Current detection circuit
By using a comparator and an adjustable reference current in the current detection circuit, the problems of high cost, high complexity, and low accuracy in the prior art are solved, achieving low power consumption, high flexibility, and high accuracy load change detection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-12
- Publication Date
- 2026-03-17
AI Technical Summary
Existing current detection circuits are inadequate in terms of cost, complexity, power consumption, accuracy, and flexibility, especially in vehicle electrical systems, where they struggle to effectively detect load changes.
A detection circuit is employed that includes a comparator to detect load changes by comparing a first voltage with a second voltage biased by a reference current. The threshold is set using an adjustable reference current, reducing cost and complexity while improving detection accuracy and flexibility.
It achieves high accuracy in detecting load changes under low power conditions, enabling early and accurate identification of load state changes, and reducing the cost and complexity of the detection circuit.
Smart Images
Figure CN121679094A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to power circuit devices, and more particularly to techniques for detecting changes in current through one or more loads supplied by a power circuit device. BACKGROUND
[0002] In some applications, a power circuit device can be used to supply energy to components of an electrical system. In some examples, the electrical system and / or components of the electrical system can operate in a low-power consumption state when not in use to reduce energy consumption. For example, when a motor vehicle is parked, one or more components of the vehicle electrical system can be turned off (i.e., disconnected from power) or operate in a sleep mode (still supplied with power but not fully operable) such that the components consume power.
[0003] In some examples, a vehicle electrical system can include a circuit device configured to periodically wake up and perform a routine that measures current supplied to components of the vehicle electrical system to determine whether one or more of the components or loads have changed state. There is a need for improved current detection circuitry that can be implemented at reduced cost and / or complexity compared to conventional circuitry. There is also a need for current detection circuitry that operates with improved power consumption, accuracy, and / or flexibility compared to conventional circuitry. SUMMARY
[0004] The present disclosure relates to improvements in current detection, such as detecting changes in one or more loads of a power stage. According to some aspects, a detection circuit includes a comparator. The comparator is configured to compare a first voltage associated with a pass device configured to supply energy to a load to a second voltage associated with a current sense device coupled to the pass device and biased with a reference current. The comparator detects a change in the load based on comparing the first voltage and the second voltage.
[0005] According to some aspects, a method is described. The method includes comparing a first voltage associated with a pass device configured to supply energy to one or more loads to a second voltage associated with a current sense device coupled to the pass device and biased with a reference current. The method also includes detecting a change in the one or more loads based on comparing the first voltage and the second voltage.
[0006] According to some aspects, a power device is described, the power device comprising at least one package and a power stage housed within the at least one package and comprising a gate controller controlling a transfer device configured to supply energy to one or more loads. The power device further comprises a current sensing device coupled to the transfer device, and a detection circuit coupled to the power stage and housed within the at least one package. The detection circuit is configured to compare a first voltage associated with the transfer device to a second voltage associated with the current sensing device and biased with a reference current. The detection circuit is further configured to detect a change in the one or more loads based on comparing the first voltage to the second voltage. BRIEF DESCRIPTION OF DRAWINGS
[0007] Figure 1 is a block diagram depicting one example of a power circuit arrangement comprising a power stage and a detection circuit according to some embodiments.
[0008] Figure 2 is a block diagram depicting one example of a power device comprising a power stage and a detection circuit according to some embodiments.
[0009] Figure 3 is a flow diagram depicting respective modes of operation of a detection circuit according to some embodiments.
[0010] Figure 4 is a timing diagram showing plots of respective first and second voltages, load current, and load detection signal versus time according to some embodiments.
[0011] Figure 5 is a timing diagram depicting operation of a detection circuit for detecting a change in one or more loads according to some embodiments.
[0012] Figure 6 is a flow diagram depicting one example of a method of detecting a current according to some embodiments. DETAILED DESCRIPTION
[0013] Figure 1This is a block diagram depicting a power circuit arrangement 101 including a power stage 110 and a detection circuit 120 according to some embodiments, the detection circuit 120 being configured to detect changes in one or more loads 137 supplied with energy by the power stage 110. The power stage 110 includes a transfer device 114, which may be a power metal-oxide-semiconductor (MOSFET) transistor configured to be turned on and off by a gate controller 116 to regulate the energy from the supply voltage Vs to one or more loads 137. An example of such a power MOSFET is a double-diffused MOSFET, which may be referred to as a DMOS. The gate controller 116 can operate based on measured feedback to turn the device 114 on and off, thereby supplying a desired amount of energy to the load 137. For example, the gate controller 116 may control the transfer device 114 at least in part based on measured feedback, for example, from a current sensing device 112 coupled to the transfer device 114 and configured to generate a current I with respect to the load current I. L Proportional sensing current I SENSE Sensing current I SENSE It can have the same load current I L The amplitude is proportional to the load current I and is used to monitor the load current I. L .
[0014] Power stage 110 can be used alone or in combination with components to implement one or more electrical systems, such as supplying energy to components used in motor vehicles. For example, power stage 110 can be a power distribution circuit (…). Figure 1 As part of (not shown), the power distribution circuit is configured to transfer energy from a power source (such as a battery, grid, or other power source) to one or more loads 137 (hereinafter referred to as load 137, meaning a singular load or plural load). Load 137 may be a component of the vehicle system, and non-limiting examples include electric motors, sensors, communication or networking components, lighting, and / or rechargeable power sources (such as batteries). In some examples, at least some components of the vehicle electrical system operate in a low-power mode to reduce power consumption when the vehicle and / or specific components are not in use.
[0015] In some examples, conventional power stages can employ circuitry to measure the load current I. L For example, some conventional power stages may include V DS Sensing circuit device, the V DS The sensing circuit is coupled to monitor the voltage across the drain and source terminals of the transfer device, and uses this voltage as the load current I. L An approximation of V. In some examples, this conventional V... DS The sensing circuit device can detect the load current I L R as a transmission deviceDS (ON) to calculate R DS (ON) represents the resistance of the pass device when operating in the linear region. In some examples, this conventional V DS sensing circuitry is not suitable for measuring load current I L . Moreover, this conventional V DS sensing can not be accurate enough for some applications (e.g., less than 30%). Furthermore, implementing an adjustable threshold for the conventional V DS sensing circuitry can be complex.
[0016] Other conventional power stages can include a current sensing device that is capable of detecting load current I DS with greater accuracy than the V L sensing circuitry. According to these examples, a conventional current sensing device can be coupled to the pass device and configured to output a sense current that is proportional to load current I L passing through the pass device. According to this conventional power stage, a copy of the load current is generated as the sense current and converted to a voltage across a resistor that is compared to a reference voltage to monitor load current I L . In some examples, the conventional current sensing device can operate with higher accuracy than the V DS sensing described above and can also be operated to measure load current I L when the pass device is operating in the linear region and when the pass device is operating in the saturation region. In some examples, a stable reference voltage for comparison in the conventional current sensing device can require expensive and / or complex components to implement (such as a bandgap reference). In some examples, a stable reference voltage for comparison in the conventional current sensing device can also be expensive or difficult to adjust. In some examples, the conventional current sensing device can consume an appreciable amount of power to measure load current I L .
[0017] Figure 1 The depicted power stage 110 includes a detection circuit 120 that is uniquely configured to detect changes in one or more loads 137 coupled to output V OUT 139 of the power stage 110. In some examples, instead of comparing a voltage that represents the difference between sense current I SENSE and load current I L to a voltage reference as a conventional current sensing circuit, Figure 1The detection circuit 120 detects a change in the load 137 based on comparing a first voltage 134 associated with the pass device 114 to a second voltage 136 associated with the current sense device 112 and biased by a reference current I REF 142. The second voltage 136 is biased.
[0018] For example, Figure 1 The detection circuit 120 shown includes a comparator 122 that compares the first voltage 134 to a second voltage 136 biased by a reference current I REF to generate a differential output 138 that can be sent as a load detection signal 135 indicating that a change in the load current I L is detected if the first voltage 134 falls below a threshold defined by the second voltage 136. In some examples, the second voltage 136 is adjustable (e.g., by reducing or increasing the reference current I REF used to bias the second voltage 136), thereby increasing or decreasing the threshold to trigger the load detection signal 135.
[0019] In some examples, the detection circuit 120 can provide advantages compared to conventional techniques for measuring the load current I L . For example, by comparing the first voltage 134 to the second voltage 136 biased by the reference current I REF to detect a change in the load 137, this can implement the detection circuit 120 at a reduced cost and / or complexity compared to conventional techniques that use a reference voltage for comparison. Further, by varying the reference current I REF , the threshold used by the detection circuit 120 to detect a change in the load 137 can be easily adjusted without the cost or complexity associated with conventional techniques. In some examples, such a threshold can be set to a lower threshold compared to conventional techniques, which can enable more accurate and / or earlier detection of a change in the load 137.
[0020] In some examples, the detection circuit 120 can operate as a wake-up circuit that operates to reduce power consumption when the power stage 110 and / or components of the power stage 110 are operating in a sleep state. In some examples, if the pass device 114 is operating in a linear region or a saturation region, the detection circuit 120 can operate to detect the current I L through the pass device 114, allowing the gate controller 116 to enable the pass device for current measurement with greater flexibility during wake-up.
[0021] When used as a wake-up circuit, the detection circuit 120 can operate in an idle state defined by the sleep timer and intermittently wake up from the idle state to measure the load current I L , e.g., to detect a change in the load 137 (i.e., the load 137 has changed state). For example, the detection circuit 120 can detect that the load 137 has started drawing current. As a non-limiting example, the load 137 can change state because one or more of the loads 137 have been woken up from a sleep mode to start operating (i.e., due to an operator input, a sensor input, and / or a timer expiration), have been turned on (i.e., coupled to a power source), and / or have experienced a fault (i.e., other fault short), which caused the load 137 to start drawing current (i.e., draw more current than the load was previously drawing). In some examples, if a change in the load 137 is detected, the detection circuit 120 generates a load detection signal 135. In some examples, the load detection signal 135 is sent to the gate controller 116 to operate the pass device 114 (e.g., to drive the pass device 114 on and off at a defined duty cycle) to supply energy to the load 137 in response to the load detection signal 135. In other examples, the load detection signal 135 can also or instead be sent to a diagnostic circuitry (not shown in Figure 1 ) that performs one or more diagnostic routines involving one or more of the power stage 110, the detection circuit 120, or other associated components in response to the load detection signal 135. In other examples, the load detection signal 135 can also or instead be supplied to a protection circuitry (not shown in Figure 1 ) that decouples one or more components of the power stage 110 from the power source or otherwise protects the power stage 110 from damage. In other examples, the load detection signal 135 can be sent as an interrupt to one or more systems / components.
[0022] In some examples, the detection circuit 120 can alternate between: 1) a drift correction phase in which the comparator 122 is deactivated (and little or no power is consumed) and the reference current I REF 142 is activated to bias and sample the second voltage 136 across the charge storage device 124; and 2) a wake-up detection phase in which the reference current I REF 142 is deactivated (and little or no power is consumed) and the comparator 122 is activated to compare the first voltage 134 to the second voltage 136 and generate the differential output 138.
[0023] Based on these examples, the detection circuit 120 can be advantageously configured to operate with reduced power consumption compared to conventional techniques, while operating with high accuracy to detect changes in the load 137 (e.g., detecting whether the load 137 has turned on and started drawing current).
[0024] Figure 2 This is a block diagram depicting an example of a power device 201 including a power stage 210 and a detection circuit 220 according to some embodiments. Figure 2 In the example, power stage 210 includes pass transistor 214, current sensing transistor 212, and gate controller 216. Figure 2 In the example, the pass transistor 214, current sensing transistor 212, gate controller 216, and detection circuitry 220 are housed in the same package 202 and coupled to external circuitry via I / O ports 203A-203C on package 202. In other examples not depicted, one or more of the pass transistor 214, current sensing transistor 212, gate controller 216, and detection circuitry 220 may be housed in separate packages. Figure 2 As shown by the dashed box, in some examples, the pass transistor 214 and the current sensing transistor 212 can be monolithically integrated on the same silicon substrate, and the gate controller 216 can be implemented in separate silicon substrates housed in the same or different packages. In some examples, the detection circuit 220 can be integrated with the gate controller 216 and / or the pass transistor 214, or implemented in separate substrates in the same or different packages.
[0025] like Figure 1 As shown in the example, the pass transistor 214 includes a gate, a drain, and a source terminal. In some examples, the pass transistor 214 is a power semiconductor device specifically configured to be driven to control the energy supply from the source to one or more loads 137. For example, the pass transistor 214 can be a silicon-based power metal-oxide-semiconductor (MOSFET), an example of which is a DMOS, a gallium nitride power device, a silicon carbide-based power device, or any device configured to turn on and off to transfer energy between the energy source and one or more loads 137.
[0026] like Figure 2 As shown, the drain terminal of the pass transistor 214 is coupled to the supply voltage Vs through the I / O port 203B on the package 202, and the source terminal of the pass transistor 214 is coupled to the output V of the power stage 210. OUT 239, the output V OUT 239 can be coupled to load 137 via I / O port 203C on package 202. For example... Figure 1 As shown in the example, load 137 can be coupled to the output voltage V.OUT Between and ground reference GND.
[0027] like Figure 2 As shown, the gate terminal of the pass transistor 214 is coupled to be driven by the gate controller 216 of the power stage 110. The gate controller 216 includes circuitry configured to generate a control signal with sufficient current to drive the pass transistor 214 to turn on and off, thereby transferring the desired amount of energy to the load 137 via the I / O port 203C.
[0028] like Figure 2 As shown, power stage 210 also includes a current sensing transistor 212, which may include a portion of the transfer transistor 214 for current sensing (e.g., a portion of the same silicon structure), or a component separate from the transfer transistor 214 as shown, coupled to the transfer transistor 214. Figure 1 As shown, the current sensing transistor 212 includes components coupled to the supply voltage V. S The drain terminal of the current sensing transistor 214 and the gate terminal of the current sensing transistor 214 are coupled to the output of the gate controller 216 and the gate terminal of the current sensing transistor 214. The source terminal of the current sensing transistor 212 senses the current I through the current sensing transistor 212. SENSE 240 is coupled to the detection circuit 220 to be measured. Current I SENSE It can represent the load current I L 244. For example, the sensed current I L It can have the same load current I L The amplitude is proportional to 244. In some examples, the key parameter of the current sensing transistor 212 can be referred to as the load current I according to the following equation. L 244 and sensing current I SENSE K between 240 ILIS ratio:
[0029] K ILIS ＝ I L / I SENSE (1)
[0030] like Figure 2 As shown, the detection circuit 220 includes a timer circuit 229, a switch 228, a current source 226, a capacitor 224, and a comparator 222. The comparator 222 is configured to input a first voltage 234 (output voltage V) at its negative input. OUTThe first voltage 234 is compared with the second voltage 236 at the positive terminal of comparator 222, and a differential output 238 is generated, timed by the clock signal CLK 231 from timer circuit 229. In some examples, comparator 222 is configured to be alternately activated (to perform the comparison) or deactivated (to reduce power consumption) in response to transitions in clock signal CLK 231. For example, comparator 222 may be operated such that in response to a first transition of clock signal CLK 231 (e.g., from low voltage to high voltage), comparator 222 operates to compare the first voltage 234 with the second voltage 236, and in response to a second transition of clock signal CLK 231 (e.g., from high voltage to low voltage, i.e., the opposite of the first transition), comparator 222 is deactivated and consumes very little or no power, and the output 238 of comparator 222 is blanked (e.g., coupled to ground reference GND).
[0031] like Figure 2 As shown, capacitor 224 is coupled, for example, between the second voltage 236 and ground reference GND via I / O port 203A on package 202. Current source 226 is coupled to the second voltage 236 to use a reference current I. REF 242 biases the second voltage 236. Switch 228 is coupled between current source 226 and ground reference GND. Switch 228 includes a gate terminal coupled to be driven by a clock signal CLK 231 from timer circuit 229 to activate or deactivate the reference current I. REF 242. In some examples, switch 228 is configured to operate based on the same clock signal CLK 231 from the timer circuit 229 controlling comparator 222. In some examples, switch 228 is configured to activate or deactivate the reference current I in response to a transition in clock signal CLK 231. REF 242. This transition can be the opposite of the transition of the clock signal CLK231 to the activation transition of the trigger comparator 222 as described above. For example, in response to the first transition of the clock signal CLK 231 (e.g., from high to low), switch 228 can be turned off to decouple the current source 226 and deactivate the reference current I. REF 242, and in response to a second transition (e.g., from low to high) of clock signal CLK 231, switch 228 can be turned on to couple current source 226 and activate reference current I. REF 242.
[0032] Figure 3 The flowcharts, based on some embodiments, depict... Figure 2 The detection circuit 220 depicted is used to detect corresponding modes of operation of changes in one or more loads 137. Figure 3In the example, the detection circuit 220 is configured to operate in the idle phase 350, where the power consumption of the power stage 210 and the detection circuit is minimized. For example, in the idle phase 350, the gate controller 216 may not operate to supply a gate drive signal to the pass transistor 214, and the pass transistor 214 and / or the current sensing transistor 212 may be turned off, and / or the current may be supplied from the supply voltage V. S Disconnect. As another example, during idle phase 350, components of detection circuit 220 can be turned off and / or disconnected from power. For example, switch 228 can be turned off, disconnecting current source 226 from power. As yet another example, comparator 222 can be deactivated during idle phase 350.
[0033] like Figure 3 As shown, the detection circuit 220 can remain in the idle phase 350 until the sleep timer has elapsed. Once the sleep timer has elapsed, the detection circuit 220 operates to detect changes in the load 137 coupled to the output of the power stage 210, such as whether the load 137 has turned on and begun to draw current. Alternatively, in some examples, once the sleep timer has elapsed, the gate controller 216 controls the pass transistor 214 to turn on, making it possible to detect changes in the load 137. For example, in response to the elapsed sleep timer, the gate controller 216 can apply a gate drive signal that operates the pass transistor 214 in the linear or saturation region.
[0034] like Figure 3 As shown, after the sleep timer has elapsed, the detection circuit 220 can operate in the drift correction stage 351, followed by the wake-up check stage 353. In the drift correction stage 351, in response to the clock signal CLK 231 from the timer circuit 229, the output of comparator 222 is blanked, and switch 228 is turned on, coupling current source 226 to the second voltage 236, causing the reference current I... REF 242 biases the second voltage 236. During the drift correction phase 351, the terminals of capacitor 224 are biased by the reference current I. REF The second voltage 242, which is biased, is sampled (i.e., stored) by 236. For example... Figure 3 As shown, in an alternative embodiment, at 352, comparator 222 performs automatic zeroing during the drift correction phase 351, which can improve the accuracy of comparator 222.
[0035] Following the drift correction phase 351, the detection circuit 220 operates in the wake-up check phase 353. In the wake-up check phase 353, the reference current I is deactivated, for example, by turning off switch 228 and decoupling current source 226 from ground reference GND. REF242. In the wake-up check phase 353, the current source 226 may consume very little or no energy. In the wake-up check phase 353, the comparator 222 is activated to compare the first voltage 234 with the second voltage 236. Figure 3 As shown at point 354 in the example, if the first voltage 234 does not drop below the second voltage 236 during the wake-up check phase 353, the detection circuit 220 may not output the load detection signal 235 and returns to the idle phase 350 at point 355, activating the sleep timer. However, if the first voltage 234 drops below the second voltage 236, then at point 356, the detection circuit 220 outputs the load detection signal 235, indicating that one or more loads 137 have changed state, for example by starting to draw load current I. L 244. In some examples, the load detection signal 235 is output to the gate controller 216, and the gate controller 216 drives the pass transistor 214 to turn on and off to transfer energy to the load 137. In other examples, the load detection signal 235 is sent to a diagnostic circuit device that executes one or more diagnostic routines in response to the load detection signal 235. In other examples, the load detection signal 235 is sent to a protection circuit device that takes protective measures (such as decoupling the pass transistor 214 and / or other components from the power source) in response to the load detection signal 235. In other examples, the load detection signal 235 may be sent as an interrupt to one or more components or systems.
[0036] After the wake-up check phase 353, if the detection circuit 220 does not determine that the load 137 has changed state (the first voltage 234 has not dropped below the second voltage 236), the detection circuit 220 can return to the idle phase 350 of the operation described above, including starting a sleep timer. The detection circuit 220 can remain in the idle phase 350 until the sleep timer has elapsed, and again operate as described in the drift correction phase 351 and the wake-up check phase 353 to detect changes in the load 137 each time the sleep timer elapses.
[0037] Figure 4 This is a timing diagram showing curves 401-403 according to some embodiments, curves 401-403 showing the corresponding first voltage 234 and second voltage 236, and load current I. L The relationship between the load detection signal 235 and time. As shown in curve 402, the load current I... L For example, it increases steadily over time due to the activation of one or more loads 137. As shown in curve 402, this is due to the reference current I. REFThe biased second voltage 236 remains substantially constant and serves as the threshold for triggering the load detection signal 235, as shown in curve 401. As shown in curve 401, when the load current I... L As the voltage increases in curve 402, the first voltage 234 decreases. As shown in curve 403, when the first voltage 234 drops below the second voltage 236 in curve 401, the detection circuit 220 causes the load detection signal 235 to change state to indicate a change in the load 137, such as the load 137 being turned on and starting to draw current.
[0038] like Figure 4 As shown in curves 401-403, the second voltage 236 serves as a threshold for triggering the detection of changes in the load 137. In some examples, the second voltage 236 is adjustable to increase or decrease the sensitivity and / or accuracy of the detection circuit 220. For example, the reference current I used to bias the second voltage 236 can be reduced by operating the current source 226. REF The amplitude of 142 is used to increase the second voltage 236. As another example, the reference current I used to bias the second voltage 236 can be increased by operating the current source 226. REF The amplitude of 242 is reduced, thereby decreasing the second voltage of 236.
[0039] Figure 5 This is a timing diagram describing the operation of the detection circuit 220 according to some embodiments. For example... Figure 5 As shown in the example, the detection circuit 220 operates based on a clock signal CLK 231, which can be generated by the timer circuit 229 or received from elsewhere (such as via an I / O port on package 202).
[0040] like Figure 5 As shown, the detection circuit 220 can operate in the idle phase 350. In the idle phase 350, the detection circuit 220 is operated to consume as little power as possible. For example, the comparator 222 and / or the current source 226 can be deactivated in the idle phase 350. In some examples, the detection circuit 220 operates in the idle phase 350 until the sleep timer 370 has elapsed. For example, the sleep timer 370 can be defined based on the number of cycles of the clock signal CLK 231. Figure 5 In the example, the sleep timer 370 has a duration of 2.5 clock cycles, or four transitions of the clock signal CLK 231. In other examples, the sleep timer 370 may be defined for a much longer duration. For example, the sleep timer 370 may have a duration much greater than... Figure 5The duration of the described drift correction phase 351 and / or wake-up check phase 353 is used to define this. In some examples, depending on the application, the sleep timer 370 may be tens of times longer than the drift correction phase 351 and / or wake-up check phase 353, or hundreds or thousands of times longer.
[0041] like Figure 5 As shown, once the sleep timer 370 has elapsed, the detection circuit 220 operates in the drift correction phase 351. After the sleep timer expires, the reference current I... REF 242 is enabled (e.g., by operating switch 228 to enable current source 226 to generate reference current I). REF 242), thereby biasing the second voltage 236. In the drift correction stage 351, the output of comparator 222 is zeroed, and the comparator is deactivated. For example... Figure 5 As shown, once the reference current I is enabled REF 242, then apply a delay of 360, and respond to the transition in clock signal CLK 231 after applying the delay of 360 (e.g., in Figure 5 In the example, the second voltage 236 is sampled across capacitor 224 from high to low; that is, capacitor 224 stores the voltage across the reference current I. REF The second voltage 242 biased by the associated charge 236. For example... Figure 5 As shown, after sampling the second voltage 236 across capacitor 224, detection circuit 220 deactivates reference current I. REF 242, for example, can be operated via switch 228 to disconnect current source 226, thereby deactivating reference current I. REF 242.
[0042] like Figure 5 As shown, after the reference current is deactivated, the detection circuit 220 operates in the wake-up check phase 353. In the wake-up check phase 353, the reference current I... REF When 242 is disabled, in response to the transition in clock signal CLK 231 (in Figure 5 In some examples, comparator 222 operates (from low to high) to compare the first voltage 234 and the second voltage 236. In some examples, detection circuitry 220 operates during the wake-up check phase 353 to compare the first voltage 234 with the second voltage 236 across multiple cycles of the clock signal CLK 231. For example, Figure 5The diagram illustrates a detection circuit 220 operating during the wake-up check phase 353 over two cycles of the clock signal CLK 231, during which a comparator 222 can perform two comparisons in response to two transitions (e.g., low to high) in the clock signal CLK 231. In other examples, the detection circuit 220 can compare... Figure 5 The comparator 222 can operate in the wake-up check phase 353 for more clock cycles, causing it to perform more comparisons, or it can operate in the wake-up check phase 353 for a single clock cycle, causing it to perform only a single comparison of the first voltage 234 and the second voltage 236 in the wake-up check phase 353.
[0043] At the end of the wake-up check phase 353, whether based on a single or multiple comparisons, if the detection circuit 220 determines that the first voltage 234 has dropped below the second voltage 236, the detection circuit 220 outputs a load detection signal 235, which indicates a change in one or more loads 137 (i.e., load 137 has begun to draw load current I). L Conversely, if during the wake-up check phase 353, the detection circuit 220 determines that the first voltage 234 has not dropped below the second voltage 236, such as Figure 6 As shown in the example, the detection circuit 220 returns to the idle phase 350 and activates the sleep timer 370. For example... Figure 6 As shown, once the sleep timer 370 has elapsed, the detection circuit 220 returns to the drift correction stage 351 and the wake-up check stage 353, respectively.
[0044] Figure 6 This is a flowchart illustrating an example of a method for operating a current detection circuit according to some embodiments. As shown, at 601, the method includes comparing a first voltage 134 with a second voltage 136, the first voltage 134 being associated with a transfer device 114 configured to supply energy to one or more loads 137, and the second voltage 136 being associated with a current sensing device 112 coupled to the transfer device 114 and with a reference current I. REF 142 is biased. Also, As shown, at 602, the method further includes detecting changes in load 137 based on comparing a first voltage 134 with a second voltage 136.
[0045] In some examples, the method also includes using a current source 226 coupled to a second voltage 236 to use a reference current I. REF 242 biases the second voltage 236. In some examples, the method also includes controlling the reference current I. REFThe amplitude of 242 is used to adjust the second voltage 236. In some examples, the method also includes timing the comparator 222 by a timer circuit 229.
[0046] In some examples, the method also includes using switch 228 to activate or deactivate current source 226. In some examples, the method also includes timing switch 228 by timer circuitry 229. In some examples, the method also includes sampling second voltage 236 using charge storage device 124 (e.g., capacitor 224).
[0047] In some examples, the method further includes operating the detection circuit 120 in a wake-up check phase 353 after the sleep timer has elapsed in the idle phase 350. In some examples, the method further includes activating comparator 122 in the wake-up check phase 353 to compare a first voltage 134 with a second voltage 136. In some examples, comparator 122 consumes current in the wake-up check phase 353, and other components of the detection circuit do not consume current in the wake-up check phase 353. In some examples, the method further includes deactivating the reference current I in the wake-up check phase 353. REF 142. In some examples, the method further includes operating the detection circuit 120 in a drift correction phase 351 prior to operation in the wake-up check phase 353, wherein the drift correction phase 351 includes blanking the output of the comparator 122 and sampling the second voltage 136. In some examples, the method further includes automatically zeroing the comparator 122 in the drift correction phase 351.
[0048] In some examples, the method further includes triggering the transmission device 114 to supply energy to the load 137 if the first voltage 134 is less than the second voltage 136. In some examples, the method further includes triggering a protection mechanism if the first voltage 134 is less than the second voltage 136. In some examples, the method further includes triggering an interrupt signal if the first voltage 134 is less than the second voltage 136. In some examples, the method further includes entering an idle phase and not triggering the transmission device to supply energy to the load if the first voltage 134 is greater than the second voltage 136.
[0049] Terms and Conditions
[0050] Clause 1. A detection circuit comprising: a comparator configured to compare a first voltage with a second voltage, the first voltage being associated with a transfer device configured to supply energy to one or more loads, the second voltage being associated with a current sensing device coupled to the transfer device and biased with a reference current; and detecting a change in one or more loads based on the comparison of the first voltage with the second voltage.
[0051] Clause 2. The detection circuit according to Clause 1, wherein the second voltage can be adjusted by controlling the amplitude of the reference current.
[0052] Clause 3. A detection circuit according to either Clause 1 or 2, wherein the comparator is timed by a timer device.
[0053] Clause 4. The detection circuit according to Clause 3 further includes: a switch configured to activate or deactivate the current source circuit that generates the reference current.
[0054] Clause 5. The detection circuit according to Clause 4, wherein the switch is timed by a timer device.
[0055] Clause 6. A detection circuit according to any one of Clauses 1 to 5, wherein the detection circuit is operable in the wake-up check phase after the sleep timer has passed during the idle phase.
[0056] Clause 7. The detection circuit according to Clause 6, wherein during the wake-up check phase, the detection circuit activates a comparator to compare a first voltage with a second voltage and deactivates a reference current.
[0057] Clause 8. A detection circuit according to any one of Clauses 6 and 7, wherein the comparator consumes current during the wake-up check phase, and other components of the detection circuit do not consume current during the wake-up check phase.
[0058] Clause 9. A detection circuit according to any one of Clauses 6 to 8, wherein the detection circuit is operable in a drift correction phase prior to operation in the wake-up check phase, wherein in the drift correction phase, the detection circuit: blanks the output of the comparator; and samples the second voltage.
[0059] Clause 10. The detection circuit according to Clause 9, wherein during the drift correction phase, the detection circuit automatically zeros the comparator.
[0060] Clause 11. A detection circuit according to any one of Clauses 1-10, wherein, in response to a first voltage dropping below a second voltage, the detection circuit triggers one or more of the following: a transmission device to provide energy to one or more loads; a protection circuit to engage the protection circuit of a protection mechanism; and an output interrupt signal.
[0061] Clause 12. A detection circuit according to any one of Clauses 1-10, wherein if the first voltage is greater than the second voltage, the detection circuit enters an idle phase and does not trigger the transmission device to supply energy to the one or more loads.
[0062] Clause 13. A method comprising: comparing a first voltage with a second voltage, the first voltage being associated with a transfer device configured to supply energy to one or more loads, the second voltage being associated with a current sensing device coupled to the transfer device and biased with a reference current; and detecting a change in one or more loads based on the comparison of the first voltage with the second voltage.
[0063] Clause 14. The method according to Clause 13 further includes: adjusting the second voltage by controlling the amplitude of the reference current.
[0064] Clause 15. The method pursuant to any one of Clauses 13 and 14 further includes: timing the comparator using a timer device.
[0065] Clause 16. The method pursuant to Clause 15 further includes: using a switch to activate or deactivate the current source circuit that generates the reference current.
[0066] Clause 17. The method pursuant to Clause 16 further includes: timing the switch using a timer device.
[0067] Clause 18. The method according to any one of Clauses 13-17 further includes: performing the operation during the wake-up check phase after the hibernation timer has elapsed during the idle phase.
[0068] Clause 19. The method according to Clause 18 further includes: during the wake-up check phase, activating a comparator to compare the first voltage with the second voltage, and deactivating the reference current.
[0069] Clause 20. The method according to any one of Clauses 18 and 19, wherein the comparator consumes current during the wake-up check phase, while other components do not consume current during the wake-up check phase.
[0070] Clause 21. The method according to any one of Clauses 18 to 20 further includes: operating in a drift correction phase prior to operation during the wake-up check phase, including: blanking the output of the comparator; and sampling the second voltage.
[0071] Clause 22. The method according to any one of Clause 21 further includes: automatically zeroing the comparator during the drift correction phase.
[0072] Clause 23. According to any one of Clauses 13-22, wherein in response to a first voltage dropping below a second voltage, the method further includes one or more of the following: triggering a transmission device to supply energy to one or more loads; triggering a protection mechanism; and triggering an interrupt signal.
[0073] Clause 24. The method according to any one of Clauses 13 to 23 further includes: if the first voltage does not drop below the second voltage, entering an idle phase and not triggering the transfer device to supply energy to one or more loads.
[0074] Clause 25. A power circuit comprising: at least one package; a power stage housed within the at least one package and including a gate controller and a current sensing device, the gate controller controlling a delivery device configured to supply energy to one or more loads, the current sensing device being coupled to the delivery device; and a detection circuit coupled to the power stage and housed within the package and configured to: compare a first voltage with a second voltage associated with the delivery device, the second voltage associated with the current sensing device and biased with a reference current; and detect a change in one or more loads based on the comparison of the first voltage with the second voltage.
[0075] Clause 26. The power circuit according to Clause 25 further includes: wherein the second voltage can be adjusted by controlling the amplitude of the reference current.
[0076] Clause 27. The power circuit pursuant to any of Clauses 25 and 26 further includes a comparator timed by a timer device.
[0077] Clause 28. A power circuit according to any one of Clauses 25 to 27, wherein the detection circuit is operable in a wake-up check phase and a drift correction phase, wherein in the wake-up check phase, the detection circuit activates a comparator to compare a first voltage and a second voltage, and in the drift correction phase, the detection circuit blanks the output of the comparator and samples the second voltage.
[0078] Although the invention has been described with reference to illustrative embodiments, this description is not intended to be limiting. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will become apparent to those skilled in the art upon reference to the specification. Therefore, the appended claims are intended to cover any such modifications or embodiments.
Claims
1. A detection circuit comprising: a comparator configured to: compare a first voltage associated with a delivery device configured to supply energy to one or more loads to a second voltage associated with a current sensing device coupled to the delivery device and biased with a reference current; and detect a change in the one or more loads based on comparing the first voltage to the second voltage.
2. The detection circuit of claim 1, wherein the second voltage is adjustable by controlling an amplitude of the reference current.
3. The detection circuit of claim 1, wherein the comparator is clocked by a timer device.
4. The detection circuit of claim 3, further comprising: a switch configured to activate or deactivate a current source circuit that generates the reference current.
5. The detection circuit of claim 4, wherein the switch is clocked by the timer device.
6. The detection circuit of claim 1, wherein the detection circuit is operable in a wake-up check phase after a sleep timer in an idle phase.
7. The detection circuit of claim 6, wherein in the wake-up check phase, the detection circuit activates the comparator to compare the first voltage to the second voltage and deactivates the reference current.
8. The detection circuit of claim 6, wherein the comparator consumes current in the wake-up check phase and other components of the detection circuit do not consume current in the wake-up check phase.
9. The detection circuit of claim 6, wherein prior to operation in the wake-up check phase, the detection circuit is operable in a drift correction phase, wherein in the drift correction phase, the detection circuit: blanking an output of the comparator; and samples the second voltage.
10. The detection circuit of claim 9, wherein in the drift correction phase, the detection circuit auto-zeroes the comparator. in response to the first voltage falling below the second voltage, the detection circuit triggers one or more of:
11. The detection circuit of claim 1, wherein, the delivery device to deliver energy to one or more loads; a protection circuit to engage a protection mechanism; and an output interrupt signal. if the first voltage is greater than the second voltage, the detection circuit enters an idle phase and does not trigger the delivery device to deliver energy to the one or more loads.
12. The detection circuit of claim 1, wherein, 13. A method comprising: comparing a first voltage associated with a delivery device configured to supply energy to one or more loads to a second voltage associated with a current sensing device coupled to the delivery device and biased with the reference current; and detecting a change in the one or more loads based on comparing the first voltage to the second voltage.
14. The method of claim 13, further comprising: adjusting the second voltage by controlling an amplitude of the reference current. 15. The method of claim 13, further comprising: timing the comparator with a timer device.
16. The method of claim 15, further comprising: using a switch to activate or deactivate a current source circuit that generates the reference current.
17. The method of claim 16, further comprising: timing the switch with the timer device.
18. A power circuit, comprising: at least one package; a power stage housed within the at least one package and including a gate controller and a current sense device, the gate controller controlling a pass device configured to supply energy to one or more loads, the current sense device coupled to the pass device, a detection circuit coupled to the power stage and housed within the package and configured to: compare a first voltage associated with the pass device to a second voltage associated with the current sense device and biased with a reference current; and detect a change in the one or more loads based on comparing the first voltage to the second voltage.
19. The power circuit of claim 18, further comprising: wherein the second voltage can be adjusted by controlling an amplitude of the reference current.
20. The power circuit of claim 18, wherein the detection circuit is operable in a wake-up check phase in which the detection circuit activates the comparator to compare the first voltage and the second voltage and a drift correction phase in which the detection circuit blanks the output of the comparator and samples the second voltage.