TW201931346A - SIBO buck-boost converter and control method thereof - Google Patents

Abstract

Provided is a control method for controlling a SIBO buck-boost converter including a first switch coupled between an input and a first node, a second switch coupled between the first node and GROUND, a third switch coupled between a second node and GROUND, a fourth switch coupled between the second node and a first output node for outputting the positive output, a fifth switch coupled between the first node and a second output node for outputting the negative output, and an inductor coupled between the first node and the second node. The first and the third switches are turned on to energize the inductor. The first and the fourth switches are turned on to generate a positive output. The third and the fifth switches are turned on to generate a negative output.

Description

Single-inductance bipolar output buck-boost converter and control method thereof

The invention relates to a single inductive bipolar output (SIBO) buck-boost converter and a control method thereof.

Mobile systems and displays require effective long-term battery use. In addition, display quality is one of the important performance characteristics, but the display quality cannot be sacrificed even in heavy load current fluctuations, fast input voltage variations, and DC-DC converter switching noise.

Active matrix OLED (AMOLED) displays are becoming more and more popular in mobile display applications because active matrix OLEDs have the advantages of high display quality, low power consumption and low material cost. Active matrix OLED panels typically require positive and negative power supplies with different voltages. Moreover, the required chopping voltage of the positive voltage and negative voltage power supply output must be small enough to avoid the occurrence of water ripple and damage the display quality of the panel. Different panels may have different output currents and voltages, depending on panel size, number of pixels, display quality, and so on.

Figure 1 shows a conventional single inductor AMOLED power supply that is a two stage SIBO converter. As shown in FIG. 1, the conventional two-stage SIBO converter 100 includes a synchronous buck-boost circuit 120, a charge pump 140, an inductor L11 and capacitors C11-C15. Capacitors C11-C13 are decoupling capacitors. Capacitors C14-C15 are fly capacitors. The conventional two-stage SIBO converter 100 generates a positive output Vop and a positive current Iop to drive the load 160 and generates a negative output Von and a negative current Ion to drive the load 180. The input terminal provides an input voltage Vin and an input current Iin.

According to the relative relationship between the input voltage Vin and the output voltage Vop, the synchronous buck-boost circuit 120 can operate in a mode such as buck, buck-boost, and boost. The input voltage Vin is usually provided by a lithium battery, and the voltage of the input voltage Vin ranges from 3.0V to 4.5V, and the required value of the output voltage Vop is related to the size of the AMOLED panel, the display brightness, and the driving chip, the output voltage Vop. Commonly used typical values include 4.6V, 3.3V, 2.8V and 2.5V, and so on.

The charge pump 140 is used to generate a negative output Von from the positive output Vop. The charge pump 140 can have a number of output steps, such as, but not limited to, -1x and -1.5x. With the flying capacitor C14, the charge pump 140 can achieve -1x, that is, Von = Vop*(-1). With the flying capacitors C14 and C15, the charge pump 140 can achieve -1.5x, that is, Von = Vop* (-1.5). The negative output Von can be set by the converter digital interface to -1x~-1.5x of the positive output Vop to meet the high brightness requirements of the AMOLED display.

As can be seen from Fig. 1, the generation of the positive output Vop and the negative output Von is independently controlled.

Figure 2 shows the energy conversion efficiency map of the two-stage SIBO converter 100. The energy conversion efficiency Eff is defined as follows: Eff=

As shown in Fig. 2, when Vop is equal to 2.8 (V), the conventional two-stage SIBO converter 100 has Von = Vop * (-1) = 2.8 * (-1) = -2.8 (V) or Von = Vop. *(-1.5)=2.8*(-1.5)=-4.2(V) has the best energy conversion efficiency. However, when Von is not equal to -2.8 (V) or -4.2 (V), the conventional two-stage SIBO converter 100 has poor energy conversion efficiency. Thus, there is a need to improve the energy conversion efficiency of conventional two-stage SIBO converters.

According to an embodiment of the present invention, a control method is provided for controlling a single-inductance bipolar output (SIBO) buck-boost converter to generate a positive output and a negative output, the SIBO buck-boost converter including a SIBO buck-boost power stage, The SIBO buck-boost power stage includes a first switch coupled between an input and a first node, a second switch coupled between the first node and the ground, and a coupling between a second node and the ground. a third switch, a fourth switch coupled between the second node and a first output node outputting the positive output, coupled to a fifth between the first node and a second output node outputting the negative output a switch, and an inductor coupled between the first node and the second node, the control method includes: controlling the first and the third switch to be turned on, and the second, the fourth, and the fifth switch being turned off, Magnetizing the inductor to operate in an inductor magnetization phase; controlling the first and fourth switches to be turned on, and the second, third, and fifth switches being turned off to generate the positive output for a positive output charging Operating phase; The system of the third and the fifth switch is turned on, and the first, the second and the fourth switch is closed to generate the negative output to the negative phase output a charging operation.

According to another embodiment of the present invention, a single inductor bipolar output (SIBO) buck-boost converter is provided to generate a positive output and a negative output, the SIBO buck-boost converter includes: a SIBO buck-boost controller; and a SIBO lift a voltage power stage coupled to the SIBO buck-boost controller, the SIBO buck-boost power stage including a first switch coupled between an input and a first node, and a second coupled between the first node and the ground a switch, a third switch coupled between the second node and the ground, a fourth switch coupled between the second node and a first output node outputting the positive output, coupled to the first node and the output a fifth switch between the second output node of the negative output, and an inductance coupled between the first and the second node. The SIBO buck-boost controller controls the first and the third switch to be turned on, and the second, fourth, and fifth switches are turned off to magnetize the inductor during an inductive magnetization operation phase. The SIBO buck-boost controller controls the first and fourth switches to be turned on, and the second, third, and fifth switches are turned off to generate the positive output during a positive output charging operation phase. The SIBO buck-boost controller controls the third and the fifth switch to be turned on, and the first, the second, and the fourth switch are turned off to generate the negative output in a negative output charging operation phase.

In order to better understand the above and other aspects of the present invention, the following detailed description of the embodiments and the accompanying drawings

The technical terms of the present specification refer to the idioms in the technical field, and some of the terms are explained or defined in the specification, and the explanation of the terms is based on the description or definition of the specification. Various embodiments of the present disclosure each have one or more of the technical features. Those skilled in the art can selectively implement some or all of the technical features of any embodiment, or selectively combine some or all of the technical features of these embodiments, where possible.

FIG. 3 is a circuit diagram showing a single inductor bipolar output (SIBO) buck-boost converter 300 according to an embodiment of the present invention. The SIBO buck-boost inverting controller 310 includes a SIBO buck-boost inverting controller 310 and a SIBO buck-boost inverting power stage 350.

The SIBO buck-boost controller 310 includes a waveform generator 312, compensation error amplifiers 314 and 316, adders 318 and 319, buffers 320 and 322, comparators 324, 326 and 328, voltage generator 330, PSM (pulse omitted mode). , pulse skipping mode) circuit 332 and PWM (pulse width modulation) logic 334.

Waveform generator 312 is coupled to adder 318. Waveform generator 312 generates periodic waveform signals such as, but not limited to, ramp signals. The periodic waveform signal generated by the waveform generator 312 is input to the adder 318.

The compensation error amplifier 314 is coupled to a voltage divider circuit that includes resistors R1, R2, and R3. The compensation error amplifier 314 receives the reference voltage Vref and the feedback signal Vop_FB, and the feedback signal Vop_FB has a positive output Vop. The compensation error amplifier 314 inputs the output signal VEAp to the buffer 320, the comparator 324, and the PSM circuit 332. That is, the output signal VEAp (also referred to as the first compensation error amplifier output signal) generated by the compensation error amplifier 314 is responsive to the positive output Vop.

Similarly, the compensation error amplifier 316 is coupled to a voltage divider circuit that includes resistors R1, R2, and R3. The compensation error amplifier 316 receives the ground terminal and the feedback signal Von_FB, and the feedback signal Von_FB has a negative output Von. The compensation error amplifier 316 inputs the output signal VEAn to the buffer 322, the comparator 328, and the PSM circuit 332. That is, the output signal VEAn (also referred to as the second compensation error amplifier output signal) generated by the compensation error amplifier 316 is responsive to the negative output Von.

The adder 318 adds the periodic waveform signal generated by the waveform generator 312 to the voltage IL*Rs, where IL represents the inductor current of the inductor L31. The output signal Vsum (i.e., the sum signal) of the adder 318 is output to the comparators 324, 326, and 328.

Buffers 320 and 322 buffer the output signals VEAp and VEAn of compensation error amplifiers 314 and 316, respectively. The outputs of buffers 320 and 322 are input to adder 319.

Adder 319 adds the outputs of buffers 320 and 322 (i.e., VEAp and VEAn) to obtain output signal VEApn (i.e., the third compensated error amplifier output signal) and inputs it to comparator 326 (i.e., VEApn = VEAp+). VEAn).

The comparator 324 is configured to receive the output signal Vsum output by the adder 318 and the output signal VEAp output by the compensation error amplifier 314. The output signal Cp (also referred to as the first comparison signal) of comparator 324 is input to PWM logic 334. When the signal Vsum is higher than or equal to the output signal VEAp, the output signal Cp is logic high.

The comparator 326 is configured to receive the output signal Vsum output by the adder 318 and the output signal VEApn output by the adder 319. The output signal Cpn (also referred to as the third comparison signal) of comparator 326 is input to PWM logic 334. When the signal Vsum is higher than or equal to the output signal VEApn, the output signal Cpn is logic high.

The comparator 328 is configured to receive the output signal Vsum output by the adder 318 and the output signal VEAn output by the compensation error amplifier 316. The output signal Cn (also referred to as the second comparison signal) of comparator 328 is input to PWM logic 334. When the signal Vsum is higher than or equal to the output signal VEAn, the output signal Cn is logic high.

The voltage generator 330 is configured to generate reference voltages Vref and VCL, which are output to the compensation error amplifier 314 and the PSM circuit 332, respectively.

The PSM circuit 332 is configured to receive the output signal VEAp generated by the compensation error amplifier 314, compensate the output signal VEAn generated by the error amplifier 316, and the reference voltage VCL generated by the voltage generator 330. The output of PSM circuit 332 is input to PWM logic 334. Details of the PSM circuit 332 are omitted here.

Based on voltage IL*RS, output signals Cp, Cpn, and Cn (generated by comparators 324, 326, and 328, respectively), and the output signal of PSM circuit 332, PWM logic 334 generates control signals S1, S2, S3, SP, and SN. . Details of the PWM logic 334 are omitted here.

That is, the SIBO buck-boost controller 310 generates control signals S1, S2, S3, SP, and SN according to the inductor current of the positive output Vop, the negative output Von, and the inductor L31.

The SIBO buck-boost power stage 350 includes an inductor L31, switches SW1, SW2, SW3, SWP and SWN, and capacitors C31, C32 and C33. Capacitors C31, C32 and C33 are decoupling capacitors.

The switch SW1 is controlled by the control signal S1. Switch SW2 is controlled by control signal S2. The switch SW3 is controlled by a control signal S3. The switch SWP is controlled by a control signal SP. The switch SWN is controlled by a control signal SN.

Switch SW1 is coupled between input Vin and node N1. The switch SW2 is coupled between the node N1 and the ground terminal GROUND. The switch SW3 is coupled between the node N2 and the ground terminal GROUND. The switch SWP is coupled between the node N2 and the first output node (to output the positive output Vop). The switch SWN is coupled between the node N1 and the second output node (for outputting the negative output Von). Inductor L31 is coupled between nodes N1 and N2. Capacitor C31 is coupled between input Vin and ground terminal GROUND. Capacitor C32 is coupled between positive output Vop and ground terminal GROUND. Capacitor C33 is coupled between negative output Von and ground terminal GROUND.

Positive output Vop, above 0V, is generated above capacitor C32. Positive output Vop can use current Iop to drive load 360. The negative output Von, below 0V, is generated above capacitor C33. The negative output Von can drive the load 380 with the current Ion.

Figure 4 shows the four operating phases P1-P4 of the SIBO buck-boost converter 300 of Figure 3. Fig. 5 is a timing chart showing a plurality of signals (IL, VEAp, VEAn, VEApn, and Vsum) of the SIBO buck-boost converter 300 of Fig. 3. As shown in FIG. 5, the SIBO buck-boost converter 300 has two modes of operation: a continuous conduction mode (CCM) and a discontinuous conduction mode (DCM).

In CCM mode, the inductor current IL of inductor L31 is continuous. Under heavy load, the SIBO buck-boost converter 300 enters the CCM mode with proper feedback control.

Conversely, under light load, the SIBO buck-boost converter 300 enters the DCM mode with proper feedback control. At light loads, the average current of the inductor current IL is small and may discharge to zero. When the average current of the inductor current IL is close to 0, the switches SW1, SWP and SWN will be turned off, however, the five switches SW1, SW2, SW3, SWP and SWN may be turned on or off, and the inductor L31 does not absorb energy. No energy is released until the next clock cycle. This can be achieved by floating one end or both ends of the inductor L31 or by short-circuiting both ends of the inductor L31. For example, the switches SW2, SW3, SWP, and SWN can be turned off, and the switch SW1 can be turned on. Alternatively, switches SW1, SWP, and SWN can be turned off, while switches SW2 and SW3 can be turned on.

Please refer to Figures 4 and 5. In the first operational phase P1, switches SW1 and SW3 are turned on and switches SW2, SWP and SWN are turned off, which is labeled "P1, 13" in Fig. 4. "P1, 13" represents that, in the first operational phase P1, the switches SW1 and SW3 are turned on. Therefore, in the first operation phase P1, the inductor current IL flows from the input Vin through the inductor L31 and the switches SW1, SW3 to the ground terminal GROUND to charge the inductor L31. Therefore, the first operational phase P1 is the phase of the inductive charging operation. The duty cycle of the inductive charging operation phase (ie, P1) can be controlled in response to the feedback signal Von_FB.

In the second operational phase P2, the switches SW1 and SWP are turned on, while the switches SW2, SW3 and SWN are turned off, and are labeled "P2, 1P" in FIG. "P2, 1P" represents that, in the second operation phase P2, the switches SW1 and SWP are turned on. Therefore, in the second operation phase P2, the inductor current flows from the inductor L31 and flows through the switch SP and the capacitor C32 to the ground terminal GROUND. The inductor L31 is magnetized if the input voltage Vin is higher than the output voltage Vop, and the inductor L31 discharges energy if the input voltage Vin is lower than the output voltage Vop. Therefore, the capacitor C32 is charged, and the positive output Vop is generated above the capacitor C32. Therefore, the second operational phase P1 is the phase of the positive output energizing operation. The ratio of the phase of the positive output charging operation (i.e., P2) can be controlled in response to the feedback signals Vop_FB and Von_FB.

In the third operational phase P3, the switches SW2 and SWP are turned on, while the switches SW1, SW3, and SWN are turned off, and are labeled "P3, 2P" in FIG. "P3, 2P" represents that, in the third operation phase P3, the switches SW2 and SWP are turned on. Thus, the third operational phase P3 is the phase of the inductor release energy operation, and the inductor current is released from the current L31 to the capacitor C32.

In the fourth operational phase P4, the switches SW3 and SWN are turned on and the switches SW1, SW2 and SWP are turned off, and are labeled "P4, 3N" in FIG. "P4, 3N" represents that, in the fourth operation phase P4, the switches SW3 and SWN are turned on. Therefore, in the fourth operation phase P4, the inductor L31 releases the stored energy, and the inductor current IL flows from the inductor L31 through the switch SN and the capacitor C33 to the ground terminal GROUND. Therefore, the capacitor C33 is charged, and the negative output Von is generated above the capacitor C33. The fourth operational phase P4 is the phase of the negative output energizing operation.

In the fifth operation phase P5 (not shown in FIG. 4), at least one end of the inductor L31 is floating, or both ends of the inductor L31 are short-circuited to each other. For example, switches SW1, SWN, and SWP are all off, while switches SW2 and SW3 can be on or off. In the fifth operation phase P5 is the 0 inductor current operation phase. At the fifth operational phase P5, at least one end of the inductor L31 is floating, and thus the inductor is not charged or discharged.

Figure 5 also shows five operating modes, that is, the operating mode under Vin>Vop and heavy load (CCM), the operating mode under VinVop and heavy load (CCM), in Vin<Vop and heavy Operating mode under load (CCM), operating mode under Vin>Vop and light load (DCM), and operating mode under Vin<Vop and light load (DCM).

As shown in Fig. 5, in the operation mode under Vin>Vop and heavy load (CCM), in the first operation phase P1, the switches SW1 and SW3 are turned on, and thus the inductor current IL rises. In the second operation phase P2, the switches SW1 and SWP are turned on, the inductor current IL rises, and the positive output Vop is generated above the capacitor C32. In the fourth operational phase P4, the switches SW3 and SWN are turned on, and thus the inductor current IL is lowered. In the fourth operational phase P4, the negative output Von is generated above the capacitor C33.

Similarly, in the operation mode under VinVop and heavy load (CCM), in the first operational phase P1, the switches SW1 and SW3 are turned on, and thus the inductor current IL rises. In the second operation phase P2, the switches SW1 and SWP are turned on, but the inductor current IL is flat, and the positive output Vop is generated above the capacitor C32. In the fourth operational phase P4, the switches SW3 and SWN are turned on, and thus the inductor current IL is lowered. In the fourth operational phase P4, the negative output Von is generated above the capacitor C33.

Similarly, in the operation mode under Vin < Vop and heavy load (CCM), in the first operational phase P1, the switches SW1 and SW3 are turned on, and thus the inductor current IL rises. In the second operation phase P2, the switches SW1 and SWP are turned on, but the inductor current IL is decreased, and the positive output Vop is generated above the capacitor C32. In the fourth operational phase P4, the switches SW3 and SWN are turned on, and thus the inductor current IL is lowered. In the fourth operational phase P4, the negative output Von is generated above the capacitor C33.

Operating phases P1, P2, and P4 in an operating mode at Vin>Vop and light load (DCM) are similar to operating phases P1, P2, and P4 in an operating mode at Vin>Vop and heavy load (CCM). However, after the fourth operational phase P4, the inductor current IL approaches zero. In the fifth operation phase P5, the inductance L31 is not magnetized, which can be achieved by floating at least one end of the inductor L31 or by short-circuiting both ends of the inductor L31.

The operating phases P1, P2, and P4 in the operating mode at Vin < Vop and light load (DCM) are similar to the operating phases P1, P2, and P4 in the operating mode at Vin < Vop and heavy load (CCM). However, after the fourth operational phase P4, the inductor current IL approaches zero. In the fifth operation phase P5, the inductance L31 is not magnetized, which can be achieved by floating at least one end of the inductor L31 or by short-circuiting both ends of the inductor L31.

Thus, in the present embodiment, all of the switches SW1, SW2, SW3, SWP, and SWN are controlled by responding to the two feedback signals (Vop_FB and Von_FB) and the inductor current IL.

Under heavy load (CCM), the control sequence is P1, P2, and P4, wherein the first operational phase P1 begins at the beginning of each clock cycle and ends at the rising edge of signal Cp (ie, Vsum is close to VEAp). The second operational phase P2 begins at the end of the first operational phase P1 and ends at the rising edge of the signal Cn (ie, Vsum is close to VEAn); and, the fourth operational phase P4 begins at the second operational phase The end of P2 ends at the beginning of the next clock cycle.

Under light load (DCM), the control sequence is P1, P2, P4 and P5, wherein the first operational phase P1 begins at the beginning of each clock cycle and ends at the rising edge of signal Cn (ie, Vsum is close) VEAn); the second operational phase P2 begins at the end of the first operational phase P1 and ends at the rising edge of the signal Cpn (ie, Vsum is close to VEApn); the fourth operational phase P4 begins at the second operational phase The end of P2 ends and the inductor current IL is discharged to near 0; and, the fifth operational phase P5 begins at the end of the fourth operational phase P4 and ends at the beginning of the next clock cycle.

An example in which the input Vin is provided by a lithium battery, in which the initial voltage of the input Vin is 4.2 V, and the required positive output Vop is 3.6 V will now be described. Initially, the input Vin is higher than the positive output Vop, and the SIBO buck-boost converter 300 of the present embodiment operates in an operating mode of Vin>Vop and heavy load (CCM). Then, since the lithium current supplies power to the SIBO buck-boost converter 300, the input voltage Vin (output by the lithium battery) gradually becomes low. The SIBO buck-boost converter 300 of the present embodiment operates in a VinVop and heavy duty (CCM) mode of operation when the input Vin is gradually degraded to near the positive output Vop. The SIBO buck-boost converter 300 of the embodiment of the present invention operates in an operation mode of Vin < Vop and heavy load (CCM) when the input Vin is gradually lower and lower than the positive output Vop.

In short, in the SIBO buck-boost converter 300 of the embodiment of the present invention, two output voltages (positive output Vop and negative output Von) can be generated by one inductor, a plurality of capacitors and a plurality of switches.

Figure 6 shows a comparison of energy conversion efficiencies between the present embodiment and the conventional two-stage SIBO converter. This figure takes Vop = 2.8V as an example. As shown in Fig. 6, the SIBO buck-boost converter of the embodiment of the present invention has smooth and high energy conversion efficiency (almost between 85% and 88%). Compared to the energy conversion efficiency (between 55% and 88%) of the conventional two-stage SIBO converter 100, the energy conversion efficiency of the SIBO buck-boost converter of the present embodiment is significantly improved.

In conclusion, the present invention has been disclosed in the above embodiments, but it is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100‧‧‧Two-stage SIBO converter

120‧‧‧Synchronous buck-boost circuit

140‧‧‧Charge pump

L11‧‧‧Inductance

C11-C15‧‧‧ capacitor

Vop‧‧‧ is output

Iop‧‧‧ positive current

160,180‧‧‧load

Von‧‧‧negative output

Ion‧‧‧negative current

Vin‧‧‧Input voltage

Iin‧‧‧ input current

300‧‧‧SIBO buck-boost converter

310‧‧‧SIBO buck-boost controller

350‧‧‧SIBO buck-boost power stage

312‧‧‧ Waveform Generator

314 and 316‧‧‧compensation error amplifier

318 and 319‧‧ ‧ adders

320 and 322‧‧‧ buffers

324, 326 and 328‧‧ ‧ comparators

330‧‧‧Voltage generator

332‧‧‧PSM circuit

334‧‧‧PWM Logic

Rs, R1, R2 and R3‧‧‧ resistors

Vref, VCL‧‧‧ reference voltage

Vop_FB, Von_FB‧‧‧ feedback signal

VEAp, VEAn, VEApn, Vsum, Cp, Cn, Cpn‧‧‧ output signals

IL‧‧‧Inductor Current

S1, S2, S3, SP and SN‧‧‧ control signals

L31‧‧‧Inductance

SW1, SW2, SW3, SWP and SWN‧‧‧ switches

C31, C32 and C33‧‧‧ capacitors

N1, N2‧‧‧ nodes

360,380‧‧‧load

P1-P5‧‧‧Operation phase

Figure 1 (Prior Art) shows a conventional two-stage SIBO converter. Fig. 2 (Prior Art) shows an energy conversion efficiency diagram of a conventional two-stage SIBO converter of Fig. 1. Figure 3 shows a circuit diagram of a SIBO buck-boost converter in accordance with an embodiment of the present invention. Figure 4 shows the four operating phases P1-P4 of the SIBO buck-boost converter of Figure 3. Fig. 5 is a timing chart showing a plurality of signals of the SIBO buck-boost converter of Fig. 3. Figure 6 shows a comparison of the energy conversion efficiencies of the present embodiment and the conventional two-stage SIBO converter.

Claims (14)

A control method for controlling a single inductor bipolar output (SIBO) buck-boost converter to generate a positive output and a negative output, the SIBO buck-boost converter including a SIBO buck-boost power stage, the SIBO buck-boost power stage including coupling a first switch between the input and the first node, a second switch coupled between the first node and the ground, a third switch coupled between the second node and the ground, coupled to the first switch a fourth switch between the second node and a first output node outputting the positive output, coupled to a fifth switch between the first node and a second output node outputting the negative output, and coupled to the first An inductive method between the second node and the second node, the control method includes: controlling the first and the third switch to be turned on, and the second, fourth, and fifth switches are turned off to magnetize the inductor Inductive magnetization operation phase; controlling the first and the fourth switch to be turned on, and the second, third and fifth switches are turned off to generate the positive output in a positive output charging operation phase; and controlling the Third and the fifth open Turned on, and the first, the second and the fourth switch is closed to generate the negative-phase output to a negative output charging operation. The control method of claim 1, further comprising: when the inductor current is close to 0, controlling the five switches of the SIBO buck-boost power stage to not charge or discharge the inductor to a zero inductor Current operating phase. The control method of claim 2, further comprising: generating a first feedback signal proportional to the positive output voltage of the SIBO buck-boost converter; generating a second feedback signal proportional to the SIBO a negative output voltage of the buck-boost converter; controlling a duty cycle of the phase of the inductive magnetization operation according to the second feedback signal; and controlling the positive output charging according to the first and second feedback signals One duty cycle of the operating phase. The control method of claim 3, further comprising: generating a first compensation error amplifier output signal responsive to the first feedback signal; generating a second compensation error responsive to the second feedback signal An amplifier output signal; and adding the first and second compensation error amplifier output signals to generate a third compensation error amplifier output signal. The control method of claim 4, further comprising: generating a periodic waveform signal; and adding a voltage of the periodic waveform signal to the inductor current associated with the inductor to generate a sum signal. The control method of claim 5, further comprising: comparing the output signal of the first compensation error amplifier with the sum signal to generate a first comparison signal; comparing the output signal of the second compensation error amplifier with the And summing the signal to generate a second comparison signal; and comparing the third compensation error amplifier output signal with the sum signal to generate a third comparison signal. The control method of claim 6, further comprising: receiving the first and second compensation error amplifier output signals, and a second reference voltage to generate a plurality of pulse ellipsis mode output signals; First, the second and the third comparison signals, and the pulse omitting mode output signals, generating a first, a second, a third, a fourth, and a fifth control signal to respectively control the first The second, the third, the fourth, and the fifth switch. A single inductive bipolar output (SIBO) buck-boost converter to generate a positive output and a negative output, the SIBO buck-boost converter comprising: a SIBO buck-boost controller; and a SIBO buck-boost power stage coupled to the SIBO a buck-boost controller, the SIBO buck-boost power stage includes a first switch coupled between an input and a first node, a second switch coupled between the first node and the ground, coupled to a second node a third switch connected to the ground, a fourth switch coupled between the second node and a first output node outputting the positive output, coupled to the first node and outputting a second output of the negative output a fifth switch between the nodes, and an inductor coupled between the first and the second node, wherein the SIBO buck-boost controller controls the first and the third switch to be turned on, and the second, the Fourth, the fifth switch is turned off to magnetize the inductor in an inductor magnetization operation phase; the SIBO buck-boost controller controls the first and the fourth switch to be turned on, and the second, the third and the The fifth switch is turned off to produce The positive output is in a positive output charging operation phase; and the SIBO buck-boost controller controls the third and the fifth switch to be turned on, and the first, the second, and the fourth switch are turned off to generate the negative output At the time of a negative output charging operation. The SIBO buck-boost converter of claim 8, wherein when the inductor current is close to 0, the SIBO buck-boost controller controls the five switches of the SIBO buck-boost power stage to not charge The inductor is not discharged during a zero inductor current operation phase. The SIBO buck-boost converter of claim 9, wherein the SIBO buck-boost controller frame is configured to: generate a first feedback signal proportional to the positive output voltage of the SIBO buck-boost converter; a second feedback signal is proportional to the negative output voltage of the SIBO buck-boost converter; controlling a duty cycle of the phase of the inductive magnetization operation according to the second feedback signal; and according to the first and the The second feedback signal controls one of the duty cycles of the positive output charging operation phase. The SIBO buck-boost converter of claim 10, wherein the SIBO buck-boost controller comprises: a first compensation error amplifier generating a first compensation error amplifier output responsive to the first feedback signal a second compensation error amplifier generating a second compensation error amplifier output signal responsive to the second feedback signal; and a first adder summing the first and second compensation error amplifier output signals, To generate a third compensation error amplifier output signal. The SIBO buck-boost converter of claim 11, wherein the SIBO buck-boost controller comprises: a waveform generator for generating a periodic waveform signal; and a second adder for adding the periodic waveform signal And a voltage associated with the inductor current of the inductor to produce a sum signal. The SIBO buck-boost converter of claim 12, wherein the SIBO buck-boost controller comprises: a first comparator that outputs a signal compared to the first compensation error amplifier output signal and the sum signal a comparison signal; a second comparator comparing the output signal of the second compensation error amplifier with the sum signal to generate a second comparison signal; and a third comparator comparing the output signal of the third compensation error amplifier with The sum signal is used to generate a third comparison signal. The SIBO buck-boost converter of claim 13, wherein the SIBO buck-boost controller comprises: a pulse omitting mode circuit, receiving the first and second compensating error amplifier output signals, and a second a reference voltage to generate a plurality of pulse omitting mode output signals; and a pulse width modulation logic to generate a first one according to the first, the second and third comparison signals, and the pulse omitting mode output signals The second, third, fourth and fifth control signals respectively control the first, the second, the third, the fourth and the fifth switch.