A multi-mode adaptive switching power supply

Abstract

The present application provides a multi-mode adaptive switching power supply, relating to the field of electronic switch technology. A transconductance operational amplifier extracts the ripple voltage amplitude from the load voltage and compares it with a fixed reference voltage, converting the ripple amplitude into a proportional analog compensation current. An analog-to-digital converter quantifies the ripple voltage into digital increments, which are then superimposed by a digital accumulator and the digital target signal output by the controller to generate a digital control code containing the real-time ripple compensation amount. The digital-to-analog converter dynamically adjusts the reference voltage, compares it with the load voltage in real time via a dynamic comparator, and drives the switch to adjust its on-time. This achieves real-time quantitative analysis and dynamic compensation of the ripple amplitude, avoiding the accumulation of low-frequency ripple components. Furthermore, the digital accumulator's superposition logic enables the compensation amount to be continuously adjusted with the ripple, resolving the hysteresis problem associated with threshold comparisons. This allows for rapid response to load changes, particularly in high-frequency switching scenarios, improving the accuracy and stability of the power supply's response to transient loads.

Description

Technical Field

[0001] The present application relates to the technical field of electronic switches, and in particular to a multi-mode adaptive switching power supply. Background Art

[0002] With the rapid development of integrated circuit technology, digital loads (such as CPUs and DSPs) are placing higher demands on the efficiency and stability of power supply systems. Among adaptive voltage regulation technologies, switching power supplies using pulse-skipping modulation (PSM) have become an important solution for improving power supply efficiency because they can reduce losses by skipping switching cycles at light loads.

[0003] The related art discloses an "adaptive voltage regulator based on PSM modulation mode", with application number "201410300318.1", which discloses the following technical solution: "An adaptive voltage regulator based on PSM modulation mode, composed of a conduction time generation module, a digital-to-analog converter, a dynamic comparator and a digital logic control module; wherein the positive input terminal of the dynamic comparator is connected to the external input voltage, the negative input terminal thereof is connected to the output terminal of the digital-to-analog converter, the output terminal of the dynamic comparator is connected to the first input terminal of the conduction time generation module; the input terminal of the digital-to-analog converter is connected to the first output terminal of the digital logic control module; the digital logic control module The module's first input is connected to an external input voltage, and its second output is connected to the second input of the on-time generation module. This enables the Buck power converter to adaptively step down and adjust the output voltage while ensuring constant on-time energy. The Buck power converter uses PSM modulation to output a stable voltage, and adjusts the duty cycle of the power transistor to different values ​​when the output voltage varies, thus improving output voltage ripple. The reduced operating voltage of the digital load further reduces the energy consumption of the digital integrated circuit. Furthermore, the circuit utilizes more digital methods to implement logic relationships and algorithms, saving chip area and facilitating integration.

[0004] However, the fixed on-time design in PSM mode in these technologies prevents the power supply from adjusting energy transfer in response to transient load changes, increasing low-frequency ripple in the output voltage. Furthermore, the control logic relies solely on simple threshold comparisons and lacks real-time quantitative analysis of the ripple voltage amplitude, making it difficult to accurately compensate for voltage deviations caused by component parameter drift or environmental changes. This drawback is further amplified in high-frequency switching scenarios, causing the power supply output ripple to exceed the allowable range, impacting load stability and accuracy.

[0005] Therefore, the related technology has poor ripple suppression effect due to insufficient low-frequency ripple suppression and delayed transient response. Summary of the Invention

[0006] The present application provides a multi-mode adaptive switching power supply for improving poor ripple suppression.

[0007] In a first aspect, the present application provides a multi-mode adaptive switching power supply, which is applied to a power converter. The power converter includes a switch tube MP, a diode D, an inductor L, a capacitor C, and a load; the input end of the switch tube MP is connected to the input voltage, and the output end is connected to the input end of the inductor L; the diode D, the capacitor C, and the load are connected in parallel, and the cathode of the diode D is connected to the connection point between the switch tube MP and the inductor L, one end of the load is connected to the output end of the inductor L, and one end of the capacitor C is connected to the connection point between the inductor L and the load; the multi-mode adaptive switching power supply includes: a transconductance operational amplifier, an analog-to-digital converter, a digital accumulator, a digital-to-analog converter, a dynamic comparator, and a controller unit; the first input end of the transconductance operational amplifier is connected to the load, and the second input end is connected to the reference voltage; it is used to detect the ripple voltage amplitude of the load, And output an analog compensation current according to the ripple voltage amplitude; the input end of the analog-to-digital converter is connected to the output end of the transconductance operational amplifier, and is used to convert the analog compensation current into a digital increment; the first input end of the digital accumulator is connected to the output end of the analog-to-digital converter, and the second input end is connected to the first output end of the controller unit, and is used to superimpose the digital increment on the digital target signal to obtain a digital control code; the input end of the digital-to-analog converter is connected to the output end of the digital accumulator, and is used to convert the digital control code into a reference voltage; the first input end of the dynamic comparator is connected to the output end of the digital-to-analog converter, and the second input end is connected to the load, and is used to generate a digital pulse according to the reference voltage and the load voltage, and the load voltage is the voltage of the load; the first input end of the controller unit is connected to the load, and is used to generate a digital target signal according to the load voltage.

[0008] Using this technical solution, a transconductance operational amplifier extracts the ripple voltage amplitude from the load voltage and compares it with a fixed reference voltage, converting the ripple amplitude into a proportional analog compensation current. An analog-to-digital converter quantifies the ripple voltage into digital increments, which are then superimposed with the digital target signal output by the controller through a digital accumulator to generate a digital control code containing the real-time ripple compensation value. The DAC dynamically adjusts the reference voltage, which is then compared with the load voltage in real time via a dynamic comparator to drive the switch to adjust its on-time. Compared to related technologies, this solution achieves real-time quantification and dynamic compensation of the ripple amplitude through a hybrid analog-digital closed-loop, avoiding the accumulation of low-frequency ripple components. Furthermore, the digital accumulator's superposition logic enables the compensation value to be continuously adjusted with the ripple, eliminating the hysteresis associated with threshold comparisons. This allows for rapid response to load changes, especially in high-frequency switching scenarios, keeping output ripple within an acceptable range and improving the power supply's response accuracy and stability to transient loads.

[0009] In combination with some embodiments of the first aspect, in some embodiments, the multi-mode adaptive switching power supply also includes: a PSM / PWM wave generator; the second input end of the controller unit is connected to the first input end of the PSM / PWM wave generator; the controller unit generates a control signal according to the load voltage; the second input end of the PSM / PWM wave generator is connected to the output end of the dynamic comparator; used to produce a PSM / PWM wave according to the control signal and the digital target signal, wherein the control signal controls the pulse waveform of the PSM / PW wave, and the digital target signal controls the time point of the pulse of the PSM / PW wave; the control end of the switch tube MP is connected to the output end of the PSM / PWM wave generator, and is used to control the switching of the input end and the output end according to the PSM / PWM wave.

[0010] By employing this technical solution, the controller unit generates a control signal based on the load voltage. Combined with the digital pulse output from the dynamic comparator, it drives the PSM / PWM generator to switch between different load modes. Under light load conditions, the control signal causes the PSM / PWM generator to skip some switching cycles, reducing energy loss. Under heavy load conditions, it switches to PWM mode and adjusts the duty cycle to stabilize output. The digital target signal controls the pulse timing (e.g., synchronizing with the load clock cycle) to ensure that switching is synchronized with the load's energy demand. The control signal adjusts the pulse waveform (e.g., the duty cycle) to optimize energy transfer efficiency. For example, when the load current increases, the controller detects a drop in load voltage and, through a control signal, increases the PWM duty cycle, extending the switch's on-time and increasing inductor energy storage, thereby rapidly increasing the output voltage. Under light load conditions, the PSM mode reduces switching losses by reducing the number of on-times. These two factors work together to automatically select the optimal operating mode across the power supply's entire load range, avoiding the idling losses associated with PWM mode under light load conditions while addressing the stability issues associated with PSM mode under heavy load conditions, achieving a balance between efficiency and dynamic performance.

[0011] In combination with some embodiments of the first aspect, in some embodiments, the PSM / PWM wave generator specifically includes a dynamic frequency adjustment module; the dynamic frequency adjustment module is used to generate a dithering code and adjust the PSM / PWM wave according to the dithering code, wherein when the dithering code is a first sequence, the switching period is increased, and when the dithering code is a second sequence, the switching period is reduced.

[0012] By employing this technical solution, a dithering code (e.g., a pseudo-random binary sequence) generated by the dynamic frequency adjustment module is applied to the switching period of the PSM / PWM wave. When the dithering code is in the first sequence, the switching period is lengthened to reduce the frequency; when it is in the second sequence, the period is shortened to increase the frequency. This mechanism causes the switching frequency to fluctuate randomly within a preset range (e.g., 40kHz-1MHz), breaking the periodicity of the associated fixed frequency and thus dispersing electromagnetic interference (EMI) energy peaks (e.g., converting a strong single-frequency interference signal into a weaker interference signal over a wide bandwidth). Furthermore, the random frequency prevents the switching period from coinciding with the circuit's natural resonant frequency, suppressing mechanical vibration and audible noise. This distributes the energy over a wider frequency band, avoiding the sensitive range of the human ear.

[0013] In combination with some embodiments of the first aspect, in some embodiments, the multi-mode adaptive switching power supply also includes: a current detection unit; the detection end of the current detection unit is connected to the connection point between the inductor L and the capacitor C; the output end is connected to the mode selection module; used to detect the inductor current of the inductor L; the controller unit includes: a mode selection module; the mode selection module is used to compare the inductor current with the current threshold; if the inductor current is not greater than the threshold, the PSM / PWM wave generator is controlled to generate a PSM wave; if the inductor current is greater than the threshold, the PSM / PWM wave generator is controlled to generate a PWM wave.

[0014] By adopting this technical solution, the current sensing unit monitors the inductor current in real time and transmits it to the mode selection module. The module then dynamically switches operating modes based on the comparison between the current and a threshold. When the inductor current exceeds the threshold (heavy load), PWM mode is activated, providing stable energy at a fixed frequency and adjustable duty cycle. When the current does not exceed the threshold (light load), the module switches to PSM mode to reduce switching losses. This dynamic mode switching mechanism enables the power supply to quickly respond to sudden load changes, reduces voltage fluctuations during the mode switching transition, and improves system reliability and energy efficiency.

[0015] In combination with some embodiments of the first aspect, in some embodiments, the mode selection module is also used to control the PWM wave of the PSM / PWM wave generator, and then determine whether the frequency of the PWM wave is within a preset frequency range; if it is within the preset frequency range, start the dynamic frequency adjustment module.

[0016] By adopting the above technical solution, after switching to PWM mode, the mode selection module further determines whether its operating frequency falls within the preset frequency range. If it does, the dynamic frequency adjustment module is activated; the dynamic frequency adjustment module fine-tunes the switching period through the dither code, thereby jumping out of the sensitive range of the human ear.

[0017] In combination with some embodiments of the first aspect, in some embodiments, the multi-mode adaptive switching power supply further includes: a compensation capacitor; one end of the compensation capacitor is connected to the connection point between the input end of the analog-to-digital converter and the output end of the transconductance operational amplifier, and the other end of the compensation capacitor is grounded.

[0018] By adopting the above technical solution, the compensation capacitor is connected in parallel between the transconductance operational amplifier and the analog-to-digital converter, and the charging and discharging characteristics of the capacitor are used to filter out the high-frequency noise in the analog compensation current, ensuring that the reference voltage generated by the subsequent digital accumulator and digital-to-analog converter truly reflects the load ripple conditions, thereby improving the accuracy of closed-loop compensation and suppressing additional voltage fluctuations introduced by noise.

[0019] In combination with some embodiments of the first aspect, in some embodiments, the multi-mode adaptive switching power supply further includes: a voltage divider network; the first input terminal of the transconductance operational amplifier is connected to the load through the voltage divider network; the voltage divider network is used to reduce the voltage of the load voltage.

[0020] By adopting this technical solution, the voltage-dividing network, composed of a resistor divider circuit, steps down the high load voltage at a fixed ratio to the safe input range of the transconductance operational amplifier, thus preventing damage to the device due to excessive voltage. Furthermore, the divided signal retains the waveform characteristics of the original ripple (for example, the ripple amplitude is proportional to the load voltage ripple), ensuring that the transconductance operational amplifier can accurately detect ripple changes.

[0021] In combination with some embodiments of the first aspect, in some embodiments, the multi-mode adaptive switching power supply also includes: a high-pass filtering module; the first input end of the transconductance operational amplifier is connected to the load in sequence through a voltage divider network and a high-pass filtering module; the high-pass filtering module is used to filter the low-frequency DC component below the frequency threshold in the reduced load voltage to obtain a ripple voltage amplitude.

[0022] By adopting the above technical solution, the high-pass filter module processes the voltage-divided signal connected to the transconductance operational amplifier, utilizes the DC-isolating characteristics of the capacitor to filter out the low-frequency DC component, and only allows the high-frequency ripple signal to pass.

[0023] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0024] 1. A transconductance operational amplifier extracts the ripple voltage amplitude from the load voltage and compares it with a fixed reference voltage, converting the ripple amplitude into a proportional analog compensation current. An analog-to-digital converter quantifies the ripple voltage into digital increments. After superimposing them with the digital target signal output by the controller through a digital accumulator, a digital control code containing the real-time ripple compensation value is generated. The DAC dynamically adjusts the reference voltage, comparing it with the load voltage in real time via a dynamic comparator to drive the switch to adjust its on-time. Compared to related technologies, this solution achieves real-time quantification and dynamic compensation of the ripple amplitude through a hybrid analog-digital closed-loop, avoiding the accumulation of low-frequency ripple components. Furthermore, the digital accumulator's superposition logic enables the compensation value to be continuously adjusted with the ripple, eliminating the hysteresis associated with threshold comparisons. This allows for rapid response to load changes, especially in high-frequency switching scenarios, keeping output ripple within an acceptable range and improving the power supply's response accuracy and stability to transient loads.

[0025] 2. The controller unit generates a control signal based on the load voltage. Combined with the digital pulse output from the dynamic comparator, it drives the PSM / PWM generator to switch between different load modes. Under light load, the control signal causes the PSM / PWM generator to skip some switching cycles, reducing energy loss. Under heavy load, it switches to PWM mode and adjusts the duty cycle to stabilize output. The digital target signal controls the pulse timing (e.g., synchronizing with the load clock cycle) to ensure that switching is synchronized with the load's energy demand. The control signal adjusts the pulse waveform (e.g., the duty cycle) to optimize energy transfer efficiency. For example, when the load current increases, the controller detects a drop in load voltage and, through a control signal, increases the PWM duty cycle, extending the switch's on-time and increasing inductor energy storage, thereby rapidly increasing the output voltage. Under light load, PSM mode reduces switching losses by reducing the number of on-times. This synergistic effect enables the power supply to automatically select the optimal operating mode across the entire load range, avoiding idling losses in PWM mode under light loads while addressing the stability issues in PSM mode under heavy loads, achieving a balance between efficiency and dynamic performance.

[0026] 3. The dynamic frequency adjustment module generates a dithering code (e.g., a pseudo-random binary sequence) that is applied to the switching period of the PSM / PWM wave. When the dithering code is in the first sequence, the switching period is extended to reduce the frequency; when it is in the second sequence, the period is shortened to increase the frequency. This mechanism causes the switching frequency to fluctuate randomly within a preset range (e.g., 40kHz-1MHz), breaking the periodicity of the associated fixed frequency and thus dispersing electromagnetic interference (EMI) energy peaks (e.g., converting a strong single-frequency interference signal into a weaker interference signal over a wide bandwidth). Furthermore, the random frequency prevents the switching period from coinciding with the circuit's inherent resonant frequency, suppressing mechanical vibration and audible noise. This distributes the energy over a wider frequency band, avoiding the sensitive range of the human ear. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a circuit diagram of a multi-mode adaptive switching power supply according to an embodiment of the present application; DETAILED DESCRIPTION

[0028] The terms used in the following examples of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. As used in the specification and appended claims of the present application, the singular expressions "a," "an," "said," "above," "the," and "this" are intended to include plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used in the present application refers to and encompasses any or all possible combinations of one or more of the listed items.

[0029] See also Figure 1 , Figure 1 This is a circuit diagram of a multi-mode adaptive switching power supply according to an embodiment of the present application;

[0030] A multi-mode adaptive switching power supply is applied to a power converter, wherein the power converter includes a switch tube MP, a diode D, an inductor L, a capacitor C, and a load;

[0031] The input end of the switch MP is connected to the input voltage, and the output end is connected to the input end of the inductor L;

[0032] It should be noted that the control terminal of the switch tube MP is controlled by the PSM / PWM wave; details will not be given here.

[0033] The diode D, capacitor C, and load are connected in parallel, and the cathode of the diode D is connected to the connection point between the switch MP and the inductor L, one end of the load is connected to the output end of the inductor L, and one end of the capacitor C is connected to the connection point between the inductor L and the load;

[0034] The diode D is used to provide a freewheeling path for the inductor L when the switch MP is turned off, avoiding high-voltage spikes across the inductor L and protecting circuit components.

[0035] The inductor L is used to store energy when the switch MP is turned on (current increases) and release energy when it is turned off (current decreases), smoothing the output current and suppressing ripple;

[0036] Capacitor C is used to filter out high-frequency ripples in the output voltage, provide instantaneous energy buffering, and stabilize the voltage across the load.

[0037] The multi-mode adaptive switching power supply includes: a transconductance operational amplifier, an analog-to-digital converter, a digital accumulator, a digital-to-analog converter, a dynamic comparator, a controller unit, a voltage divider network, a high-pass filter module, a compensation capacitor, a PSM / PWM wave generator, and a current detection unit;

[0038] The first input terminal of the transconductance operational amplifier is connected to the load through a voltage divider network and a high-pass filter module in sequence, and the second input terminal is connected to a reference voltage; it is used to detect the ripple voltage amplitude of the load and output an analog compensation current according to the ripple voltage amplitude;

[0039] The voltage divider network is used to step down the load voltage.

[0040] The high-pass filter module is used to filter the low-frequency DC component below the frequency threshold in the reduced load voltage to obtain the ripple voltage amplitude.

[0041] One end of the compensation capacitor is connected to a connection point between the input end of the analog-to-digital converter and the output end of the transconductance operational amplifier, and the other end of the compensation capacitor is grounded.

[0042] The input end of the analog-to-digital converter is connected to the output end of the transconductance operational amplifier to convert the analog compensation current into a digital increment;

[0043] A first input terminal of the digital accumulator is connected to the output terminal of the analog-to-digital converter, and a second input terminal is connected to the first output terminal of the controller unit, for superimposing the digital increment on the digital target signal to obtain a digital control code;

[0044] The input end of the digital-to-analog converter is connected to the output end of the digital accumulator, and is used to convert the digital control code into a reference voltage;

[0045] The dynamic comparator has a first input terminal connected to the output terminal of the digital-to-analog converter and a second input terminal connected to the load, and is used to generate a digital pulse according to a reference voltage and a load voltage, where the load voltage is the voltage of the load;

[0046] The second input terminal of the PSM / PWM wave generator is connected to the output terminal of the dynamic comparator; it is used to generate a PSM / PWM wave according to a control signal and a digital target signal, wherein the control signal controls the pulse waveform of the PSM / PWM wave, and the digital target signal controls the timing of the pulse of the PSM / PWM wave;

[0047] The control end of the switch tube MP is connected to the output end of the PSM / PWM wave generator, and is used to control the switching of the input end and the output end according to the PSM / PWM wave.

[0048] Therefore, in some embodiments, the PSM / PWM wave generator specifically includes a dynamic frequency adjustment module;

[0049] The reference voltage dynamic frequency adjustment module is used to generate a jitter code and adjust the PSM / PWM wave according to the reference voltage jitter code. When the reference voltage jitter code is a first sequence, the switching period is increased; when the reference voltage jitter code is a second sequence, the switching period is decreased.

[0050] The first input terminal of the controller unit is connected to the load, and is used to generate a digital target signal according to the load voltage. The second input terminal of the controller unit is connected to the first input terminal of the PSM / PWM wave generator; the controller unit generates a control signal according to the load voltage;

[0051] The controller unit includes: a mode selection module;

[0052] The mode selection module is used to compare the inductor current with the current threshold;

[0053] If the inductor current is not greater than the threshold, the PSM / PWM wave generator is controlled to generate a PSM wave;

[0054] If the inductor current is greater than the threshold, the PSM / PWM wave is controlled to generate a PWM wave. The detection end of the current detection unit is connected to the connection point between the inductor L and the capacitor C; the output end is connected to the mode selection module; and is used to detect the inductor current of the inductor L;

[0055] The mode selection module is also used to control the PSM / PWM wave generator PWM wave and then determine whether the frequency of the PWM wave is within a preset frequency range;

[0056] If it is within the preset frequency range, the dynamic frequency adjustment module is activated.

[0057] In related technologies, the fixed on-time design in PSM mode prevents the power supply from adjusting energy transfer in response to transient load changes, increasing low-frequency ripple in the output voltage. Furthermore, the control logic relies solely on simple threshold comparisons and lacks real-time quantitative analysis of the ripple voltage amplitude, making it difficult to accurately compensate for voltage deviations caused by component parameter drift or environmental changes. This defect is further amplified in high-frequency switching scenarios, causing the power supply output ripple to exceed the allowable range, affecting load stability and accuracy.

[0058] Therefore, the related technology has poor ripple suppression effect due to insufficient low-frequency ripple suppression and delayed transient response.

[0059] In some embodiments, a voltage divider network refers to a circuit consisting of two or more resistor elements connected in series, which is used to reduce the input voltage at a fixed ratio so that subsequent circuit elements (such as a transconductance operational amplifier) ​​can operate within a safe voltage range.

[0060] In some embodiments, when the load voltage is higher than the input range of the transconductance operational amplifier, the voltage must be reduced before the transconductance operational amplifier detects the ripple to ensure device safety.

[0061] In some embodiments, the voltage divider network consists of two resistors connected in series, one end connected to the load output and the other end grounded. After resistor division, the divided voltage signal retains the ripple characteristics of the load voltage (e.g., the peak-to-peak ripple is proportionally reduced from ±50mV to ±10mV) while reducing the DC component to the safe input range of the transconductance operational amplifier, laying the foundation for subsequent ripple detection.

[0062] As can be seen, the voltage divider network, composed of a resistor divider circuit, steps down the high load voltage at a fixed ratio to the safe input range of the transconductance amplifier. This prevents damage to the device due to excessive voltage. Furthermore, the divided signal retains the waveform characteristics of the original ripple (for example, the ripple amplitude is proportional to the load voltage ripple), ensuring that the transconductance amplifier can accurately detect ripple changes.

[0063] A high-pass filter is an RC circuit consisting of a capacitor and a resistor. It blocks low-frequency signals (such as DC components) while allowing high-frequency signals (such as ripple) to pass. The low-frequency DC component represents the DC component in the load voltage and must be filtered out to prevent interference with the transconductance operational amplifier's ripple detection.

[0064] In some embodiments, it is necessary to separate the DC and AC components before detection by the transconductance operational amplifier to ensure that the transconductance operational amplifier only processes the ripple signal.

[0065] In some specific embodiments, a high-pass filter module is connected in series between the voltage divider network and the transconductance operational amplifier. A capacitor and the equivalent resistance of the voltage divider network form an RC high-pass circuit. After the load voltage is divided, the DC component below the frequency threshold is blocked by the capacitor, while the ripple signal above the frequency threshold passes smoothly.

[0066] It can be seen that the high-pass filter module processes the voltage-divided signal connected to the transconductance operational amplifier, uses the DC isolation characteristics of the capacitor to filter out the low-frequency DC component, and only allows the high-frequency ripple signal to pass.

[0067] The ripple voltage amplitude represents the peak value of the AC fluctuation component contained in the load voltage, reflecting the stability of the output voltage. The smaller the ripple, the more stable the voltage. The reference voltage represents a fixed base voltage, which serves as a reference value for the transconductance operational amplifier to compare and extract the ripple component in the load voltage.

[0068] Specifically, the transconductance operational amplifier obtains the ripple voltage amplitude and compares it with a reference voltage to generate a differential voltage. When the ripple voltage amplitude is higher than the reference voltage, a positive current is output, indicating that energy compensation needs to be increased to suppress the ripple. When the ripple voltage amplitude is lower than the reference voltage, a negative current is output, indicating that energy compensation needs to be reduced. In some embodiments, the device cannot output negative current, so in this case, no negative current is output.

[0069] It should be noted that the subsequent dynamic comparator is also connected to the load, but the dynamic comparator obtains the load voltage instead of the ripple voltage amplitude; this is because the transconductance operational amplifier extracts the ripple voltage amplitude from the load voltage.

[0070] The digital increment is used to represent the digital signal after analog-to-digital conversion, reflecting the magnitude and direction of the analog compensation current, and serving as a quantitative basis for ripple compensation.

[0071] The digital target signal represents the reference digital signal generated by the controller based on the load voltage. It reflects the load's baseline voltage requirement under the current state (e.g., a low voltage target for light loads, a high voltage target for heavy loads). The digital control code represents the superimposed digital signal, including the baseline voltage command and the ripple compensation command, and serves as the input code for the digital-to-analog converter.

[0072] The reference voltage is used to represent the analog voltage output by the digital-to-analog converter. It serves as the reference value of the dynamic comparator and directly affects the output voltage target value of the power converter.

[0073] The dynamic comparator compares the reference voltage and the load voltage in real time. It is suitable for scenarios where the output voltage needs to be adjusted quickly (such as load transient response and ripple suppression) to ensure timely operation of the switching tube.

[0074] When the load voltage is less than the reference voltage, the comparator outputs a low level, triggering the switch MP to turn on. The input voltage charges the inductor and capacitor, increasing the load voltage. When the load voltage exceeds the reference voltage, the comparator outputs a high level, triggering the switch MP to turn off. The inductor freewheels through the diode, causing the load voltage to decrease. This hysteresis control mechanism stabilizes the output and load voltage near the reference voltage, limiting the ripple amplitude to within the allowable range. For example, when the load voltage drops to the reference voltage -ΔV due to an increase in load, the comparator outputs a low level, extending the MP on-time and causing the load voltage to recover. When the load voltage exceeds the reference voltage +ΔV, the MP turns off, causing the load voltage to fall back, achieving a dynamic equilibrium.

[0075] As can be seen, the controller unit generates a control signal based on the load voltage. Combined with the digital pulse output by the dynamic comparator, it drives the PSM / PWM generator to switch between different load modes. Under light load, the control signal causes the PSM / PWM generator to skip some switching cycles, reducing energy loss. Under heavy load, it switches to PWM mode and adjusts the duty cycle to stabilize output. The digital target signal controls the pulse timing (e.g., synchronizing with the load clock cycle) to ensure that switching is synchronized with the load energy demand. The control signal adjusts the pulse waveform (e.g., the duty cycle) to optimize energy transfer efficiency. For example, when the load current increases, the controller detects a drop in load voltage and, through a control signal, increases the PWM duty cycle, extending the switch on time and increasing inductor energy storage, thereby rapidly increasing the output voltage. Under light load, the PSM mode reduces switching losses by reducing the number of on-times. These two factors work together to automatically select the optimal operating mode across the power supply's entire load range, avoiding the idling losses of the PWM mode under light loads while addressing the stability issues of the PSM mode under heavy loads, achieving a balance between efficiency and dynamic performance.

[0076] The pulse timing represents the start and interval of the pulses in the PSM / PWM wave, which is dynamically determined by the feedback relationship between the digital target signal and the load voltage. The digital target signal reflects the target voltage required by the load (e.g., a digital code value generated by the controller based on the load voltage), while the load voltage feedback represents the actual state of the output voltage in real time. A dynamic comparator generates digital pulses (logic 0 or 1) from both, which are then arranged in chronological order into a pulse train.

[0077] Specifically, in PSM (Pulse Skip Modulation) mode, when the load voltage is lower than the reference voltage corresponding to the digital target signal, the dynamic comparator outputs a logic 1, triggering the PSM / PWM wave generator to generate an on-pulse at that moment. Otherwise, it outputs a logic 0 and skips the cycle. At this time, the position and interval of the logic 1 in the pulse sequence (such as "10010010") directly reflect the energy demand of the load: the interval of the logic 1 is longer under light load (for example, once every five cycles), and the interval is shorter under heavy load (for example, once every two cycles), thereby reducing light load switching losses through "pulsing on demand."

[0078] In PWM (Pulse Width Modulation) mode, a digital target signal is converted to a reference voltage via a digital-to-analog converter. This voltage is then compared with the load voltage feedback value to generate a continuous pulse train with a fixed frequency. For example, when the digital target signal corresponds to a 50% duty cycle, the pulse train appears as a "101010..." pattern of alternating levels at equal intervals. The duration of the logic 1 (pulse width) is determined by the deviation between the digital target signal and the feedback voltage, ensuring that the output voltage remains stable near the target value even under heavy loads.

[0079] It's important to note that digital pulses are essentially binary logic signals (0 indicates off, 1 indicates on). The time-sequencing sequence they form directly controls the gate drive signal for the switching transistor MP. For example, in PSM mode, the sequence "1000" indicates on-state for the first cycle and off-state for the next three cycles. In PWM mode, the sequence "11001100" (50% duty cycle) indicates on-state for the first half of each cycle and off-state for the second half. This digital pulse sequence-based control approach enables the power supply to dynamically adjust the energy delivery rhythm based on real-time load demand, achieving a balance between light-load efficiency and heavy-load stability.

[0080] The control signal is a binary signal (e.g., high / low level) output by the controller unit, indicating whether the PSM / PWM wave generator operates in PSM or PWM mode. This signal is typically triggered by a load current threshold or system power consumption status. The pulse waveform describes the morphological characteristics of the PSM / PWM wave, including parameters such as pulse width (duty cycle), period, frequency, and continuity. In PSM mode, this waveform appears as a discrete, non-continuous pulse; in PWM mode, it appears as a continuous, adjustable pulse with a fixed frequency. These models can be pre-configured and are not limited here.

[0081] As can be seen, the controller unit generates a control signal based on the load voltage. Combined with the digital pulse output by the dynamic comparator, it drives the PSM / PWM generator to switch between different load modes. Under light load, the control signal causes the PSM / PWM generator to skip some switching cycles, reducing energy loss. Under heavy load, it switches to PWM mode and adjusts the duty cycle to stabilize output. The digital target signal controls the pulse timing (e.g., synchronizing with the load clock cycle) to ensure that switching is synchronized with the load energy demand. The control signal adjusts the pulse waveform (e.g., the duty cycle) to optimize energy transfer efficiency. For example, when the load current increases, the controller detects a drop in load voltage and, through a control signal, increases the PWM duty cycle, extending the switch on time and increasing inductor energy storage, thereby rapidly increasing the output voltage. Under light load, the PSM mode reduces switching losses by reducing the number of on-times. These two factors work together to automatically select the optimal operating mode across the power supply's entire load range, avoiding the idling losses of the PWM mode under light loads while addressing the stability issues of the PSM mode under heavy loads, achieving a balance between efficiency and dynamic performance.

[0082] In actual use, the switching frequency of the switching transistor MP may fall into the audible range of the human ear (20Hz-20kHz), causing component vibration and noise.

[0083] In some embodiments, the detection terminal of the current detection unit is connected to the connection point between the inductor L and the capacitor C; the output terminal is connected to the mode selection module; and is used to detect the inductor current of the inductor L;

[0084] The controller unit includes: a mode selection module;

[0085] The mode selection module is used to compare the inductor current with the current threshold;

[0086] If the inductor current is not greater than the threshold, the PSM / PWM wave generator is controlled to generate a PSM wave;

[0087] If the inductor current is greater than the threshold, the PSM / PWM wave generator is controlled to generate a PWM wave. The mode selection module is also used to control the PSM / PWM wave generator to generate a PWM wave and then determine whether the frequency of the PWM wave is within a preset frequency range;

[0088] If it is within the preset frequency range, the dynamic frequency adjustment module is activated.

[0089] The dynamic frequency adjustment module is used to generate a dithering code and adjust the PSM / PWM wave according to the dithering code. When the dithering code is in the first sequence, the switching period is increased, and when the dithering code is in the second sequence, the switching period is decreased.

[0090] In some embodiments,

[0091] Dithering codes represent binary digit sequences (e.g., 0 / 1 sequences). These codes are divided into first and second sequences (e.g., "101" and "010"), corresponding to instructions for increasing or decreasing the switching period, respectively. They represent the duration of a complete PSM / PWM cycle (i.e., on-time + off-time). Adjusting the period changes the switching frequency (frequency = 1 / period).

[0092] The module's internal pseudo-random number generator (e.g., linear feedback shift register (LFSR)) generates a continuous binary jitter code sequence. For example, the first sequence "101" corresponds to an instruction to increase the switching cycle, while the second sequence "010" corresponds to an instruction to decrease the switching cycle.

[0093] When the jitter code is detected as the first sequence, the module sends an "extend period" signal to the PSM / PWM wave generator, for example, extending the original period from 2μs (frequency 500kHz) to 2.2μs (frequency 454.5kHz).

[0094] When the jitter code is detected to be the second sequence, the module sends a "shorten period" signal, for example, shortening the period from 2μs to 1.8μs (frequency 555.5kHz).

[0095] By randomly switching the cycle, the switching frequency fluctuates around the center frequency, dispersing the EMI energy from a single frequency point to a wide frequency band, reducing the peak interference intensity.

[0096] Continuously detect the inductor current and trigger mode switching when the current change exceeds the threshold;

[0097] PSM / PWM wave generator: Generates the corresponding switch drive pulse according to the mode code (Mode_sel) and the digital target signal.

[0098] CS signal: represents the control signal output by the mode selection module, used to switch the pulse waveform (PSM or PWM).

[0099] T0 signal: converted from the digital target signal, controls the starting time and interval of the pulse.

[0100] Frequency jitter: Pseudo-random code is used to modulate the switching period so that the switching frequency fluctuates around the center frequency, preventing the fixed frequency from falling into the audible frequency band (20Hz-20kHz).

[0101] Heavy load scenario (inductor current > threshold): If the device is running at full load (for example, the CPU is operating at full speed), PWM mode (code 10) is enabled to stabilize the output voltage at a fixed frequency (for example, 500kHz) to ensure continuous energy supply.

[0102] Light load scenario (inductor current ≤ threshold): For example, when the device is in standby or low power mode, the frequency strategy in PSM mode is automatically selected based on the switching frequency:

[0103] If the initial frequency f in PSM mode is less than 30kHz (falls into the audible frequency band), frequency dithering (code 00) is enabled and the on-time Ton is adjusted using a pseudo-random code to increase the frequency to above 30kHz.

[0104] If f≥30kHz, directly enable the jitter-free PSM mode (code 01) to reduce unnecessary frequency modulation loss.

[0105] The mode selection block compares the inductor current with a threshold (e.g. 100mA):

[0106] If the inductor current is greater than 100mA, the mode code 10 is output, triggering the PWM mode. The PSM / PWM wave generator outputs continuous pulses at a fixed frequency of 500kHz, and the duty cycle is controlled by the digital target signal T0.

[0107] If the inductor current is ≤100mA, further detect the initial switching frequency f in PSM mode (calculated from the load voltage and reference voltage):

[0108] If f<30kHz, output mode code 00, start PSM mode and activate frequency dithering;

[0109] If f≥30kHz, the mode code 01 is output and the jitter-free PSM mode is enabled.

[0110] PWM mode (code 10): The PSM / PWM wave generator generates fixed-frequency pulses based on the T0 signal. The CS signal controls the duty cycle (for example, when T0 corresponds to a 50% duty cycle, the output is a 101010... sequence), ensuring stable voltage under heavy loads.

[0111] PSM mode (code 01 / 00):

[0112] Code 01 (no jitter): Generates non-continuous pulses, outputting a single pulse (such as the sequence 10001000) only when the load voltage is lower than the reference, with a frequency f≥30kHz to avoid howling.

[0113] Code 00 (with jitter): A pseudo-random code (such as the 101101 sequence generated by a linear feedback shift register) is superimposed on the original on-time Ton. For example, when the reference Ton is 1μs, it is randomly adjusted to 1.1μs or 0.9μs, causing the frequency to fluctuate within the range of 30kHz-50kHz, avoiding the frequency band that is sensitive to the human ear.

[0114] The dynamic comparator monitors the load voltage in real time. If the ripple exceeds the threshold, a compensating digital increment is generated through a transconductance operational amplifier and an analog-to-digital converter, and the T0 signal is adjusted through a digital accumulator to achieve ripple suppression.

[0115] The mode selection module periodically verifies whether the frequency deviates from the preset range (for example, once every 1ms). If the frequency drops below 30kHz after jitter, the modulation amplitude of the pseudo-random code is automatically increased (for example, the adjustment range is expanded from ±10% to ±20%).

[0116] As can be seen, the current sensing unit monitors the inductor current in real time and transmits it to the mode selection module. The module then dynamically switches operating modes based on the comparison between the current and the threshold. When the inductor current exceeds the threshold (heavy load), PWM mode is activated, providing stable energy at a fixed frequency and adjustable duty cycle. When the current does not exceed the threshold (light load), the module switches to PSM mode to reduce switching losses. This dynamic mode switching mechanism enables the power supply to quickly respond to sudden load changes, reduces voltage fluctuations during the mode switching transition, and improves system reliability and energy efficiency.

[0117] It can be seen that after switching to PWM mode, the mode selection module further determines whether its operating frequency falls within the preset frequency range. If it does, the dynamic frequency adjustment module is activated; the dynamic frequency adjustment module fine-tunes the switching period through the dither code, thereby jumping out of the sensitive range of the human ear.

[0118] As can be seen, the dithering code (e.g., a pseudo-random binary sequence) generated by the dynamic frequency adjustment module acts on the switching period of the PSM / PWM wave: when the dithering code is in the first sequence, the switching period is extended to reduce the frequency; when it is in the second sequence, the period is shortened to increase the frequency. This mechanism causes the switching frequency to fluctuate randomly within a preset range (e.g., 40kHz-1MHz), breaking the periodicity of the associated fixed frequency and thus dispersing electromagnetic interference (EMI) energy peaks (e.g., converting a strong single-frequency interference signal into a weaker interference signal over a wide bandwidth). Furthermore, the random frequency prevents the switching period from coinciding with the circuit's natural resonant frequency, suppressing mechanical vibration and audible noise. This distributes the energy over a wider frequency band, avoiding the sensitive range of the human ear.

[0119] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to imply or suggest relative importance or implicitly indicate the number of the technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of this application, unless otherwise specified, "plurality" means two or more.

[0120] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A multi-mode adaptive switching power supply, characterized in that: The invention is applied to a power converter, comprising a switch tube MP, a diode D, an inductor L, a capacitor C, and a load. The input end of the switch tube MP is connected to an input voltage, and the output end is connected to the input end of the inductor L. The capacitor C and the load are connected in parallel, with one end of the load connected to the output end of the inductor L, one end of the capacitor C connected to the connection point between the inductor L and the load, the cathode of the diode D connected to the connection point between the switch tube MP and the inductor L, and the anode of the diode D connected to the other end of the capacitor C. The multi-mode adaptive switching power supply comprises: a transconductance operational amplifier, an analog-to-digital converter, a digital accumulator, a digital-to-analog converter, a dynamic comparator, a controller unit, and a PSM / PWM wave generator. The first input terminal of the transconductance operational amplifier is connected to the load, and the second input terminal is connected to a reference voltage; the transconductance operational amplifier is used to detect the ripple voltage amplitude of the load and output an analog compensation current according to the ripple voltage amplitude; the input terminal of the analog-to-digital converter is connected to the output terminal of the transconductance operational amplifier, and is used to convert the analog compensation current into a digital increment; The first input terminal of the digital accumulator is connected to the output terminal of the analog-to-digital converter, and the second input terminal is connected to the first output terminal of the controller unit, for superimposing the digital increment on the digital target signal to obtain a digital control code; The input end of the digital-to-analog converter is connected to the output end of the digital accumulator, and is used to convert the digital control code into a reference voltage; The dynamic comparator has a first input terminal connected to the output terminal of the digital-to-analog converter, and a second input terminal connected to the load, and is configured to generate a digital pulse according to the reference voltage and a load voltage, wherein the load voltage is the voltage of the load; The first input terminal of the controller unit is connected to the load, and is used to generate the digital target signal according to the load voltage; The second input terminal of the controller unit is connected to the first input terminal of the PSM / PWM wave generator; the controller unit generates a control signal according to the load voltage; The second input terminal of the PSM / PWM wave generator is connected to the output terminal of the dynamic comparator; and is used to generate a PSM / PWM wave according to the control signal and the digital target signal, wherein the control signal controls the pulse waveform of the PSM / PWM wave, and the digital target signal controls the time point of the pulse of the PSM / PWM wave; The control end of the switch tube MP is connected to the output end of the PSM / PWM wave generator, and is used to control the switching of the input end and the output end according to the PSM / PWM wave.

2. The power supply according to claim 1, wherein: The PSM / PWM wave generator specifically includes a dynamic frequency adjustment module; The dynamic frequency adjustment module is used to generate a dithering code and adjust the PSM / PWM wave according to the dithering code. When the dithering code is a first sequence, the switching period is increased, and when the dithering code is a second sequence, the switching period is decreased.

3. The power supply according to claim 2, wherein: The multi-mode adaptive switching power supply further includes: a current detection unit; The detection end of the current detection unit is connected to the connection point between the inductor L and the capacitor C; the output end is connected to the mode selection module; and is used to detect the inductor current of the inductor L; The controller unit includes: the mode selection module; The mode selection module is used to compare the inductor current with a current threshold; If the inductor current is not greater than a threshold value, controlling the PSM / PWM wave generator to generate a PSM wave; If the inductor current is greater than a threshold, the PSM / PWM wave is controlled to generate a PWM wave.

4. The power supply according to claim 3, characterized in that The mode selection module is further configured to control the PSM / PWM wave generator to generate a PWM wave and then determine whether the frequency of the PWM wave is within a preset frequency range; If it is within the preset frequency range, the dynamic frequency adjustment module is started.

5. The power supply according to claim 1, wherein: The multi-mode adaptive switching power supply further includes: a compensation capacitor; One end of the compensation capacitor is connected to a connection point between the input end of the analog-to-digital converter and the output end of the transconductance operational amplifier, and the other end of the compensation capacitor is grounded.

6. The power supply according to claim 1, wherein: The multi-mode adaptive switching power supply further comprises: a voltage dividing network; The first input terminal of the transconductance operational amplifier is connected to the load through the voltage divider network; The voltage divider network is used to reduce the voltage of the load voltage.

7. The power supply according to claim 6, characterized in that The multi-mode adaptive switching power supply further includes: a high-pass filter module; The first input terminal of the transconductance operational amplifier is connected to the load through the piezoelectric network and the high-pass filter module in sequence; The high-pass filter module is used to filter the low-frequency DC component below the frequency threshold in the reduced load voltage to obtain the ripple voltage amplitude.

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