Driving circuit and method thereof

Abstract

The present disclosure relates to a circuit (200) comprising: an output terminal (208) configured to be coupled with a load; a power source (202) configured to generate a current according to a current ramp such that the generated current exhibits a plurality of different current values within a range of current values from a minimum current value to a maximum current value during a predefined time period; a switching element (210) configured to selectively enable or disable delivery of the generated current to the output terminal (208); and a control circuit (212) configured to control the switching element (210) to deliver a predefined average current value at the output terminal (208) during a predefined time period.

Description

Technical Field

[0001] This disclosure generally relates to a drive circuit configured to implement an adaptive drive scheme for powering a load, and a method thereof (e.g., a method for powering a load according to an adaptive drive scheme). Background Technology

[0002] Lighting and display devices are typically found in a wide range of technological contexts and applications, such as illuminating environments and displaying images. Driving individual pixels or combinations of pixels in a display (e.g., ambient lighting inside a vehicle) requires high levels of dynamic range and uniformity. Two methods are commonly used to drive pixels. The first method is based on time modulation, preferably pulse width modulation (PWM), where the drive current is kept constant and different brightness sensations are produced by varying the ratio of on-time to off-time. The second method is based on amplitude modulation, where the current varies for each brightness value. Combinations of these two methods are also known, where discrete amplitude settings are combined with PWM, where the amplitude is controlled for the entire display rather than on a pixel-by-pixel basis. Given this combination of methods, creating linear gradations without visible jumps in shadows is challenging. Pure current control is complex due to the different operating points along the P / I characteristics and the different wavelength shifts of individual light-emitting diodes (LEDs) across operating modes. Therefore, improvements to the driving schemes for lighting and display devices are needed, which may be particularly relevant to further technological developments. Attached Figure Description

[0003] In the accompanying drawings, the same reference numerals generally refer to the same parts in different views. The drawings are not necessarily drawn to scale and generally focus on illustrating the principles of the invention. In the following description, various aspects of the invention are described with reference to the following drawings, wherein:

[0004] Figure 1 Various charts related to the pulse width modulation-based driving scheme are shown, according to different aspects;

[0005] Figure 2A The circuit is illustrated in schematic form, according to various aspects, as configured to implement an adaptive drive scheme for delivering power to a load;

[0006] Figure 2B The diagram illustrates, in schematic form, the load, which also includes components coupled to the output terminals, according to various aspects. Figure 2A The circuit;

[0007] Figure 3A An exemplary configuration of a switchable element coupled to a load comprising multiple load elements is shown in schematic form, according to various aspects.

[0008] Figure 3B An exemplary configuration of a switchable element coupled to a load comprising multiple light-emitting elements is shown in schematic form, according to various aspects.

[0009] Figures 4A to 4E An exemplary configuration of the power ramp is shown, depending on various aspects;

[0010] Figures 5A to 5D The diagrams illustrating the adaptive driving scheme and its comparison with pulse width modulation are shown; and

[0011] Figure 6 A schematic flowchart illustrating methods for supplying power to a load based on various aspects is shown. Detailed Implementation

[0012] The following detailed description refers to the accompanying drawings, which illustrate by way of illustration specific details and aspects in which the invention may be practiced. These aspects are described in sufficient detail to enable those skilled in the art to practice the invention. Other aspects may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the invention. The aspects are not necessarily mutually exclusive, as some aspects may be combined with one or more other aspects to form new aspects. The aspects are described in conjunction with methods, and in conjunction with devices (e.g., circuits, switchable elements, power supplies, loads). However, it should be understood that the aspects described in conjunction with methods can be equally applied to devices, and vice versa.

[0013] A common driving scheme used to control the delivery of electrical energy (e.g., current or voltage) from a power source to a load is so-called pulse width modulation (PWM), which can be applied to control light-emitting elements (e.g., LEDs), motors, battery chargers, solar panels, etc. PWM technology is based on pulsed switching of a power source on and off at a specific frequency and pulse width, thereby allowing control over the electrical energy delivered to the load during a specific time period (exemplarily, the average power delivered to the load). Generally, PWM driving schemes are well known in the art. This document describes some basic concepts to introduce various aspects relevant to this disclosure.

[0014] In brief, PWM can be described as using digital signals to obtain analog results. A PWM signal can be a square wave that switches between a high state (e.g., an "on state") and a low state (e.g., an "off state"). The percentage of time the PWM signal is in the high state is called the duty cycle. For example, a PWM signal that is always on will have a 100% duty cycle, a PWM signal that is always off will have a 0% duty cycle, a PWM signal that is on for half a cycle will have a 50% duty cycle, and so on. Besides the duty cycle, another important parameter of a PWM signal is the frequency of the waveform (i.e., the reciprocal of the period, which is the reciprocal of the full on and off times of the PWM signal). By controlling the duty cycle of the PWM signal, the electrical power sensed by the load can be controlled. For example, by changing the duty cycle (relative to the on time), the average voltage of the signal will change accordingly.

[0015] One relevant use case for PWM technology is controlling the brightness of light emitted by a light-emitting diode (LED), a process known as "dimming." When using PWM, the LED is switched on and off with a duty cycle and frequency defined by the PWM signal. By changing the on-time, the perceived brightness of the emitted light can be changed accordingly. The frequency of the PWM signal should be high enough to avoid flicker; that is, the on / off frequency should be faster than the human eye's perception (the so-called flicker fusion rate). For LED dimming, the frequency of the PWM signal can be, for example, around 100 Hz.

[0016] in this regard, Figure 1 Figures 110, 120, and 130 illustrate exemplary cases of using PWM to drive a display device. Combined with... Figure 1 The various aspects described can be applied in a corresponding manner to the use of PWM in other applications (e.g., for controlling the speed of a motor, for controlling a fan in a computer, etc.). As mentioned above, PWM can allow the electrical energy (e.g., current) perceived by an LED during a time period (e.g., a video frame) to be controlled by controlling the proportion of the LED's on-time within that time period, and accordingly control the brightness of the emitted light perceived by the human eye.

[0017] For example, with a 100% duty cycle, meaning the LED is always on for a frame, maximum brightness (100%, for example) can be achieved. Conversely, by keeping the LED on for only a portion of a frame's duration, the brightness may be reduced accordingly (dimming, for example). Referring to Figures 110, 120, and 130, with a 25% duty cycle, the LED can be on for 25% of a frame's duration (Figure 110), and 25% of the maximum achievable brightness can be obtained. With a 50% (Figure 120) or 75% (Figure 130) duty cycle, the LED can be on for 50% or 75% of a frame's duration, and 50% or 75% of the maximum achievable brightness can be obtained, and so on.

[0018] For example, an LED has a power quantity sufficient to produce its maximum output (e.g., light at maximum brightness). PWM technology is based on switching the LED on and off at high frequencies, causing the power sensed by the LED to vary between 0 and a power value corresponding to maximum output, thereby adjusting the brightness according to the ratio of on-time to off-time. Therefore, PWM provides a method where the current is constant, and the LED is switched on and off in time “blocks” to obtain a variation in brightness based on the length of the “block.”

[0019] Therefore, PWM can provide a relatively simple solution for adjusting the brightness of an LED. However, PWM has drawbacks, especially at low brightness values ​​(corresponding to short on-time and long off-time), such as its relation to the persistence of light on the retina. For example, due to the inertia of the human eye, visual illusions can occur caused by the rapid movement of the eye toward or away from the pulsed light source (e.g., a pulsed LED), resulting in the light source appearing multiple times in the viewer's eyes.

[0020] Another LED dimming method is called constant current reduction (CCR), where the LED is kept constantly on and the level of current supplied to the LED is adjusted to change the brightness of the emitted light. Therefore, CCR technology provides an "analog dimming" where an increase or decrease in the magnitude of the current causes a corresponding increase or decrease in the LED brightness. For applications involving long lead lengths, CCR may be more suitable than PWM. However, CCR is less suitable for dimming at relatively low brightness levels, such as below 10% of maximum brightness.

[0021] This disclosure may relate to a drive scheme for delivering electrical power from a power source to a load, which is adapted to overcome at least some limitations of conventional drive methods (e.g., classical PWM or amplitude modulation). This disclosure may be based on the understanding that typical aspects of PWM can be combined with typical aspects of amplitude modulation to obtain a drive scheme applicable over a wide dynamic range and with improved characteristics at low power values ​​(e.g., corresponding to low brightness values ​​of light-emitting elements).

[0022] This disclosure relates to a driving scheme that includes pulsedly delivering electrical power from a power source to a load, wherein the power generated by the power source does not remain constant over time as in classic PWM schemes, but rather varies according to a ramp. This variation in power generated by the power source over time introduces an additional degree of control to the driving of the load. Exemplarily, the driving scheme proposed in this disclosure may be a combination of amplitude modulation (for which the amplitude of the generated power varies over time) and pulse width modulation (for which the power delivery is “pulsated”).

[0023] Therefore, according to the proposed driving scheme, the amount of electrical power delivered to the load can be controlled not only by selecting the proportion of the "on time" (e.g., within one frame of the display device), but also by selecting the times at which power delivery should be enabled, since different times correspond to different amplitudes. Thus, the proposed driving scheme enables more precise and flexible control of power delivery to the load while maintaining a simple overall architecture.

[0024] The proposed strategy can be exemplarily described from two different perspectives. As a first illustrative description, according to the proposed method, a switchable element is used to selectively enable or disable power delivery to the load, for example, by selectively connecting or disconnecting the conductive path from the power source to the load. As a second illustrative description, according to the proposed method, power is delivered to the load according to a ramp-up, and the load is selectively switched on and off, thereby utilizing the power delivered at the point when the load is "on" to provide pulsed power to the load.

[0025] Depending on various aspects, a circuit may include: an output terminal configured to be coupled to a load; a power supply configured to generate electrical power according to a power ramp, such that the generated electrical power presents multiple different power values ​​within a power value range from a minimum power value to a maximum power value during a predefined time period; a switchable element configured to selectively enable or disable the delivery of the generated electrical power to the output terminal (and, correspondingly, the load coupled to the output terminal); and a control circuit configured to control the switchable element to provide a predefined average power value at the output terminal during the predefined time period.

[0026] Depending on various aspects, a circuit may include: a power supply configured to generate electrical power according to a power ramp and deliver the generated electrical power to a load, such that the power delivered to the load during a predefined time period presents multiple different power values ​​within a power value range from a minimum power value to a maximum power value; and a control circuit configured to turn the load on and off during the predefined time period based on the average power value to be sensed by the load during the predefined time period.

[0027] The proposed method offers the advantages of significantly higher dynamic range while simultaneously reducing the workload of amplitude modulation. For example, for controlling the brightness of emitted light (e.g., in a display), the proposed strategy can be implemented using a centralized power supply, with switching controlled at the pixel level, rather than controlling the current level pixel by pixel.

[0028] In the proposed strategy, for each frame (e.g., frame rates of 50Hz (20ms), 100Hz (10ms), and 200Hz (5ms) as examples), a defined current ramp can be generated and switched to the load (e.g., a light-emitting element, LED). Using the current ramp can provide the same integral as classical PWM. However, considering the exemplary application of driving a light-emitting element, the proposed method allows for the resolution of significantly smaller brightness values ​​than PWM. While with classical PWM, the order of the on / off blocks in the image has no significant impact on brightness perception, but by using the proposed ramp combined with the switching, 2 n There are several brightness levels, where "n" is the number of current values ​​within the ramp, depending on which parts of the ramp are combined in the image.

[0029] One relevant use case for the proposed driving scheme is dimming of light-emitting elements (e.g., LEDs), as the adapter driving scheme allows for fine control of the emitted light brightness, providing a particularly advantageous solution for creating lighting patterns. Therefore, reference may be made in the following text specifically to using an adapter driving scheme with ramps and switching to drive light-emitting elements, such as LEDs. However, it should be understood that the application of the adapter driving scheme described herein is not limited to brightness control and can generally be applied to powering any suitable load, where fine-tuning the delivered power can improve load operation. As other examples, this adapter driving scheme can be implemented to drive motors, battery chargers, computer fans, etc.

[0030] Typically, to control LED light emission, it is preferable to control the current supplied to the LED rather than the voltage applied to it, because for an LED, a small change in voltage can cause a large change in the current conducted through the LED. Therefore, relying on voltage to precisely control the behavior of an LED can be difficult. Thus, in this disclosure, the proposed driving scheme can be implemented with particular reference to generating current according to a current ramp. Exemplarily, a configuration can be particularly referenced in which the power supplied to the load varies according to the ramp by changing the generated current according to the current ramp. However, it should be understood that the aspects described herein related to a current ramp or a power supply configured to generate current according to a current ramp can be applied in a corresponding manner to a voltage ramp or a power supply configured to generate voltage according to a voltage ramp, and vice versa. For example, a voltage ramp can be used to drive cells of a liquid crystal display (LCD) device.

[0031] Figure 2A and Figure 2B The circuit 200, configured to implement an adaptive drive scheme for delivering power to a load, is shown in schematic form according to various aspects. Figure 2B It shows Figure 2A Further configuration 200b of circuit 200.

[0032] Circuit 200 may include power supply 202, which is configured to generate electrical power according to power ramp 204 (see also) Figures 4A to 4E For example, power supply 202 can be configured to provide (e.g., deliver) electrical power to supply terminal 206, which has behavior defined by power ramp 204 during a predefined time period. In other words, power supply 202 can be configured to provide (e.g., ramp-regulated) electrical power at supply terminal 206 during a predefined time period according to predefined ramp behavior. Therefore, the generated electrical power during the predefined time period can be continuous power, which exhibits different values ​​according to power ramp 204. Hereinafter, "electrical power" may be simply referred to as "power".

[0033] In a preferred configuration, power supply 202 can be configured to generate current according to a current ramp. For example, power supply 202 can be configured to provide a current with behavior defined by the current ramp at supply terminal 206 during a predefined time period. For example, during the predefined time period, the generated current can exhibit multiple different current values ​​ranging from a minimum current value to a maximum current value, depending on the behavior defined by the current ramp. Therefore, in this scenario, power supply 202 can be a constant current source that generates a continuous current that varies according to the current ramp during the predefined time period.

[0034] In other aspects, power supply 202 can be configured to generate voltage according to a voltage ramp. For example, power supply 202 can be configured to provide a voltage with behavior defined by the voltage ramp at supply terminal 206 during a predefined time period. In this configuration, the generated voltage during the predefined time period can exhibit multiple different voltage values ​​ranging from a minimum voltage value to a maximum voltage value, depending on the behavior defined by the voltage ramp. Therefore, in this scenario, power supply 202 can be a constant voltage source that generates a continuous voltage that varies according to the voltage ramp during the predefined time period.

[0035] In the following text, the operational aspects of power supply 202 may be described with reference to the generated current and current ramp, but it should be understood that these aspects apply in a corresponding manner to the generated voltage and voltage ramp.

[0036] Typically, there are various implementations for a power supply 202 configured to generate power according to ramp 204, for example, for a power supply configured to generate current according to a current ramp or voltage according to a voltage ramp, and any suitable configuration can be used, thus omitting a detailed explanation in this regard. By way of example only, power supply 202 may include a signal generator configured to generate a ramp signal (exemplarily, a sawtooth signal) by charging a capacitor with a constant current and discharging the capacitor via a transistor when a certain voltage is reached. Therefore, in this exemplary implementation, power supply 202 may include a capacitor, a voltage source defining a voltage drop across the capacitor, one or more resistors (e.g., at least one resistor coupled in series with the capacitor), and a transistor for controlling the discharge of the capacitor.

[0037] Typically, power supply 202 may also include an output stage that maintains the characteristics of the generated signal (e.g., generated power) independently of the load being switched on or off in fast mode. The output stage can be fed any signal form (e.g., directly feeding the ON segment of a sawtooth wave), or it can generate a clean triangular or sawtooth wave signal (e.g., triangular or sawtooth wave current) switched by external circuitry. As an exemplary implementation, a commercially available benchtop device can be used for this purpose. In more complex implementations, the output stage can be implemented using a suitably configured application-specific integrated circuit (ASIC) or driver integrated circuit.

[0038] The term "ramp" in this article can be used to refer to the power generated by power source 202 at the beginning of a predefined time period (also known as time point t). I It has an initial value (or starting value) at point t, and changes throughout the predefined time period to reach the end of the predefined time period (also known as time point t). FThe slope reaches its final value (or end value) at a given point. The behavior of the slope during a predefined time period (exemplarily, the profile) can be adapted to define how the power changes from its initial value to its final value. Therefore, as combined with... Figures 4A to 4E As further described herein, the term "ramp" is not limited to a linear change from an initial value to a final value, but rather refers to any suitable waveform in this document that includes a power ramp 204 (e.g., a current ramp or a voltage ramp) during a predefined time period. Furthermore, as in conjunction with Figures 4A to 4E As further described herein, the term “ramp” is not limited to a change from a minimum to a maximum value, but is used in this paper to include any suitable initial value and any suitable final value.

[0039] Power supply 202 can be configured to generate power according to ramp 204 in a periodic or non-periodic manner. Exemplarily, power supply 202 can be configured to generate power according to ramp 204 in multiple instances of a predefined time period. For example, power supply 202 can be configured to generate power according to ramp 204 in a first instance of the predefined time period, further generate power according to ramp 204 in a second instance of the predefined time period, further generate power according to ramp 204 in a third instance of the predefined time period, and so on. Typically, each instance of the predefined time period can have the same duration, exemplarily, the same length. However, in some aspects, the duration of the predefined time period providing the ramp may vary in different instances.

[0040] Typically, instances within a predefined time period can be spaced out periodically or non-periodically. For example, after an instance within a predefined time period terminates (and the power reaches its final value), a subsequent instance can begin (starting from the initial value), and after the subsequent instance terminates, a further subsequent instance can begin, and so on. In a preferred configuration, the time interval between consecutive instances within a predefined time period can be equal throughout the multiple instances, thereby providing periodic operation of the power supply 202. However, in some aspects, the time interval between consecutive instances within a predefined time period can vary throughout the multiple instances, for example, to adapt the drive scheme to the specific requirements of a particular device.

[0041] In a preferred configuration, the behavior of power supply 202 can remain consistent across multiple instances within a predefined time period. For example, power supply 202 can generate power according to the same ramp 204 in each instance of the predefined time period, e.g., starting with the same initial value, terminating at the same final value, having the same ramp profile, etc. This ensures more reproducible and predictable load driving.

[0042] However, it should be understood that, in principle, one or more parameters of power generation can vary throughout multiple instances of a predefined time period. For example, one or more of the initial value, final value, and / or ramp curve can vary from one instance of the predefined time period to another. As an example, in a first instance of the predefined time period, power supply 202 can generate power according to a first initial value to a first final value and a first ramp curve. In a second instance of the predefined time period, power supply 202 can generate power according to a second initial value to a second final value and a second ramp curve. In this configuration, the first initial value can differ from the second initial value, and / or the first final value can differ from the second final value, and / or the first ramp curve can differ from the second ramp curve. The same applies to a third instance of the predefined time period, and so on.

[0043] Depending on various aspects, circuit 200 may also include an output terminal 208 configured to be coupled to a load, such as an active load driven by power supplied by power supply 202. In various aspects, such as Figure 2B As shown in the configuration, circuit 200b may also include a load 214 coupled to output terminal 208. Output terminal 208 may be electrically connected to power supply 202, for example, to supply terminal 206, such that power generated by power supply 202 can be delivered to output terminal 208 and to load 214. For example, current generated by power supply 202 may be delivered to output terminal 208, such that the current flowing through output terminal 208 (towards load 214) varies according to a current ramp. As another example, voltage generated by power supply 202 may be delivered to output terminal 208, such that the voltage at output terminal 208 (and across load 214) varies according to a voltage ramp. Although not shown, load 214 may also be connected to a reference potential, such as ground.

[0044] Load 214 can be any suitable electrical device or component that can be driven according to the proposed drive scheme. In the preferred configuration (see also) Figure 3BLoad 214 may include one or more light-emitting elements, such as multiple light-emitting elements, such as multiple LEDs. As an example, load 214 may be a display device comprising multiple pixels, and each pixel may include a corresponding light-emitting element (e.g., a corresponding LED). As mentioned above, the proposed driving scheme may be particularly suitable for adjusting the brightness level of the emitted light with fine resolution. In other aspects, the light-emitting elements of load 214 may include one or more laser sources, such as multiple laser sources. For example, the light-emitting elements may include one or more vertical-cavity surface-emitting lasers (VCSELs) or edge-emitting laser devices. As an example, load 214 may include a VCSEL array. Applying the proposed strategy to drive laser sources may be based on the understanding that, in some applications, such as in "flying-spot" scanners, the problems of conventional PWM may be more relevant than those of LED arrays. However, it should be understood that, in principle, load 214 may also include other types of electrically driven devices or components. As other examples, load 214 may include a motor, fan, battery charger circuitry, solar cell, etc.

[0045] Considering that the load 214 includes the configuration of a display device, the predefined time period can correspond to the frame period of the display device, exemplarily, a video frame. In this scenario, the duration of the predefined time period can be adjusted according to the frame rate of the display device. For example, for a frame rate of 50 Hz, the duration of the predefined time period can be 20 ms; for a frame rate of 100 Hz, the duration of the predefined time period can be 10 ms, and so on.

[0046] Depending on various aspects, circuit 200 may also include a switchable element 210 configured to selectively enable or disable the supply of power generated by power supply 202 to output terminal 208, for example, supplying generated current or generated voltage. In other words, switchable element 210 may be configured to selectively enable or disable the power generated by power supply 202 to supply power to load 214, for example, driving load 214 with the current / voltage generated by power supply 202. The switchable element (e.g., switchable element 210) may also be referred to herein as a switching element or a coupling element.

[0047] exist Figure 2A and Figure 2B In the exemplary representation, output terminal 208 and switchable element 210 are shown as being external to power supply 202. It should be understood that output terminal 208 and switchable element 210 can also be considered as part of power supply 202, for example, as part of a power supply device that includes power supply 202, output terminal 208 and switchable element 210.

[0048] As an exemplary configuration, the switchable element 210 can be configured (e.g., controllable) to selectively present one of several possible states. In the exemplary configuration, the switchable element 210 can have a (first) state and a (second) state, in which the switchable element 210 allows power from the power supply 202 to reach the output terminal 208 (and the load 214), and in the second state, the switchable element 210 blocks power from the power supply 202 from reaching the output terminal 208 (and the load 214). For example, in the first state, the switchable element 210 can connect the output terminal 208 to the power supply 202, and in the second state, the switchable element 210 can disconnect the output terminal 208 from the power supply 202.

[0049] There are various ways to selectively enable / disable power delivery. As an example, the switchable element 210 can be configured to selectively connect or disconnect the conductive path between the power source 202 and the load 214. This conductive path can be between the power source 202 and the output terminal 208, or between the output terminal 208 and the load. Exemplarily, the switchable element 210 can be controlled to close the path and allow power to reach the load 214, or it can be controlled to disconnect the path and prevent power from reaching the load 214.

[0050] As another example, the switchable element 210 can be configured to selectively connect a conductive path that bypasses the load 214. Exemplarily, the switchable element 210 can be controlled to close a low-resistance path, allowing current to bypass the load 214 and flow through the low-resistance path; or it can be controlled to open a low-resistance path, allowing current to flow through the load 214. This low-resistance path can be a conductive path with lower resistance than the load 214, so closing the switchable element 210 can short-circuit the load 214.

[0051] As an exemplary implementation, the switchable element 210 may include transistors such as metal-oxide-semiconductor (MOS) transistors (e.g., NMOS or PMOS), field-effect transistors (FETs), MOSFETs, bipolar junction transistors (BJTs), etc. However, it should be understood that the switchable element 210 may be implemented in any suitable manner, such as as a single element or as a combination of elements to achieve switching of power delivery.

[0052] Circuit 200 may also include control circuitry 212 configured to control the switchable element 210. Typically, control circuitry 212 may be configured to control the switchable element 210 to deliver average power (e.g., average current or average voltage) to the load 214 during a predefined time period (e.g., within each instance of the predefined time period). Exemplarily, control circuitry 212 may be configured to control the switchable element 210 such that the load 214 senses average power during the predefined time period, for example, such that the load 214 senses average current during the predefined time period.

[0053] consider Figure 2A In the configuration described above, control circuitry 212 can be configured to control switchable element 210 to deliver a predefined average power (e.g., predefined average current or predefined average voltage) at output terminal 208 during a predefined time period. Exemplarily, control circuitry 212 can control switchable element 210 such that the current at output terminal 208 has a predefined average current value when the current value at output terminal 208 is averaged over the predefined time period. The same applies to the average voltage value. Considering multiple instances of the predefined time period, control circuitry 212 can be configured to control switchable element 210 in each instance to deliver a predefined average power at output terminal 208 within that instance of the predefined time period.

[0054] Therefore, by way of illustration, the strategy proposed herein may include a power supply 202 that generates power according to the ramp and a switching device for power delivery. Thus, the delivered power can be defined by a combination of power values ​​at the points where power delivery is enabled. By synchronizing the enable / disable timing (as the first control "knob") with the ramp curve (as the second control "knob") to select which power values ​​to use and to more flexibly adapt the power sensed by the load 214, power delivery and the corresponding power supply to the load 214 can be controlled with finer resolution than classic PWM.

[0055] In some aspects, control circuitry 212 can be configured to control switchable element 210 based on the desired operation of load 214. For example, delivering a specific average power to load 214 during a predefined time period may correspond to specific behavior of load 214. Control circuitry 212 can be configured to control switchable element 210 to obtain predefined behavior of load 214 based on the average power (e.g., average current) sensed by load 214 during the predefined time period.

[0056] Given the exemplary configuration of load 214 including one or more light-emitting elements, control circuitry 212 can be configured to control switchable element 210 based on a target brightness level of light emitted by one or more light-emitting elements during a predefined time period (or within one or more instances of a predefined time period). The target brightness level can be a brightness level to be achieved, such as a brightness level to be achieved during a video frame of a display device.

[0057] Control circuitry 212 can therefore be configured to generate and use control signals to control the behavior of switchable element 210. For example, considering a transistor as a switchable element, the control signal could be a gate signal provided by control circuitry 212 at the gate terminal of the transistor to control the electrical behavior of the channel. The control signal can be configured according to (e.g., synchronously) ramp 204. Exemplarily, the power varying according to ramp 204 can present multiple power values ​​over a predefined time period, and the control signal can be configured to control switchable element 210 to enable power delivery based on the power value that results in an average power value to be delivered at output terminal 208 (and to load 214).

[0058] For example, the control signal may include multiple pulses corresponding to a point in time at which the generated power presents a power value that results in the average power perceived by the load 214 over a predefined time period. In other words, the control signal may be in a first state (e.g., a high state) and a second state (e.g., a low state), in which the control signal controls the switchable element 210 to enable power delivery; and in the second state, the control signal controls the switchable element 210 to disable power delivery. The control signal may be in a first state corresponding to a point in time at which the generated power presents a power value that results in the average power perceived by the load 214 over a predefined time period. The same applies to the average current or average voltage perceived by the load 214 over the predefined time period. Therefore, the control signal may be time-synchronized with the amplitude of the generated power (e.g., the amplitude of the generated current or voltage).

[0059] From another perspective, pulsed power supply to load 214 can be achieved by controlling the activation and deactivation of load 214 during a predefined time period in which power is generated by power supply 202 according to ramp 204. Exemplarily, according to the proposed method, power supply 202 can be configured to deliver the generated power to load 214, and control circuitry 212 can be configured to selectively turn load 214 on and off during a predefined time period based on the average power value to be sensed by load 214. Exemplarily, the control signal generated by control circuitry 212 for controlling switchable element 210 can be understood as a control signal for activating / deactivating load 214 according to (e.g., synchronously) ramp 204 (e.g., current ramp or voltage ramp).

[0060] Depending on the specifics, the proposed method can be combined with other methods for powering load 214. For example, the proposed method can be combined with conventional PWM or conventional amplitude modulation to provide more flexible configuration and offer more options to adapt to the drive scheme. For example, conventional PWM can be used to deliver generally higher power to the load, such as to obtain higher emitted light brightness.

[0061] Depending on various aspects, in addition to power supply 202, circuit 200 may also include an additional power supply (not shown) to implement conventional PWM (e.g., an additional current source or an additional voltage source). This additional power supply may be configured to generate a current with a fixed current value or a voltage with a fixed voltage value, rather than based on a ramp. For example, during a predefined time period, power supply 202 may generate current based on a current ramp, while the additional power supply may generate a current with a fixed current value. Circuit 200 may also include an additional switchable element configured to selectively enable or disable the delivery of a current with a fixed current value at output terminal 208, for example, to load 214. Control circuit 212 may also be configured to control the additional switchable element to provide an additional average current value at output terminal 208. This additional power supply may operate in combination with power supply 202 or independently of power supply 202.

[0062] According to various aspects, such as Figure 3A and Figure 3B As shown, the switchable element 210 may include multiple switchable elements to individually enable or disable power delivery to multiple load elements. For example, Figure 3A A load 302 with multiple load elements 304 is shown as an exemplary configuration of a load 214, and a switchable element 306 with multiple switchable elements 308 is shown as an exemplary configuration of a switchable element 210. Figure 3B An exemplary case is shown in which the load 312 includes multiple light-emitting elements 314 (e.g., multiple LEDs, such as MicroLEDs, multiple VCSELs, etc.) as multiple load elements.

[0063] In an exemplary configuration, load 302 may include multiple load elements 304, each of which can be individually driven by pulsed power. In this scenario, switchable element 306 may be configured to allow individual enabling or disabling of power delivery to load element 304. Therefore, switchable element 306 may include multiple switchable elements 308, such as multiple transistors, each associated with one or more load elements 304. For example, a one-to-one correspondence may exist between switchable elements 308 and load elements 304 (e.g., ...). Figure 3A(As shown). As another example, there may be a one-to-many correspondence between the switchable element 308 and the load element 304, whereby the switchable element 308 controls the selective enabling or disabling of power delivery to multiple load elements 304.

[0064] exist Figure 3A In an exemplary configuration, the switchable element 308 is configured to selectively allow current to flow through the associated load element 304, or to close a low-resistance path to allow current to bypass the associated load element 304. However, it should be understood that, in conjunction with Figure 3A The aspects discussed in the exemplary configuration are applicable in a corresponding manner to other configurations of the switchable element 308, such as in configurations where the switchable element 308 electrically connects or disconnects conductive paths for supplying current to associated load elements.

[0065] In a preferred configuration, multiple load elements 304 can be connected in series with each other. In this scenario, the switchable element 308 can be configured as follows: Figure 3A and Figure 3B The "bypass switch" shown allows current to flow through the corresponding load element 304 or provides a low-resistance path for bypassing the load element 304. Consider a set of LEDs ( Figure 3B For example, an LED pixel, each LED may have an associated switchable element 308 that enables the LED to be short-circuited (and bypassed) to keep the circuit closed but the individual LED is dark. By opening the switch, current flows through the LED to light it up. In this configuration, the current flowing through the series load element 304 (e.g., LEDs in series) can remain constant regardless of whether the load element is active or inactive (e.g., whether the LED is emitting light). If the load element 304 is inactive (e.g., not emitting light), the voltage across the short-circuited load element 304 is close to 0, and therefore the power is close to 0 in this case. Thus, this configuration provides an energy-efficient system.

[0066] Another advantage of the proposed driving scheme is that a single power supply (e.g., power supply 202) can be used to individually drive multiple load elements 304, requiring only a corresponding switchable element 308 for each load element 304 instead of multiple power supplies. Exemplarily, in various aspects, the power supply providing the power ramp can be shared for all load elements 304. For example, the power supply providing the current ramp can be shared for all light-emitting elements (e.g., all LEDs) among the multiple light-emitting elements 312. Considering a display device, a common power supply can be used to power all pixels of the display device. In another configuration, the common power supply can be used to power a subset of pixels (e.g., pixel rows, pixel columns, pixel quadrants, etc.).

[0067] Considering a configuration with multiple switchable elements 308, a control circuit (e.g., control circuit 212) can be configured to individually control each switchable element 308. Exemplarily, the control circuit can be configured to control the switchable elements to deliver a corresponding predefined average power value to the respective load element 304 (or multiple load elements 304) during a predefined time period. For example, the control circuit can be configured to control the switchable elements so that one or more corresponding load elements sense a predefined average current (or voltage) during the predefined time period.

[0068] Such as combination Figure 2A and Figure 2B The ramp used to generate power can be adjusted in various ways, such as having specific maximum and minimum values, a specific profile, or a specific duration. In principle, the ramp can take any suitable form depending on the characteristics of the load to be powered and the load's expected operation. Some exemplary ramp configurations will be discussed below.

[0069] Figures 4A to 4E Exemplary configurations of power ramps 400a-400e according to various aspects are shown. It should be understood that, in conjunction with... Figures 4A to 4E The aspects discussed can be applied accordingly to current ramps or voltage ramps. By way of explanation, Figures 4A to 4E An exemplary implementation of power ramp 204 is shown, according to which power supply 202 generates power. Some general characteristics of power ramps 400a-400e will be described below, followed by a description of specific exemplary features in conjunction with illustrated examples.

[0070] Typically, considering the power ramp 400a-400e, the power value can vary within a predefined time period 408a-408e, defined by the minimum power value 402a-402e and the maximum power value 404a-404e. Considering the current / voltage ramp, the generated current / voltage can vary within a range between the minimum and maximum current / voltage values.

[0071] In this regard, based on the power generated by the power ramp 400a-400e, multiple power values ​​can be presented within a predefined time period 408a-408e. These power values ​​include a minimum power value 402a-402e, a maximum power value 404a-404e, and one or more intermediate power values ​​406a-406e between the minimum power value 402a-402e and the maximum power value 404a-404e. Considering the current / voltage ramp, the generated current / voltage can present multiple current / voltage values ​​within the predefined time period 408a-408e. These current / voltage values ​​include a minimum current / voltage value, a maximum current / voltage value, and one or more intermediate current / voltage values ​​between the minimum current / voltage value and the maximum current / voltage value.

[0072] The duration of the predefined time periods 408a-408e (e.g., in at least one instance, in more than one instance, in each instance) can be selected based on the intended application of the driving scheme (e.g., based on the intended operation of the load to be driven). As a numerical example that may be related to controlling the brightness of the emitted light, the duration of the predefined time periods 408a-408e can be in the range of 1 millisecond to 1 second, for example, in the range of 5 milliseconds to 500 milliseconds, for example, in the range of 10 milliseconds to 100 milliseconds. As mentioned above, in some aspects, the duration of the predefined time periods 408a-408e can have a duration corresponding to the duration of a video frame of the display device (where the circuitry configured herein is integrated to drive the pixels of the display device). However, it should be understood that, depending on the application, the predefined time periods 408a-408e can have any suitable duration.

[0073] Accordingly, the power values ​​of the power ramp 400a-400e can be adjusted according to the load to be driven. For example, considering the current ramp, the current value can be in the range of 0mA to 1A, such as in the range of 10mA to 500mA, or even in the range of 50mA to 300mA. As another example, considering the voltage ramp, the voltage value can be in the range of 0V to 20V, such as in the range of 1V to 10V, or even in the range of 2V to 5V.

[0074] Depending on various aspects, one or more power values ​​(e.g., at least the maximum power values ​​404a-404e) may exceed the rated nominal power supply to the load. For example, considering the light-emitting element, one or more power values ​​may exceed the maximum rated power of the light-emitting element. As an example, at least one current value may exceed the rated maximum drive current of the light-emitting element (e.g., LED). This ensures that the load perceives sufficient average power, while taking into account that the ramp may include relatively low power values.

[0075] In this scenario, control circuitry 212 can be configured to allow power to be delivered to the load at least one power value (e.g., multiple power values) greater than the rated nominal power supply to the load (e.g., allowing power to be delivered to the load at least one current value greater than the rated nominal current or nominal voltage used to operate the load). Exemplarily, in some aspects, power ramps 402a-402e and control circuitry 212 can be configured to enable overcurrent (or overvoltage) operation of the load. This type of operation can allow, for example, higher brightness while remaining within the allowable thermal stress range of the load. By illustration, in conventional PWM, a fixed value of current or voltage can be equal to or less than the rated nominal current / voltage of the load. In the proposed scheme, one or more power values ​​of power ramps 402a-402e delivered to the output terminals (and the load) during a predefined time period may exceed the rated nominal specification of the load to balance the overall effective power perceived by the load (considering the presence of lower values ​​within the range defined by the ramps).

[0076] like Figures 4A to 4E As shown, the predefined time periods 408a-408e can be subdivided into multiple time intervals, and the power ramps 402a-402e can be configured such that within each time interval, the power exhibits a corresponding power value (within that range) (e.g., within each time interval, the current / voltage exhibits a corresponding current / voltage value). The power ramps 402a-402e can have “stepped” behavior, where the power exhibits and remains at a corresponding power value within each time interval. As another example, the power ramps 402a-402e can have “pulsed” behavior, where the power ramp comprises multiple pulses, each pulse having a corresponding power value.

[0077] The number of power values ​​and the corresponding number / duration of time intervals can be adjusted according to the desired granularity of power delivery. Compared to conventional driving schemes such as PWM, the proposed method can resolve lower power values ​​(e.g., lower current values ​​and correspondingly lower luminance values). In turn, considering exemplary applications for driving light emission, this can allow for lower minimum luminance values ​​for light emission, or high resolution of high dynamic range luminance levels achieved by combining several on / off steps. Therefore, the granularity of the power ramp can be selected according to the desired resolution of the power delivery. As a numerical example, the duration of the time intervals into which the predefined time period 408a-408e is subdivided can range from 1 µs (microseconds) to 1 ms, for example, from 10 µs to 500 µs, or from 50 µs to 200 µs. In a corresponding manner, the number of power values ​​generated within the predefined time period 408a-408e can be in the range of 3 to 100,000, for example, in the range of 50 to 10,000, or in the range of 100 to 1,000.

[0078] Such as combination Figure 2A As discussed, to achieve the proposed scheme, control circuitry 212 can be configured to enable power delivery within one or more time intervals to select which power values ​​contribute to the average value within predefined time periods 408a-408e. Exemplarily, control circuitry can be configured to control the switchable element to enable power delivery (e.g., current delivery) within one or more first time intervals and disable power delivery within one or more second time intervals based on the average power value to be perceived by the load during the predefined time period.

[0079] Depending on various aspects, the minimum power values ​​402a-402e of ramps 400a-400e can be greater than 0W. For example, the minimum current value can be greater than 0A, or the minimum voltage value can be greater than 0V. This configuration can be provided to adapt the delivered power to the requirements of the load (e.g., in cases where a very small power value does not contribute sufficiently to the operation of the load). As an exemplary implementation, the circuit proposed herein may include a bias power supply configured to generate a bias power that defines a minimum power value of 0 watts; for example, the circuit may include a bias current source configured to generate a bias current.

[0080] Typically, the power ramp 400a-400e can be configured such that the power value varies monotonically over a predefined time period 408a-408e. For example, as Figure 4A and Figure 4CAs shown, power ramps 400a and 400c can change from minimum power values ​​402a and 402c to maximum power values ​​404a and 404c. Exemplarily, power ramps 400a and 400c can be configured such that the power values ​​increase from minimum power values ​​402a and 402c to maximum power values ​​404a and 404c within a predefined time period 408a and 408c (e.g., a current / voltage ramp can be configured such that the current / voltage values ​​increase from minimum current / voltage values ​​to maximum current / voltage values ​​within a predefined time period 408a and 408c). This configuration can be referred to as ramp-up.

[0081] As another example, such as Figure 4B As shown, the power ramp 400b can change from a maximum power value 404b to a minimum power value 402b. Exemplarily, the power ramp 400b can be configured such that the power value decreases from the maximum power value 404b to the minimum power value 402b within a predefined time period 408b (e.g., a current / voltage ramp can be configured such that the current / voltage value decreases from the maximum current / voltage value to the minimum current / voltage value within a predefined time period 408b). This configuration can be referred to as a ramp-down, and in some scenarios, it can be easier to implement than a ramp-up.

[0082] As another example, such as Figure 4D and Figure 4E As shown, a combination of ramp-up and ramp-down can be provided. This configuration can provide more complex curves to achieve more tailored control for certain applications. In this configuration, for example, the power ramp 400d can change from a minimum power value 402d to a maximum power value 404d, and then return to the minimum power value 402d (or another power value less than the maximum power value 404d). Exemplarily, the power can increase from the minimum power value 402d to the maximum power value 404d (in the first part, e.g., the first half, of a predefined time period 408d), and then decrease from the maximum power value 404d to the minimum power value 402d (in the second part, e.g., the second half, of the predefined time period 408d).

[0083] As another example, the power ramp 400e can change from a maximum power value 404e to a minimum power value 402e, and then return to the maximum power value 404e (or another power value greater than the minimum power value 402e). Exemplarily, the power can decrease from the maximum power value 404e to the minimum power value 402e (in the first part of a predefined time period 408e, such as the first half), and then increase from the minimum power value 402e to the maximum power value 404 (in the second part of a predefined time period 408e, such as the second half).

[0084] As mentioned above, the power ramp 400a-400e can have any suitable curve. Therefore, the power value can vary within the power value range according to any suitable behavior. In a simple configuration, such as Figure 4A and Figure 4B As shown, power ramps 400a and 400b can be configured to make the power value vary linearly within the power value range. As another example, such as... Figure 4C As shown, the power ramp 400c can be configured such that the power value varies within a range according to an exponential curve (either rising or falling, as shown, not shown). As another example, the power ramp can be configured such that the power value varies according to a parabolic curve, a logarithmic curve, or any other suitable behavior. Therefore, considering the current / voltage ramp, the current / voltage value can vary linearly, or according to an exponential curve, parabolic curve, logarithmic curve, etc.

[0085] Considering the combined ramp-up / ramp-down configuration, power ramps 400d and 400e can be configured such that the power value varies along the same curve in both parts of the predefined time periods 408d and 408e (e.g., as shown in the image). Figure 4D and Figure 4E (The linear curve shown or other suitable curve). In some aspects, different curves can be selected for the ramp-up and ramp-down, for example, to suit specific load requirements. For example, power ramps 400d, 400e can be configured such that the power value varies with a first curve (e.g., increases or decreases) in the first part of the predefined time periods 408d, 408e, and varies with a second curve (e.g., decreases or increases) in the second part of the predefined time periods 408d, 408e. The first curve can be different from the second curve; for example, the first curve can be linear and the second curve can be parabolic, or vice versa, or can be configured according to any other suitable combination.

[0086] Typically, the steepness of the power ramp 400a-400e can remain constant within a predefined time period 408a-408e. For example, among the multiple power values ​​forming the power ramp 400a-400e, the relative differences between consecutive power values ​​within the power ramp 400a-400e can be equal. Consecutive power values ​​can be power values ​​within consecutive time intervals within the predefined time period 408a-408e.

[0087] However, in some respects, the steepness of the power ramp 400a-400e can vary within a predefined time period 408a-408e. For example, the power ramp 400a-400e can be less steep at lower power values ​​to provide finer granularity when driving loads at low power, while it can be steeper at higher power values ​​where granularity may be less relevant. However, it should be understood that the steepness of the power ramp 400a-400e can be adjusted based on the load's response to the supplied power.

[0088] Therefore, the power ramps 400a-400e can have different steepnesses (exemplarily, different slopes or rates of change) in different portions of the predefined time periods 408a-408e. The power ramps 400a-400e can have a first steepness in the first portion of the predefined time periods 408a-408e, a second steepness in the second portion of the predefined time periods 408a-408e, where the first steepness differs from the second steepness. As another example, the power ramps 400a-400e can have a third steepness in the third portion of the predefined time periods 408a-408e, and so on. For example, the first steepness can be lower than the second steepness, and the first steepness can be located in the portion of the ramp corresponding to a power value closer to the minimum power value 402a-402e compared to the maximum power value 404a-404e.

[0089] Statements can be made in different ways, power ramps 400a-400e can be configured such that the difference between consecutive power values ​​has a first difference in a first portion of a predefined time period 408a-408e, and a second difference in a second portion of the predefined time period 408a-408e, wherein the first difference is different from the second difference. As another example, power ramps 400a-400e can have a third difference in a third portion of the predefined time period 408a-408e, and so on. For example, the first difference can be less than the second difference, and the first difference can lie in the portion of the ramp corresponding to power values ​​that are closer to the minimum power values ​​402a-402e than the maximum power values ​​404a-404e.

[0090] Similar to the minimum and maximum power values, the difference between the continuous power values ​​in ramps 400a-400e can also be adjusted according to the desired application. As a numerical example only, the difference between the continuous power values ​​in ramps 400a-400e can be in the range of 0.001% to 10% of the maximum power values ​​404a-404e, for example, in the range of 0.005% to 5% of the maximum power values ​​404a-404e, or for example, in the range of 0.01% to 1% of the maximum power values ​​404a-404e. As a numerical example, the minimum power value 402a-402e can be in the range of 0 to 1% of the maximum power value 404a-404e, for example, in the range of 0.001% to 0.5% of the maximum power value 404a-404e, for example, in the range of 0.003% to 0.1% of the maximum power value 404a-404e.

[0091] Figures 5A to 5D Charts 500-570 are shown, illustrating the driver adaptation scheme. Figure 5A and Figure 5B ) and a comparison with pulse width modulation ( Figure 5C and Figure 5D Figures 500-570 refer to current ramps with exemplary current values ​​(from 0 to 250 mA), but it should be understood that, in conjunction with... Figures 5A to 5D The aspects described can be applied to voltage ramps in a corresponding manner.

[0092] Figure 5A Figure 500 illustrates an exemplary pulsed current delivery. As shown, pulsed power supply to a load can be achieved by enabling power delivery at selected time points corresponding to certain selected current values ​​of a current ramp. Therefore, the delivered current can be provided by the current value corresponding to the time point at which current delivery is enabled (e.g., the average current sensed by the load can be the integral result of the shaded portion below the ramp in Figure 500).

[0093] Figure 5B Figures 510-530 illustrate exemplary pulsed current delivery, where current delivery is enabled at different percentages for predefined time periods, for example, 25% in Figure 510, 50% in Figure 520, and 75% in Figure 530, thus producing different “integrals” defined by the shaded portions below the corresponding ramps in Figures 510-530.

[0094] Figure 5C and Figure 5D A comparison of the proposed scheme (in Figures 540 and 560) with PWM (in Figures 550 and 570) is shown. Figure 5CAs shown, using conventional PWM, the smallest switchable time unit might be 6% of the image, thus corresponding to 6% brightness in classic PWM. On the other hand, using the proposed current ramp, the smallest switchable brightness level could be even smaller (e.g., 0.6%) over the same time base, thus allowing for finer resolution. This also accommodates the eye's non-linear brightness perception, where differences in low brightness are perceived more clearly than differences in high brightness. Figure 5D As shown, when using a full ramp, the proposed method can deliver less power than PWM, making it possible in some respects for conventional PWM to be combined with the proposed ramp to obtain a more flexible drive that can adapt to higher power requirements.

[0095] Another advantage of the proposed configuration over PWM can be illustrated by a rough estimate of real-world timing. For example, considering conventional PWM, at a display device's 120 Hz frame rate (8 milliseconds per frame) and 15-bit luminance resolution, a switching operation of approximately 300 nanoseconds is required to achieve a 0.003% luminance share. On the other hand, using the proposed ramp method, a 0.003% luminance step size can be achieved at 8-bit resolution with a switching time of only 33 microseconds, which is 110 times slower than PWM, thus relaxing system requirements.

[0096] Figure 6 A schematic flowchart of a method 600 for supplying power to a load according to various aspects is shown. It should be understood that the aspects discussed in conjunction with circuit 200 can be applied to method 600 in a corresponding manner, and vice versa.

[0097] Method 600 may include generating power based on a power ramp in 610, such that the generated power exhibits multiple different power values ​​within a power value range from a minimum power value to a maximum power value during a predefined time period. For example, method 600 may include generating current based on a current ramp, such that the generated current exhibits multiple different current values ​​within a current value range from a minimum current value to a maximum current value during a predefined time period. As another example, method 600 may include generating voltage based on a voltage ramp, such that the generated voltage exhibits multiple different voltage values ​​within a voltage value range from a minimum voltage value to a maximum voltage value during a predefined time period.

[0098] Method 600 may further include, in step 620, selectively enabling or disabling the delivery of generated power to the load during a predefined time period to deliver a predefined average power value to the load during the predefined time period. Exemplarily, method 600 may include selectively allowing or blocking power supply to the load via a power ramp, such that the load perceives a predefined average power during the predefined time period. For example, method 600 may include enabling or disabling the delivery of generated power to the load during a predefined time period to deliver a predefined average current value or average voltage value to the load during the predefined time period.

[0099] As an example, method 600 may include selectively connecting or disconnecting a conductive path between a load and a power source. As another example, method 600 may include selectively connecting a path between a load and a power source or selectively connecting a low-resistance path of a bypass load.

[0100] As an example, method 600 may include selectively enabling or disabling the delivery of generated power to a load including a light-emitting element (e.g., LED, VCSEL, etc.) to obtain an average brightness value of emitted light over a predefined time period.

[0101] From another perspective, method 600 may include generating power based on a power ramp and delivering the generated power to the load. Method 600 may also include turning the load on and off (e.g., activating or deactivating the load) during a predefined time period based on an average power value sensed by the load during the predefined time period.

[0102] As used herein, the terms “processor,” “processing circuit,” or “control circuit” can be understood as any type of technical entity that allows the processing of data. Data can be processed according to one or more specific functions that the processor / processing circuit / control circuit can perform. Furthermore, the processor / processing circuit / control circuit used herein can be understood as any type of circuit (e.g., any type of analog or digital circuit). Therefore, a processor / processing circuit / control circuit can be or includes analog circuits, digital circuits, mixed-signal circuits, logic circuits (e.g., hard-wired logic circuits or programmable logic circuits), microprocessors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), field-programmable gate arrays (FPGAs), integrated circuits, application-specific integrated circuits (ASICs), etc., or any combination thereof. It should be understood that any two (or more) processors / processing circuits / control circuits described in detail herein can be implemented as a single entity with equivalent functions, and vice versa, any single processor / processing circuit / control circuit described in detail herein can be implemented as two (or more) independent entities with equivalent functions.

[0103] The term "connection" as used herein refers to an electrical connection in relation to terminals, integrated circuit elements, devices, etc. A "connection" can include direct or indirect connections, where an indirect connection may only include additional structures in the current path that do not affect the substantial function of the circuit or device. The term "conductive connection" as used herein describes an electrical connection between one or more terminals, devices, areas, contacts, etc., and can be understood as an electrical connection exhibiting, for example, ohmic behavior, provided by metal or degenerate semiconductors, in the absence of a pn junction in the current path. The term "conductive connection" may also be referred to as "electrical connection." The term "coupling" may be used herein in the same manner as the term "connection."

[0104] The term "terminal" is used herein to describe a location (e.g., a point) or structure of a device or device element at which a signal (e.g., an analog signal, such as current or voltage) can be provided and / or connected to another device or element. Exemplarily, a terminal can be a location or structure that is electrically connected to a device or element. A terminal may also be referred to herein as a port, pin, contact, or contact point.

[0105] The word “exemplary” is used herein to mean “as an example, instance, or illustration.” Any embodiment or design described herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments or designs.

[0106] The phrases “at least one” and “one or more” can be understood to include a numerical quantity greater than or equal to one (e.g., one, two, three, four, [...] etc.). The phrase “at least one” relating to a group of elements can be used herein to mean at least one element in a group consisting of those elements. For example, the phrase “at least one” relating to a group of elements can be used herein to mean the following selection: one of the listed elements, multiple of the listed elements, multiple individually listed elements, or multiple of multiple individually listed elements.

[0107] All acronyms defined in the above description also apply to all claims contained herein.

[0108] While the invention has been specifically shown and described with reference to particular aspects, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the scope of the invention is indicated by the appended claims, and thus, modifications within the equivalent meaning and scope of the claims are intended to be included.

[0109] List of reference numerals

[0110] 110 Chart 120 charts 130 charts 200 circuits 200b Circuit Configuration 200c Circuit Configuration 202 Power Supply 204 Power Ramp 206 Supply Terminals 208 Output Terminals 210 Switchable Component 212 Control Circuit 214 load 302 Load 304 load element 306 Switchable Component 308 Switchable Component 312 load 314 Light-emitting element 400A power ramp 400b power ramp 400d power ramp 400e power ramp 402a Minimum value 402b Minimum Value 402c minimum value 402d minimum value 402e minimum value 404a maximum value 404b maximum value 404c maximum value 404d maximum value 404e Maximum value 406a Intermediate Value 406b median 406c median 406d median 406e median 408a Predefined time period 408b Predefined time period 408c Predefined time period 408d Predefined time period 408e Predefined time period 500 charts 510 Chart 520 Chart 530 Chart 540 charts 550 charts 560 Charts 570 charts 600 methods 610 Method and Steps 620 Method and Steps

Claims

1. A circuit (200), comprising: The output terminal (208) is configured to be coupled to the load; The power supply (202) is configured to generate current according to a current ramp, such that the generated current has multiple different current values ​​within a range from a minimum current value to a maximum current value during a predefined time period. A switching element (210) is configured to selectively enable or disable the supply of generated current to the output terminal (208); as well as A control circuit (212) is configured to control the switching element (210) to deliver a predefined average current value at the output terminal (208) during the predefined time period.

2. The circuit (200) according to claim 1. in, The current ramp includes the minimum current value, the maximum current value, and one or more intermediate current values ​​between the maximum current value and the minimum current value.

3. The circuit (200) according to claim 1 or 2. in, The current ramp is configured such that the value of the generated current varies monotonically within the range of current values.

4. The circuit (200) according to any one of claims 1 to 3. in, The current ramp is configured such that the current value of the generated current decreases from the maximum current value to the minimum current value during the predefined time period. or The current ramp is configured such that the current value of the generated current increases from the minimum current value to the maximum current value during the predefined time period.

5. The circuit (200) according to any one of claims 1 to 4. in, The current ramp has a first steepness in the first part of the predefined time period and a second steepness in the second part of the predefined time period. The first steepness is different from the second steepness.

6. The circuit (200) according to any one of claims 1 to 5. in, The predefined time period includes multiple time intervals, and The current ramp is configured such that during each time interval, the generated current exhibits a corresponding current value within the range of the stated current values, and The control circuit (212) is configured to control the switching element (210) to enable current delivery to the output terminal (208) during a plurality of first time intervals and disable current delivery to the output terminal (208) during a plurality of second time intervals, based on the average current value to be delivered to the output terminal (208) during the predefined time period.

7. The circuit (200) according to any one of claims 1 to 6 further comprises: An additional power source is configured to generate an additional current with a fixed value; as well as Additional switching elements are configured to selectively enable or disable the delivery of additional current generated to the output terminal (208); and The control circuit is also configured to control the additional switching element to deliver a predefined additional average current value to the output terminal (208).

8. The circuit (200) according to any one of claims 1 to 7, further comprising: The load (214) is coupled to the output terminal (208).

9. The circuit according to claim 8, in, The load (214, 302) includes a plurality of load elements (304). The switching elements (210, 306) include a plurality of switching elements (308). Each switching element (210, 306) is configured to selectively enable or disable the delivery of the generated current to one or more of the plurality of load elements (304), and The control circuit (212) is configured to control the switching element (308) to deliver a corresponding predefined average current value to one or more load elements (304) during the predefined time period.

10. The circuit according to claim 9, in, The power supply (202) is shared by all load elements (304) among the plurality of load elements (304).

11. The circuit (200) according to any one of claims 8 to 10. in, The load (214) includes one or more light-emitting elements configured to be driven by current supplied by the power source (202), and The control circuit (212) is configured to control the switching element (210) to obtain a predefined brightness value of the light emitted by the one or more light-emitting elements during the predefined time period.

12. The circuit according to claim 11, in, At least one current value in the current value range is greater than the rated maximum driving current of at least one of the one or more light-emitting elements.

13. A circuit comprising: Power supply (202), which is configured as follows: Electric power is generated according to the power ramp (204), and The generated electrical power (204) is delivered to the load (214) such that the power delivered to the load (214) during a predefined time period presents multiple different power values ​​within a power value range from the minimum power value to the maximum power value; as well as A control circuit (212) is configured to turn the load (214) on and off during the predefined time period based on the average power value that the load (214) is to sense during the predefined time period.

14. A method (600) for supplying power to a load, the method comprising: The current is generated according to the current ramp (610) so that the generated current has multiple different current values ​​in the range of current values ​​from the minimum current value to the maximum current value during a predefined time period. as well as Selectively enable or disable (620) the delivery of generated current to the load during the predefined time period to deliver a predefined average current value to the load during the predefined time period.

15. A method (600) for supplying power to a load, the method comprising: Power is generated based on the power ramp, so that the generated power exhibits multiple different power values ​​within a predefined time period, ranging from the minimum power value to the maximum power value. The generated power is delivered to the load; as well as The load is switched on and off during the predefined time period based on the average power value that the load is to be perceived during the predefined time period.

Images