Multiphase power supply and method for generating output voltage thereof

Abstract

Disclosed are a multiphase power supply and a method for generating an output voltage. The multiphase power supply includes a multiphase conductive inductive regulator, an average inductor direct current resistance (DCR) current sampling circuit, and a pulse width modulation (PWM) controller. The secondary windings of multiple transformers and a compensation inductor of the multiphase conductive inductive regulator are connected in series to form a conductive inductor loop, which is coupled to the output voltage. The average inductor DCR current sampling circuit generates an average sampled voltage based on the output voltage, multiple switch node voltages of multiple voltage regulation blocks of the multiphase conductive inductive regulator, and the compensation inductor voltage across the compensation inductor. The PWM controller generates multiple PWM signals to drive the multiple voltage regulation blocks to generate the output voltage of the multiphase conductive inductive regulator based on the average sampled voltage. The multiphase power supply reduces the phase lag of the average sampled voltage during load transients, thereby improving stability.

Description

Technical Field

[0001] Embodiments of the present invention relate to an electronic circuit, and more particularly, to a multi-phase power supply. Background Art

[0002] A trans-inductor voltage regulator (TLVR) uses the primary winding of a transformer as the output inductor. In a multiphase TLVR, all corresponding transformer secondary windings are connected in series to a reference ground. Because these secondary windings are connected in series, changes in load current affect each phase, allowing the TLVR to achieve faster transient response than other regulator topologies.

[0003] Transductive inductor regulators can use constant on-time current-mode control to generate and stabilize the output voltage. Current-mode control uses a sampled current to indicate the current flowing through the output inductor as part of the constant on-time current control loop. Multiphase transductive inductor regulators can use a sampled current for each phase or an average sampled current for all phases. The sampled current can be obtained by using a sampling resistor, the output inductor's DC resistance (DCR), or other methods to sense the current flowing through the output inductor. Summary of the Invention

[0004] The present invention provides a multi-phase power supply and a method for generating an output voltage thereof.

[0005] According to an embodiment of the present invention, a multi-phase power supply is provided, comprising a multi-phase conductive inductor regulator, an average inductor direct current resistance (DCR) current sampling circuit, and a pulse width modulation (PWM) controller. The conductive inductor regulator includes multiple voltage regulation blocks, multiple transformers, and compensation inductors. Each transformer includes a primary winding that serves as the output inductor of the corresponding voltage regulation block. The secondary windings of the multiple transformers and the compensation inductor are connected in series to form a conductive inductor loop. The conductive inductor loop is coupled to the output voltage of the conductive inductor regulator, rather than to a reference ground. An average inductor DCR current sampling circuit is coupled to the output voltage of the conductive inductor regulator, multiple switch node voltages of the multiple voltage regulation blocks, and the compensation inductor voltage across the compensation inductor to generate an average sampled voltage. In one embodiment, a transconductance amplifier converts the average sampled voltage into an average sampled current. The PWM controller generates multiple PWM signals to drive the multiple voltage regulation blocks to generate an output voltage for each phase of the conductive inductor regulator based at least on the average sampled current.

[0006] In another embodiment, a multi-phase power supply includes a compensation inductor, multiple transformers, and multiple voltage regulation blocks. Each transformer includes a first winding and a second winding separated by an iron core. The second windings of the multiple transformers and the compensation inductor are connected in series to form a conductive inductor loop, which is coupled to the output voltage of a conductive inductor regulator rather than to a reference ground. Each voltage regulation block is configured as one phase of the conductive inductor regulator to provide an output voltage. The first winding of the corresponding transformer serves as the output inductor of the voltage regulation block, and the output current of the voltage regulation block flows through the output inductor.

[0007] In yet another embodiment, a method for generating an output voltage in a multi-phase power supply includes: coupling a conductive inductor loop of a conductive inductor regulator to an output voltage of the conductive inductor regulator rather than to a reference ground, wherein the conductive inductor loop includes a compensation inductor connected in series with the second windings of the plurality of transformers; detecting a current flowing through the compensation inductor and a current flowing through the first windings of the transformers to generate an average sampled current; and generating a plurality of control signals for driving a plurality of voltage regulation blocks based at least on the average sampled current, each voltage regulation block generating a current flowing through the first winding of the corresponding transformer to generate an output voltage of one phase of the conductive inductor regulator.

[0008] The multi-phase power supply and the method for generating an output voltage thereof improve the stability of the average sampling current when the load is in a transient changing state, and reduce the phase lag of the average sampling current, so that the phase of the average sampling current is consistent with the output current, thereby making the method of generating a PWM signal based on the average sampling current to drive the voltage regulation block to generate the output voltage more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to better understand the present invention, the present invention will be described in detail with reference to the following drawings, wherein the same elements have the same reference numerals.

[0010] Figure 1 FIG. 1 shows a schematic structural diagram of a conventional multi-phase conductive inductor regulator 100 .

[0011] Figure 2 Shown Figure 1 A waveform diagram 200 of the average sampled current and the output current of the conductive inductor regulator 100 is shown.

[0012] Figure 3 FIG. 4 shows a schematic structural diagram of a multi-phase conductive inductor regulator 300 according to an embodiment of the present invention.

[0013] Figure 4 FIG. 4 shows a circuit diagram of an inductor direct current resistance (DCR) current sampling circuit 400 according to an embodiment of the present invention.

[0014] Figure 5 FIG. 4 shows a circuit diagram of an average inductor DCR current sampling circuit 450 according to an embodiment of the present invention.

[0015] Figure 6 FIG. 4 is a schematic diagram illustrating an average inductor DCR current sampling circuit 450 coupled to a pulse width modulation (PWM) controller 500 according to an embodiment of the present invention.

[0016] Figure 7 FIG. 4 is a schematic diagram of a multi-phase power supply circuit 600 according to an embodiment of the present invention.

[0017] Figure 8 The embodiment of the present invention is shown Figure 7 A waveform diagram 650 of the average sampled current and the output current of the multi-phase power supply circuit 600 is shown.

[0018] Figure 9 A method 700 for generating an output voltage of a conductive inductor regulator according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0019] Specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the present invention. In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that these specific details are not necessarily required to practice the present invention. In other instances, well-known circuits, materials, or methods are not described in detail to avoid obscuring the present invention.

[0020] Figure 1 FIG1 shows a schematic diagram of the structure of a conventional multi-phase conductive inductor regulator 100. The conductive inductor regulator 100 includes a plurality of voltage regulator blocks 110 (i.e., 110-1, 110-2, ..., 110-n). Each voltage regulator block 110 generates one phase of the conductive inductor regulator 100 to provide an output voltage VOUT. Figure 1 In the illustrated embodiment, voltage regulation block 110-1 generates a first phase ("PHASE 1") of output voltage VOUT, voltage regulation block 110-2 generates a second phase ("PHASE 2") of output voltage VOUT, and so on. Each voltage regulation block 110 includes a pair of switches driven by corresponding PWM signals generated by a pulse width modulation (PWM) controller (not shown). The high-side switch of each voltage regulation block 110 is connected to input voltage VIN, and the low-side switch of each voltage regulation block 110 is coupled to a reference ground. The multiple PWM signals interleave to drive the voltage regulation blocks 110 to generate output voltage VOUT.

[0021] A transformer typically has a primary winding and a secondary winding separated by an iron core. The windings of a transformer may also be referred to as the primary winding and the secondary winding. Figure 1 In the illustrated embodiment, each voltage regulator block 110 has a corresponding transformer, whose primary winding serves as the output inductor Lo of the voltage regulator block 110. The output current of each voltage regulator block 110 flows through its output inductor Lo. The secondary winding of this transformer is coupled in series with the secondary windings of the transformers corresponding to the other voltage regulator blocks 110. A compensation inductor Lc is connected in series with the secondary windings of all transformers, forming a conductive inductor loop. The conductive inductor loop of the conductive inductor regulator 100 is coupled to a reference ground.

[0022] The inventors have discovered a potential problem with the conductive inductor regulator 100. Specifically, when using average inductor DC resistance (DCR) current sensing, the average sampled current may introduce instability and phase lag in the constant on-time current mode control loop. Figure 2 To illustrate this problem, a curve 121 shows an average sampling current obtained by using average inductor DCR current detection, and a curve 122 shows an output current of the conductive inductor regulator 100. The curves 121 and 122 are obtained by simulation.

[0023] exist Figure 2 In FIG, the left vertical axis represents the level of the output voltage VOUT in volts; the horizontal axis represents time in seconds; and the right vertical axis represents the level of the output current in amperes. It should be noted that in some embodiments, Figure 2 The signal shown can be scaled and used internally by the PWM controller to implement a load line. For example, under load transient conditions, i.e., when the output current changes rapidly (see curve 122), the average sampled current lags behind the output current, resulting in a loss of phase margin and thus instability (see the oscillation in curve 121). This makes the average sampled current unreliable as a basis for generating a PWM signal to drive the voltage regulation block to generate the output voltage VOUT.

[0024] Figure 3 FIG. 3 shows a schematic structural diagram of a multi-phase conductive inductor regulator 300 according to an embodiment of the present invention. Figure 3 In the embodiment shown, the conductive inductor regulator 300 includes a plurality of voltage regulation blocks 320 (i.e., 320-1, 320-2, ..., 320-n). Each voltage regulation block 320 generates one phase of the conductive inductor regulator 300 to provide an output voltage VOUT. Figure 3 In the illustrated embodiment, the voltage regulation block 320 - 1 generates a first phase PHASE1 of the output voltage VOUT, the voltage regulation block 320 - 2 generates a second phase PHASE2 of the output voltage VOUT, and so on.

[0025] The voltage regulation block 320 may be, for example, a buck regulator. Figure 3 In the illustrated embodiment, each voltage regulation block 320 includes a high-side switch M1 and a low-side switch M2. Each switch M1 and M2 may include a metal oxide semiconductor field effect transistor, a bipolar transistor, or other types of transistors. Figure 3 In the illustrated embodiment, a first terminal of the high-side switch M1 is coupled to the input voltage VIN of the conductive inductor regulator 300 at node 306, and a second terminal of the high-side switch M1 is coupled to a switching node formed by the high-side switch M1 and the low-side switch M2. A first terminal of the low-side switch M2 is coupled to the second terminal of the high-side switch M1 to form a switching node, and a second terminal of the low-side switch M2 is coupled to a reference ground. Figure 3 In the illustrated embodiment, the switch node 301 of the voltage regulation block 320 - 1 has a switch node voltage VSW1 , the switch node 302 of the voltage regulation block 320 - 2 has a switch node voltage VSW2 , and so on.

[0026] exist Figure 3 In the embodiment shown, the third terminals of switches M1 and M2 are coupled together and driven by corresponding control signals. In one embodiment, the control signals may be PWM signals. Figure 3 In the illustrated embodiment, a first PWM signal PWM1 drives switches M1 and M2 of the voltage regulation block 320-1, a second PWM signal PWM2 drives switches M1 and M2 of the voltage regulation block 320-2, and so on. The multiple PWM signals (i.e., PWM1, PWM2, ..., PWMn) are interleaved to generate the output voltage VOUT of the conductive inductor regulator 300 at the output node 305.

[0027] The output current of the voltage regulation block 320 flows through its output inductor Lo. Figure 3 In the illustrated embodiment, each voltage regulation block 320 has a corresponding transformer, with the primary winding of the transformer serving as the output inductor Lo of the voltage regulation block 320. Taking voltage regulation block 320-1 as an example, transformer T1 includes a primary winding 321 having a first end coupled to the switch node 301 and a second end coupled to the output node 305. Primary winding 321 serves as the output inductor Lo of voltage regulation block 320-1. Similarly, for voltage regulation block 320-2, transformer T2 includes a primary winding 322 having a first end connected to the switch node 302 and a second end connected to the output node 305. Primary winding 322 serves as the output inductor Lo of voltage regulation block 320-2. The turns ratio between the primary winding and the secondary winding of each transformer can be, for example, 1:1.

[0028] The secondary windings of the multiple transformers T1, T2, ..., Tn corresponding to the voltage regulation block 320 are connected in series with the compensation inductor Lc to form a conductive inductance loop (for example, but not limited to Figure 3 More specifically, the compensation inductor Lc, the secondary winding 331 of the transformer T1, the secondary winding 332 of the transformer T2, and the secondary windings of other transformers are connected in series to form a conductive inductor loop of the conductive inductor regulator 300.

[0029] It should be noted that the conductive inductor loop of the conductive inductor regulator 300 is not coupled to the reference ground, which is significantly different from the traditional conductive inductor regulator. On the contrary, the conductive inductor loop of the conductive inductor regulator 300 is coupled to the output voltage VOUT. Accordingly, the current flowing through the conductive inductor loop generates a compensation inductor voltage VLc at the node 341 located at one end of the compensation inductor Lc, and the node 342 located at the other end of the compensation inductor Lc is coupled to the output voltage VOUT. This allows the output inductance value of the conductive inductor regulator 300 to be introduced into the average inductor DCR current sampling circuit to stabilize the constant conduction time current control loop, which will be further explained below. In general, the output inductance value of each phase of the conductive inductor regulator can be approximately equal to Lc / n, and the total output inductance value of the conductive inductor regulator can be approximately equal to Lc / n. 2 , where Lc is the inductance value of the compensation inductor, and n is the number of phases of the conductive inductor regulator.

[0030] exist Figure 3 In the illustrated embodiment, for ease of description, each transformer includes a primary winding and a secondary winding. Those skilled in the art will appreciate that the conductive inductor regulator in the embodiment of the present invention may also include transformers with different numbers of windings or different winding configurations.

[0031] Figure 4 A circuit diagram of an inductor DCR current sampling circuit 400 according to an embodiment of the present invention is shown. The current sampling circuit 400 is used in a single phase. A multi-phase conductive inductor regulator has multiple current sampling circuits 400, each of which is used in one phase circuit.

[0032] Generally, inductor DCR current sensing utilizes the parasitic DCR of the output inductor Lo to detect the current flowing through the output inductor Lo. The output inductor Lo can be considered to consist of a series-connected inductor value L and a parasitic DCR, placed in parallel with a resistor-capacitor network. A sampled voltage is obtained across the capacitor in the resistor-capacitor network. The time constant of the resistor-capacitor network is designed to match the time constant of the series-connected inductor value L and the parasitic DCR. It should be noted that the DCR of the output inductor Lo can be the parasitic DCR between the switch node and the output node. For example, to perform inductor DCR current sensing on the first phase circuit, the resistor-capacitor network can be placed between the switch node 301 and the output node 305.

[0033] The current sampling circuit 400 is Figure 3 The first phase (i.e., voltage regulation block 320-1) of the conductive inductive regulator 300 is used as an example for explanation. The winding 321 of the transformer T1 serves as the output inductor Lo of the voltage regulation block 320-1. The current sampling circuit 400 includes a resistor-capacitor network consisting of a capacitor C1 and resistors R3 and R4. Resistor R3 serves as a series resistor, and variable resistor R4 serves as a thermal compensation resistor (e.g., a negative thermal coefficient (NTC) thermistor). One end of the winding 321 has a pin 461, and the other end has a pin 471. The resistor-capacitor network is connected to both ends of the winding 321, for example, coupled to pin 471 through resistor R1 and coupled to pin 461 through resistor R2. Pin 461 is coupled to the output node 305 of the output voltage VOUT, and pin 471 is coupled to the switching node 301 of the switching node voltage VSW1. In order to accurately detect the effects of the parasitic DCR, pins 461 and 471 are located as close as possible to the endpoints of the primary winding 321.

[0034] The voltage across capacitor C1 is the sampling voltage, which is located between node 401 and node 402. The sampling voltage indicates or represents the current flowing through winding 321. Nodes 401 and 402 can be connected to corresponding input pins of a PWM controller (labeled "CSAP" and "CSAN" in this embodiment). The PWM controller may include a transconductance amplifier for converting the sampling voltage into a sampling current. The PWM controller may use the sampling current to generate a first PWM signal (PWM1) to drive the first phase, i.e., the voltage regulation block 320-1. The conductive inductor regulator 300 has a multi-phase circuit, and therefore requires multiple sampling circuits 400, each sampling circuit 400 for one of the phase circuits. In addition, for each phase, the PWM controller may include a separate sampling voltage input pin and a transconductance amplifier.

[0035] Considering cost, design simplicity or other reasons, the constant on-time current mode control loop of the PWM controller may adopt an average sampled current, where the average sampled current indicates or represents multiple currents, each current flowing through the output inductor of a corresponding phase. Figure 5 FIG4 shows a circuit diagram of an average inductor DCR current sampling circuit 450 according to an embodiment of the present invention. The average inductor DCR current sampling circuit 450 detects the current flowing through the compensation inductor and the current flowing through each output inductor.

[0036] Similar to the inductor DCR current sampling circuit 400, the average inductor DCR current sampling circuit 450 includes a resistor-capacitor network 453 for inductor DCR current detection. Figure 5 In the illustrated embodiment, the RC network 453 is composed of a capacitor C2 and resistors R5 and R6. Resistor R5 serves as a series resistor, and variable resistor R6 serves as a thermal compensation resistor (e.g., an NTC thermistor). The current sampling circuit 450 further includes an averaging network comprising resistors R11, R21, multiple resistors R10 (i.e., R10-1, R10-2, ..., R10-n), and multiple resistors R20 (i.e., R20-1, R20-2, ..., R20-n).

[0037] The output inductor Lo of each voltage regulation block 320 is coupled between the switch node voltage of that voltage regulation block 320 and the output voltage VOUT. More specifically, the output inductor Lo of voltage regulation block 320-1 is coupled between the output voltage VOUT at output node 305 and the switch node voltage VSW1 at switch node 301; the output inductor Lo of voltage regulation block 320-2 is coupled between the output voltage VOUT at output node 305 and the switch node voltage VSW1 at switch node 302; and so on. The RC network 453 includes a node 451 and a node 452, and an average sampled voltage is obtained across the RC network. Through the RC network 451, node 451 is connected to the output node 305, node 452 is connected to each switch node, and the RC network 453 is connected in parallel with each output inductor Lo, thereby obtaining an average sampled current. The average sampled current indicates or represents the current flowing through the output inductors Lo of all phases.

[0038] exist Figure 5 In the illustrated embodiment, each switch node is connected to node 452 via a corresponding resistor R10. More specifically, switch node 301 is connected to node 452 via resistor R10-1, switch node 302 is connected to node 452 via resistor R10-2, and so on. In one embodiment, all resistors R10 have equal resistance. The compensation inductor voltage VLc at node 341 is connected to node 452 via resistor R11.

[0039] exist Figure 5 In the embodiment shown, the output voltage VOUT is connected to the node 451 through a plurality of resistors R20 and R21. The resistor R21 is used to connect the conductive inductor loop and the output voltage VOUT, and each resistor R20 is used to conduct one phase of the inductive regulator 300. Figure 5 In the embodiment shown, the resistance values ​​of all resistors R20 and R21 are equal. In one embodiment, the resistance values ​​of all resistors R20 and R21 are 10Ω.

[0040] The multiple resistors R20 and R21 can be directly connected to corresponding pins of the inductor to achieve more accurate DCR current sensing. In this embodiment, the pins are connected to the output voltage VOUT. Similarly, the multiple resistors R10 and R11 can be directly connected to corresponding pins of the inductor. In this embodiment, the pins are connected to the switch node voltage VSW or the compensation inductor voltage VLC. For example, the primary winding 321 of the voltage regulation block 320-1 has pins 461 and 471, where pin 461 is connected to the output voltage VOUT and pin 471 is connected to the switch node voltage VSW1. To include the primary winding 321 in DCR current sensing, pin 461 is connected to node 451 through resistor R20-1, and pin 471 is connected to node 452 through resistor R10-1. Similarly, the compensation inductor Lc has pins 462 and 472, where pin 462 is connected to the output voltage VOUT and pin 472 is connected to the compensation inductor voltage VLc. In order to introduce the compensation inductor Lc into the DCR current detection, the pin 462 is connected to the node 451 through the resistor R21, and the pin 472 is connected to the node 452 through the resistor R11.

[0041] In order to stabilize the constant on-time current mode control loop for regulating the output voltage VOUT, the conductive inductor loop of the conductive inductor regulator 300 is coupled to the output voltage VOUT instead of being coupled to the reference ground; and the input of the averaging network of the current sampling circuit 450 includes the output inductance value of the conductive inductor regulator 300. Figure 5 In the illustrated embodiment, the compensation inductor voltage VLc at node 341 is connected to node 452 via resistor R11, and node 451 is connected to the output voltage VOUT at output node 305 via resistor R21, so that the input of the averaging network of the current sampling circuit 450 includes the output inductance value of the conductive inductor regulator 300. This allows the current sampling circuit 450 to detect the current flowing through the compensation inductor Lc and the current flowing through each output inductor Lo to generate an average sampling voltage, which is converted into an average sampling current and used in the constant on-time current mode control loop.

[0042] In general, the values ​​of the components described in the embodiments of the present invention depend on the requirements of the specific application. For example, the output current, the steady-state time constant of the resistor-capacitor network, and the impedance required by the PWM controller between node 452 and node 451, etc. In one embodiment, the resistance of resistor R11 is equal to the resistance of resistor R10 divided by the number of phases. For example, assuming that the resistance of each resistor R10 is 13.4KΩ and there are 8 phases, the resistance of resistor R11 can be approximately equal to 13.4KΩ / 8 (for example, 1.65KΩ). Reducing the ratio of resistor R11 to resistor R10 can increase the contribution of the output inductance of the conductive inductor regulator 300 to the average sampled current. This ratio can be adjusted to optimize the various performance parameters of the conductive inductor regulator 300.

[0043] Figure 6 FIG2 shows a schematic diagram of an average inductor DCR current sampling circuit 450 coupled to a PWM controller 500 according to an embodiment of the present invention. The PWM controller 500 includes a PWM signal generator 501 and a transconductance amplifier 502. For the sake of brevity and clarity, other components of the PWM controller 500 that are not relevant to understanding the embodiments of the present invention are not shown in the figure.

[0044] In one embodiment, PWM controller 500 can be a multi-phase, constant on-time, current-mode PWM controller. PWM controller 500 can be a commercially available PWM controller or an improved PWM controller. Generally, such PWM controllers can be provided by various vendors, including Monolithic Power Systems, Inc.

[0045] exist Figure 6 In the illustrated embodiment, PWM controller 500 is packaged as an integrated circuit with multiple pins, including pins CSAN and CSAP, which receive the average sampled voltage between nodes 451 and 452 of current sampling circuit 450. A transconductance amplifier 502 receives the average sampled voltage and converts it into an average sampled current. This average sampled current serves as input to PWM signal generator 501. PWM signal generator 501 employs a conventional PWM algorithm to generate multiple interleaved PWM signals (i.e., PWM1, PWM2, etc.) based on the average sampled current.

[0046] Figure 7 FIG. 1 shows a schematic diagram of a multi-phase power supply circuit 600 according to an embodiment of the present invention. Figure 7In the illustrated embodiment, a multi-phase power supply circuit 600 includes a conductive inductor regulator 300, a current sampling circuit 450, and a PWM controller 500. The conductive inductor regulator 300 receives an input voltage VIN and generates an output voltage VOUT. The current sampling circuit 450 is coupled to the node of the output voltage VOUT, the compensation inductor voltage VLc, and the switch node voltages VSW (i.e., VSW1, VSW2, etc.) to detect the current flowing through the compensation inductor Lc of the conductive inductor regulator 300 and the current flowing through the multiple output inductors Lo. The current sampling circuit 450 generates an average sampled voltage based on the sampled currents flowing through the compensation inductor Lc and the multiple output inductors Lo. This average sampled voltage is input to pins CSAN and CSAP of the PWM controller 500. The PWM controller 500 converts the average sampled voltage into an average sampled current, and uses the average sampled current to generate a plurality of interleaved PWM signals (PWM1, PWM2, etc.) to drive the voltage regulation block 320 of the conductive inductor regulator 300 to generate the output voltage VOUT.

[0047] Figure 8 The embodiment of the present invention is shown Figure 7 The waveform diagram 650 of the average sampling current and output current of the multi-phase power supply circuit 600 is shown. Curve 651 represents the average sampling current, and curve 652 represents the output current. Curves 651 and 652 are obtained by simulation. Figure 8 In the embodiment shown, the left vertical axis represents the level of the output voltage VOUT in volts; the horizontal axis represents time in seconds; and the right vertical axis represents the level of the output current in amperes. Figure 8 The signal shown can be scaled and used internally by the PWM controller 500 to implement a load line. Using the average inductor DCR current sampling circuit 450 in the conductive inductor regulator 300 helps the average sampled current (curve 651) remain stable and maintain phase consistency with the output current (curve 652) when the load is in a transient state.

[0048] Figure 9 A method 700 for generating an output voltage of a conductive inductor regulator according to an embodiment of the present invention is shown. For ease of description, the method 700 for generating an output voltage of a conductive inductor regulator is described using the components disclosed above. Those skilled in the art will appreciate that other components may also be applied to the present invention without affecting its advantages.

[0049] exist Figure 9In the illustrated embodiment, the conductive inductor loop of the conductive inductor regulator is connected to the output voltage rather than to a reference ground (step 701). The conductive inductor loop includes the secondary windings of multiple transformers connected in series with the compensation inductor of the conductive inductor regulator. The primary winding of the transformer serves as the output inductor of the voltage regulation block of the conductive inductor regulator.

[0050] The current flowing through the compensation inductor and the current flowing through the output inductor of each voltage regulation block are detected to generate an average sampled current (step 702). For example, an average sampled voltage can be obtained by using the output inductance value of the conductive inductor regulator and the inductance value of each output inductor as inputs to an average inductor DCR current sampling circuit. The average sampled voltage can be generated across the capacitor of the resistor-capacitor network of the average inductor DCR current sampling circuit. In one embodiment, a transconductance amplifier can be used to convert the average sampled voltage into an average sampled current. A PWM controller generates a plurality of interleaved PWM signals based at least on the average sampled current, and the plurality of PWM signals serve as control signals (step 703). The plurality of PWM signals drive the corresponding voltage regulation blocks in the conductive inductor regulator to generate the output voltage of the conductive inductor regulator (step 704).

[0051] While the present invention has been described with reference to several exemplary embodiments, it should be understood that the terms used are descriptive and illustrative, rather than restrictive. Since the present invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above-described embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope of the appended claims. All changes and modifications that fall within the scope of the claims or their equivalents are intended to be covered by the appended claims.

Claims

1. A multiphase power supply comprising: A multi-phase conductive inductor regulator includes a plurality of voltage regulation blocks, a plurality of transformers, and a compensation inductor. Each transformer includes a primary winding and a secondary winding. The primary winding serves as an output inductor of the corresponding voltage regulation block. The secondary windings and the compensation inductor of the plurality of transformers are connected in series to form a conductive inductor loop. The conductive inductor loop is coupled to the output voltage of the conductive inductor regulator instead of being coupled to a reference ground. an average inductor direct current resistance (DCR) current sampling circuit, receiving the output voltage of the conductive inductor regulator, a plurality of switch node voltages of a plurality of voltage regulation blocks, and a compensation inductor voltage across the compensation inductor to generate an average sampling voltage; as well as A pulse width modulation (PWM) controller generates a plurality of PWM signals to drive the plurality of voltage regulation blocks to generate an output voltage of a conductive inductor regulator based on at least the average sampling voltage.

2. The multi-phase power supply of claim 1 , wherein the PWM controller comprises: a transconductance amplifier, converting the average sampled voltage into an average sampled current; as well as The PWM signal generator generates a plurality of PWM signals according to the average sampling current.

3. The multi-phase power supply of claim 1 , wherein the average inductor DCR current sampling circuit comprises an averaging network and a resistor-capacitor network, the resistor-capacitor network comprises a series resistor and a capacitor, and the average sampled voltage is obtained across at least one capacitor in the resistor-capacitor network.

4. The multi-phase power supply of claim 3, wherein the resistor-capacitor network in the average inductor DCR current sampling circuit further comprises: Thermal compensation resistor; in The series resistor and the thermal compensation resistor form a series circuit, and the series circuit is connected in parallel with the capacitor.

5. The multi-phase power supply of claim 3 , wherein the averaging network of the average inductor DCR current sampling circuit comprises: a first resistor, connecting the compensation inductor voltage to the first terminal of the RC network; a plurality of second resistors, wherein the first end of the RC network is connected to a plurality of switch node voltages respectively through the plurality of second resistors; as well as A plurality of third resistors, the second end of the RC network is connected to the output voltage through the plurality of third resistors.

6. The multi-phase power supply of claim 1 , wherein each voltage regulation block comprises a high-side switch and a low-side switch, a first end of the high-side switch being connected to an input voltage, a second end of the high-side switch being connected to a first end of the low-side switch to form a switch node of the voltage regulation block, a second end of the low-side switch being coupled to a reference ground, a third end of the high-side switch being connected to a third end of the low-side switch and being driven by a corresponding PWM signal.

7. A multiphase power supply comprising: Compensation inductance; a plurality of transformers, each transformer comprising a first winding and a second winding separated by an iron core, the second windings of the plurality of transformers being connected in series with a compensation inductor to form a conductive inductor loop, the conductive inductor loop being connected to an output voltage of a conductive inductor regulator; and Multiple voltage regulation blocks are provided, each of which is configured as one phase of a conductive inductor regulator to provide an output voltage. Each voltage regulation block includes a first winding of a corresponding transformer as an output inductor of the voltage regulation block.

8. The multi-phase power supply of claim 7 , further comprising an average inductor direct current resistance (DCR) current sampling circuit, the average inductor DCR current sampling circuit comprising a resistor-capacitor network, a first end of the resistor-capacitor network connected to the output voltage of the conductive inductor regulator, and a second end of the resistor-capacitor network connected to a compensation inductor voltage across the compensation inductor and multiple switch node voltages of the multiple voltage regulation blocks to generate an average sampled voltage.

9. The multi-phase power supply of claim 8, wherein the average inductor DCR current sampling circuit generates an average sampling voltage across the capacitor in the RC network.

10. The multi-phase power supply of claim 8, further comprising: A transconductance amplifier converts the average sampling voltage into an average sampling current.

11. The multi-phase power supply of claim 7, wherein each voltage regulation block comprises a high-side switch and a low-side switch, wherein the high-side switch and the low-side switch generate an output voltage under the control of a control signal.

12. The multi-phase power supply of claim 11, wherein a first terminal of the high-side switch is connected to an input voltage, a second terminal of the high-side switch is connected to a first terminal of the low-side switch to form a switch node, and a second terminal of the low-side switch is coupled to a reference ground.

13. The multi-phase power supply of claim 12, wherein the third terminal of the high-side switch is connected to the third terminal of the low-side switch to receive a control signal, and generates an output voltage of one phase of the conductive inductor regulator under the control of the control signal.

14. The multi-phase power supply of claim 13, wherein the control signal comprises a pulse width modulation (PWM) signal.

15. A method for generating an output voltage from a multi-phase power supply, comprising: connecting a conductive inductor loop of a conductive inductor regulator to an output voltage of the conductive inductor regulator without being coupled to a reference ground, wherein the conductive inductor loop includes a compensation inductor connected in series with the second winding of each transformer of the plurality of transformers; detecting a current flowing through the compensation inductor and a current flowing through the first winding of each transformer to generate an average sampled current; as well as A plurality of control signals are generated. The plurality of control signals respectively drive a plurality of voltage regulation blocks of the conductive inductor regulator based at least on the average sampled current. Each voltage regulation block generates a current flowing through a first winding of a corresponding transformer, thereby generating one phase of the conductive inductor regulator.

16. The method of generating an output voltage with a multi-phase power supply as claimed in claim 15, wherein the plurality of control signals comprise interleaved pulse width modulation (PWM) signals.

17. The method for generating an output voltage from a multi-phase power supply as claimed in claim 15, wherein detecting the current flowing through the compensation inductor and the current flowing through the first winding of each transformer to generate the average sampled current comprises: Using the output inductance value of the conductive inductor regulator and the inductance value of the first winding of each transformer as inputs of an average inductor DCR current sampling circuit to generate an average sampling voltage; as well as The average sampled voltage is converted into an average sampled current.

18. The method for generating an output voltage from a multi-phase power supply as claimed in claim 17, wherein the average inductor DCR current sampling circuit comprises a resistor-capacitor network, and the average sampling voltage is generated across a capacitor in the resistor-capacitor network.

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