected to the ground. Thereby, when the switching element is turned on or off, the first capacitor of the positive voltage output circuit, the third capacitor and the second capacitor of the negative voltage output circuit both supply current to the first inductor to make the first inductor Magnetically boosts the positive output and the negative output. The technical feature of the present invention is that when the switching element is turned on or off, the positive voltage output circuit and the negative voltage output circuit supply current to the inductor to excite the inductor and boost the positive and negative outputs. It can be used by electronic devices that supply positive and negative voltage supply sources that require regulated output. The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention. Referring to FIG. 1, in a preferred embodiment of the present invention, a buck-boost converter 1A includes a switching element G, a first inductor 々, a positive voltage output circuit 101, a negative power output circuit 102, and a positive output. Terminal 61 and a negative output 62.

The switching element 0 has a first end ii and a second end 12 electrically connected to the power source 60. The first inductor & has a grounded first end 21 and a switching element 0, and the second end 12 The second end 22 is electrically connected. The positive voltage output circuit ιοί is electrically connected between the second end 22 of the first inductor horse and the positive output terminal 61. The negative voltage output circuit is electrically connected between the second end 22 and the negative output end 62 of the first inductor & The technical feature of the present invention is that the first inductor has a function similar to boost (Boost-Boost), and the capacitors of the positive voltage output circuit 1〇1 and the negative voltage output circuit 102 are used to achieve a positive and negative boost output, regardless of When the switching element G is turned on or off, the positive voltage output circuit (8) and the negative voltage output circuit 102 both supply current to the first inductor A to cause the first inductor & excitation to boost the positive output terminal 61 and the negative output terminal 62. Therefore, it can be supplied to an electronic device that requires a positive and negative voltage supply source with a regulated output. The detailed circuit of the secret embodiment is described below. The first end of the component (10) is connected to the second terminal 12 in a reverse connection, and the switching element is a metal oxide half field effect transistor. The first terminal u is a source terminal. The second terminal 12 is a secret, and its gate is Controlled decision to turn on the disk. The positive voltage output circuit 101 has a -capacitor C, a -conductor 201220659 connected to the first -electrode 912 and the second-capacitor-capacitor -the second-end 22 of the second end 22 of the -electro-ductive Α "#❹和-第二端32; the tenth fourth has a first end 4... with a first capacitor c-terminal 41 and a grounded second end 42. a second element 42 electrically connected to the second... The first inductor has a first end 51 connected to the second end of the first lead-out terminal 61 and a first end 51 electrically connected to the second output C2, and the second capacitor C3 has an electrical connection to the second inductor. The first end 52 of J and the positive output end 61 are: the second end 72. The blade is 71 and a grounded component: the voltage output is "2" - the second capacitor. 2 and a second conduction 2 . The second conducting component A has a second terminal capacitance of the first inductor 4 electrically connected to the second terminal of the first inductor 4... the second terminal of the second terminal I of the negative output terminal 62 is connected to the second terminal of the negative output terminal 62 and - When the grounding of the 101st switch 70 pieces of beta is turned on or off, the positive voltage output circuit - the capacitor ς, the third capacitor q and the first voltage valley c2 of the negative voltage output circuit 102 supply current to the first inductor A The first inductor 々 is excited to boost the positive output terminal 61 and the negative output terminal 62. Before introducing the principle, it must first be assumed that the first capacitor C has been charged to the first valley voltage vci' and the second capacitor voltage V. Equal to the negative output voltage 匕. The component constraints and labels are (1) the on-period is fine od) the voltage on the switching element Qt and the first and second conduction elements, 坧 is 〇; (") input power (four) d1 · 1 ·) dual output power 4匕 and ^, the positive output is repeatedly ^ and the negative output of the electric dust G; (iv) the driving signal of the switching element β is Vgs, the voltage Vds on the switching element Q is and the current is Ids; (v) The currents of the first 201220659 capacitor C, the second capacitor Q and the third capacitor C3 are 丨Cl, Ic2 and I, respectively. The voltages corresponding to 3' are VC1, VC2 and VC3; (vi) through the first conduction component A and The current of the two-conducting element 1)2 is Id 1 and Id2; (vii) in the continuous conduction state, the current through the first inductor 1 为 is IL1 and the voltage is Vli 'current through the second inductor A For lu and the voltage is vu.

The following is a schematic diagram of the analog current and voltage timing waveforms of the respective components, and FIG. 3 is a switching element 2, and the conduction period is a current flow from time t〇 to ti (hereinafter referred to as a first state), and FIG. 5 is a switch. The non-conduction period of the element 01 is the current flow from time t to k (hereinafter referred to as the second state), and the principle of operation of each element of the preferred embodiment will be described below. First state: Referring to FIG. 4, the switching element 0| is turned on (time "to..., the first inductor A is excited to cause 1 current to rise, and at the same time, the first conducting component is turned on and the second capacitor voltage vC2 is superimposed on the input voltage. After L, the second inductor Z is excited, so the second inductor is electrically "rising", since the second conducting element A is reverse biased, the negative output voltage 匕2 is provided by the second capacitor Q. Second state: see the figure 5 'Switching element 2|non-conducting (when time t| to y 'first-electrical "discharge demagnetization" causes second conducting element A to be turned on positively" - inductor A simultaneously charges the first and second capacitors ( Since the voltage vC2 is negative), the second inductor (4) is demagnetized by the second conducting element to charge the three capacitor c3. 2 second balance) For the first inductor A, according to the volt-second balance (v〇lt· principle) The first inductor voltage can be expressed as:

Equation 1 In the first state, the first inductor A simultaneously charges the second capacitor and the first capacitor 201220659 according to Equation 1 and Equation 2 F〇2 = VC2 simultaneously, = ~Va Equation 2 -D ~ ~~~~~xV 1-D m Equation 3 =0 Equation 4 In the first state, 'because the voltage across the first capacitor ^ is still stabilized by the voltage expressed by the formula, therefore, C2

-D ~^D formula

Vd'=Vci+K=^V, Equation 6 is the voltage 匕 described in Equation 4 and Equation 6, and the positive output V can be obtained.

D

1-D

Vin at the same time by the average of Equation 3 and Equation 5. The negative output voltage 匕2 is: V.

-D Therefore ο2~τ^χ v〇y Equation 7 ' can be given Equation 8 Equation 9 The experimental conditions of the preferred embodiment are: (1) DC input voltage 匕 is 1〇DC output) Voltage 匕 is +20 to 28 volts; (1)) Equal-proportional positive output (_d volts and negative output voltage...Λ (d... 02 von-20 volts, (ui) proportional output current is 1 amp; 201220659 (four) proportional output power is 40 watts; (7) The switching frequency is 2〇2; (10) The capacitance of the second capacitor C1 is 22"F; (vii) The capacitance value of the first capacitor and the third capacitor Q is 470 v F ; (viii) The model of the switching element a IRF3705ZS; and (ix) 帛 two-conducting component A, number ST 5A/100V. 2 Refer to Figure 6 and Figure 7, for the circuit structure using the aforementioned components, when the input voltage L is 10 volts, corresponding to Figure 2 The actual measured current and voltage timing waveforms of different components.

Referring to FIG. 8, FIG. 9 and FIG. 10, FIG. 8 is a waveform of voltages Vgs, Vds and inductor currents Iu, lL2 generated when the input voltage 匕 is 1 ;; FIG. 9 is generated when the input voltage 匕 is 19 volts. The waveforms of voltages Vgs, Vds, and inductor currents, II2, and FIG. 10 are waveforms of voltages Vgs, Vds and inductor currents IL1 and 1 generated at an input voltage 匕 of 28 volts. Referring to FIG. 1 and FIG. 12 and FIG. 13, the input voltages are 1 〇, 19 volts, and 28 volts, respectively, and the voltages of the gate driving signals of the switching elements q are shown in the respective figures. A timing waveform diagram of voltages Vc], VC2, and vc3 of a capacitor ς, a second capacitor ^, and a second capacitor c3. As can be seen from FIG. 2 and the foregoing timing waveform diagram, a single positive voltage power supply can obtain a stable boost output at the positive output terminal 61 and the negative wheel output terminal 62, respectively. Further, referring to FIG. 14, no matter what the load rate (L〇atj) Percentage), the conversion efficiency of the input voltage of 10 volts, 12 volts, 19 volts, 24 volts and 28 volts is above 80%. In summary, the present invention has the advantages that only a single power supply input voltage 匕 can obtain a boosted positive output voltage 负 and a negative output voltage 匕, 201220659 can be applied to a class D amplifier, and the circuit is easy to implement, so It is indeed possible to achieve the object of the invention. The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing a preferred embodiment of a buck-boost converter of the present invention; φ FIG. 2 is a timing waveform diagram illustrating an analog current and voltage waveform of a portion of the components of FIG. 1; FIG. 4 is a circuit diagram illustrating the current flow of the switching element of FIG. 1; FIG. 5 is a circuit diagram illustrating the switching element of FIG. Figure 6 is a timing waveform diagram illustrating the current and voltage waveforms of a portion of the components of Figure 1 actually measured _; Figure 7 is a timing waveform diagram illustrating the actual measured current of another component of Figure 1, Figure 8 is a timing waveform diagram showing the waveforms of the voltages Vgs, Vds and the inductor currents I1I and I2 at an input voltage of 1 〇V; Figure 9 is a timing waveform diagram illustrating the voltage at an input voltage of 12 volts. Vgs, Vds, and inductor currents IL1, 1 port waveform; 10 201220659 Figure 10 is a timing waveform diagram illustrating the waveforms of voltages Vgs, Vds and inductor currents I1I, I2 at an input voltage of 16 volts; 11 is a timing waveform diagram illustrating the gate drive voltage of the switching element having an input voltage of 10 volts and the voltage waveforms of the first, second, and third capacitors; FIG. 12 is a timing waveform diagram illustrating the input voltage of 19 volts. The driving voltage of the gate of the switching element and the voltage waveform of the first, second and third capacitors; FIG. 13 is a timing waveform diagram illustrating the driving voltage of the gate of the switching element with an input voltage of 28 volts and the first and second (four) waveform of the third capacitor; & Figure 14 is a waveform diagram illustrating the conversion efficiency at different output voltages corresponding to different load rates. Power out 201220659 [Description of main component symbols] 100 • Buck-Boost converter c2 ••... •...Second capacitor 101. Positive voltage output 'circuit Q...·..second capacitor 102•negative voltage output' circuit A...····first conduction element 11 ' 21, 31 , 41 ' 51 ' 71, A ••....second conduction element 81, 91 ·. First end A丨...· One pole 12, 22 , 32 , 42 , 52 , 72 , A ... .... first inductance 82, 92 · . second end ^ 2 .... second inductance 60 · · power supply Q, ·.. .... switching element 61 · · Positive output terminal K...·. ____ΑΛ. 丨J input voltage 62.. • Negative output terminal K,...· · •... positive m output voltage ς··. •First capacitor V〇2 .... •...negative fm Voltage 12

Claims (1)

201220659 VII. Patent application scope: 1. A buck-boost converter with positive and negative outputs, including: 70 switches, having - the first end and one end of an input voltage; - the first inductance a grounded first end and a second end electrically connected to the second end of the switching element; a positive voltage output circuit electrically connected between the first inductor and the positive output terminal, having: • a first capacitor a first end and a second end electrically connected to the second end of the first inductor, a first conducting component having a first end electrically connected to the second end of the first capacitor and a grounding a second end, a second inductor having a first end electrically connected to the first end of the first conductive element and a second end electrically connected to the negative output end, and a third capacitor having an electric a first end connected between the second end of the second inductor and the δ-hai negative output terminal and a grounded second end; and a negative voltage output circuit electrically connecting the first inductor and the negative output terminal Between, having: a second conductive element 'having an electrical connection a first end of the second end of the first inductor and a second end electrically connected to the negative output end, and a second capacitor 'having a first end electrically connected to the negative output end and a second end connected to the ground; When the switching element is turned on or off, the first capacitor of the positive-powered bucking circuit, the third capacitor, and the second capacitor 13201220659 of the negative voltage output circuit supply the current to the first inductor. - Inductive excitation causes the positive output and the negative output to boost. 2. The lift house converter having a positive and negative output according to the scope of the patent application, wherein the first end and the second end of the switching element are connected in reverse: a diode 'and The switching element is an N-type gold-oxygen half-field effect transistor, and the first source is a second end which is a drain, and its gate is controlled to determine whether it is conducting or not. 14