Band-gap reference circuit and voltage compensation method of band-gap reference circuit

Abstract

The invention provides a band-gap reference circuit and a voltage compensation method of the band-gap reference circuit. The band-gap reference circuit and the voltage compensation method can be applied to the technical field of integrated circuits. The circuit comprises a band-gap reference core module used for generating a first-order compensation reference voltage; the resistance control module is electrically connected with the band-gap reference core module, and is used for determining a segment resistance value corresponding to the at least one temperature segment interval, and compensating the first-order compensation reference voltage based on the segment resistance value to obtain a target reference voltage, the at least one temperature segment interval is obtained by dividing the working temperature range of the band-gap reference circuit.

Description

Technical Field

[0001] The present disclosure relates to the technical field of integrated circuits, and in particular to a bandgap reference circuit and a voltage compensation method for the bandgap reference circuit. Background Art

[0002] With the booming development of the Internet of Things, most integrated circuit systems used in IoT devices require a reference voltage that is insensitive to process, power supply voltage, and temperature changes. IoT devices, which are known for their wireless functions and portability, generally operate under limited power consumption. Therefore, low power consumption is more important for integrated circuits and even reference voltages in IoT devices. In addition, sufficient temperature stability must be ensured on the basis of low power consumption.

[0003] In the process of implementing the present disclosure, the inventors found that in the related art, the temperature drift of the bandgap reference circuit is mainly reduced by injecting segmented current into the bandgap reference circuit, but as the number of segments of the segmented current increases, the consumption current branch of the bandgap reference circuit also increases, resulting in higher power consumption of the bandgap reference circuit. Summary of the invention

[0004] In view of the above problems, the present disclosure provides a bandgap reference circuit and a voltage compensation method for the bandgap reference circuit.

[0005] According to a first aspect of the present disclosure, a bandgap reference circuit is provided, comprising: a bandgap reference core module, for generating a first-order compensation reference voltage; a resistance control module, the resistance control module being electrically connected to the bandgap reference core module, for determining a segmented resistance corresponding to at least one temperature segment interval, and compensating the first-order compensation reference voltage based on the segmented resistance value to obtain a target reference voltage, wherein the at least one temperature segment interval is obtained by dividing the operating temperature range of the bandgap reference circuit.

[0006] According to an embodiment of the present disclosure, the above-mentioned bandgap reference core module is also used to generate a first bias voltage and a second bias voltage; the above-mentioned resistance control module includes a temperature-sensitive voltage generating submodule, and the above-mentioned temperature-sensitive voltage generating submodule is used to generate an absolute voltage proportional to the absolute temperature based on the above-mentioned first bias voltage as a temperature-sensitive voltage, and to generate a quantized reference voltage based on the above-mentioned first bias voltage and the above-mentioned second bias voltage.

[0007] According to an embodiment of the present disclosure, the resistance control module further includes an analog-to-digital converter, which is used to receive the absolute voltage and the quantization reference voltage, and quantize the absolute voltage based on the quantization reference voltage to obtain a binary code that is positively correlated with the temperature.

[0008] According to an embodiment of the present disclosure, the resistance control module further includes a memory, which is used to receive the binary code and store the binary code based on an enable signal, wherein the enable signal represents turning on or off a storage function of the memory.

[0009] According to an embodiment of the present disclosure, the resistance control module further includes a thermal decoder, and the thermal decoder is used to convert the binary code stored in the memory into a thermal code.

[0010] According to an embodiment of the present disclosure, the above-mentioned thermal decoder is used to convert the binary code stored in the above-mentioned memory into a thermal code through the following operations: in a conversion cycle, the switch of the static current consumption submodule of the above-mentioned resistance control module is turned on, and the above-mentioned thermal decoder converts the above-mentioned binary code into a thermal code; in a sleep cycle, the switch of the static current consumption submodule of the above-mentioned resistance control module is turned off, and the above-mentioned thermal code is maintained.

[0011] According to an embodiment of the present disclosure, the resistance control module further includes a segmented resistance submodule, which is used to receive the thermal code and control the segmented resistance value corresponding to at least one temperature segment interval based on the thermal code.

[0012] According to an embodiment of the present disclosure, the segmented resistance submodule includes at least one first switch and at least one second switch, and the segmented resistance corresponding to at least one temperature segment interval is controlled according to the thermal code, including: determining the state of the at least one first switch and the at least one switch according to the thermal code, wherein the first switch and the second switch correspond to different temperature segment intervals respectively; determining the segmented resistance corresponding to the at least one temperature segment interval according to the state of the at least one first switch and the at least one switch.

[0013] A second aspect of the present disclosure provides a voltage compensation method for a bandgap reference circuit, comprising: obtaining a first-order compensation reference voltage; determining a segmented resistance corresponding to at least one temperature segment interval, and compensating the first-order compensation reference voltage based on the segmented resistance value to obtain a target reference voltage, wherein the at least one temperature segment interval is obtained by dividing the operating temperature range of the bandgap reference circuit.

[0014] According to an embodiment of the present disclosure, the above-mentioned determination of the segmented resistance corresponding to at least one temperature segment interval, compensating the above-mentioned first-order compensation reference voltage based on the above-mentioned segmented resistance, and obtaining the target reference voltage includes: obtaining a first bias voltage and a second bias voltage; generating an absolute voltage and a quantization reference voltage proportional to the absolute temperature based on at least one of the above-mentioned first bias voltage and the second bias voltage; quantizing the above-mentioned absolute voltage based on the above-mentioned quantization reference voltage to generate a binary code that is positively correlated with the temperature; converting the binary code to generate a thermal code; determining the segmented resistance of the segmented resistor based on the above-mentioned thermal code; and compensating the above-mentioned first-order compensation reference voltage based on the segmented resistance of the above-mentioned segmented resistor to obtain the target reference voltage.

[0015] According to the bandgap reference circuit and the voltage compensation method of the bandgap reference circuit provided by the present disclosure, the segmented resistance value corresponding to at least one temperature segmented interval is determined by the resistance control module. Based on the segmented resistance values ​​corresponding to different temperature segmented intervals, compensation for the first-order compensation reference voltage generated by the bandgap reference core module can be achieved, thereby reducing the temperature drift of the target reference voltage and obtaining the target reference voltage. In addition, since a large number of static consumption current branches are not required when implementing curvature compensation, the power consumption of the bandgap reference circuit is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above contents and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0017] Figure 1 The structure diagram of the bandgap reference circuit in the related art is schematically shown;

[0018] Figure 2 A schematic diagram schematically shows a voltage compensation process of a bandgap reference circuit in the related art;

[0019] Figure 3 Schematically shows a block diagram of a bandgap reference circuit according to an embodiment of the present disclosure;

[0020] Figure 4 The structure diagram of the bandgap reference circuit according to the embodiment of the present disclosure is schematically shown;

[0021] Figure 5 The circuit diagram of the temperature-sensing voltage generating submodule according to an embodiment of the present disclosure is schematically shown;

[0022] Figure 6 A schematic diagram schematically illustrates the temperature change rate in different application fields according to an embodiment of the present disclosure;

[0023] Figure 7 Schematically shows a timing diagram of a resistance control module according to an embodiment of the present disclosure;

[0024] Figure 8 The structure diagram of the resistance control module according to the embodiment of the present disclosure is schematically shown;

[0025] Fig. 9 Schematically shows a circuit diagram of an analog-to-digital converter, a memory, and a thermal decoder according to an embodiment of the present disclosure;

[0026] Fig.10 Schematically shows a structural diagram of a bandgap reference circuit according to another embodiment of the present disclosure;

[0027] Fig.11 A schematic diagram schematically shows a voltage compensation process of a bandgap reference circuit according to an embodiment of the present disclosure;

[0028] Fig.12 A flow chart schematically shows a voltage compensation method for a bandgap reference circuit according to an embodiment of the present disclosure; and

[0029] Fig.13 A simulation diagram of compensating a first-order compensation reference voltage according to an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0031] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0032] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0033] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0034] In the process of implementing the present invention, it is found that with the vigorous development of the Internet of Things, Internet of Things devices play an important role in various application scenarios of human life and the Internet of Things. Most integrated circuit systems used in Internet of Things devices require a reference voltage that is insensitive to process, power supply voltage and temperature changes. Since such Internet of Things devices, which are famous for their wireless functions and portability, generally operate under limited power consumption. Therefore, low power consumption is crucial for integrated circuits and reference voltages in Internet of Things applications. In addition, sufficient temperature stability of the reference voltage must be ensured.

[0035] The temperature drift of the first-order compensated bandgap reference voltage circuit in the related art is limited by the base-to-emitter voltage (V BE ) makes it impossible to apply it to circuits with high temperature drift requirements. There are many methods to reduce the temperature drift of bandgap reference, mainly using curvature compensation technology of current injection. Curvature compensation technology often uses the subtraction between the proportional to absolute temperature (PTAT) current and the complementary to absolute temperature (CTAT) current or the subtraction between the PTAT current and the reference current to obtain the segmented compensation current. The generated segmented compensation current is injected into the resistor of the output branch of the bandgap reference circuit to perform segmented curvature compensation on the temperature curve of the bandgap reference, thereby obtaining a bandgap reference output voltage with a low temperature coefficient. However, the generation of this segmented compensation current requires the consumption of additional static current. In addition, as the number of segments of the segmented compensation current increases, the current consumption branches required also increase, thereby increasing the power consumption of the overall circuit.

[0036] Figure 1 The structure of a bandgap reference circuit in the related art is schematically shown.

[0037] like Figure 1As shown in FIG. 1 , the bandgap reference circuit in the related art includes a bandgap reference core module 110 and a current segmented compensation module 120. The bandgap reference core module 110 is composed of a P-type metal-oxide-semiconductor field-effect transistor (PMOS tube) M A , PMOS tube M B , PMOS tube M C , PMOS tube M D , PMOS tube M E , operational amplifier A A , operational amplifier A B , resistor R A , resistor R B , transistor Q A , transistor Q B And the output resistance R OA Composed of PMOS tube M B , PMOS tube M C , operational amplifier A A , resistor R A , transistor Q A , transistor Q B The negative feedback loop formed generates PTAT current I PTAT1 . By PMOS tube M A , operational amplifier A B , resistor R B The negative feedback loop formed will convert the CTAT voltage V BE Converted into CTAT current I CTAT1 Through the PMOS tube M D , PMOS tube M E Mirror PTAT current I PTAT1 and CTAT current I CTAT1 At the same time, it is injected into the output resistor R OA , generating a first-order temperature compensated bandgap reference voltage V REFA In the current segment compensation module 120, by adjusting the PMOS tube M PA With PMOS tube M PB The trigger temperature threshold of the segmented compensation current can be adjusted by adjusting the ratio of the number of parallel connections of the PMOS tube M PC With PMOS tube M PD The ratio of the number of parallel connections can adjust the segmented compensation current I COMP The size of is also the slope of the compensation current temperature curve.

[0038] Figure 2 The diagram schematically shows a voltage compensation process of a bandgap reference circuit in the related art.

[0039] like Figure 2 As shown in A, it is the above Figure 1 The bandgap reference circuit shown generates a first-order temperature compensated bandgap reference voltage V REFA , by setting the bandgap reference voltage V REFA Plus Figure 2 The compensation voltage V corresponding to the segmented compensation current shown in B COMP , we can get Figure 2 The compensated reference voltage V shown in C REF1 .

[0040] In view of this, an embodiment of the present disclosure provides a bandgap reference circuit, including: a bandgap reference core module, used to generate a first-order compensation reference voltage; a resistance control module, the resistance control module is electrically connected to the bandgap reference core module, and is used to determine a segmented resistance corresponding to at least one temperature segment interval, and compensate the first-order compensation reference voltage based on the segmented resistance value to obtain a target reference voltage, wherein at least one temperature segment interval is obtained by dividing the operating temperature range of the bandgap reference circuit.

[0041] Figure 3 The block diagram of a bandgap reference circuit according to an embodiment of the present disclosure is schematically shown.

[0042] like Figure 3 As shown, the bandgap reference circuit 300 of this embodiment includes a bandgap reference core module 310 and a resistance control module 320 .

[0043] According to an embodiment of the present disclosure, the bandgap reference core module 310 is used to generate a first-order compensation reference voltage.

[0044] According to an embodiment of the present disclosure, the resistance control module 320 is electrically connected to the bandgap reference core module 310, and is used to determine the segmented resistance corresponding to at least one temperature segment interval, and compensate the first-order compensation reference voltage based on the segmented resistance to obtain the target reference voltage.

[0045] According to an embodiment of the present disclosure, the first-order compensated reference voltage can represent a first-order temperature-compensated bandgap reference voltage, and the influence of temperature changes on the bandgap reference voltage is reduced by using compensation technology.

[0046] According to an embodiment of the present disclosure, an absolute current proportional to the absolute temperature and an absolute current complementary to the absolute temperature can be generated in the bandgap reference core module 310. The absolute current proportional to the absolute temperature and the absolute current complementary to the absolute temperature are simultaneously injected into the output resistance of the bandgap reference core module to generate a first-order compensated reference voltage.

[0047] According to an embodiment of the present disclosure, the resistance control module 320 may be electrically connected to the bandgap reference core module 310 .

[0048] According to an embodiment of the present disclosure, at least one temperature segment interval is obtained by dividing the operating temperature range of the bandgap reference circuit. The operating temperature range of the bandgap reference circuit can be determined based on factors such as the environment and application field of the bandgap reference circuit. For example, the operating temperature range of the bandgap reference circuit can be -40°C~125°C. When the operating temperature range of the bandgap reference circuit is determined, the operating temperature range of the bandgap reference circuit can be divided. For example, the operating temperature range of the bandgap reference circuit -40°C~125°C can be divided into three temperature segment intervals, namely, a low temperature segment interval of -40°C~16°C, a medium temperature segment interval of 17°C~69°C, and a high temperature segment interval of 70°C~125°C.

[0049] According to an embodiment of the present disclosure, the resistance control module 320 may be used to determine a segmented resistance value corresponding to at least one temperature segmented interval. Different temperature segmented intervals may correspond to different segmented resistance values, for example, the segmented resistance value corresponding to the high temperature segmented interval is different from the segmented resistance value corresponding to the medium temperature segmented interval. For another example, the segmented resistance value corresponding to the medium temperature segmented interval is different from the segmented resistance value corresponding to the low temperature segmented interval.

[0050] According to an embodiment of the present disclosure, the first-order compensation reference voltage can be compensated based on the segmented resistance value, that is, the segmented curvature compensation voltage corresponding to different segmented resistance values ​​can be determined based on the segmented resistance value, and the first-order compensation reference voltage can be compensated based on the segmented curvature compensation voltage, so as to obtain the target reference voltage. The process of compensating the first-order compensation reference voltage based on the segmented resistance value to obtain the target reference voltage can be called curvature compensation.

[0051] According to an embodiment of the present disclosure, by determining the segmented resistance corresponding to at least one temperature segment interval through a resistance control module, compensation for the first-order compensation reference voltage generated by a bandgap reference core module can be achieved based on the segmented resistance corresponding to different temperature segment intervals, thereby reducing the temperature drift of the target reference voltage and obtaining the target reference voltage. Furthermore, since curvature compensation does not require a large number of static consumption current branches, the power consumption of the bandgap reference circuit is reduced.

[0052] According to an embodiment of the present disclosure, the bandgap reference core module is also used to generate a first bias voltage and a second bias voltage; the resistance control module includes a temperature-sensitive voltage generating submodule, which is used to generate an absolute voltage proportional to the absolute temperature based on the first bias voltage as a temperature-sensitive voltage, and to generate a quantized reference voltage based on the first bias voltage and the second bias voltage.

[0053] According to an embodiment of the present disclosure, the resistance control module includes a temperature-sensitive voltage generation submodule, which can be used to generate a temperature-sensitive voltage, and the temperature-sensitive voltage can characterize a voltage related to temperature changes. The bandgap reference core module is also used to generate a first bias voltage and a second bias voltage, and input the first bias voltage and the second bias voltage into the temperature-sensitive voltage generation submodule.

[0054] According to an embodiment of the present disclosure, the temperature-sensing voltage generating submodule can generate an absolute voltage proportional to the absolute temperature based on the first bias voltage as the temperature-sensing voltage, and can also generate a quantized reference voltage based on the first bias voltage and the second bias voltage, and transmit the absolute voltage proportional to the absolute temperature and the quantized reference voltage to the analog-to-digital converter.

[0055] According to an embodiment of the present disclosure, based on at least one of the first bias voltage and the second bias voltage, the resistance control module can generate an absolute voltage proportional to the absolute temperature and a quantized reference voltage, thereby realizing the generation of an absolute voltage proportional to the absolute temperature and a quantized reference voltage.

[0056] Figure 4 The structure diagram of a bandgap reference circuit according to an embodiment of the present disclosure is schematically shown.

[0057] like Figure 4 As shown, the bandgap reference core module 310 is composed of a first MOS transistor M 1 , the second MOS tube M 2 , the third MOS tube M 3 , the fourth MOS tube M 4 , the fifth MOS tube M 5 , the first resistor R 1 , the second resistor R 2 , the first operational amplifier A 1 , the second operational amplifier A 2 , the first transistor Q 1 , the second transistor Q 2 , segment resistance R c And the power supply V DD Power supply V DD The resistance control module 320 controls the segmented resistance R c Take control.

[0058] According to an embodiment of the present disclosure, the bandgap reference core module 310 can generate a first bias voltage V P and the second bias voltage V C , by making the current I proportional to the absolute temperature PTAT and the current complementary to the absolute temperature I CTAT At the same time, it is injected into the output resistor R O, can generate a first-order compensation reference voltage V REF1 , the resistance control module 320 controls the segment resistance R c By controlling, the segment resistance R C The segmented resistance value can then determine the segmented curvature compensation voltage V COMP , the first-order compensation reference voltage V REF1 and segmented curvature compensation voltage V COMP Adding, we can realize the first-order compensation reference voltage V REF1 The target reference voltage V REF .

[0059] Figure 5 The circuit diagram of the temperature-sensitive voltage generating submodule according to an embodiment of the present disclosure is schematically shown.

[0060] like Figure 5 As shown, the temperature sensing voltage generating submodule may include a MOS tube M p1 、MOS tube M p2 And MOS tube M p3 , resistor R p1 , resistor R p2 and power supply V DD . Power supply V DD It can be used for MOS tube M p1 、MOS tube M p2 And MOS tube M p3 Power supply. Resistor R p1 The first end of the MOS tube M p1 Connection, resistor R p1 The second end of the resistor R p2 The first end of the MOS tube M p3 Connection, resistor R p2 The second end is grounded.

[0061] According to an embodiment of the present disclosure, the MOS tube M biased by the first bias voltage Vp p3 The resulting current is injected into the resistor R p2 An absolute voltage V proportional to the absolute temperature is generated PTAT , where the absolute voltage V PTAT The MOS tube M is sensitive to temperature and can be used as a temperature sensing voltage. p3 The generated current and the second bias voltage Vc bias the MOS tube M p1 The resulting current is injected into the resistor R p1 The quantization reference voltage V REF , where the quantized reference voltage V REF Not sensitive to temperature.

[0062] According to an embodiment of the present disclosure, the resistance control module further includes an analog-to-digital converter, which is used to receive an absolute voltage and a quantized reference voltage, and quantize the absolute voltage based on the quantized reference voltage to obtain a binary code that is positively correlated with the temperature.

[0063] According to an embodiment of the present disclosure, the resistance control module may further include an analog-to-digital converter, which may represent a device that converts a continuous analog signal into a discrete digital signal. In an embodiment of the present disclosure, the analog-to-digital converter may be a successive approximation register analog-to-digital converter (SARDAC), which may be composed of a capacitor digital-to-analog converter, a comparator, a successive approximation logic unit, and the like.

[0064] According to an embodiment of the present disclosure, the absolute voltage generated by the temperature-sensitive voltage generating submodule can be converted based on the quantized reference voltage to obtain a binary code that is positively correlated with the temperature, and the binary code is transmitted to a memory, wherein the binary code that is positively correlated with the temperature is a binary code in digital form, that is, a binary digital code.

[0065] According to the embodiments of the present disclosure, an absolute voltage in analog form may be converted into a binary code in digital form by using an analog-to-digital converter, thereby improving the storage efficiency and stability of a subsequent memory.

[0066] According to an embodiment of the present disclosure, the resistance control module further includes a memory, and the memory is used to receive the binary code and store the binary code based on the enable signal.

[0067] According to an embodiment of the present disclosure, the resistance control module may further include a memory for storing the received binary code. The enable signal may represent turning on or off the storage function of the memory. When the enable signal represents turning on the storage function of the memory, the quantized binary code is stored until the next quantization is completed, and the data in the memory is updated and transmitted to the thermal decoder.

[0068] According to the embodiments of the present disclosure, by storing the binary code based on the enable signal, accurate control of the storage of the binary code can be achieved, thereby ensuring that the binary code can be stably transmitted to the hot decoder.

[0069] According to an embodiment of the present disclosure, the resistance control module further includes a thermal decoder, which is used to convert the binary code stored in the memory into a thermal code.

[0070] According to an embodiment of the present disclosure, a thermal decoder may characterize a device that converts a binary input signal into a thermometer code, wherein the thermometer code may include multiple output bits, each output bit of the thermometer code may represent a specific threshold, and the output bits are activated in sequence from the lowest bit to the highest bit until the bit corresponding to the input signal is reached.

[0071] According to an embodiment of the present disclosure, a binary code stored in a memory may be converted into a thermometer code using a thermal decoder, that is, a binary code stored in a memory may be converted into a thermal code using a thermal decoder.

[0072] According to an embodiment of the present disclosure, the hot decoder has a truth table for characterizing the correspondence between the binary code input to the hot decoder and the hot code outputted therefrom. The binary code input to the hot decoder may be 6 bits, namely 000000, 000001, ..., 111110, 111111; the hot code outputted by the hot decoder may be 9 bits, namely 1111111111, 111111110, ..., 100000000, 000000000.

[0073] According to an embodiment of the present disclosure, the thermal decoder is used to convert the binary code stored in the memory into a hot code through the following operations: in the conversion cycle, the switch of the static current consumption submodule of the resistance control module is turned on, and the thermal decoder converts the binary code into a hot code; in the sleep cycle, the switch of the static current consumption submodule of the resistance control module is turned off, and the hot code is maintained.

[0074] According to the embodiment of the present disclosure, it takes a certain amount of time for the thermal decoder to convert the binary code stored in the memory into the thermal code, and this time is a conversion time of the temperature sensor. The conversion time of the temperature sensor may include a conversion cycle and a sleep cycle. In the conversion cycle, the switch of the static current consumption submodule of the resistance control module is turned on, and the thermal decoder may convert the binary code into a thermal code. In the sleep cycle, the switch of the static current consumption submodule of the resistance control module is turned off to maintain the thermal code. After each conversion is completed, the sleep cycle may be entered. In the sleep cycle, the thermal code may be latched to maintain the thermal code. During this period, static power consumption is not required, that is, the switch of the static current consumption submodule of the resistance control module may be turned off to put the static current consumption submodule of the resistance control module into a sleep state, thereby realizing intermittent shutdown of the static current consumption submodule of the resistance control module.

[0075] According to the embodiments of the present disclosure, if the temperature has changed significantly, and the thermal code is not updated in time according to the temperature change, the segmented resistance of the segmented resistance will not be timely changed in a segmented manner with the temperature, that is, the segmented change of the segmented resistance has a time lag relative to the temperature change, and the temperature changes but is not compensated in time, so that the voltage compensation effect of the bandgap reference circuit will be poor. In order to ensure that the bandgap reference circuit can effectively reduce the temperature drift of the target reference voltage, the frequency of the resistance control module needs to be much smaller than the temperature change frequency.

[0076] According to the embodiments of the present disclosure, even if the frequency of the resistance control module is much smaller than the temperature change frequency, the higher the temperature change frequency is, the higher the frequency of the resistance control module needs to be. When the static current consumption submodule of the resistance control module is intermittently shut down, the power consumption can be reduced more.

[0077] Figure 6 A schematic diagram schematically illustrates the temperature change rate in different application fields according to an embodiment of the present disclosure.

[0078] like Figure 6 As shown, for the medical field, the temperature change rate range is 10 -4 ℃ / s~10 -3 ℃ / s, for food industry, the temperature change rate range is 10 -3 ℃ / s~10 -2 ℃ / s, for implantable medical field, the temperature change rate is 10 -2 ℃ / s, for the automotive field, the minimum temperature change rate is 10 -2 ℃ / s and 10 -1 ℃ / s, the minimum temperature change rate is 10 0 ℃ / s, and the temperature change rate ranges in the food field and the implant medical field overlap.

[0079] According to an embodiment of the present disclosure, the process of converting the binary code stored in the memory into the hot code is divided into a conversion cycle and a sleep cycle. Static power consumption is not required in the sleep cycle, so that the switch of the static current consumption submodule of the resistance control module can be disconnected, and the intermittent shutdown of the static current consumption submodule of the resistance control module can be achieved, thereby reducing the power consumption of the resistance control module.

[0080] Figure 7 The timing diagram of the resistance control module according to the embodiment of the present disclosure is schematically shown.

[0081] like Figure 7As shown, the process of converting a binary code stored in the memory into a hot code can be called a working cycle. A working cycle can be divided into a conversion cycle and a sleep cycle. The resistance control module 320 can include a static current consumption submodule 321 and a dynamic current consumption submodule 322. In the conversion cycle, the switch of the static current consumption submodule 321 of the resistance control module 320 is turned on, and in the sleep cycle, the switch of the static current consumption submodule 322 of the resistance control module 320 is turned off. The dynamic current consumption submodule 322 is in a working state in both the conversion cycle and the sleep cycle.

[0082] According to an embodiment of the present disclosure, the resistance control module further includes a segmented resistance submodule, which is used to receive a thermal code and control a segmented resistance value corresponding to at least one temperature segment interval based on the thermal code.

[0083] According to an embodiment of the present disclosure, the resistance control module may further include a segmented resistance submodule for receiving a thermal code and controlling the segmented resistance corresponding to at least one temperature segment interval based on the thermal code. For example, when the temperature segment interval includes a high temperature segment interval, a medium temperature segment interval, and a high temperature segment interval, the segmented resistance corresponding to the high temperature segment interval and the low temperature segment interval may be controlled based on the thermal code.

[0084] For example, the segment resistance corresponding to the medium temperature segment interval is a fixed value, that is, the segment resistance corresponding to the medium temperature segment interval is a fixed resistance.

[0085] According to an embodiment of the present disclosure, controlling a segmented resistance value corresponding to at least one temperature segment interval according to a thermal code includes: determining a state of at least one first switch and at least one second switch according to the thermal code; and determining a segmented resistance value corresponding to at least one temperature segment interval according to the state of at least one first switch and at least one second switch.

[0086] According to an embodiment of the present disclosure, the segmented resistor submodule may include at least one first switch and at least one second switch, and the first switch and the second switch correspond to different temperature segment intervals, for example, the first switch corresponds to a low temperature segment interval, and the second switch corresponds to a high temperature segment interval.

[0087] According to an embodiment of the present disclosure, a segmented resistance value corresponding to at least one temperature segment interval may be determined according to the states of at least one first switch and at least one second switch.

[0088] For example, for the high temperature segmented interval, when the number of bits of the hot code is 9, the off of one of the 9 second switches in the segmented resistance submodule can be controlled based on each bit value of the hot code. Each second switch is connected in parallel with a resistor. When the second switch is turned on, the resistor connected in parallel with the second switch is not connected to the circuit. When the second switch is turned off, the resistor connected in parallel with the switch is connected to the circuit, thereby realizing the control of the segmented resistance value corresponding to the high temperature division interval. For example, when the hot code is 111111111, it can represent 9 second switches SW H1 , S.W. H2 , ..., SW H9 All are turned on, that is, the segment resistance of the high temperature segment interval is equal to the fixed resistance of the medium temperature segment interval.

[0089] According to an embodiment of the present disclosure, the states of at least one first switch and at least one second switch can be determined based on the received thermal code, and then the resistance in the connected circuit can be determined, thereby realizing the segmented resistance value control corresponding to one less temperature segment interval in the resistance control module, thereby improving the accuracy of the segmented resistance value.

[0090] Figure 8 The structure diagram of the resistance control module according to the embodiment of the present disclosure is schematically shown.

[0091] like Figure 8 As shown, the resistance control module may include a temperature sensing voltage generation submodule, an analog-to-digital converter, a memory, a thermal decoder, and a segmented resistance submodule. It can be seen that the temperature sensing voltage generation submodule can generate an absolute voltage V PTAT and quantization reference voltage V REF , the absolute voltage V PTAT and quantization reference voltage V REF Input analog-to-digital converter, the analog-to-digital converter can be based on the quantization reference voltage V REF For absolute voltage V PTAT Quantization is performed to generate a binary code, and the binary code is input into a memory. The memory stores the binary code based on an enable signal, and the stored binary code is input into a thermal decoder. The thermal decoder converts the binary code to generate a thermal code, and transmits the thermal code to a segmented resistor submodule. The segmented resistor submodule controls the states of the first switch and the second switch based on the thermal code, thereby controlling the segmented resistance value of the segmented resistor.

[0092] like Figure 8As shown, the segmented resistor submodule may include a low temperature segmented interval switch and a high temperature segmented interval switch, which are used to determine the temperature segmented interval to which the temperature belongs. For the temperature segmented interval, N second switches may be included, namely SH1, SH2, ..., SHN. Each second switch may be connected in parallel with a resistor, and the N resistors are respectively RH1, RH2, ..., RHN, wherein the resistor RH1 is connected in parallel with the second switch SH1, and so on. For the low temperature segmented interval, M second switches may be included, namely SL1, SL2, ..., SLM. Each first switch may be connected in parallel with a resistor, and the M resistors are respectively RL1, RL2, ..., RLN, wherein the resistor RL1 is connected in parallel with the first switch SL1, and so on.

[0093] Fig. 9 The circuit diagram of an analog-to-digital converter, a memory, and a thermal decoder according to an embodiment of the present disclosure is schematically shown.

[0094] like Fig. 9 As shown, the analog-to-digital converter can be composed of a capacitor digital-to-analog converter, a comparator, and a successive approximation logic unit. The capacitor digital-to-analog converter receives an absolute voltage V PTAT and quantization reference voltage V REF , and based on the quantized reference voltage V REF For absolute voltage V PTAT Analog-to-digital conversion is performed, and the converted data is transmitted to the comparator. After being processed by the successive approximation logic unit, a binary code can be obtained, and the binary code is input into the memory. The binary code is stored in the memory based on the enable signal, and the stored binary code is input into the thermal decoder. The thermal decoder converts the binary code into a thermal code based on a truth table, and transmits the thermal code to the segmented resistor sub-module.

[0095] Fig.10 The structure of a bandgap reference circuit according to another embodiment of the present disclosure is schematically shown. Fig.11 A schematic diagram schematically shows a voltage compensation process of a bandgap reference circuit according to an embodiment of the present disclosure.

[0096] like Fig.10 As shown, it is Figure 4 The output current branch shown in the figure is simplified to obtain the structure diagram of the bandgap reference circuit, which can convert the current I proportional to the absolute temperature PTAT and the current complementary to the absolute temperature I CTAT At the same time, it is injected into the output resistor R O Simplified to current I O Injected into the output resistor R O , thus producing Fig.11 The first-order compensation reference voltage V shown in A REF1 , the first-order compensation reference voltage V REF1It changes with temperature in a parabolic shape. Fig.10 In the case of O Through the segment resistor R c , a first-order compensation reference voltage V REF1 The opposite segment curvature compensation voltage V COMP , segmented curvature compensation voltage V COMP ,like Fig.11 As shown in B, the first-order compensation reference voltage V REF1 With the segmented curvature compensation voltage V COMP Adding can generate a low temperature drift target reference voltage V REF ,like Fig.11 As shown in C. Segment resistance R c The resistance control module senses the temperature through a low-resolution temperature sensor, and then controls the segmented resistance R according to the thermal code output by the temperature sensor. c , segment resistance R c The segment resistance, such as Fig.11 As shown in D, the first-order compensation reference voltage V REF1 compensation. Fig.11 In A~D, T L Indicates the low temperature segmentation interval, T M Indicates the middle temperature segment interval, T H Indicates the high temperature segmentation interval.

[0097] Based on the above bandgap reference circuit, the present disclosure also provides a voltage compensation method for the bandgap reference circuit. Fig.12 The method is described in detail.

[0098] Fig.12 The flowchart of the voltage compensation method of the bandgap reference circuit according to the embodiment of the present disclosure is schematically shown.

[0099] like Fig.12 As shown, the voltage compensation method 1200 of the bandgap reference circuit of this embodiment includes operation S1210 and operation S1220.

[0100] In operation S1210 , a first-order compensation reference voltage is acquired.

[0101] In operation S1220, a segmented resistance value corresponding to at least one temperature segment interval is determined, and the first-order compensation reference voltage is compensated based on the segmented resistance value to obtain a target reference voltage.

[0102] According to an embodiment of the present disclosure, a first-order compensation reference voltage may be generated by a bandgap reference core module.

[0103] According to an embodiment of the present disclosure, at least one temperature segment interval is obtained by dividing the operating temperature range of the bandgap reference circuit, and the operating temperature range of the bandgap reference circuit can be divided into multiple temperature segment intervals. For example, the operating temperature range of the bandgap reference circuit is divided into a high temperature segment interval, a medium temperature segment interval, and a low temperature segment interval.

[0104] According to an embodiment of the present disclosure, the first-order compensation reference voltage may be compensated based on the segmented resistance corresponding to at least one temperature segment interval, thereby obtaining a target reference voltage.

[0105] According to an embodiment of the present disclosure, a target reference voltage can be obtained by compensating a first-order compensation reference voltage by determining a segmented resistance corresponding to at least one temperature segment interval. Since the segmented resistance corresponding to at least one temperature segment interval is related to temperature, the temperature drift of the target reference voltage can be reduced.

[0106] According to an embodiment of the present disclosure, determining a segmented resistance value corresponding to at least one temperature segment interval, compensating a first-order compensation reference voltage based on the segmented resistance value, and obtaining a target reference voltage includes: obtaining a first bias voltage and a second bias voltage; generating an absolute voltage and a quantization reference voltage proportional to the absolute temperature based on at least one of the first bias voltage and the second bias voltage; quantizing the absolute voltage based on the quantization reference voltage to generate a binary code that is positively correlated with the temperature; converting the binary code to generate a thermal code; determining the segmented resistance value of the segmented resistor based on the thermal code; and compensating the first-order compensation reference voltage based on the segmented resistance value of the segmented resistor to obtain the target reference voltage.

[0107] According to an embodiment of the present disclosure, the first bias voltage and the second bias voltage may also be generated by a bandgap reference core module. An absolute voltage proportional to the absolute temperature may be generated based on the first bias voltage, and the absolute voltage proportional to the absolute temperature is sensitive to temperature and may be a temperature-sensitive voltage. A quantized reference voltage may be generated based on the first bias voltage and the second bias voltage.

[0108] According to an embodiment of the present disclosure, the absolute voltage can be quantized based on the quantized reference voltage to generate a binary code that is positively correlated with the temperature. The quantization process of the absolute voltage is a process of converting the absolute voltage in analog form into a binary code in digital form.

[0109] According to an embodiment of the present disclosure, by converting the binary code, a thermal code for controlling the segmented resistance of the segmented resistor can be obtained. When the segmented resistance is determined, the first-order compensation reference voltage can be compensated based on the segmented resistance to obtain the target reference voltage.

[0110] According to an embodiment of the present disclosure, the process of converting a binary code into a hot code may include a conversion period and a sleep period. During the sleep period, the power consumption of the resistance control module may be reduced by disconnecting the switch of the static current consumption submodule.

[0111] According to an embodiment of the present disclosure, a thermal code can be generated by converting a binary code. Based on the thermal code, the segmented resistance value of the segmented resistor can be determined. The first-order compensation reference voltage can be compensated based on the segmented resistance value to obtain a target reference voltage. Since the process of converting the binary code into the thermal code can turn off the switch of the static current consumption sub-module, the power consumption of the resistance control module is reduced, and the first-order compensation reference voltage is compensated based on the temperature-related segmented resistance, thereby improving the temperature drift of the target reference voltage.

[0112] Fig.13 A simulation diagram of compensating a first-order compensation reference voltage according to an embodiment of the present disclosure is schematically shown.

[0113] like Fig.13 As shown, without first-order compensation reference voltage V REF1 Before compensation, the first-order compensation reference voltage V REF1 Parabolic shape, first-order compensation reference voltage V REF1 The voltage variation range is 2.495~2.052. For the first-order compensation reference voltage V REF1 After compensation, the target reference voltage V can be obtained. REF , target reference voltage V REF The voltage variation range is 2.501~2.052, so the temperature coefficient is reduced from 16ppm / ℃ to 3ppm / ℃.

[0114] According to the embodiments of the present disclosure, compared with the bandgap reference circuit in the related art, the temperature drift performance is improved by using segmented resistors that change in a segmented manner with temperature to realize the temperature compensation of the first-order compensation reference voltage output by the bandgap reference circuit, thereby improving the V BE The nonlinearity of the bandgap reference circuit causes large output temperature drift. At the same time, the current consumed by the bandgap reference circuit is small, which has an energy consumption advantage.

[0115] The flow charts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flow chart or block diagram can represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0116] It will be appreciated by those skilled in the art that the features described in the various embodiments of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations or combinations are not explicitly described in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features described in the various embodiments of the present disclosure may be combined and / or combined in a variety of ways. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0117] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A bandgap reference circuit, characterized in that: include: A bandgap reference core module for generating a first-order compensation reference voltage; A resistance control module, the resistance control module is electrically connected to the bandgap reference core module, and is used to determine a segmented resistance corresponding to at least one temperature segment interval, and compensate the first-order compensation reference voltage based on the segmented resistance value to obtain a target reference voltage, wherein the at least one temperature segment interval is obtained by dividing the operating temperature range of the bandgap reference circuit.

2. The circuit according to claim 1, characterized in that The bandgap reference core module is also used to generate a first bias voltage and a second bias voltage; the resistance control module includes a temperature-sensitive voltage generating submodule, which is used to generate an absolute voltage proportional to the absolute temperature based on the first bias voltage as a temperature-sensitive voltage, and to generate a quantized reference voltage based on the first bias voltage and the second bias voltage.

3. The circuit according to claim 2, characterized in that The resistance control module further includes an analog-to-digital converter, which is used to receive the absolute voltage and the quantized reference voltage, and quantize the absolute voltage based on the quantized reference voltage to obtain a binary code that is positively correlated with the temperature.

4. The circuit according to claim 1, characterized in that The resistance control module further includes a memory, wherein the memory is used to receive the binary code and store the binary code based on an enable signal, wherein the enable signal represents turning on or off a storage function of the memory.

5. The circuit according to claim 1, characterized in that The resistance control module further includes a thermal decoder, which is used to convert the binary code stored in the memory into a thermal code.

6. The circuit according to claim 5, characterized in that The hot decoder is used to convert the binary code stored in the memory into a hot code by the following operations: In the conversion cycle, the switch of the static current consumption submodule of the resistance control module is turned on, and the thermal decoder converts the binary code into a thermal code; In the sleep cycle, the switch of the static current consumption submodule of the resistance control module is turned off to maintain the hot code.

7. The circuit according to claim 5, characterized in that The resistance control module further includes a segmented resistance submodule, and the segmented resistance submodule is used to receive the thermal code and control the segmented resistance value corresponding to at least one temperature segment interval based on the thermal code.

8. The circuit according to claim 7, characterized in that The segmented resistance submodule includes at least one first switch and at least one second switch, and controls the segmented resistance corresponding to at least one temperature segment interval according to the thermal code, including: Determining the states of the at least one first switch and the at least one switch according to the thermal code, wherein the first switch and the second switch correspond to different temperature segment intervals respectively; According to the states of the at least one first switch and the at least one switch, a segmented resistance value corresponding to the at least one temperature segment interval is determined.

9. A voltage compensation method for a bandgap reference circuit, characterized in that: The method comprises: Obtaining a first-order compensation reference voltage; Determine a segmented resistance value corresponding to at least one temperature segmented interval, and compensate the first-order compensation reference voltage based on the segmented resistance value to obtain a target reference voltage, wherein the at least one temperature segmented interval is obtained by dividing the operating temperature range of the bandgap reference circuit.

10. The method according to claim 9, characterized in that The determining of the segmented resistance corresponding to at least one temperature segment interval, and compensating the first-order compensation reference voltage based on the segmented resistance to obtain the target reference voltage comprises: Obtaining a first bias voltage and a second bias voltage; generating an absolute voltage proportional to absolute temperature and a quantized reference voltage according to at least one of the first bias voltage and the second bias voltage; quantizing the absolute voltage based on the quantized reference voltage to generate a binary code that is positively correlated with temperature; Convert the binary code to generate hot code; Determining the segmented resistance values ​​of the segmented resistors according to the thermal code; The first-order compensation reference voltage is compensated according to the segmented resistance values ​​of the segmented resistors to obtain a target reference voltage.

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