Voltage comparator and method of operation thereof

Abstract

The present application provides a voltage comparator and an operating method thereof. The voltage comparator includes an amplification circuit, a reference current source and a transient current source. A first input terminal and a second input terminal of the amplification circuit receive a first corresponding voltage and a reference voltage corresponding to a target voltage respectively. The reference current source is coupled to the amplification circuit to provide a reference current. The transient current source is coupled to the amplification circuit to selectively provide a transient current. The transient current source detects a transition of a second corresponding voltage corresponding to the target voltage to dynamically adjust the transient current. Thus, when the target voltage has a voltage surge, the transient current source can temporarily increase the current of the amplification circuit, thereby accelerating the response speed of the amplification circuit.

Description

Technical Field

[0001] This invention relates to an electronic circuit, and more particularly to a voltage comparator and its operating method. Background Technology

[0002] Voltage comparators are commonly used in electronic circuits. A voltage comparator compares two voltages (e.g., a target voltage and a reference voltage). The current of the voltage comparator (e.g., the reference current of the input pair) affects its response speed. Generally, the larger the reference current of the input pair, the faster the voltage comparator's response speed. Existing voltage comparators have fixed reference currents for their input pairs (or are independent of the target voltage's state transition). In other words, the response speed of existing voltage comparators is fixed regardless of whether the target voltage is in a steady state or a transition state. To meet product power consumption requirements, the voltage comparator's current is set as small as possible, which means that the voltage comparator's response speed is limited. Summary of the Invention

[0003] This invention provides a voltage comparator and its operation method to meet the requirements of "small current" and "fast response".

[0004] In one embodiment of the present invention, the voltage comparator includes a first comparison terminal, a second comparison terminal, a detection terminal, an amplifier circuit, a reference current source, and a first transient current source. One of the first and second comparison terminals is adapted to receive a first corresponding voltage corresponding to a target voltage. The other of the first and second comparison terminals is adapted to receive a first reference voltage. The detection terminal is adapted to receive a second corresponding voltage corresponding to the target voltage. A first input terminal and a second input terminal of the amplifier circuit are respectively coupled to the first and second comparison terminals. The output terminal of the amplifier circuit is coupled to the output terminal of the voltage comparator. The reference current source is coupled to the amplifier circuit to provide a reference current. The first transient current source is coupled to the amplifier circuit to selectively provide a first transient current. The input terminal of the first transient current source is coupled to the detection terminal of the voltage comparator to receive the second corresponding voltage, and the first transient current source detects a first transition state of the second corresponding voltage to dynamically adjust the first transient current.

[0005] In one embodiment of the present invention, the above-described operation method includes: receiving a first corresponding voltage corresponding to a target voltage via one of the first comparison terminal and the second comparison terminal of a voltage comparator; receiving a first reference voltage via the other of the first comparison terminal and the second comparison terminal, wherein the first input terminal and the second input terminal of the amplifier circuit of the voltage comparator are respectively coupled to the first comparison terminal and the second comparison terminal, and the output terminal of the amplifier circuit is coupled to the output terminal of the voltage comparator; receiving a second corresponding voltage corresponding to the target voltage via the detection terminal of the voltage comparator, wherein the input terminal of the first transient current source of the voltage comparator is coupled to the detection terminal to receive the second corresponding voltage; providing a reference current to the amplifier circuit via a reference current source; detecting a first transition state of the second corresponding voltage via the first transient current source to dynamically adjust the first transient current; and selectively providing a first transient current to the amplifier circuit via the first transient current source.

[0006] Based on the above, the reference current source described in the embodiments of the present invention can provide a reference current applicable to the target voltage in steady state to the amplifier circuit. During the steady state of the target voltage, the absolute value of the first transient current source can be reduced as much as possible (even to 0 amperes) to meet the power consumption requirements of the product. When the target voltage experiences a rapid voltage increase, the absolute value of the first transient current source can be temporarily increased to increase the current of the amplifier circuit, thereby accelerating the response speed of the amplifier circuit during the target voltage transition. Therefore, the voltage comparator can meet the requirements of both "small current" and "fast response".

[0007] To make the above features and advantages of the present invention more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings for detailed explanation. Attached Figure Description

[0008] Figure 1 This is a schematic diagram illustrating the application circuit of a voltage comparator according to an embodiment of the present invention.

[0009] Figure 2 This is a schematic diagram illustrating the application circuit of a voltage comparator according to another embodiment of the present invention.

[0010] Figure 3 This is a schematic diagram illustrating the application circuit of a voltage comparator according to another embodiment of the present invention.

[0011] Figure 4 This is a schematic diagram of a voltage comparator circuit block according to an embodiment of the present invention.

[0012] Figure 5 This is a schematic flowchart illustrating the operation method of a voltage comparator according to an embodiment of the present invention.

[0013] Figure 6 This is described according to an embodiment of the present invention. Figure 4 The circuit block diagram shown is a combination of an amplifier circuit and a transient current source.

[0014] Figure 7 This is described according to an embodiment of the present invention. Figure 6 The circuit block diagram shown includes the amplifier circuit, the reference current source, and the transient current source.

[0015] Figure 8 This is described according to another embodiment of the present invention. Figure 4 The circuit block diagram shown is a combination of an amplifier circuit and a transient current source.

[0016] Figure 9 This is described according to an embodiment of the present invention. Figure 8 The circuit block diagram shown includes the amplifier circuit, the reference current source, and the transient current source.

[0017] Figure 10 This is described according to another embodiment of the present invention. Figures 1 to 3 The circuit block diagram of the voltage comparator shown is shown.

[0018] Figure 11 This is described according to an embodiment of the present invention. Figure 10 The diagram shows the amplifier circuit, transient current source, and circuit block diagram of the transient current source. Detailed Implementation

[0019] The term "coupled (or connected)" as used throughout this specification (including the claims) may refer to any direct or indirect means of connection. For example, if the text describes a first device coupled (or connected) to a second device, it should be interpreted as the first device being directly connected to the second device, or the first device being indirectly connected to the second device through other devices or some means of connection. The terms "first," "second," etc., used throughout this specification (including the claims) are used to name components or distinguish different embodiments or scopes, and are not intended to limit the upper or lower limit of the number of components, nor to limit the order of components. Furthermore, wherever possible, components / components / steps using the same reference numerals in the drawings and embodiments represent the same or similar parts. Components / components / steps using the same reference numerals or the same terms in different embodiments may be referred to mutually in the relevant descriptions.

[0020] Figure 1 This is a schematic diagram illustrating the application circuit of the voltage comparator 400 according to an embodiment of the present invention. Figure 1The voltage comparator 400 shown receives the system voltage VCC and the reference voltage VSS (e.g., ground voltage or other fixed voltage) at its power supply and reference voltage terminals, respectively. The output of the voltage comparator 400 is an amplified voltage Vo. The voltage comparator 400 also includes a comparison terminal IN1, a comparison terminal IN2, and a detection terminal DET. Depending on the actual design, in some embodiments, the comparison terminal IN1 can be a non-inverting input, while the comparison terminal IN2 can be an inverting input. In other embodiments, the comparison terminal IN1 can be an inverting input, while the comparison terminal IN2 can be a non-inverting input.

[0021] exist Figure 1 In the application example shown, the comparison terminal IN1 of voltage comparator 400 can receive the target voltage VIN as the first corresponding voltage. The comparison terminal IN2 of voltage comparator 400 can receive the reference voltage VREF. The level of the reference voltage VREF can be determined according to the actual design. The detection terminal DET of voltage comparator 400 can receive the target voltage VIN as the second corresponding voltage. That is, in Figure 1 In the application example shown, the first corresponding voltage of the comparison terminal IN1 and the second corresponding voltage of the comparison terminal IN2 are both the same as the target voltage VIN.

[0022] Figure 2 This is a schematic diagram illustrating the application circuit of the voltage comparator 400 according to another embodiment of the present invention. Figure 2 The voltage comparator 400 shown can be referenced. Figure 1 The relevant descriptions of the voltage comparator 400 shown are omitted here. Figure 2 In the illustrated application example, the detection terminal DET of voltage comparator 400 can receive the target voltage VIN as the second corresponding voltage. The first terminal of resistor R21 receives the target voltage VIN. The first terminal of resistor R22 is coupled to the second terminal of resistor R21 to receive the divided voltage Vd2 (the first corresponding voltage) corresponding to the target voltage VIN. The second terminal of resistor R22 receives the reference voltage VSS. The comparison terminal IN1 of voltage comparator 400 can be coupled to the second terminal of resistor R21 to receive the divided voltage Vd2 as the first corresponding voltage. That is, in Figure 2 In the application example shown, the first corresponding voltage of the comparison terminal IN1 is the voltage division Vd2 of the target voltage VIN, while the second corresponding voltage of the comparison terminal IN2 is the same as the target voltage VIN.

[0023] Figure 3 This is a schematic diagram illustrating the application circuit of the voltage comparator 400 according to another embodiment of the present invention. Figure 3 The voltage comparator 400 shown can be referenced. Figure 1 The relevant descriptions of the voltage comparator 400 shown are omitted here. Figure 3In the application example shown, the comparison terminal IN1 of voltage comparator 400 can receive the target voltage VIN as the first corresponding voltage. The first terminal of resistor R31 receives the target voltage VIN. The first terminal of resistor R32 is coupled to the second terminal of resistor R31 to receive the divided voltage Vd3 (the second corresponding voltage) corresponding to the target voltage VIN. The second terminal of resistor R32 receives the reference voltage VSS. The detection terminal DET of voltage comparator 400 can be coupled to the second terminal of resistor R31 to receive the divided voltage Vd3 as the second corresponding voltage. That is, in Figure 3 In the application example shown, the first corresponding voltage of the comparison terminal IN1 is the same as the target voltage VIN, while the second corresponding voltage of the comparison terminal IN2 is the voltage Vd3 of the target voltage VIN.

[0024] Figure 4 This is described according to an embodiment of the present invention. Figures 1 to 3 The diagram shows a circuit block representation of the voltage comparator 400. Depending on the specific application, Figure 4 The voltage comparator 400 shown can be referenced. Figure 1 , Figure 2 Or Figure 3 The voltage comparator 400 shown is described below. Figure 4 In the illustrated embodiment, the voltage comparator 400 includes an amplifier circuit 410, a reference current source 420, and a transient current source 430. The first and second input terminals of the amplifier circuit 410 are coupled to the comparator terminals IN1 and IN2, respectively. Depending on the actual design, in some embodiments, the first input terminal of the amplifier circuit 410 may be a non-inverting input terminal, while the second input terminal may be an inverting input terminal. In other embodiments, the first input terminal of the amplifier circuit 410 may be an inverting input terminal, while the second input terminal may be a non-inverting input terminal. The output terminal of the amplifier circuit 410 is coupled to the output terminal of the voltage comparator 400 to output an amplified voltage Vo.

[0025] A reference current source 420 is coupled to amplifier circuit 410 to provide a reference current Iref. The level of the reference current Iref can be determined according to the actual design. For example, the level of the reference current Iref can meet the power consumption requirements of the product. Reference current source 420 can provide amplifier circuit 410 with a reference current Iref applicable to the target voltage VIN in steady state. In some embodiments, the reference current Iref can be provided to the input pair of amplifier circuit 410.

[0026] A transient current source 430 is coupled to an amplifier circuit 410 to selectively provide a transient current I430 to the amplifier circuit 410. The input terminal of the transient current source 430 is coupled to the detection terminal DET of a voltage comparator 400 to receive a second corresponding voltage. The transient current source 430 can detect the transition state of the second corresponding voltage at the detection terminal DET of the voltage comparator 400 to dynamically adjust the transient current I430. Depending on the actual design, in some embodiments, the transient current source 430 can dynamically adjust the transient current I430 to a positive value or 0. "A positive transient current I430" indicates that the transient current I430 flows from the transient current source 430 to the amplifier circuit 410. In other embodiments, the transient current source 430 can dynamically adjust the transient current I430 to a negative value or 0. "A negative transient current I430" indicates that the transient current I430 flows from the amplifier circuit 410 to the transient current source 430.

[0027] Figure 5 This is a schematic flowchart illustrating the operation method of a voltage comparator according to an embodiment of the present invention. Please refer to... Figure 4 and Figure 5 In step S510, one of the first comparison terminals and one of the second comparison terminals of the voltage comparator 400 (e.g., comparison terminal IN1) receives the first corresponding voltage corresponding to the target voltage VIN, while the other of the first comparison terminal and one of the second comparison terminals of the voltage comparator 400 (e.g., comparison terminal IN2) receives the reference voltage VREF. The detection terminal DET of the voltage comparator 400 can receive the second corresponding voltage corresponding to the target voltage VIN in step S510. Figure 1 In the application example shown, the first corresponding voltage and the second corresponding voltage are the same as the target voltage VIN. Figure 2 In the application example shown, the first corresponding voltage is a voltage divider of the target voltage VIN, while the second corresponding voltage is the same as the target voltage VIN. Figure 3 In the application example shown, the first corresponding voltage is the same as the target voltage VIN, while the second corresponding voltage is a voltage division of the target voltage VIN.

[0028] Please refer to Figure 4 and Figure 5 In step S520, the reference current source 420 can provide a reference current Iref to the amplifier circuit 410. Furthermore, in step S520, the transient current source 430 can detect the change in the second corresponding voltage at the detection terminal DET of the voltage comparator 400 to dynamically adjust the transient current I430. The transient current source 430 can selectively provide the transient current I430 to the amplifier circuit 410.

[0029] For example, in some embodiments, the transient current source 430 can detect whether a rapid voltage increase has occurred in the second corresponding voltage. When a rapid voltage increase occurs in the second corresponding voltage at the detection terminal DET (i.e., a rapid voltage increase occurs in the target voltage VIN), the transient current source 430 increases the transient current I430 from a first current value to a second current value during a transient period corresponding to the rising edge of the voltage increase. The first current value of the transient current I430 can be applied to the target voltage VIN in steady state to meet the product power consumption requirements. The second current value of the transient current I430 can be applied to the target voltage VIN in transition state to meet the response speed requirements. The first current value and the second current value can be determined according to the actual design. For example, the first current value can be 0 (or a positive value), and the second current value can be a positive value greater than the first current value. "The transient current I430 is positive" means that the transient current I430 flows from the transient current source 430 to the amplifier circuit 410. After the transient period ends, the transient current source 430 can adjust the transient current I430 back from the second current value to the first current value to meet the product power consumption requirements.

[0030] In summary, for the target voltage VIN in steady state, the reference current source 420 and the transient current source 430 can provide suitable reference current Iref and transient current I430 to the amplifier circuit 410. During the steady-state period of the target voltage VIN, the transient current source 430 can minimize the absolute value of the transient current I430 (even setting the transient current I430 to 0 amperes) to meet the power consumption requirements of the product. When the target voltage VIN experiences a voltage surge, the transient current source 430 can temporarily increase the absolute value of the transient current I430 to accelerate the response speed of the amplifier circuit 410 during the transition of the target voltage VIN. Therefore, the voltage comparator 400 can meet the requirements of "small current" and "fast response".

[0031] Figure 6 This is described according to an embodiment of the present invention. Figure 4 The circuit block diagram of amplifier circuit 410 and transient current source 430 is shown. Figure 6 The amplifier circuit 410, reference current source 420, and transient current source 430 shown can be referenced. Figure 4 The relevant descriptions of the amplifier circuit 410, reference current source 420 and transient current source 430 shown will not be repeated here. Figure 6The amplifier circuit 410 shown includes an input stage 411 and an output stage 413. The first and second input terminals of the input stage 411 are coupled to the comparator terminals IN1 and IN2 of the voltage comparator 400, respectively. In some embodiments, the first input terminal of the input stage 411 may be a non-inverting input, while the second input terminal may be an inverting input. In other embodiments, the first input terminal of the input stage 411 may be an inverting input, while the second input terminal may be a non-inverting input. The reference power supply terminal of the input stage 411 is coupled to a reference current source 420 to receive a reference current Iref. The current terminal of the transient current source 430 is coupled to the reference power supply terminal of the input stage 411 to selectively provide a transient current I430. The input terminal of the output stage 413 is coupled to the output terminal of the input stage 411. The output terminal of the output stage 413 is coupled to the output terminal of the voltage comparator 400 to output an amplified voltage Vo.

[0032] exist Figure 6 In the illustrated embodiment, the transient current source 430 includes a detection circuit 431 and a voltage-controlled current source 433. The input terminal of the detection circuit 431 is coupled to the detection terminal DET of the voltage comparator 400 to receive the second corresponding voltage. The detection circuit 431 can detect the transition state of the second corresponding voltage at the detection terminal DET of the voltage comparator 400 to output a detection result. The voltage-controlled current source 433 is coupled to the detection circuit 431 to receive the detection result. The voltage-controlled current source 433 is controlled by the detection result to dynamically adjust the transient current I430.

[0033] For example, in some embodiments, the detection circuit 431 can detect whether a voltage surge has occurred at the second corresponding voltage of the detection terminal DET of the voltage comparator 400. When a voltage surge occurs at the second corresponding voltage of the detection terminal DET (i.e., a voltage surge occurs at the target voltage VIN), the voltage-controlled current source 433 can, based on the detection result of the detection circuit 431, increase the transient current I430 from a first current value to a second current value (e.g., from 0 to a positive value) during a transient period corresponding to the rising edge of the voltage surge, to meet the requirements of response speed. After the transient period ends, the voltage-controlled current source 433 can, based on the detection result of the detection circuit 431, adjust the transient current I430 back from the second current value to the first current value (e.g., from a positive value back to 0), to meet the requirements of product power consumption.

[0034] Figure 7 This is described according to an embodiment of the present invention. Figure 6 The circuit block diagram of amplifier circuit 410, reference current source 420 and transient current source 430 is shown. Figure 7 The amplifier circuit 410, reference current source 420, and transient current source 430 shown can be referenced. Figure 6 The relevant descriptions of the amplifier circuit 410, reference current source 420, and transient current source 430 shown are omitted here. Figure 7 In the illustrated embodiment, the reference current source 420 includes a current source CS420 and a current mirror CM420. The main current terminal of the current mirror CM420 is coupled to the current source CS420. The secondary current terminal of the current mirror CM420 is coupled to the amplifier circuit 410 to provide a reference current Iref.

[0035] exist Figure 7 In the illustrated embodiment, the input stage 411 of the amplifier circuit 410 includes input pairs ( Figure 7 The diagram shows transistors M71 and M72, and a current mirror CM411. The first terminals (e.g., sources) of transistors M71 and M72 are coupled to a reference current source 420 and a transient current source 430 to receive a reference current Iref and a transient current I430. The control terminal (e.g., gate) of transistor M71 is coupled to the comparator terminal IN1 of voltage comparator 400. The second terminal (e.g., drain) of transistor M71 is coupled to the main current terminal of current mirror CM411. The control terminal (e.g., gate) of transistor M72 is coupled to the comparator terminal IN2 of voltage comparator 400. The second terminal (e.g., drain) of transistor M72 is coupled to the slave current terminal of current mirror CM411. The second terminal of transistor M72 is also coupled to the input terminal of output stage 413.

[0036] exist Figure 7 In the illustrated embodiment, the output stage 413 of the amplifier circuit 410 includes transistors M73 and M74. A first terminal (e.g., source) of transistor M73 is coupled to the system voltage VCC. A control terminal (e.g., gate) of transistor M73 is coupled to the current mirror CM420 of the reference current source 420 to receive the bias voltage VCS. A second terminal (e.g., drain) of transistor M73 is coupled to the output of voltage comparator 400 to output the amplified voltage Vo. A first terminal (e.g., drain) of transistor M74 is coupled to the second terminal of transistor M73. A control terminal (e.g., gate) of transistor M74 is coupled to the second terminal of transistor M72 in the input stage 411. A second terminal (e.g., source) of transistor M74 is coupled to the reference voltage VSS.

[0037] exist Figure 7In the illustrated embodiment, the detection circuit 431 of the transient current source 430 includes a capacitor C71, a resistor R71, a resistor R72, and a transistor M75. The first terminal of capacitor C71 is coupled to the detection terminal DET of voltage comparator 400 to receive the second corresponding voltage. The first terminal of resistor R71 is coupled to the second terminal of capacitor C71. The second terminal of resistor R71 receives a first power voltage (e.g., reference voltage VSS). The control terminal (e.g., gate) of transistor M75 is coupled to the second terminal of capacitor C71. The first terminal (e.g., source) of transistor M75 receives the first power voltage (e.g., reference voltage VSS). The first terminal of resistor R72 is coupled to the second terminal (e.g., drain) of transistor M75. The second terminal of resistor R72 receives a second power voltage (e.g., system voltage VCC). The second terminal of transistor M75 and the first terminal of resistor R72 together provide the detection result to voltage-controlled current source 433.

[0038] exist Figure 7 In the illustrated embodiment, the voltage-controlled current source 433 of the transient current source 430 includes a transistor M76. The control terminal (e.g., gate) of the transistor M76 is coupled to a detection circuit 431 to receive the detection result. A first terminal (e.g., source) of the transistor M76 receives a power voltage (e.g., system voltage VCC). A second terminal (e.g., drain) of the transistor M76 is coupled to an amplifier circuit 410 to selectively provide the transient current I430 to the input pair of the input stage 411. Figure 7 Transistors M71 and M72 are shown.

[0039] The detection circuit 431 can detect whether a voltage surge occurs at the second corresponding voltage of the detection terminal DET of the voltage comparator 400. When a voltage surge occurs at the second corresponding voltage of the detection terminal DET (i.e., a voltage surge occurs at the target voltage VIN), the voltage surge can raise the voltage at the control terminal of transistor M75, thereby turning on transistor M75. The turned-on transistor M75 can lower the voltage at the control terminal of transistor M76, thereby turning on transistor M76. The turned-on transistor M76 can increase the transient current I430 from a first current value to a second current value (e.g., from 0 to a positive value) during a transient period corresponding to the rising edge of the voltage surge to meet the response speed requirements. After the transient period ends, transistors M75 and M76 can be turned off in real time to adjust the transient current I430 back from the second current value to the first current value (e.g., from a positive value back to 0) to meet the product power consumption requirements.

[0040] In summary, for the target voltage VIN in steady state, the reference current source 420 can provide a suitable reference current Iref to the input pair of the input stage 411. Figure 7Transistors M71 and M72 are shown to meet the product's power consumption requirements. During the steady-state period of the target voltage VIN, transistor M76 can minimize the absolute value of the transient current I430 (even setting the transient current I430 to 0 amperes) to meet the product's power consumption requirements. When a voltage surge occurs at the second corresponding voltage of the detection terminal DET (i.e., a voltage surge occurs at the target voltage VIN), transistor M76 can temporarily increase the absolute value of the transient current I430 to increase the current of the input pair of the input stage 411, thereby accelerating the response speed of the amplifier circuit 410 during the transition of the target voltage VIN. Therefore, the voltage comparator 400 can meet the requirements of "small current" and "fast response".

[0041] Figure 8 This is described according to another embodiment of the present invention. Figure 4 The circuit block diagram of amplifier circuit 410 and transient current source 430 is shown. Figure 8 The amplifier circuit 410 and the reference current source 420 shown can be referenced. Figure 4 The relevant descriptions of the amplifier circuit 410 and the reference current source 420 shown will not be repeated here. Figure 8 The amplifier circuit 410 shown includes an input stage 411 and an output stage 413. Figure 8 The input stage 411 and output stage 413 shown can be referred to Figure 6 The relevant descriptions of input stage 411 and output stage 413 shown are omitted here. Figure 8 In the illustrated embodiment, the current terminal of the transient current source 430 is coupled to the output terminal of the output stage 413 to selectively draw transient current I430.

[0042] exist Figure 8 In the embodiment shown, the transient current source 430 includes a detection circuit 435 and a voltage-controlled current source 437. Figure 8 The detection circuit 435 and voltage-controlled current source 437 shown can be referenced. Figure 6 The descriptions of the detection circuit 431 and the voltage-controlled current source 433 are omitted here. The detection circuit 435 can detect the change in the second corresponding voltage at the detection terminal DET of the voltage comparator 400 and output the detection result. The voltage-controlled current source 437 is controlled by the detection result to dynamically adjust the transient current I430.

[0043] For example, in some embodiments, the detection circuit 435 can detect whether a rapid voltage decrease has occurred at the second corresponding voltage of the detection terminal DET of the voltage comparator 400. When a rapid voltage decrease occurs at the second corresponding voltage of the detection terminal DET (i.e., a rapid voltage decrease occurs at the target voltage VIN), the voltage-controlled current source 437 can draw a transient current I430 at the output terminal of the output stage 413 during a transient period corresponding to the falling edge of the voltage decrease, based on the detection result of the detection circuit 435, to quickly pull down the amplified voltage Vo to meet the response speed requirements. After the transient period ends, the voltage-controlled current source 437 no longer draws the transient current I430 to meet the product power consumption requirements.

[0044] Figure 9 This is described according to an embodiment of the present invention. Figure 8 The circuit block diagram of amplifier circuit 410, reference current source 420 and transient current source 430 is shown. Figure 9 The amplifier circuit 410, reference current source 420, and transient current source 430 shown can be referenced. Figure 8 The relevant descriptions of the amplifier circuit 410, reference current source 420, and transient current source 430 shown are omitted here. Figure 9 In the illustrated embodiment, the detection circuit 435 of the transient current source 430 includes a capacitor C91, a resistor R91, a resistor R92, and a transistor M95. The first terminal of capacitor C91 is coupled to the detection terminal DET of voltage comparator 400 to receive the second corresponding voltage. The first terminal of resistor R91 is coupled to the second terminal of capacitor C91. The second terminal of resistor R91 receives a first power voltage (e.g., system voltage VCC). The control terminal (e.g., gate) of transistor M95 is coupled to the second terminal of capacitor C91. The first terminal (e.g., source) of transistor M95 receives the first power voltage (e.g., system voltage VCC). The first terminal of resistor R92 is coupled to the second terminal (e.g., drain) of transistor M95. The second terminal of resistor R92 receives a second power voltage (e.g., reference voltage VSS). The second terminal of transistor M95 and the first terminal of resistor R92 together provide the detection result to voltage-controlled current source 437.

[0045] exist Figure 9 In the illustrated embodiment, the voltage-controlled current source 437 of the transient current source 430 includes a transistor M96. The control terminal (e.g., gate) of the transistor M96 is coupled to a detection circuit 435 to receive the detection result. A first terminal (e.g., source) of the transistor M96 receives a power voltage (e.g., a reference voltage VSS). A second terminal (e.g., drain) of the transistor M96 is coupled to an amplifier circuit 410 to selectively draw transient current I430 from the output of the output stage 413.

[0046] The detection circuit 435 can detect whether a voltage drop has occurred at the second corresponding voltage of the detection terminal DET of the voltage comparator 400. When a voltage drop occurs at the second corresponding voltage of the detection terminal DET (i.e., a voltage drop occurs at the target voltage VIN), the voltage drop can pull down the voltage at the control terminal of transistor M95, thereby turning on transistor M95. The turned-on transistor M95 can pull down the voltage at the control terminal of transistor M96, thereby turning on transistor M96. The turned-on transistor M96 can draw a transient current I430 at the output terminal of the output stage 413 during a transient period corresponding to the falling edge of the voltage drop, so as to pull down the amplified voltage Vo to approximately the level of the reference voltage VSS in real time to meet the requirements of response speed. After the transient period ends, transistors M95 and M96 can be turned off in real time, and the voltage-controlled current source 437 will not draw transient current I430 to meet the requirements of product power consumption.

[0047] In summary, for the target voltage VIN in steady state, the reference current source 420 can provide a suitable reference current Iref to the input pair of the input stage 411. Figure 9 Transistors M71 and M72 are shown to meet the product's power consumption requirements. During the steady-state period of the target voltage VIN, transistor M96 can minimize the absolute value of the transient current I430 (even setting the transient current I430 to 0 amperes, i.e., not interfering with the level of the amplified voltage Vo). When a voltage drop occurs at the second corresponding voltage of the detection terminal DET (i.e., a voltage drop occurs at the target voltage VIN), transistor M96 can temporarily increase the absolute value of the transient current I430 to pull the amplified voltage Vo down to approximately the level of the reference voltage VSS in real time, thereby accelerating the response speed of the amplifier circuit 410 during the transition of the target voltage VIN. Therefore, the voltage comparator 400 can meet the requirements of "small current" and "fast response".

[0048] Figure 10 This is described according to another embodiment of the present invention. Figures 1 to 3 The circuit block diagram of voltage comparator 400 is shown. Depending on the actual application, Figure 10 The voltage comparator 400 shown can be referenced. Figure 1 , Figure 2 Or Figure 3 The voltage comparator 400 shown is described below. Figure 10 In the illustrated embodiment, the voltage comparator 400 includes an amplifier circuit 1010, a reference current source 1020, a transient current source 1030, and a transient current source 1040. Figure 10 The amplifier circuit 1010 and the reference current source 1020 shown can be referenced. Figure 4 and Figures 6 to 9The relevant descriptions of the amplifier circuit 410 and the reference current source 420 shown will not be repeated here. Figure 10 The transient current source 1030 and transient current source 1040 shown can be referenced. Figure 4 and Figures 6 to 9 The following is a description of the transient current source 430 shown.

[0049] A transient current source 1030 is coupled to an amplifier circuit 1010 to selectively provide a transient current I1030 to the amplifier circuit 1010. The input terminal of the transient current source 1030 is coupled to the detection terminal DET of a voltage comparator 400 to receive a second corresponding voltage. The transient current source 1030 can detect changes in the state of the second corresponding voltage at the detection terminal DET of the voltage comparator 400 (e.g., detect a voltage surge) to dynamically adjust the transient current I1030. Depending on the actual design, in some embodiments, the transient current source 1030 can dynamically adjust the transient current I1030 to a positive value or 0. "A positive transient current I1030" indicates that the transient current I1030 flows from the transient current source 1030 to the amplifier circuit 410.

[0050] When a voltage surge occurs at the second corresponding voltage of the detection terminal DET (i.e., a voltage surge occurs at the target voltage VIN), the transient current source 1030 can increase the transient current I1030 from a first current value to a second current value during a transient period (first transient period) corresponding to the rising edge of the voltage surge. The first current value of the transient current I1030 can be applied to the target voltage VIN in steady state to meet the product power consumption requirements. The second current value of the transient current I1030 can be applied to the target voltage VIN in transition state to meet the response speed requirements. The first current value and the second current value can be determined according to the actual design. For example, the first current value can be 0 (or a positive value), and the second current value can be a positive value greater than the first current value. After the first transient period ends, the transient current source 1030 can adjust the transient current I1030 back from the second current value to the first current value to meet the product power consumption requirements.

[0051] A transient current source 1040 is coupled to an amplifier circuit 1010 to selectively draw transient current I1040 from the amplifier circuit 1010. The input terminal of the transient current source 1040 is coupled to the detection terminal DET of a voltage comparator 400 to receive a second corresponding voltage. The transient current source 1040 can detect changes in the state of the second corresponding voltage at the detection terminal DET of the voltage comparator 400 (e.g., detect a voltage drop) to dynamically adjust the transient current I1040.

[0052] When a voltage drop occurs at the second corresponding voltage of the detection terminal DET (i.e., a voltage drop occurs at the target voltage VIN), the transient current source 1040 can draw a transient current I1040 from the output of the amplifier circuit 1010 during a transient period (the second transient period) corresponding to the falling edge of the voltage drop, in order to quickly pull down the amplified voltage Vo to meet the response speed requirements. After the transient period ends, the voltage-controlled current source 437 no longer draws the transient current I1040 to meet the product power consumption requirements.

[0053] Figure 11 This is described according to an embodiment of the present invention. Figure 10 The circuit block diagram of amplifier circuit 1010, transient current source 1030 and transient current source 1040 is shown. Figure 11 The amplifier circuit 1010, reference current source 1020, transient current source 1030, and transient current source 1040 shown can be referenced. Figure 10 The relevant descriptions of the amplifier circuit 1010, reference current source 1020, transient current source 1030 and transient current source 1040 shown will not be repeated here. Figure 11 The amplifier circuit 1010 shown includes an input stage 1011 and an output stage 1013. Figure 11 The input stage 1011 and output stage 1013 shown can be referenced. Figures 6 to 9 The relevant descriptions of the input stage 411 and output stage 413 shown are omitted here.

[0054] exist Figure 11 In the embodiment shown, the transient current source 1030 includes a detection circuit 1031 and a voltage-controlled current source 1033. Figure 11 The detection circuit 1031 and voltage-controlled current source 1033 shown can be referenced. Figure 6 and Figure 7 The descriptions of the detection circuit 431 and the voltage-controlled current source 433 are omitted here. For example, in some embodiments, the detection circuit 1031 can detect whether a voltage surge has occurred at the second corresponding voltage of the detection terminal DET of the voltage comparator 400. When a voltage surge occurs at the second corresponding voltage of the detection terminal DET (i.e., a voltage surge occurs at the target voltage VIN), the voltage-controlled current source 1033 can, based on the detection result of the detection circuit 1031, increase the transient current I1030 from a first current value to a second current value (e.g., from 0 to a positive value) during a transient period corresponding to the rising edge of the voltage surge, to meet the requirements of response speed. After the transient period ends, the voltage-controlled current source 1033 can, based on the detection result of the detection circuit 1031, adjust the transient current I1030 back from the second current value to the first current value (e.g., from a positive value back to 0), to meet the requirements of product power consumption.

[0055] exist Figure 11 In the embodiment shown, the transient current source 1040 includes a detection circuit 1041 and a voltage-controlled current source 1043. Figure 11 The detection circuit 1041 and voltage-controlled current source 1043 shown can be referenced. Figure 8 and Figure 9 The descriptions of the detection circuit 435 and the voltage-controlled current source 437 are omitted here. For example, in some embodiments, the detection circuit 1041 can detect whether a voltage drop has occurred at the second corresponding voltage of the detection terminal DET of the voltage comparator 400. When a voltage drop occurs at the second corresponding voltage of the detection terminal DET (i.e., a voltage drop occurs at the target voltage VIN), the voltage-controlled current source 1043 can draw a transient current I1040 at the output terminal of the output stage 1013 during a transient period corresponding to the falling edge of the voltage drop, based on the detection result of the detection circuit 1041, to quickly pull down the amplified voltage Vo to meet the response speed requirements. After the transient period ends, the voltage-controlled current source 1043 no longer draws the transient current I1040 to meet the product power consumption requirements.

[0056] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0057] [Symbol Explanation]

[0058] 400: Voltage comparator

[0059] 410, 1010: Amplifier circuit

[0060] 411, 1011: Input level

[0061] 413, 1013: Output stage

[0062] 420, 1020: Reference current source

[0063] 430, 1030, 1040: Transient current sources

[0064] 431, 435, 1031, 1041: Detection circuits

[0065] 433, 437, 1033, 1043: Voltage-controlled current sources

[0066] C71, C91: Capacitors

[0067] CM411, CM420: Current mirror

[0068] CS420: Current Source

[0069] DET: Detection Terminal

[0070] I430, I1030, I1040: Transient current

[0071] IN1, IN2: Comparison terminals

[0072] Iref: Reference current

[0073] M71, M72, M73, M74, M75, M76, M95, M96: Transistors

[0074] R21, R22, R31, R32, R71, R72, R91, R92: Resistors

[0075] S510, S520: Steps

[0076] VCC: System voltage

[0077] VCS: Bias voltage

[0078] Vd2, Vd3: Divider voltage

[0079] VIN: Target voltage

[0080] Vo: Amplified voltage

[0081] VREF, VSS: Reference voltage

Claims

1. A voltage comparator, comprising: A first comparison terminal and a second comparison terminal, wherein one of the first comparison terminal and the second comparison terminal is adapted to receive a first corresponding voltage corresponding to a target voltage, and the other of the first comparison terminal and the second comparison terminal is adapted to receive a first reference voltage; A detection terminal is adapted to receive a second corresponding voltage corresponding to the target voltage; An amplifier circuit has a first input terminal and a second input terminal respectively coupled to the first comparison terminal and the second comparison terminal, wherein an output terminal of the amplifier circuit is coupled to an output terminal of the voltage comparator. A reference current source is coupled to the amplifier circuit to provide a reference current; as well as A first transient current source is coupled to the amplifier circuit to selectively provide a first transient current, wherein an input terminal of the first transient current source is coupled to the detection terminal of the voltage comparator to receive the second corresponding voltage, and the first transient current source detects a first transition state of the second corresponding voltage to dynamically adjust the first transient current.

2. The voltage comparator of claim 1, wherein the first corresponding voltage and the second corresponding voltage are the same as the target voltage.

3. The voltage comparator as claimed in claim 1, wherein the first corresponding voltage is a division of the target voltage, and the second corresponding voltage is the same as the target voltage.

4. The voltage comparator of claim 1, wherein the first corresponding voltage is the same as the target voltage, and the second corresponding voltage is a voltage divider of the target voltage.

5. The voltage comparator as claimed in claim 1, wherein, When the second corresponding voltage experiences a voltage surge, the first transient current source increases the first transient current from a first current value to a second current value during a transient period corresponding to a rising edge of the voltage surge, wherein the second current value is positive. as well as After the transient period ends, the first transient current source adjusts the first transient current from the second current value back to the first current value.

6. The voltage comparator of claim 1, further comprising: A second transient current source is coupled to the amplifier circuit to selectively draw a second transient current, wherein an input terminal of the second transient current source is coupled to the detection terminal of the voltage comparator to receive the second corresponding voltage, and the second transient current source detects a second transition state of the second corresponding voltage to dynamically adjust the second transient current.

7. The voltage comparator as claimed in claim 6, wherein, When a voltage drop occurs in the second corresponding voltage, the second transient current source draws the second transient current from the output terminal of the amplifier circuit during a second transient period corresponding to a falling edge of the voltage drop. as well as After the transient period ends, the second transient current source no longer draws the second transient current.

8. The voltage comparator of claim 6, wherein the amplifier circuit comprises: An input stage has a first input terminal and a second input terminal respectively coupled to the first comparator terminal and the second comparator terminal, wherein a reference power supply terminal of the input stage is coupled to the reference current source to receive the reference current; as well as An output stage having an input terminal coupled to an output terminal of the input stage, wherein an output terminal of the output stage is coupled to the output terminal of the voltage comparator; One current terminal of the second transient current source is coupled to the output terminal of the output stage to selectively draw the second transient current.

9. The voltage comparator of claim 6, wherein the second transient current source comprises: A detection circuit has an input terminal coupled to the detection terminal of the voltage comparator to receive the second corresponding voltage, wherein the detection circuit detects the second transition state of the second corresponding voltage to output a detection result; as well as A voltage-controlled current source is coupled to the detection circuit to receive the detection result, wherein the voltage-controlled current source is controlled by the detection result to dynamically adjust the second transient current.

10. The voltage comparator of claim 9, wherein the detection circuit comprises: A capacitor having a first terminal coupled to the detection terminal of the voltage comparator to receive the second corresponding voltage; A first resistor having a first end coupled to a second end of the capacitor, wherein the second end of the first resistor receives a first power voltage; A transistor having a control terminal coupled to the second terminal of the capacitor, wherein a first terminal of the transistor receives the first power voltage; as well as A second resistor has a first end coupled to a second end of the transistor, wherein the second end of the second resistor receives a second power voltage, and the second end of the transistor and the first end of the second resistor together provide the detection result to the voltage-controlled current source.

11. The voltage comparator of claim 10, wherein the first power voltage is a system voltage and the second power voltage is a second reference voltage.

12. The voltage comparator of claim 9, wherein the voltage-controlled current source comprises: A transistor has a control terminal coupled to the detection circuit to receive the detection result, wherein a first terminal of the transistor receives a first power voltage, and a second terminal of the transistor is coupled to the amplifier circuit to selectively draw the second transient current.

13. The voltage comparator of claim 1, wherein the amplifier circuit comprises: An input stage has a first input terminal and a second input terminal respectively coupled to the first comparator terminal and the second comparator terminal, wherein a reference power supply terminal of the input stage is coupled to the reference current source to receive the reference current; as well as An output stage having an input terminal coupled to an output terminal of the input stage, wherein an output terminal of the output stage is coupled to the output terminal of the voltage comparator; One current terminal of the first transient current source is coupled to the reference power supply terminal of the input stage to selectively provide the first transient current.

14. The voltage comparator of claim 1, wherein the reference current source comprises: A current source; as well as A current mirror has a main current terminal coupled to the current source, wherein a secondary current terminal of the current mirror is coupled to the amplifier circuit to provide the reference current.

15. The voltage comparator of claim 1, wherein the first transient current source comprises: A detection circuit has an input terminal coupled to the detection terminal of the voltage comparator to receive the second corresponding voltage, wherein the detection circuit detects the first transition state of the second corresponding voltage to output a detection result; as well as A voltage-controlled current source is coupled to the detection circuit to receive the detection result, wherein the voltage-controlled current source is controlled by the detection result to dynamically adjust the first transient current.

16. The voltage comparator of claim 15, wherein the detection circuit comprises: A capacitor having a first terminal coupled to the detection terminal of the voltage comparator to receive the second corresponding voltage; A first resistor having a first end coupled to a second end of the capacitor, wherein the second end of the first resistor receives a first power voltage; A transistor having a control terminal coupled to the second terminal of the capacitor, wherein a first terminal of the transistor receives the first power voltage; as well as A second resistor has a first end coupled to a second end of the transistor, wherein the second end of the second resistor receives a second power voltage, and the second end of the transistor and the first end of the second resistor together provide the detection result to the voltage-controlled current source.

17. The voltage comparator of claim 16, wherein the first power voltage is a second reference voltage and the second power voltage is a system voltage.

18. The voltage comparator of claim 15, wherein the voltage-controlled current source comprises: A transistor has a control terminal coupled to the detection circuit to receive the detection result, wherein a first terminal of the transistor receives a first power voltage, and a second terminal of the transistor is coupled to the amplifier circuit to selectively provide a first transient current.

19. A method for operating a voltage comparator, comprising: A first corresponding voltage corresponding to a target voltage is received by one of the first comparison terminals and one of the second comparison terminals of the voltage comparator. A first reference voltage is received by one of the first comparison terminal and the second comparison terminal, wherein a first input terminal and a second input terminal of an amplifier circuit of the voltage comparator are respectively coupled to the first comparison terminal and the second comparison terminal, and an output terminal of the amplifier circuit is coupled to an output terminal of the voltage comparator; A second corresponding voltage corresponding to the target voltage is received by a detection terminal of the voltage comparator, wherein an input terminal of a first transient current source of the voltage comparator is coupled to the detection terminal of the voltage comparator to receive the second corresponding voltage; A reference current is provided to the amplifier circuit by a reference current source; The first transient current source detects a first transition state of the second corresponding voltage to dynamically adjust a first transient current; as well as The first transient current is selectively supplied to the amplifier circuit by the first transient current source.

20. The operating method of claim 19, wherein the first corresponding voltage and the second corresponding voltage are the same as the target voltage.

21. The operating method of claim 19, wherein the first corresponding voltage is a voltage division of the target voltage, and the second corresponding voltage is the same as the target voltage.

22. The operating method of claim 19, wherein the first corresponding voltage is the same as the target voltage, and the second corresponding voltage is a voltage divider of the target voltage.

23. The operating method as described in claim 19, further comprising: When the second corresponding voltage experiences a voltage surge, the first transient current source increases the first transient current from a first current value to a second current value during a transient period corresponding to a rising edge of the voltage surge, wherein the second current value is positive. as well as After the transient period ends, the first transient current source adjusts the first transient current from the second current value back to the first current value.

24. The operating method as described in claim 19, further comprising: A second transient current source of the voltage comparator detects a second transition state of the second corresponding voltage to dynamically adjust a second transient current; as well as The second transient current is selectively drawn from the amplifier circuit by the second transient current source.

25. The operating method as described in claim 24, further comprising: When the second corresponding voltage experiences a voltage drop, the second transient current source will draw the second transient current from the output terminal of the amplifier circuit during a second transient period corresponding to a falling edge of the voltage drop. as well as After the transient period ends, the second transient current source no longer draws the second transient current.

Images