Low noise power conversion system and method

Abstract

A system comprising a current-mode switcher for providing a direct current (DC) voltage for a noise sensitive load and a linear amplifier connected to an output of the current-mode switcher; the linear amplifier for drawing a reduced supply voltage through at least one power conversion device coupled between a power source and the linear amplifier.

Description

Technical Field

[0001] This disclosure relates to a high-efficiency, low-noise power conversion system, and in certain embodiments, to a high-efficiency, low-noise power supply for noise-sensitive loads. Background Technology

[0002] With technological advancements, various electronic devices (such as mobile phones, tablet PCs, digital cameras, MP3 players, etc.) have become popular. Each electronic device requires a relatively constant DC current power, and even if the current drawn by the device may vary over a wide range, the voltage can be regulated within a specified range. When the input voltage is below a certain range, a boost converter can be used to convert the input voltage to a regulated voltage within that range. Conversely, when the input voltage is above a certain range, a buck converter can be used to convert the input power supply voltage to a lower voltage to meet the specific power supply voltage requirements of the electronic circuitry.

[0003] There may be multiple conversion topologies. Based on the topology, power converters can be divided into three categories: switching power converters, linear regulators, and switched-capacitor converters. Inductor-based switching converters or switched-capacitor converters are commonly used in high-efficiency power supplies. A drawback of these high-efficiency converters is the potential generation of switching noise (e.g., ripple current components) at their output.

[0004] In many applications, such as radio frequency (RF) transmitters and receivers, noise requirements are extremely stringent. Therefore, additional effort is needed to reduce switching noise. Low dropout regulators (LDOs) can be used as downstream regulators connected between a switch-mode power supply and a noise-sensitive load to reduce noise applied to the load. An LDO is effective when its output voltage is close to its input voltage. Otherwise, it is less efficient than a switching converter. There are some design and performance limitations associated with placing the LDO's input and output close to each other.

[0005] In applications requiring high efficiency and low noise (e.g., multiple input and multiple output antennas), there is a need for power conversion systems that can efficiently convert power and provide noiseless output voltage. Summary of the Invention

[0006] These and other problems can generally be solved or circumvented by providing a highly efficient, low-noise power supply for noise-sensitive loads, and technical advantages can generally be achieved.

[0007] According to an embodiment, a system includes: a current-mode switch for providing a direct current (DC) voltage to a noise-sensitive load; and a linear amplifier connected to the output of the current-mode switch, the linear amplifier being used to extract a reduced supply voltage via at least one power conversion device coupled between the power supply and the linear amplifier.

[0008] The first voltage rail of the linear amplifier is connected to the output of the sourcing power converter. The second voltage rail of the linear amplifier is connected to the output of the sinking power converter. The linear amplifier is used to reduce the ripple current component generated by the current-mode switch, while the sourcing and sinking power converters are used to reduce the supply voltage of the linear amplifier.

[0009] In some embodiments, the source-type power converter is a buck power converter connected between the power supply and a first voltage rail of the linear amplifier. The drain-type power converter is a switched-capacitor power converter configured as a 2:1 buck power converter having an input connected to the output of the buck power converter.

[0010] In some embodiments, the source-type power converter is a first buck power converter connected between a power supply and a first voltage rail of a linear amplifier. The sink-type power converter is a second buck power converter having an input terminal connected to the output terminal of the first buck power converter.

[0011] In some embodiments, a source-type power converter is a boost power converter connected between a power supply and a first voltage rail of a linear amplifier. A sink-type power converter is a buck power converter having an input terminal connected to the output terminal of the boost power converter.

[0012] In some embodiments, a source-type power converter is a boost power converter connected between the output of a sink-type power converter and the first voltage rail of a linear amplifier. A sink-type power converter is a buck power converter connected between a power supply and the second voltage rail of a linear amplifier.

[0013] In some embodiments, a source-type power converter is a buck-to-boost power converter connected between a power supply and a first voltage rail of a linear amplifier. A sink-type power converter is a buck power converter having an input terminal connected to the output terminal of the buck-to-boost power converter.

[0014] The aforementioned current-mode switch includes: a first switch and a second switch connected in series; an inductor connected between the output of the current-mode switch and the common node of the first and second switches; a pulse width modulation (PWM) driver for generating gate drive signals for the first and second switches; and a current comparator having an inverting input and a non-inverting input, wherein the inverting input is used to receive a current sensing signal proportional to the current flowing through the inductor, and the non-inverting input is grounded.

[0015] The linear amplifier includes a third switch and a fourth switch connected in series between a first voltage rail and a second voltage rail of the linear amplifier, and a comparator for generating gate drive signals for the third switch and the fourth switch.

[0016] In some embodiments, a first voltage rail of the linear amplifier is used to connect to a power supply via a source-type power converter. A second voltage rail of the linear amplifier is grounded. The linear amplifier is used to reduce the ripple current component generated by the current-mode switch, and the source-type power converter is used to reduce the supply voltage of the linear amplifier.

[0017] In some embodiments, the first voltage rail of the linear amplifier is used to be directly connected to a power supply. The second voltage rail of the linear amplifier is used to be connected to the output of a sinking power converter, which has an input connected to a power supply. The linear amplifier is used to reduce the ripple current component generated by the current-mode switch, and the sinking power converter is used to reduce the supply voltage of the linear amplifier.

[0018] According to other embodiments, a system includes: a current-mode power converter for generating a voltage for a load; a linear amplifier connected to the output of the current-mode power converter, the linear amplifier being used to reduce the ripple current component generated by the current-mode power converter; and a rail voltage generator for generating a reduced supply voltage for the linear amplifier.

[0019] In some embodiments, the rail voltage generator includes: a first buck power converter connected between a power supply and a first voltage rail of a linear amplifier, and a second buck power converter connected between the first voltage rail and a second voltage rail of the linear amplifier.

[0020] In some embodiments, the rail voltage generator is a single-inductor-dual-output (SIDO) power converter having a first output connected to a first voltage rail of a linear amplifier and a second output connected to a second voltage rail of the linear amplifier.

[0021] The current-mode power converter includes a first current-mode power conversion device and a second current-mode power conversion device connected in parallel, wherein the transient response of the first current-mode power conversion device is faster than that of the second current-mode power conversion device.

[0022] The first current-mode power conversion device is used to reduce the ripple current component generated by the second current-mode power conversion device. The linear amplifier is used to reduce the ripple current component generated by the first current-mode power conversion device.

[0023] According to other embodiments, a method includes: configuring a current-mode power converter to operate in a switching mode; configuring a linear amplifier to reduce the ripple current component generated by the current-mode power converter; and reducing the power loss of the linear amplifier by applying a reduced supply voltage to the linear amplifier.

[0024] The method further includes: converting the output voltage of the power supply to a first voltage through a source-type power converter and converting the first voltage to a second voltage through a sink-type power converter to generate a reduced supply voltage, wherein the source-type power converter and the sink-type power converter are buck power converters.

[0025] In some embodiments, the sourcing power converter is a buck power converter. The sinking power converter is a switched-capacitor power converter. The linear amplifier includes a sourcing leg connected to the sourcing power converter and a sinking leg connected to the sinking power converter.

[0026] The method also includes disabling the sink power converter, sink branch, and current-mode power converter during light-load operating modes.

[0027] The advantage of embodiments of this disclosure is that they enable a highly efficient, low-noise power supply for driving noise-sensitive loads.

[0028] The foregoing has provided a fairly broad overview of the features and technical advantages of this disclosure in order to better understand the specific embodiments described below. Other features and advantages of this disclosure, which form the subject matter of the claims, will be described below. Those skilled in the art will understand that the disclosed concepts and specific embodiments can be readily used as the basis for modifying or designing other structures or processes to achieve the same purpose as this disclosure. Those skilled in the art will also recognize that such equivalent structures do not depart from the spirit and scope of this disclosure as set forth in the appended claims. Attached Figure Description

[0029] To gain a more complete understanding of this disclosure and its advantages, the following description is now taken in conjunction with the accompanying drawings, in which:

[0030] Figure 1 Block diagrams of low-noise power conversion systems according to various embodiments of the present disclosure are shown;

[0031] Figure 2 Various embodiments according to this disclosure are shown. Figure 1 A block diagram of a first embodiment of the low-noise power conversion system shown;

[0032] Figure 3 Various embodiments according to this disclosure are shown. Figure 1 A block diagram of a second embodiment of the low-noise power conversion system shown;

[0033] Figure 4 Various embodiments according to this disclosure are shown. Figure 2 The block diagram shown is of a linear amplifier and a power converter.

[0034] Figure 5 Various embodiments according to this disclosure are shown. Figure 2 A schematic diagram of a first embodiment of the low-noise power conversion system shown;

[0035] Figure 6 Various embodiments according to this disclosure are shown. Figure 2 A schematic diagram of a second embodiment of the low-noise power conversion system shown;

[0036] Figure 7 Various embodiments according to this disclosure are shown. Figure 2 A schematic diagram of the third embodiment of the low-noise power conversion system shown;

[0037] Figure 8 Various embodiments according to this disclosure are shown. Figure 2 A schematic diagram of the fourth embodiment of the low-noise power conversion system shown;

[0038] Figure 9 Various embodiments according to this disclosure are shown. Figure 2 A schematic diagram of the fifth embodiment of the low-noise power conversion system shown;

[0039] Figure 10 The following diagram illustrates various embodiments of the present disclosure operating under low-power conditions. Figure 4 The block diagram shown is of a low-noise power conversion system.

[0040] Figure 11 Block diagrams of low-noise power conversion systems including only source-type power converters according to various embodiments of the present disclosure are shown;

[0041] Figure 12 Various embodiments according to this disclosure are shown. Figure 11A schematic diagram of a low-noise power conversion system is shown.

[0042] Figure 13 Block diagrams of low-noise power conversion systems including only a sink power converter according to various embodiments of the present disclosure are shown.

[0043] Figure 14 Various embodiments according to this disclosure are shown. Figure 13 A schematic diagram of a low-noise power conversion system is shown.

[0044] Figure 15 A block diagram of another low-noise power conversion system according to various embodiments of the present disclosure is shown;

[0045] Figure 16 Various embodiments according to this disclosure are shown. Figure 15 A schematic diagram of a low-noise power conversion system is shown.

[0046] Figure 17 The following diagram illustrates various embodiments of the present disclosure operating under low-power conditions. Figure 15 The block diagram shown is of a low-noise power conversion system.

[0047] Figure 18 A block diagram of another low-noise power conversion system according to various embodiments of the present disclosure is shown;

[0048] Figure 19 Various embodiments according to this disclosure are shown. Figure 18 A schematic diagram of a low-noise power conversion system is shown.

[0049] Figure 20 A block diagram of another low-noise power conversion system according to various embodiments of the present disclosure is shown; and

[0050] Figure 21 Various embodiments according to this disclosure are shown. Figure 20 The diagram shows a low-noise power conversion system.

[0051] Unless otherwise stated, the numbers and symbols corresponding to different figures generally refer to the corresponding parts. These figures are drawn to clearly illustrate relevant aspects of the various embodiments and are not necessarily drawn to scale. Detailed Implementation

[0052] The making and use of the presently preferred embodiments will now be discussed in detail. However, it should be understood that this disclosure provides many applicable inventive concepts that can be embodied in various specific contexts. The specific embodiments discussed are merely illustrative of specific ways of making and using this disclosure and do not limit the scope of this disclosure.

[0053] This disclosure will be described with reference to preferred embodiments in a specific context (i.e., high-efficiency, low-noise power conversion systems). However, this disclosure is also applicable to various power conversion systems. Various embodiments will be described in detail below with reference to the accompanying drawings.

[0054] Figure 1 Block diagrams of low-noise power conversion systems according to various embodiments of the present disclosure are shown. The low-noise power conversion system 100 includes a power converter 104, a linear amplifier 102, a source-type converter 101, and a sink-type converter 103. Figure 1 As shown, the output of power converter 104 is connected to the output of linear amplifier 102. The common node of power converter 104 and linear amplifier 102 is the output Vo of low-noise power conversion system 100. Linear amplifier 102 consists of two voltage rails (i.e., as shown in the diagram). Figure 1 The first voltage rail V+ and the second voltage rail V- are shown. A source-type converter 101 is used to establish the first voltage rail V+ for the linear amplifier 102. A sink-type converter 103 is used to establish the second voltage rail V- for the linear amplifier 102.

[0055] Linear amplifier 102 is connected between a first voltage rail V+ and a second voltage rail V-. In some embodiments, both source-type converter 101 and sink-type converter 103 are implemented as buck power converters. Source-type converter 101 is used to convert the output voltage of the power supply to a lower voltage applied to the first voltage rail V+. Similarly, sink-type converter 103 is used to generate a voltage higher than the ground voltage potential. The output voltage of sink-type converter 103 is applied to the second voltage rail V-. As a result, the first voltage rail V+ and the second voltage rail V- form a reduced supply voltage for linear amplifier 102. Throughout, source-type converter 101 and sink-type converter 103 may be collectively referred to as rail voltage generators, which are used to reduce the supply voltage of linear amplifier 102.

[0056] In operation, the power converter 104 is used to operate in switching mode. The power converter 104 generates a DC voltage for the noise-sensitive load. The linear amplifier 102 generates a ripple current component to eliminate or nearly eliminate the ripple current component generated by the power converter 104. Because the ripple current component generated by the power converter 104 is eliminated, a DC voltage with zero ripple current component is applied to the noise-sensitive load.

[0057] In some embodiments, the power loss of the linear amplifier 102 is proportional to the product of the ripple current component generated by the linear amplifier 102 and the voltage difference between the first voltage rail V+ and the second voltage rail V-. Therefore, the power loss of the linear amplifier 102 can be reduced by decreasing the voltage difference between the first voltage rail V+ and the second voltage rail V-.

[0058] Source-type converter 101 and sink-type converter 103 are used to control the rail voltage applied to linear amplifier 102. More specifically, source-type converter 101 and sink-type converter 103 are used to reduce the voltage difference between the first voltage rail V+ and the second voltage rail V-. In other words, source-type converter 101 and sink-type converter 103 are used to reduce the voltage variation range of linear amplifier 102. As the voltage difference between the first voltage rail V+ and the second voltage rail V- is reduced, the power losses (conduction losses and switching losses) of linear amplifier 102 are correspondingly reduced.

[0059] In some embodiments, the power converter 104 is implemented as a current-mode switch. Reference will be made below. Figure 5 The detailed structure of the current-mode switcher is discussed. Throughout this document, power converter 104 may be referred to as a current-mode switcher or a current-mode power converter. The source converter 101 can be implemented as a buck power converter, such as a step-down power converter. Alternatively, depending on the application and design requirements, the source converter 101 can be implemented as any suitable power converter, such as a boost power converter, a buck-boost converter, a linear regulator, a switched-capacitor converter, or any combination thereof. Similarly, the sink converter 103 can be implemented as a buck power converter, such as a step-down power converter. Alternatively, depending on the application and design requirements, the sink converter 103 can be implemented as any suitable power converter, such as a boost power converter, a buck-boost converter, a linear regulator, a switched-capacitor converter, or any combination thereof.

[0060] Figure 2 Various embodiments according to this disclosure are shown. Figure 1 The diagram shows a block diagram of a first embodiment of a low-noise power conversion system. The low-noise power conversion system 200 includes a power converter 104, a linear amplifier 102, a source-type converter 101, and a sink-type converter 103. Figure 2 As shown, a source-to-type converter 101 is connected between the power supply VIN and the first voltage rail V+. The source-to-type converter 101 receives a reference signal VREF+. The reference signal VREF+ is used to set the voltage on the first voltage rail V+. The source-to-type converter 101 converts VIN to the lower voltage determined by the reference signal VREF+.

[0061] like Figure 2 As shown, a sink converter 103 is connected between a first voltage rail V+ and a second voltage rail V-. The sink converter 103 receives a reference signal VREF-. The reference signal VREF- is used to set the voltage on the second voltage rail V+. The sink converter 103 converts V+ to the lower voltage determined by the reference signal VREF-.

[0062] like Figure 2 As shown, power converter 104 is connected to the power supply VIN. Power converter 104 converts VIN to Vo. Linear amplifier 102 generates a ripple current component to eliminate or nearly eliminate the ripple current component generated by power converter 104.

[0063] It should be noted that the settings of voltage rails V+ and V- may vary depending on different applications and design requirements. Reference signals VREF+ and VREF- can be generated internally or externally. Furthermore, in alternative embodiments, voltage rails V+ and / or V- can be generated using an open-loop configuration. In other words, reference signals VREF+ and / or VREF- may not be present.

[0064] It should also be noted that the control circuitry (not shown) of the linear amplifier 102 may or may not be connected to the voltage rails V+ and V-. For example, the power switch of the linear amplifier 102 may be connected to the voltage rails V+ and V-. The control circuitry of the linear amplifier 102 may be directly connected to VIN. It should be noted that the second voltage rail V- is used for energy recovery. Negative load current flows through the second voltage rail V-.

[0065] Figure 3 Various embodiments according to this disclosure are shown. Figure 1 The diagram shows a second embodiment of the low-noise power conversion system. The low-noise power conversion system 300 is similar to... Figure 2 The low-noise power conversion system 200 shown differs in that the input of power converter 104 is connected to a first voltage rail V+. Power converter 104 converts V+ to Vo. Linear amplifier 102 generates a ripple current component to eliminate or nearly eliminate the ripple current component generated by power converter 104.

[0066] One advantage of connecting the input of power converter 104 to the first voltage rail V+ is that the power loss of power converter 104 can be reduced by decreasing the supply voltage applied to power converter 104.

[0067] Figure 4 Various embodiments according to this disclosure are shown. Figure 2 The block diagram shown depicts a linear amplifier and a power converter. The linear amplifier 102 includes a source-type branch 402 and a sink-type branch 404. (As shown...) Figure 4 As shown, the source branch 402 and the sink branch 404 are connected in series between the first voltage rail V+ and the second voltage rail V-. The common node of the source branch 402 and the sink branch 404 is connected to the output terminal of the power converter 104.

[0068] Comparator 406 is used to control the operation of the source branch 402 and the sink branch 404. For example... Figure 4 As shown, the inverting input of comparator 406 is connected to a predetermined reference VREF. The non-inverting input of comparator 406 is connected to the output of power converter 104. Figure 4 As shown, based on a predetermined reference VREF and the detected output voltage Vo, comparator 406 generates control signals that are applied to the source branch 402 and the sink branch 404, respectively. It should be noted that VREF is greater than VREF- and less than VREF+.

[0069] In operation, the source branch 402 and the drain branch 404 are used to generate ripple current components to eliminate or almost eliminate the ripple components generated by the power converter 104.

[0070] The power converter 104 is implemented as a current-mode switcher. The following will refer to... Figure 5 The detailed structure of power converter 104 is described below. Current sensor 408 is used to detect the current flowing from power converter 104. The detected current signal is fed into power converter 104. Based on the detected current signal ISENSE, power converter 104 generates an output voltage Vo. Current sensor 408 can be implemented as any suitable current sensor, such as a sensing resistor, current transformer, etc.

[0071] Figure 5 Various embodiments according to this disclosure are shown. Figure 2 This is a schematic diagram of a first embodiment of a low-noise power conversion system. In some embodiments, VIN is equal to 12V. The output voltage Vo is equal to 1.8V. The first voltage rail V+ is equal to 2.4V. The source-type converter 101 is implemented as a buck converter. The source-type converter 101 is used to convert VIN to an output voltage equal to 2.4V, which is used to power the first voltage rail V+.

[0072] In some embodiments, the second voltage rail V- is set to 1.2V. The sink converter 103 is implemented as a switched-capacitor converter. The switched-capacitor converter employs open-loop control. In the open-loop configuration, the aforementioned switched-capacitor converter is configured as a 2:1 switched-capacitor converter. In other words, the output voltage of the sink converter 103 is equal to half the input voltage of the sink converter 103. The sink converter 103 is used to convert the output voltage of the source converter to an output voltage equal to 1.2V, which is used to power the second voltage rail V-.

[0073] Source converter 101 is implemented as a buck converter. Throughout this document, source converter 101 may be alternatively referred to as buck converter 101. The operation of source converter 101 is controlled by pulse width modulation (PWM) driver 110. Figure 5As shown, the source-to-source converter 101 includes a first switch Q1, a second switch Q2, an inductor L1, and an output capacitor C1. (As...) Figure 5 As shown, the first switch Q1 and the second switch Q2 are connected in series between the power supply VIN and ground. Inductor L1 is connected between the common node of the first switch Q1 and the second switch Q2 and the positive terminal of the output capacitor C1.

[0074] In some embodiments, such as Figure 5 As shown, the first switch Q1 and the second switch Q2 are implemented as n-type transistors. The gates of the first switch Q1 and the second switch Q2 are controlled by the PWM driver 110.

[0075] It should be noted that Figure 5 The buck converter 101 shown is merely an example and should not unduly limit the scope of the claims. Those skilled in the art will recognize many variations, substitutions, and modifications. For example, the first switch Q1 can be implemented as a p-type transistor. Furthermore, the switches of the buck converter 101 (e.g., the first switch Q1) can be implemented as a plurality of n-type transistors connected in parallel.

[0076] like Figure 5 As shown, amplifier 112 is used to receive the output voltage of buck converter 101 and a predetermined reference VREF+. Specifically, the non-inverting input of amplifier 112 is used to receive the predetermined reference VREF+. The inverting input of amplifier 112 is used to receive the output voltage V+. Based on the output voltage V+ and the predetermined reference VREF+, amplifier 112 generates a control signal, which is fed into PWM driver 110. Based on this control signal, PWM driver 110 generates two gate signals for controlling the operation of switches Q1 and Q2. The use of PWM drivers to control buck converters is well known in the art, and therefore will not be discussed further in detail to avoid repetition.

[0077] It should be noted that Figure 5 The control circuitry of the buck converter 101 shown is merely an example and should not unduly limit the scope of the claims. Those skilled in the art will recognize many variations, substitutions, and modifications. For example, the inverting input of amplifier 112 can be connected to the output of buck converter 101 via a suitable resistor divider. Furthermore, a suitable compensation network can be added to the output of amplifier 112 to improve the transient response performance of buck converter 101.

[0078] The power converter 104 is implemented as a current-mode switch. The current-mode switch includes a third switch Q3 and a fourth switch Q4 connected in series between VIN and ground, an inductor L2 connected between the common node of the third switch Q3 and the fourth switch Q4 and the output of the current-mode switch, and a PWM driver 140 for generating gate drive signals for the third switch Q3 and the fourth switch Q4. The current-mode switch also includes a current comparator 142 having an inverting input and a grounded non-inverting input. The inverting input is used to receive a current-sensing signal proportional to the current flowing through the inductor L2. Based on the detected current signal, the current comparator 142 generates a control signal, which is fed into the PWM driver 140. Based on the control signal, the PWM driver 140 generates two gate signals for controlling the operation of switches Q3 and Q4. The operating principle of the current-mode switch is well known in the art and will not be discussed further in detail to avoid repetition.

[0079] The linear amplifier 102 includes a fifth switch Q5 and a sixth switch Q6 connected in series between a first voltage rail V+ and a second voltage rail V-, and a comparator 406 for generating gate drive signals for the fifth switch Q5 and the sixth switch Q6. Figure 5 As shown, the inverting input of comparator 406 is used to receive a predetermined reference VREF. The non-inverting input of comparator 406 is connected to Vo. Based on the predetermined reference VREF and the detected output voltage, comparator 406 generates two gate signals for controlling the operation of switches Q5 and Q6, respectively. More specifically, the sourcing current flows through switch Q5, and the sinking current flows through switch Q6. The sourcing and sinking currents form the ripple current component of the linear amplifier 102, used to eliminate or nearly eliminate the ripple current component generated by the power converter 104.

[0080] like Figure 5 As shown, the fifth switch Q5 is implemented as a p-type transistor. The sixth switch Q6 is implemented as an n-type transistor. It should be noted that the p-type and n-type transistors are merely examples. Those skilled in the art will recognize that many variations, modifications, and substitutions are possible. For example, depending on different applications and design requirements, the fifth switch Q5 can be implemented as an n-type transistor.

[0081] like Figure 5As shown, the sink converter 103 is implemented as a switched-capacitor power converter. Throughout the document, the sink converter 103 may be referred to as the switched-capacitor power converter 103. The switched-capacitor power converter 103 includes a seventh switch Q7, an eighth switch Q8, a ninth switch Q9, a tenth switch Q10, a capacitor C4, and an output capacitor C3. The capacitor C4 serves as a charge pump capacitor. Throughout the document, the capacitor C4 may be referred to as the charge pump capacitor.

[0082] like Figure 5 As shown, the seventh switch Q7, the eighth switch Q8, the ninth switch Q9, and the tenth switch Q10 are connected in series between the first voltage rail V+ and ground. The charge pump capacitor C4 is connected between the common node of the seventh switch Q7 and the eighth switch Q8 and the common node of the ninth switch Q9 and the tenth switch Q10. The output capacitor C3 is connected between the common node of the eighth switch Q8 and the ninth switch Q9 and ground.

[0083] It should be noted that, although Figure 5 The diagram shows switches Q7 and Q8 implemented as single p-type transistors, but those skilled in the art will recognize that many variations, modifications, and alternatives are possible. For example, depending on the application and design requirements, switches Q7 and Q8 can be implemented as n-type transistors. Furthermore, Figure 5 Each switch of the switched capacitor power converter 103 shown can be implemented as multiple switches connected in parallel. Furthermore, a capacitor can be connected in parallel with a switch to achieve zero-voltage switching (ZVS) / zero-current switching (ZCS).

[0084] In some embodiments, the switched-capacitor power converter 103 is configured to operate in a switching mode. The output voltage of the switched-capacitor power converter 103 is equal to half of the input voltage of the switched-capacitor power converter 103. In other words, the voltage on the second voltage rail V- is equal to half of the voltage on the first voltage rail V+.

[0085] In switch mode, the switched capacitor power converter 103 functions as a charge pump power converter. The charge pump power converter can operate in two distinct phases. In the first phase of switch mode, switches Q7 and Q9 are turned on, while switches Q8 and Q10 are turned off. With switches Q7 and Q9 on, a first conductive path is established between V+ and V-. This first conductive path is formed by switch Q7, the charge pump capacitor C4, and switch Q9. Current flows from V+ to V- through this first conductive path. In the first phase of switch mode, the charge pump capacitor C4 is charged, and energy is correspondingly stored in it.

[0086] In the second phase of the switching mode, switches Q7 and Q9 are turned off, while switches Q8 and Q10 are turned on. Because switches Q8 and Q10 are on, a second conductive path is established. This second conductive path is formed by switch Q10, charge pump capacitor C4, and switch Q8. During the second phase of the switching mode, the current causes charge pump capacitor C4 to discharge, and the energy stored in charge pump capacitor C4 is correspondingly reduced.

[0087] In switch mode, the switched capacitor power converter 103 functions as a charge pump power converter, which is a voltage divider. More specifically, by controlling the on / off times of switches Q7-Q10, the output voltage of the switched capacitor power converter 103 is equal to half of its input voltage.

[0088] According to an embodiment, Figure 5 The switches (e.g., switches Q1-Q10) can be metal oxide semiconductor field-effect transistor (MOSFET) devices. Alternatively, the switching element can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field-effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0089] Figure 6 Various embodiments according to this disclosure are shown. Figure 2 A schematic diagram of a second embodiment of the low-noise power conversion system shown. Figure 6 The low-noise power conversion system shown is similar to Figure 5 The low-noise power conversion system shown differs in that the sink converter 103 is implemented as a buck converter. The buck converter (sink converter 103) includes switches Q7 and Q8 connected in series between V+ and ground, and an inductor L3 connected between the common node of Q7 and Q8 and the output capacitor C3.

[0090] In some embodiments, Figure 6The sink converter 103 shown operates with a fixed duty cycle (e.g., 50%). Because of the 50% duty cycle, the output voltage of the sink converter 103 is equal to half the input voltage (V+). Since the output of the sink converter 103 is connected to the second voltage rail V-, and the input of the sink converter 103 is connected to the first voltage rail V+, the voltage on the second voltage rail V- is approximately half the voltage on the first voltage rail V+. In an alternative embodiment, Figure 6 The sinker converter 103 shown operates with an adjustable duty cycle. The voltage on the second voltage rail V- can be dynamically adjusted according to various operating conditions, thereby reducing the power loss of the linear amplifier 102.

[0091] Figure 7 Various embodiments according to this disclosure are shown. Figure 2 A schematic diagram of the third embodiment of the low-noise power conversion system shown. Figure 7 The low-noise power conversion system shown is similar to Figure 6 The low-noise power conversion system shown differs in that the source converter 101 and the power converter 104 are implemented as boost converters.

[0092] like Figure 7 As shown, the source-type converter 101 includes a first switch Q1, a second switch Q2, an inductor L1, and an output capacitor C1. Switches Q2 and Q2 are connected in series between V+ and ground. Inductor L1 is connected between the input terminal of the source-type converter 101 and the common node of Q1 and Q2. The source-type converter 101 is a boost converter used to provide an output voltage higher than the input voltage by modulating the width of the pulse applied to switch Q1. The operating principle of boost converters is well known in the art and will not be discussed further in detail herein.

[0093] Power converter 104 includes a third switch Q3, a fourth switch Q4, and an inductor L2. Switches Q3 and Q4 are connected in series between Vo and ground. Inductor L2 is connected between VIN and the common node of Q3 and Q4. Power converter 104 is a boost converter used to provide an output voltage higher than the input voltage by modulating the width of the pulse applied to switch Q4. The operating principle of boost converters is well known in the art and will not be discussed further in detail herein.

[0094] have Figure 7 One advantage of the illustrated boost converter is that the low-noise power conversion system is suitable for boost applications. Power converter 104 is capable of converting the input voltage to a higher voltage. Linear amplifier 102 is capable of eliminating or nearly eliminating the ripple component generated by power converter 104.

[0095] Figure 8Various embodiments according to this disclosure are shown. Figure 2 A schematic diagram of the fourth embodiment of the low-noise power conversion system shown. Figure 8 The low-noise power conversion system shown is similar to Figure 6 The low-noise power conversion system shown differs in that the source converter is implemented as a boost converter.

[0096] like Figure 8 As shown, the input of the sink converter 103 is connected to VIN. The sink converter 103 (as a buck converter) is used to convert VIN to a lower voltage (e.g., 1.2V). The source converter 101 has an input connected to the second voltage rail V- and an output connected to the first voltage rail V+. The source converter 101 (as a boost converter) is used to convert the lower voltage on the second voltage rail V- to a higher voltage (e.g., 2.4V).

[0097] In some embodiments, Figure 8 The source-to-source converter 101 shown operates with a fixed duty cycle (e.g., 50%). Because of the 50% duty cycle, the output voltage of the source-to-source converter 101 is equal to twice the input voltage. In an alternative embodiment, Figure 8 The source-type converter 101 shown operates with an adjustable duty cycle. The voltage on the first voltage rail V+ can be dynamically adjusted according to various operating conditions, thereby reducing the power loss of the linear amplifier 102. Furthermore, Figure 8 The sinker converter 103 shown operates with an adjustable duty cycle. The voltage on the second voltage rail V- can be dynamically adjusted, thereby reducing the power loss of the linear amplifier 102.

[0098] It should be noted that the duty cycle of the sink converter 103 and the duty cycle of the source converter 101 can be dynamically adjusted individually or in combination. As a result, the voltage on the first voltage rail V+ and / or the voltage on the second voltage rail V- can be dynamically adjusted, thereby reducing the voltage variation range of the linear amplifier 102 and thus reducing the power loss of the linear amplifier 102.

[0099] Figure 9 Various embodiments according to this disclosure are shown. Figure 2 A schematic diagram of the fifth embodiment of the low-noise power conversion system shown. Figure 9 The low-noise power conversion system shown is similar to Figure 6 The low-noise power conversion system shown differs in that the source converter 101 and the power converter 104 are both implemented as buck-boost converters.

[0100] like Figure 9As shown, the source-type converter 101 includes switches Q11, Q12, Q13, and Q14, and an inductor L1, which together form a buck-boost converter. The buck-boost converter (source-type converter 101) can operate in three different operating modes (boost mode, buck mode, and buck-boost mode). When the buck-boost converter operates in boost mode, switch Q11 is configured to be always on, and switch Q12 is configured to be always off. As a result, inductor L1 and switches Q13 and Q14 form a boost converter. Conversely, when the buck-boost converter operates in buck mode, switch Q14 is configured to be always on, and switch Q13 is configured to be always off. As a result, switches Q11, Q12, and inductor L1 form a buck converter. Furthermore, when the input voltage is approximately equal to the output voltage of the source converter 101, the buck-boost converter can operate in buck-boost mode. In buck-boost mode, switches Q11-Q14 are turned on and off based on the detected input and output voltage signals. The operating principle of the buck-boost converter is well known in the art, and therefore will not be discussed further in detail to avoid unnecessary repetition.

[0101] Power converter 104 includes switches Q21, Q22, Q23, and Q24, and inductor L2. Switches Q21, Q22, Q23, and Q24, inductor L2, current comparator 142, and PWM driver 140 form a current-mode buck-boost converter. The operating principle of a current-mode buck-boost converter is well known in the art, and therefore will not be discussed further in detail to avoid unnecessary repetition.

[0102] have Figure 9 One advantage of the buck-boost converter shown is that the low-noise power conversion system is suitable for both buck and boost applications. Power converter 104 is capable of converting the input voltage to a lower or higher voltage. Linear amplifier 102 is capable of eliminating or nearly eliminating the ripple component generated by power converter 104.

[0103] Figure 10 The following diagram illustrates various embodiments of the present disclosure operating under low-power conditions. Figure 4 The block diagram shown is of a low-noise power conversion system. Figure 10As shown, the current flowing from the power converter 104 is sensed by the current sensor 408. When the current flowing from the power converter 104 is below a certain threshold, a low-power condition is identified. Under the low-power condition, the power converter 104 is disabled, as indicated by the arrow on the symbol of the power converter 104. Once the power converter 104 is disabled, its switch is tri-stated. Similarly, as indicated by the arrow on the symbol of the sinking branch 404, the sinking branch 404 of the linear amplifier 102 is also disabled. Furthermore, as indicated by the arrow on the symbol of the sinking converter 103, the sinking converter 103 is also disabled. By disabling the power converter 104, the sinking branch 404, and the sinking converter 103, power losses from the power converter 104, the sinking branch 404, and the sinking converter 103 are saved.

[0104] It should be noted that after power converter 104, sinking branch 404, and sinking converter 103 are disabled, Figure 10 The illustrated low-noise power conversion system is transformed into a switching converter followed by an LDO. The source-type converter 101 functions as a switching converter, and the source-type branch 402 functions as an LDO. By applying appropriate power-saving control schemes (e.g., pulse skipping, burst mode, or pulse frequency modulation (PFM) type control mechanisms) to the source-type converter 101, the cascaded switching converter and LDO can provide relatively good efficiency under light load conditions. Furthermore, the LDO can attenuate noise to meet the requirements of noise-sensitive loads connected to Vo.

[0105] It should also be noted that under low power conditions, the voltage on the first voltage rail V+ can be adjusted to different voltage levels to further improve the efficiency of the low-noise power conversion system. As mentioned above, under low power conditions, the source branch 402 is used as an LDO. To improve the efficiency of the LDO, the voltage on the first voltage rail V+ can be set slightly lower to reduce the voltage drop across the LDO.

[0106] Figure 11 A block diagram of a low-noise power conversion system including only a source-type power converter according to various embodiments of the present disclosure is shown. Figure 11 The low-noise power conversion system shown is similar to Figure 4 The low-noise power conversion system shown differs in that the second voltage rail of the linear amplifier 102 is directly grounded.

[0107] In some applications, if the source branch 402 of the linear amplifier 102 has significantly greater losses than the drain branch 404, or if the losses from the drain branch 404 are insignificant from the perspective of system efficiency, then... Figure 11It may be advantageous to include only the source-type converter 101 as shown.

[0108] Under low power conditions, Figure 11 The low-noise power conversion system shown can be used with Figure 10 The low-noise power conversion system shown is handled similarly. To save unnecessary power loss, power converter 104 and sinker branch 404 can be disabled when the low-noise power conversion system is operating under low-power conditions.

[0109] Figure 12 Various embodiments according to this disclosure are shown. Figure 11 The diagram shows a low-noise power conversion system. Figure 12 The low-noise power conversion system shown is similar to Figure 5 The low-noise power conversion system shown differs in that the second rail of the linear amplifier 102 is directly grounded.

[0110] It should be noted that Figures 6-9 The various embodiments shown are applicable to Figure 12 The low-noise power conversion system shown is an example. Figure 12 The source converter 101 shown can be replaced by any suitable power converter (e.g., boost converter, buck-boost converter, any combination thereof, etc.).

[0111] Figure 13 A block diagram of a low-noise power conversion system including only a sinker power converter according to various embodiments of the present disclosure is shown. Figure 13 The low-noise power conversion system shown is similar to Figure 4 The low-noise power conversion system shown differs in that the first voltage rail of the linear amplifier 102 is directly connected to VIN.

[0112] In some applications, if the sink branch 404 of the linear amplifier 102 has significantly greater losses than the source branch 402, or if the losses from the source branch 402 are insignificant from the perspective of system efficiency, then... Figure 13 It may be advantageous to include only the sink converter 103 shown.

[0113] Under low power conditions, Figure 13 The low-noise power conversion system shown can be used with Figure 10 The low-noise power conversion system shown is similarly handled. To save unnecessary power loss, power converter 104, sink converter 103, and sink branch 404 can be disabled. Under these low-power conditions, Figure 13 The low-noise power conversion system shown behaves as an LDO. In particular, the source branch 402 is used as an LDO.

[0114] Figure 14 Various embodiments according to this disclosure are shown. Figure 13 The diagram shows a low-noise power conversion system. Figure 14 The low-noise power conversion system shown is similar to Figure 5 The low-noise power conversion system shown differs in that the first rail of the linear amplifier is directly connected to VIN. In some embodiments, VIN is equal to 2.5V. Vo is equal to 1.8V. The sinker converter 103 converts VIN to a voltage of approximately 1.25V, which is used to power the second voltage rail V- of the linear amplifier 102.

[0115] It should be noted that Figures 6-9 The various embodiments shown are applicable to Figure 14 The low-noise power conversion system shown is an example. Figure 14 The sink converter 103 shown can be replaced by any suitable power converter (e.g., buck converter, boost converter, buck-boost converter, any combination thereof, etc.).

[0116] Figure 15 A block diagram of another low-noise power conversion system according to various embodiments of the present disclosure is shown. Figure 15 The low-noise power conversion system shown is similar to Figure 5 The low-noise power conversion system shown differs in that the first rail of the linear amplifier is directly connected to VIN, and the second voltage rail of the linear amplifier is directly grounded.

[0117] Figure 16 Various embodiments according to this disclosure are shown. Figure 15 The diagram shows a low-noise power conversion system. Figure 16 As shown, the linear amplifier 102 includes switches Q5 and Q6 connected in series between VIN and ground. Figure 16 The low-noise power conversion system shown is suitable for low-voltage applications. For example, when the input voltage is approximately 2.5V, there is no need for the aforementioned source-type converter and sink-type converter to further reduce the power loss of the linear amplifier 102.

[0118] Figure 17 The following diagram illustrates various embodiments of the present disclosure operating under low-power conditions. Figure 15 The diagram shows a block diagram of a low-noise power conversion system. Under low-power conditions, Figure 17 The low-noise power conversion system shown can be used with Figure 10 The low-noise power conversion system shown is similarly handled. To save unnecessary power loss, power converter 104 and sinker branch 404 can be disabled. Under these low-power conditions, Figure 17The low-noise power conversion system shown behaves as an LDO. In particular, the source branch 402 is used as an LDO.

[0119] It should be noted that, under low power conditions, the source branch 402 of the linear amplifier 102 can be used to operate in bypass mode to further reduce the power loss of the linear amplifier 102. In bypass mode, the switch of the source branch 402 stops switching and becomes a always-on switch, thereby reducing the power loss of the source branch 402.

[0120] Figure 18 A block diagram of another low-noise power conversion system according to various embodiments of the present disclosure is shown. Figure 18 The low-noise power conversion system shown is similar to Figure 5 The low-noise power conversion system shown differs in that it has two power converters used to generate the output voltage Vo for noise-sensitive loads.

[0121] like Figure 18 As shown, a first power converter 104 and a second power converter 106 are connected in parallel between VIN and Vo. In some embodiments, the first power converter 104 is a slow buck converter, and the second power converter 106 is a fast buck converter for transferring power from VIN to Vo. The slow buck converter 104 operates at low frequencies and has a large inductance and a high-power switch, while the fast buck converter 106 operates at high switching frequencies and has a small inductance and a small-power switch. The purpose of these two buck converters is to improve the load transient response using the fast buck converter and to eliminate the large ripple current generated by the slow buck converter, while the linear amplifier 102 is used to eliminate the small ripple current generated by the fast buck converter. These two buck converters can be controlled using any suitable control scheme, such as nested current-mode control. Applying nested current-mode control schemes to buck converters is well known in the art and is therefore not discussed herein.

[0122] Figure 19 Various embodiments according to this disclosure are shown. Figure 18 The diagram shows a low-noise power conversion system. Figure 19 As shown, the first power converter 104 and the second power converter 106 are connected in parallel between VIN and Vo. The first power converter 104 includes Q31, Q32, inductor L21, PWM driver 140, and current comparator 142. The second power converter 106 includes Q33, Q34, inductor L22, PWM driver 160, and current comparator 162. Both the first power converter 104 and the second power converter 106 are implemented as buck converters. The operating principle of buck converters has been described above. Figure 5 It has already been described, so it will not be discussed further.

[0123] It should be noted that Figures 6-9 The various embodiments shown are applicable to Figure 19 The low-noise power conversion system shown is an example. Figure 19 The sinker converter 103 shown can be replaced by any suitable power converter (e.g., buck converter, boost converter, buck-boost converter, any combination thereof, etc.). Similarly, Figure 19 The source converter 101 shown can be replaced by any suitable power converter (e.g., buck converter, boost converter, buck-boost converter, any combination thereof, etc.).

[0124] It should also be noted that the second power converter 106 helps reduce the size of switches Q5 and Q6. As mentioned above, the fast buck converter helps reduce the ripple current component generated by the low buck converter. The linear amplifier is used to eliminate or almost eliminate the ripple current component of the fast buck converter. Because the fast buck converter operates at a higher switching frequency, its ripple current component is relatively small. As a result, switches Q5 and Q6 can be implemented as small switches to eliminate the ripple current component generated by the fast buck converter.

[0125] Figure 20 A block diagram of another low-noise power conversion system according to various embodiments of the present disclosure is shown. Figure 20 The low-noise power conversion system shown is similar to Figure 5 The low-noise power conversion system shown differs in that the voltages on the first voltage rail V+ and the second voltage rail V- are provided by a single-inductor dual-output (SIDO) power converter 150.

[0126] like Figure 20 As shown, the SIDO power converter 150 has an input terminal connected to VIN. The SIDO power converter 150 receives a first reference signal VREF+ and a second reference signal VREF-. The first reference signal VREF+ is used to set the voltage of V+. The second reference signal VREF- is used to set the voltage of V-. Figure 20 As shown, V+ is the first voltage rail of the linear amplifier 102. V- is the second voltage rail of the linear amplifier 102.

[0127] Figure 21 Various embodiments according to this disclosure are shown. Figure 20 The diagram shows a low-noise power conversion system. The SIDO power converter 150 includes switches Q1, Q2, Q51, Q52, inductor L1, and output capacitor C1. Figure 21As shown, switches Q1 and Q2, inductor L1, and output capacitor C1 form a buck converter. Q51 is connected between the output terminal of the buck converter and V+. Q52 is connected between the output terminal of the buck converter and V-. SIDO controller 151 is used to receive reference signals VREF+ and VREF-. Figure 21 As shown, based on reference signals VREF+ and VREF-, SIDO controller 151 generates gate drive signals for controlling Q1, Q2, Q51, and Q52.

[0128] V+ is the sourcing terminal, and V- is the sinking terminal. The load current flowing through Q51 and Q52 flows in opposite directions. SIDO controller 151 controls the operation of Q51 to regulate the voltage on the first voltage rail V+. Similarly, SIDO controller 151 controls the operation of Q52 to regulate the voltage on the first voltage rail V-.

[0129] It should be noted that the above-mentioned various energy-saving control mechanisms (e.g., Figure 10 The control mechanism shown is applicable to Figure 21 The low-noise power conversion system shown. For example, under light load operating conditions, switches Q52 and Q6, as well as power converter 104, can be disabled to reduce power loss.

[0130] It should also be noted that, depending on the specific application and design requirements, Figure 21 The SIDO power converter shown can be replaced by a single-inductor multiple-output (SIMO) power converter.

[0131] exist Figures 4-21 In the illustrated embodiment, the input of the power converter 104 (current-mode switch) is connected to VIN. This connection is merely an example. Those skilled in the art will recognize many variations, alternatives, and modifications. For instance, depending on the application and design requirements, the input of the power converter 104 may be connected to a first voltage rail V+.

[0132] exist Figures 1-21 In the illustrated embodiment, the current comparator 142 can be implemented as a hysteresis comparator. The hysteresis of the current comparator 142 helps to set upper and lower thresholds to eliminate various transitions caused by noise or signal variations.

[0133] While embodiments of the present disclosure and their advantages have been described in detail, it should be understood that various changes, substitutions, and alternatives may be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims.

[0134] Furthermore, the scope of this application is not limited to the specific embodiments of the processes, machines, manufactures, compositions of matter, apparatuses, methods, and steps described in the specification. As will be readily understood by those skilled in the art from the disclosure of this disclosure, existing or future processes, machines, manufactures, compositions of matter, apparatuses, methods, or steps that perform substantially the same functions or achieve substantially the same results as the corresponding embodiments described herein can be utilized according to this disclosure. Therefore, the appended claims are intended to include such processes, machines, manufactures, compositions of matter, apparatuses, methods, or steps within their scope. Consequently, this specification and drawings are to be regarded only as an illustration of this disclosure as defined by the appended claims and are intended to cover any and all modifications, variations, combinations, or equivalents falling within the scope of this disclosure.

Claims

1. A system, characterized in that, include: A current-mode switch for providing DC voltage to noise-sensitive loads; as well as A linear amplifier, connected to the output of the current-mode switch, is used to generate a ripple current component to reduce the ripple current component generated by the current-mode switch. The resulting DC voltage after reducing the ripple current component is applied to the noise-sensitive load. The linear amplifier is powered by two voltage rails. The linear amplifier is used to extract a reduced supply voltage from the linear amplifier by means of at least one power conversion device coupled between the power supply and the linear amplifier, the supply voltage being the voltage difference between the two voltage rails; Wherein, the first voltage rail of the linear amplifier is used to connect to the output terminal of the source-type power converter, the second voltage rail of the linear amplifier is used to connect to the output terminal of the sink-type power converter, the source-type power converter and the sink-type power converter are used to reduce the supply voltage of the linear amplifier, the source-type power converter is a buck power converter connected between the power supply and the first voltage rail of the linear amplifier, the sink-type power converter is a switched capacitor power converter, and the switched capacitor power converter is configured as a 2:1 buck power converter having an input terminal connected to the output terminal of the buck power converter.

2. A system, characterized in that, include: A current-mode switch for providing DC voltage to noise-sensitive loads; as well as A linear amplifier, connected to the output of the current-mode switch, is used to generate a ripple current component to reduce the ripple current component generated by the current-mode switch. The resulting DC voltage after reducing the ripple current component is applied to the noise-sensitive load. The linear amplifier is powered by two voltage rails. The linear amplifier is used to extract a reduced supply voltage from the linear amplifier by means of at least one power conversion device coupled between the power supply and the linear amplifier, the supply voltage being the voltage difference between the two voltage rails; Wherein, the first voltage rail of the linear amplifier is used to connect to the output terminal of the source-type power converter, the second voltage rail of the linear amplifier is used to connect to the output terminal of the sink-type power converter, the source-type power converter and the sink-type power converter are used to reduce the supply voltage of the linear amplifier, the source-type power converter is a first buck power converter connected between the power supply and the first voltage rail of the linear amplifier, and the sink-type power converter is a second buck power converter having an input terminal connected to the output terminal of the first buck power converter.

3. A system, characterized in that, include: A current-mode switch for providing DC voltage to noise-sensitive loads; as well as A linear amplifier, connected to the output of the current-mode switch, is used to generate a ripple current component to reduce the ripple current component generated by the current-mode switch. The resulting DC voltage after reducing the ripple current component is applied to the noise-sensitive load. The linear amplifier is powered by two voltage rails. The linear amplifier is used to extract a reduced supply voltage from the linear amplifier by means of at least one power conversion device coupled between the power supply and the linear amplifier, the supply voltage being the voltage difference between the two voltage rails; Wherein, the first voltage rail of the linear amplifier is used to connect to the output terminal of the source-type power converter, the second voltage rail of the linear amplifier is used to connect to the output terminal of the sink-type power converter, the source-type power converter and the sink-type power converter are used to reduce the supply voltage of the linear amplifier, the source-type power converter is a boost power converter connected between the power supply and the first voltage rail of the linear amplifier, and the sink-type power converter is a buck power converter having an input terminal connected to the output terminal of the boost power converter.

4. A system, characterized in that, include: A current-mode switch for providing DC voltage to noise-sensitive loads; as well as A linear amplifier, connected to the output of the current-mode switch, is used to generate a ripple current component to reduce the ripple current component generated by the current-mode switch. The resulting DC voltage after reducing the ripple current component is applied to the noise-sensitive load. The linear amplifier is powered by two voltage rails. The linear amplifier is used to extract a reduced supply voltage from the linear amplifier by means of at least one power conversion device coupled between the power supply and the linear amplifier, the supply voltage being the voltage difference between the two voltage rails; Wherein, the first voltage rail of the linear amplifier is used to connect to the output terminal of the source-type power converter, the second voltage rail of the linear amplifier is used to connect to the output terminal of the sink-type power converter, the source-type power converter and the sink-type power converter are used to reduce the supply voltage of the linear amplifier, the source-type power converter is a boost power converter connected between the output terminal of the sink-type power converter and the first voltage rail of the linear amplifier, and the sink-type power converter is a buck power converter connected between the power supply and the second voltage rail of the linear amplifier.

5. A system, characterized in that, include: A current-mode switch for providing DC voltage to noise-sensitive loads; as well as A linear amplifier, connected to the output of the current-mode switch, is used to generate a ripple current component to reduce the ripple current component generated by the current-mode switch. The resulting DC voltage after reducing the ripple current component is applied to the noise-sensitive load. The linear amplifier is powered by two voltage rails. The linear amplifier is used to extract a reduced supply voltage from the linear amplifier by means of at least one power conversion device coupled between the power supply and the linear amplifier, the supply voltage being the voltage difference between the two voltage rails; Wherein, the first voltage rail of the linear amplifier is used to connect to the output terminal of the source-type power converter, the second voltage rail of the linear amplifier is used to connect to the output terminal of the sink-type power converter, the source-type power converter and the sink-type power converter are used to reduce the supply voltage of the linear amplifier, the source-type power converter is a buck-boost power converter connected between the power supply and the first voltage rail of the linear amplifier, and the sink-type power converter is a buck power converter having an input terminal connected to the output terminal of the buck-boost power converter.

6. A system, characterized in that, The system comprising any one of claims 1-5, wherein the current mode switch comprises: The first and second switches are connected in series; An inductor is connected between the output terminal of the current mode switch and the common node of the first switch and the second switch; A pulse width modulation (PWM) driver for generating gate drive signals for the first switch and the second switch; and A current comparator has an inverting input and a non-inverting input. The inverting input is used to receive a current-sensing signal proportional to the current flowing through the inductor, and the non-inverting input is grounded.

7. The system according to claim 6, characterized in that, in, The linear amplifier includes a third switch and a fourth switch connected in series between the first voltage rail and the second voltage rail of the linear amplifier, and a comparator for generating gate drive signals for the third switch and the fourth switch.

8. A system, characterized in that, include: A current-mode power converter used to generate voltage for the load; A linear amplifier is connected to the output of the current-mode power converter. The linear amplifier is used to reduce the ripple current component generated by the current-mode power converter. The voltage obtained after reducing the ripple current component is applied to the load. The linear amplifier is powered by two voltage rails. as well as A rail voltage generator is used to generate a reduced supply voltage for the linear amplifier, the supply voltage being the voltage difference between the two voltage rails; The orbital voltage generator includes: A first buck power converter is connected between the power supply and the first voltage rail of the linear amplifier; and A second buck power converter is connected between the output of the first buck power converter of the linear amplifier and the second voltage rail of the linear amplifier. The first buck power converter and the second buck power converter are used to reduce the supply voltage of the linear amplifier.

9. A system, characterized in that, include: A current-mode power converter used to generate voltage for the load; A linear amplifier is connected to the output of the current-mode power converter. The linear amplifier is used to reduce the ripple current component generated by the current-mode power converter. The voltage obtained after reducing the ripple current component is applied to the load. The linear amplifier is powered by two voltage rails. as well as A rail voltage generator is used to generate a reduced supply voltage for the linear amplifier, the supply voltage being the voltage difference between the two voltage rails; The rail voltage generator is a single-inductor dual-output SIDO power converter, which has a first output terminal connected to a first voltage rail of the linear amplifier and a second output terminal connected to a second voltage rail of the linear amplifier.

10. A system, characterized in that, The system includes the system of claim 8 or 9, wherein the current-mode power converter includes a first current-mode power conversion device and a second current-mode power conversion device connected in parallel, and wherein the transient response of the first current-mode power conversion device is faster than the transient response of the second current-mode power conversion device.

11. The system according to claim 10, characterized in that, in, The first current-mode power conversion device is used to reduce the ripple current component generated by the second current-mode power conversion device, and the linear amplifier is used to reduce the ripple current component generated by the first current-mode power conversion device.

12. A method, characterized in that, The method includes: Configure the current-mode power converter to operate in switching mode; Configure the linear amplifier to reduce the ripple current component generated by the current-mode power converter; and The power loss of the linear amplifier is reduced by applying a reduced supply voltage to the linear amplifier; wherein the linear amplifier is powered by two voltage rails, and the supply voltage is the voltage difference between the two voltage rails. The reduced supply voltage is generated by converting the output voltage of the power supply to a first voltage through a source-type power converter and converting the first voltage to a second voltage through a sink-type power converter. The first voltage rail of the linear amplifier is connected to the output terminal of the source-type power converter, and the second voltage rail of the linear amplifier is connected to the output terminal of the sink-type power converter. The source-type power converter is a first buck power converter connected between the power supply and the first voltage rail of the linear amplifier, and the sink-type power converter is a second buck power converter having an input terminal connected to the output terminal of the first buck power converter.

13. The method according to claim 12, characterized in that, in, The source-type power converter is a buck power converter, the sink-type power converter is a switched-capacitor power converter, and the linear amplifier includes a source-type branch connected to the source-type power converter and a sink-type branch connected to the sink-type power converter.

14. The method according to claim 13, characterized in that, The method further includes: During light-load operation, the sinking power converter, the sinking branch, and the current-mode power converter are disabled.

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