A reference voltage generation circuit, an integrated circuit chip, and an electronic device
By combining bias modules, comparison modules, current source modules, temperature compensation modules, and voltage divider modules, the problems of compensation failure and high power consumption in extremely low temperature environments are solved, achieving high precision and microwatt-level low power consumption of the reference voltage source in a wide temperature range, which is suitable for quantum computing and deep space exploration.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTHERN UNIVERSITY OF SCIENCE AND TECHNOLOGY
- Filing Date
- 2026-01-22
- Publication Date
- 2026-06-05
AI Technical Summary
Existing technologies fail to compensate for nonlinear mutations in extremely low-temperature environments, making it impossible to achieve ultra-low power consumption at the microwatt level while maintaining ZTC accuracy.
It adopts a combination structure of bias module, comparator module, current source module, temperature compensation module, voltage divider module and reference transistor. Through the complementary temperature coefficient resistor unit and impedance element, it realizes closed-loop control of reference voltage, decouples the drain-source voltage and gate-source voltage of control reference transistor, uses voltage divider module to reduce drain-source voltage, and combines compensation module to balance AC impedance, so as to achieve high accuracy and low power consumption in a wide temperature range.
Maintaining stable circuit output over a wide temperature range of 4K to 300K, with static power consumption reduced to the microwatt level, ensures the output accuracy and low power consumption of the reference voltage source in extreme environments, making it suitable for quantum computing and deep space exploration.
Smart Images
Figure CN122152064A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of integrated circuit technology, and in particular to a reference voltage generating circuit, an integrated circuit chip, and an electronic device. Background Technology
[0002] A reference voltage source is a core module in analog and mixed-signal systems, widely used in data converters, power management chips, and sensor interface circuits. It provides the system with a stable reference voltage independent of power supply voltage, process fluctuations, and temperature changes. Especially in extreme environments such as quantum computing, deep space exploration, and cryogenic physics experiments, circuit systems typically need to operate normally over an ultra-wide temperature range from liquid helium (approximately 4K) to room temperature (approximately 300K), and have even stricter limitations on static power consumption, usually requiring it to be in the microwatt range.
[0003] In existing technologies, to achieve a low temperature coefficient output over a wide temperature range, a bandgap or bandgap-like reference circuit architecture based on high-order resistor compensation is typically employed. For example, an operational amplifier circuit locks the terminal voltage of a ZTC-MOS (zero-temperature coefficient field-effect transistor), and a regulating resistor network composed of positive and negative temperature coefficient resistors is used for high-order compensation with the ZTC-MOS. Furthermore, this technology also employs a resistor-switching array tuning circuit, which uses digital control to adjust the resistor values to reduce the impact of process, voltage, and temperature (PVT) fluctuations on the output voltage, thereby achieving a low temperature coefficient over a temperature range of -65°C to 225°C.
[0004] However, the aforementioned existing technologies still have the following significant drawbacks when targeting ultra-wide temperature ranges from 4K to 300K and ultra-low power applications: The resistor compensation networks of the existing technologies are designed based on the device physical model at normal temperatures. When the ambient temperature drops below 20K, the silicon-based semiconductor material will experience a carrier freezing effect, causing a drastic nonlinear change in the threshold voltage and mobility of the MOSFET. This results in severe drift of the ZTC operating point in the circuit at the extremely low temperature of 4K, leading to the failure of output voltage stability. At the same time, in order to maintain the linearity of the operational amplifier circuit, the drain-source voltage Vds of the ZTC device in the existing technologies is usually clamped at a high level and has a strong coupling relationship with the gate-source voltage Vgs. This structure cannot independently reduce Vds to the edge of the saturation region while maintaining the gate-source voltage Vgs, resulting in unnecessary redundant power consumption in the circuit, making it difficult to meet the ultra-low power consumption index of microwatts in quantum computing scenarios.
[0005] Therefore, this application aims to solve the problem of compensation failure caused by nonlinear mutation in the prior art under extremely low temperature environment, and at the same time solve the technical problem that the circuit cannot achieve microwatt-level ultra-low power operation while maintaining ZTC accuracy. Summary of the Invention
[0006] The main purpose of this application is to provide a reference voltage generation circuit, integrated circuit chip and electronic device, which aims to solve the problem of compensation failure caused by nonlinear mutation in the existing technology under extremely low temperature environment, and at the same time solve the technical problem that the circuit cannot achieve microwatt-level ultra-low power operation while maintaining ZTC accuracy.
[0007] To achieve the above objectives, this application proposes a reference voltage generating circuit, comprising: The bias module is used to provide bias voltage; A comparison module, electrically connected to the bias module, is used to obtain the bias voltage, compare the voltage difference between its two input terminals, and output a control signal. A current source module is electrically connected to the output terminal of the comparison module. The current source module is controlled by the control signal and provides current to the first branch and the second branch, respectively. A temperature compensation module is connected in series on the first branch, and its first feedback node is electrically connected to the first input terminal of the comparison module. The temperature compensation module has a complementary temperature coefficient. A voltage divider module is connected in series on the second branch, and its second feedback node is electrically connected to the second input terminal of the comparator module. The voltage divider module has a reference voltage output. A reference transistor is connected in series in the second branch, its control terminal is connected to the voltage divider node of the voltage divider module, and its first current terminal is connected to the current source module through the voltage divider module.
[0008] Furthermore, the temperature compensation module includes: The first resistor unit has one end electrically connected to the current source module and also electrically connected to the first input terminal of the comparison module; The second resistor unit has one end electrically connected to the first resistor unit and the other end grounded. The first resistor unit has a positive temperature coefficient, and the second resistor unit has a negative temperature coefficient; The first resistor unit and the second resistor unit generate reference voltages at the first feedback node and the second feedback node, respectively. The reference voltages are used to compensate for the voltage temperature drift at the control terminal of the reference transistor.
[0009] Furthermore, the first resistor unit is an N-well diffusion resistor, and the second resistor unit is a P-type polysilicon resistor.
[0010] Furthermore, the voltage divider module includes: The first impedance element has one end electrically connected to the current source module and another end electrically connected to the second input terminal of the comparator module to form the voltage divider node. The second impedance element has one end electrically connected to the first impedance element and the other end electrically connected to the first current terminal of the reference transistor. The reference voltage is led out between the first impedance element and the second impedance element; The control terminal of the reference transistor is connected to the voltage divider node, so that the voltage at the first current terminal of the reference transistor is lower than the voltage at its control terminal.
[0011] Furthermore, the first impedance element is an adjustable resistor, which is used to adjust the voltage difference between the voltage divider node and the first current terminal of the reference transistor, so as to compress the voltage of the first current terminal of the reference transistor to a predetermined threshold.
[0012] Furthermore, it also includes: The first compensation module has one end electrically connected to the first input terminal of the comparison module and the other end grounded. The second compensation module has one end electrically connected to the second input terminal of the comparison module, and the other end grounded. The first compensation module and the second compensation module are respectively used to balance the AC impedance of the first input terminal and the second input terminal of the comparison module.
[0013] Furthermore, the first compensation module includes a compensation resistor and a compensation capacitor. The second compensation module has the same components as the first compensation module; One end of the compensation resistor is electrically connected to the input terminal of the comparator module, and the other end of the compensation resistor is electrically connected to one end of the compensation capacitor. The other end of the compensation capacitor is grounded.
[0014] Furthermore, the current source module includes a first transistor and a second transistor; the source of the first transistor and the source of the second transistor are connected to the power supply voltage, and the gates of the first transistor and the second transistor share a common connection point with the output terminal of the comparison module to form a controlled current mirror. The drain of the first transistor is connected to the first branch. The drain of the second transistor is connected to the second branch.
[0015] This application also discloses an integrated circuit chip, including the aforementioned reference voltage generating circuit.
[0016] This application also discloses an electronic device, including the aforementioned integrated circuit chip, wherein the electronic device is a quantum computer control device, a deep space probe, or a low-temperature physics experimental instrument.
[0017] The above technical solution has the following advantages: This application uses a closed-loop system consisting of a current source, a first branch, a second branch, and a comparator module. The control terminal of the reference transistor is connected to the voltage divider node of the voltage divider module, while its first current terminal is connected to the low-potential terminal of the voltage divider module. By utilizing the voltage drop across the resistor in the voltage divider module, the voltage V at the first current terminal is achieved. ds_ZTC With control terminal voltage V gs_ZTC The decoupling control effectively solves the problem that existing technologies are forced to clamp Vds at a high level in order to maintain the ZTC (zero temperature coefficient) operating point, enabling the circuit to maintain stable output over a wide temperature range of 4K to 300K while reducing static power consumption to the microwatt level.
[0018] This application employs a temperature compensation module with complementary temperature coefficients in the first branch. Specifically, it uses an N-well diffusion resistor with a positive temperature coefficient and a P-type polysilicon resistor with a negative temperature coefficient in series to synthesize a specific temperature and voltage curve at the feedback node. This curve can accurately compensate for the threshold voltage drift and mobility nonlinear change caused by the carrier freezing effect in the reference transistor under extremely low temperature conditions, ensuring the output accuracy of the reference voltage source in the range from liquid helium temperature to room temperature, making it suitable for extreme environments such as quantum computing and deep space exploration. Attached Figure Description
[0019] The present application will now be described in detail with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is a schematic diagram of the structure of a traditional bandgap voltage. Figure 2 This is a structural block diagram of this application; Figure 3 This is the circuit schematic diagram of this application; Figure 4 This is a graph of the temperature compensation module in this application; Figure 5 This is the fitting curve of the threshold voltage measured under the TSMC 180nm process in this application; Figure 6 This is a fitting curve of the mobility measured under the TSMC 180nm process in this application; Figure 7 This is a comparison chart of ZTC point distribution and TC with and without the temperature compensation module in this application.
[0020] In the diagram: 100, bias module; 200, comparator module; 300, current source module; 400, temperature compensation module; 500, voltage divider module; 600, reference transistor; 700, first compensation module; 800, second compensation module. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the following specific embodiments are merely illustrative of this application and do not constitute a limitation thereof.
[0022] In the field of integrated circuit design, especially in applications such as quantum computing and deep space exploration, the operating temperature required for quantum computing is approximately 4K, while the operating temperature range required for deep space exploration is much wider. The stability and power consumption of reference voltage sources at 4K and with such a wide operating temperature range are still insufficient to meet the requirements. Existing bandgap reference circuits perform well at room temperature, but when the ambient temperature drops below 20K, silicon-based semiconductor materials experience carrier freezing, leading to a sharp increase in the threshold voltage (Vth) of MOS transistors, along with a nonlinear abrupt change in mobility.
[0023] like Figure 1 As shown, the core idea behind traditional bandgap voltage is to use two voltages with opposite temperature coefficients, add them in a certain proportion, and ultimately achieve a zero temperature coefficient for the output voltage; specifically, Figure 1 The voltage reference is designed using a bipolar junction transistor (BJT), with the base-emitter voltage V0. BE2 (and V) BE1 It has a negative temperature coefficient (CTAT), while the two ΔV values under different bias conditions BE (i.e. V) BE1 V BE2 It has a positive temperature coefficient (PTAT), and the final reference voltage V ref The formula is: ; Here, α is an adjustment factor, the value of which is chosen to minimize the temperature coefficient deviation between the PTAT and CTAT parts. However, at ultra-low temperatures, due to carrier freezing, V... BE The drastic change in characteristics leads to a significant increase in the output voltage's temperature coefficient (TC). To maintain the normal operation of the operational amplifier in the circuit, existing technologies typically require clamping the drain-source voltage (Vds) of the reference device at a higher level. However, a higher Vds design prevents the static power consumption from being reduced to the microwatt (μW) level. Furthermore, the gate-source voltage Vgs exhibits a strong coupling relationship, making it difficult to lower Vds without changing Vgs. This results in unnecessary redundant power consumption in the circuit, making it difficult to meet the ultra-low power consumption requirements at the microwatt level in quantum computing scenarios.
[0024] Therefore, this application does not use the bandgap principle, but instead uses the ZTC (zero temperature coefficient point) principle to design a reference voltage source.
[0025] Based on this, this embodiment provides a reference voltage generation circuit suitable for extremely low temperature environments, specifically as follows: Figures 2 to 3 As shown, the system includes a bias module 100, a comparator module 200, a current source module 300, a temperature compensation module 400, a voltage divider module 500, and a reference transistor 600. The bias module 100 provides a bias voltage. The comparator module 200 is electrically connected to the bias module 100 to obtain the bias voltage, compares the voltage difference between its two input terminals, and outputs a control signal. The current source module 300 is electrically connected to the output terminal of the comparator module 200 and is controlled by the control signal to provide current to the first branch and the second branch, respectively. A temperature compensation module 400 is connected in series on the first branch, and its first feedback node is electrically connected to the first input terminal of the comparator module 200. The temperature compensation module 400 has a complementary temperature coefficient. A voltage divider module 500 is connected in series on the second branch, and its second feedback node is electrically connected to the second input terminal of the comparator module 200. The voltage divider module 500 has a reference voltage. A reference transistor 600 is connected in series on the second branch, and its control terminal is connected to the voltage divider node of the voltage divider module 500. Its first current terminal is connected to the current source module 300 through the voltage divider module 500.
[0026] Specifically, the bias module 100 mainly consists of a startup circuit and a self-biasing core unit. Upon power-up, the bias module 100 generates an initial voltage to supply to the comparator module 200, preventing the circuit from locking into a zero-current state. During normal operation, the bias module 100 provides a stable bias voltage to the tail current source of the comparator module 200. Figure 3 The V shown bias .
[0027] The comparator module 200 is preferably an operational amplifier (Op-Amp) or an operational transconductance amplifier (OTA). Its non-inverting input serves as the first input, connected to the first feedback node of the first branch, and its inverting input serves as the second input, connected to the second feedback node of the second branch. By comparing the voltage difference between the first and second inputs, the comparator module 200 outputs an analog control signal to adjust the conduction level of the current source module 300, thereby achieving negative feedback regulation of the first and second branches.
[0028] The current source module 300 serves as the system's energy supply terminal. Controlled by the analog control signal output by the comparator module 200, it converts the power supply voltage VDD into two currents, applied to the first and second branches respectively. The first branch includes a temperature compensation module 400. Due to the complementary temperature coefficient of the temperature compensation module 400, the voltage at the first feedback node exhibits a preset temperature characteristic, serving as the target voltage. The second branch includes a voltage divider module 500 and a reference transistor 600. The comparator module 200 utilizes the virtual short principle to force the voltage at the second feedback node to equal the voltage at the first feedback node.
[0029] Furthermore, the voltage divider module 500 is located between the current source and the reference transistor 600. The control terminal of the reference transistor 600 is connected to the voltage divider node of the voltage divider module 500, while its first current terminal is connected to the lower end of the voltage divider module 500. This means that the potential of the control terminal of the reference transistor 600 is controlled by closed-loop feedback, while the potential of the first current terminal is the control terminal potential minus the voltage drop of the voltage divider module 500. This avoids the limitation of gate-drain short-circuiting in conventional diode connections and achieves independent regulation of the drain-source voltage.
[0030] like Figure 2 and Figure 3 As shown, the temperature compensation module 400 includes a first resistor unit and a second resistor unit. One end of the first resistor unit is electrically connected to the current source module 300 and also electrically connected to the first input terminal of the comparator module 200. One end of the second resistor unit is electrically connected to the first resistor unit, and the other end is grounded. The first resistor unit has a positive temperature coefficient, and the second resistor unit has a negative temperature coefficient. The first resistor unit and the second resistor unit generate reference voltages at the first feedback node and the second feedback node, respectively. The reference voltages are used to compensate for the voltage temperature drift at the control terminal of the reference transistor 600.
[0031] Specifically, such as Figure 3 As shown, the first resistor unit R1_P is located above, and its top end is electrically connected to the first branch of the current source module 300 and to the first input terminal of the comparator module 200; the second resistor unit R1_C is located below the first resistor unit R1_P, and its end away from the first resistor unit R1_P is grounded.
[0032] The first resistor unit R1_P has a positive temperature coefficient (PTAT), meaning its resistance increases with increasing temperature; the second resistor unit R1_C has a negative temperature coefficient (CTAT), meaning its resistance decreases with increasing temperature. In the actual compensation process, the current flowing through the first branch generates a voltage drop across the first resistor unit R1_P and the second resistor unit R1_C. By adjusting the resistance ratio of the first resistor unit R1_P and the second resistor unit R1_C, a voltage-temperature curve with a specific slope can be synthesized at the first feedback node. This curve matches the gate-source voltage temperature drift characteristics of the reference transistor 600 near the ZTC (zero temperature coefficient) point. For example, when the ambient temperature drops below 20K, due to the carrier freezing effect, the control terminal voltage required for the reference transistor 600 to maintain zero temperature coefficient (ZTC) current increases non-linearly. The temperature compensation module 400 uses the non-linear combination of the first resistor unit R1_P and the second resistor unit R1_C with positive and negative temperature coefficients to make the reference voltage generated by the first feedback node rise synchronously at low temperature, thereby automatically meeting the bias requirements of the reference transistor 600 in closed-loop control and offsetting the output deviation of the reference transistor 600.
[0033] This embodiment also establishes a device empirical model applicable to the entire temperature range from 4K to 300K based on the BSIM model framework.
[0034] Existing technologies typically lack accurate models for extremely low temperatures. At extremely low temperatures (e.g., below 20K), the threshold voltage (Vth) and mobility of the reference transistor 600 no longer follow a linear or power-law relationship as at room temperature. Therefore, this application first extracts Vth and mobility data of TSMC's 180nm process at key temperature points through simulation, and then models the threshold voltage using a piecewise function, specifically as follows: Figure 5 and Figure 6 As shown, Figure 5 The horizontal axis represents temperature (temp), and the vertical axis represents the threshold voltage Vth (represented by double y_high and double y_low in the piecewise function). Figure 5 The black squares in the figure represent simulation data points, and the lines represent the fitting curves calculated by the piecewise function model proposed in this application. As can be seen from the figure, when the temperature is 40K to 50K above the critical temperature, Vth decreases linearly with increasing temperature; when the temperature is below the critical temperature, i.e., entering the carrier freezing region, Vth shows a nonlinear and sharp increase. The piecewise function model is as follows: ; Where a and b are constants independent of temperature, and b is related to the Debye temperature, with the value of b being approximately 1 to 2.5 times the Debye temperature; k1 and k2 are the slopes of the threshold voltage with respect to temperature, respectively; and C and D are used to correct the continuity of the piecewise function. A critical temperature T_CRITICAL is set. When the temperature is higher than this critical value, a linear decreasing model is adopted, as can be seen from the piecewise function model above.
[0035] Based on the simplified wide-temperature-range model described above, this application derives the optimal resistance ratio between the first and second resistor units in the temperature compensation module 400. This ensures that the first and second derivatives of the voltage and temperature curves generated by the first resistor unit R1_P and the second resistor unit R1_C match the control terminal voltage characteristic curve of the reference transistor 600 within the target temperature range, thereby theoretically eliminating the main temperature drift component. Figure 6 and Figure 7 As shown, the simplified model has a very high degree of fit with the measured data across the entire temperature range, ensuring the circuit's startup success rate and steady-state accuracy at an extremely low temperature of 4K.
[0036] The first resistive unit is an N-well diffused resistor, and the second resistive unit is a P-type polysilicon resistor. This embodiment uses standard CMOS technology to implement the above resistive units without the need for a special mask. The N-well diffused resistor utilizes the bulk resistance characteristics of the N-type well region; its mobility decreases with increasing temperature, leading to an increase in resistivity and exhibiting a significant positive temperature coefficient (PTAT). The P-type polysilicon resistor (High-Res P-Poly Resistor), at a specific doping concentration, exhibits a negative temperature coefficient (CTAT) or a low temperature coefficient close to zero at the polysilicon grain boundaries due to the change in barrier height with temperature.
[0037] This embodiment utilizes an N-well resistor to compensate for mobility degradation in the high-temperature range and a P-type polysilicon resistor to compensate for carrier freezing effects in the low-temperature range.
[0038] like Figure 4 As shown, both the temperature compensation module 400 and the voltage divider module 500 of this application employ a 4-bit resistor trimming circuit. Specifically, the resistor unit consists of a fixed resistor connected in series with a 4-bit binary weighted resistor array. Each resistor sub-unit in the resistor array is connected in parallel with an NMOS switch. The switch can be opened and closed by an externally input 4-bit digital control code, thereby finely adjusting the ratio of R1_P to R1_C, and also adjusting the resistance value of the voltage divider module 500. This not only calibrates the output voltage accuracy at room temperature but also allows for trimming of the ZTC point drift at extremely low temperatures during the testing phase, ensuring that the operating points of the control terminal and the first current terminal of the reference transistor 600 can be adjusted in a 4K environment to achieve the optimal temperature coefficient (TC).
[0039] in, Figure 4 The right side shows the connection network between the first resistor unit R1_P and the second resistor unit R1_C. Figure 4The left side is a graph, with the horizontal axis representing temperature in Kelvin (K) and the vertical axis representing the change in resistance value relative to a reference value at 27 degrees Celsius. Figure 4 A 4-bit resistor trimming circuit was used, and the temperature coefficients of two complementary temperature coefficient resistors, N-well Under STI (R1_P) and P-Poly HRI (R1_C), were demonstrated. The dotted line in the attached figure can be used as a dividing line. The temperature coefficients of the resistors below 230K were fitted based on data from existing literature, while those above 230K were derived from simulation models. At an ambient temperature of 300K, the resistance values of the first resistor unit R1_P and the second resistor unit R1_C changed proportionally relative to the reference value.
[0040] like Figure 2 and Figure 7 As shown, Figure 7 The image shows a detailed comparison of the temperature compensation module 400. The left image (a) shows the position of the Vgs_ZTC point when operating at different temperatures. The comparison shows that after introducing the temperature compensation module 400, the concentration of the ZTC point is improved, and it is concentrated in the inner dotted coil. Without the temperature compensation module 400, the ZTC point is more dispersed, and some of it is separated from the inner dotted coil. The right image (b) shows the percentage change of the TC of the output voltage Vref before and after introducing the temperature compensation module 400. The TC is optimized from 1214 ppm / ℃ to 110 ppm / ℃, thus showing the temperature coefficient stability under different ambient temperatures from 4K to 300K after introducing the temperature compensation module 400.
[0041] like Figure 2 and Figure 3 As shown, the voltage divider module 500 includes a first impedance element and a second impedance element. One end of the first impedance element is electrically connected to the current source module 300 and also electrically connected to the second input terminal of the comparator module 200 to form a voltage divider node. One end of the second impedance element is electrically connected to the first impedance element, and the other end is electrically connected to the first current terminal of the reference transistor 600. A reference voltage is led out between the first impedance element and the second impedance element. The control terminal of the reference transistor 600 is connected to the voltage divider node, so that the voltage at the first current terminal of the reference transistor 600 is lower than the voltage at its control terminal.
[0042] The first impedance element is preferably... Figure 3 The resistor R in 2a resistance R 2a The upper end is connected to a current source, and the lower end is connected to a second impedance element; the second impedance element is preferably... Figure 3 The resistor R in 2b The control terminal of the reference transistor 600 is connected to resistor R. 2a At the upper end, i.e., the voltage divider node, the first current terminal of the reference transistor 600 is connected to resistor R.2b At the lower end, the reference voltage is drawn from resistor R. 2a and resistance R 2b The reference transistor 600's second current terminal is grounded, as shown below. Figure 3 It can be seen that the first current terminal of the reference transistor 600 is the drain, the second current terminal is the source, and the voltage V at the first current terminal is... ds_ZTC This is the drain-source voltage.
[0043] The current flowing through the second branch is I. d_ZTC The control terminal voltage V of the reference transistor 600 gs_ZTC Equal to the voltage of the second feedback node, and the voltage V at the first current terminal of the reference transistor 600. ds_ZTC The voltage drop of the voltage divider module 500 is subtracted from the voltage of the second feedback node by the following formula: ; Due to resistance R 2b The presence of this ensures that the reference transistor 600 always operates at V. gs_ZTC Greater than V ds_ZTC In this embodiment, compared to the traditional diode connection method, when the gate-drain voltages are equal, V can be... ds_ZTC The voltage is reduced to the edge of the saturation region or even the subthreshold linear region of the reference transistor 600, thereby maintaining V. gs_ZTC With only the temperature compensation module 400, the voltage loss and static power consumption on the second branch are significantly reduced.
[0044] Furthermore, the first impedance element is an adjustable resistor, which is used to adjust the voltage difference between the voltage divider node and the first current terminal of the reference transistor 600, so as to compress the voltage of the first current terminal of the reference transistor 600 to a predetermined threshold.
[0045] The first impedance element is designed as a variable resistor array, consisting of several binary-weighted resistor units and parallel-connected switching MOSFETs. Adjusting the resistance of the first impedance element changes the total impedance between the voltage divider node and the first current terminal of the reference transistor 600. Under closed-loop control, the potential of the voltage divider node is clamped to the reference potential by the comparator module 200; therefore, adjusting the resistance of the first impedance element actually changes the potential of the first current terminal. In this embodiment, the first current terminal of the reference transistor 600 is compressed to a predetermined threshold range, which is slightly higher than the saturation voltage drop of the reference transistor 600. This ensures that the reference transistor 600 operates in the saturation region to maintain high output impedance while avoiding excessive power consumption due to excessively high voltage at the first current terminal of the reference transistor 600. Through precise adjustment of the first impedance element, the circuit power consumption is controlled at the microwatt level, such as below 3μW, while maintaining the ZTC point.
[0046] Due to resistance R2b The presence of this ensures that the reference transistor 600 always operates at V. gs_ZTC Greater than V ds_ZTC The state of the reference transistor 600. It should be noted that the zero temperature coefficient (ZTC) current point is not fixed, but rather varies with the drain-source voltage V. ds_ZTC There is a correlation. Experimental and simulation data show that as V... ds_ZTC The reduction in voltage, especially when lowered to the edge of the saturation region, significantly reduces the operating current of the reference transistor 600 to maintain its zero temperature coefficient characteristic. Therefore, this application uses a voltage divider module 500 to divide the voltage V at the first current terminal of the reference transistor 600. ds_ZTC Independent compression to a predetermined threshold, such as slightly above the saturation voltage drop, forces the ZTC operating point of the reference transistor 600 to shift along its characteristic curve towards the low-current region. This allows the circuit to operate without changing the gate-source voltage V. gs_ZTC Under the premise of ensuring that the ZTC state can be maintained with a quiescent current at the microwatt level, the problem of the traditional reference transistor 600 V-voltage is effectively solved. ds_ZTC The technical challenge of high clamping pressure preventing power consumption reduction.
[0047] like Figure 3 As shown, this application also includes a first compensation module 700 and a second compensation module 800. One end of the first compensation module 700 is electrically connected to the first input terminal of the comparison module 200, and the other end is grounded. One end of the second compensation module 800 is electrically connected to the second input terminal of the comparison module 200, and the other end is grounded. The first compensation module 700 and the second compensation module 800 are respectively used to balance the AC impedance of the first input terminal and the second input terminal of the comparison module 200.
[0048] Since the first branch is a purely resistive network, while the second branch includes a reference transistor 600, the difference in their AC output impedances causes power supply noise to generate different coupling voltages in the first and second branches, reducing the power supply rejection ratio (PSRR). Therefore, this application addresses this by adding compensation modules to ground at the two input terminals of the comparator module 200, thereby controlling the high-frequency impedance of the two input nodes. The parameters of the first compensation module 700 and the second compensation module 800 are preferably designed to be identical or matched, so that at high frequencies, the ground impedance of the two input terminals is primarily determined by the compensation modules, thus tending to be consistent. In this way, power supply noise will appear as a common-mode signal and be filtered out by the first compensation module 700 and the second compensation module 800.
[0049] The first compensation module 700 includes a compensation resistor and a compensation capacitor. The second compensation module 800 has the same components as the first compensation module 700. One end of the compensation resistor is electrically connected to the input terminal of the comparator module 200, and the other end of the compensation resistor is electrically connected to one end of the compensation capacitor. The other end of the compensation capacitor is grounded.
[0050] The compensation module specifically adopts a series connection of resistor Rc and capacitor Cc. In the first compensation module 700, it uses compensation resistor Rc+ and compensation capacitor Cc+, and in the second compensation module 800, it uses compensation resistor Rc- and compensation capacitor Cc-. In the DC and low frequency range, the impedance of capacitor Cc is infinite, and the compensation module is open-circuited, which does not affect the DC bias accuracy. In the high frequency range, the impedance of capacitor Cc decreases.
[0051] like Figure 3 As shown, the current source module 300 includes a first transistor and a second transistor; the source of the first transistor and the source of the second transistor are connected to the power supply voltage, and the gates of the first transistor and the second transistor are connected to the output terminal of the comparator module 200 to form a controlled current mirror; the drain of the first transistor is connected to the first branch, and the drain of the second transistor is connected to the second branch.
[0052] In the current source module 300, a PMOS transistor is used as the current source. Specifically, the sources of transistors P9 and P10 are connected to VDD, and the drains of transistors P9 and P10 are electrically connected to the first branch and the second branch, respectively. Transistors P9 and P10 together form a current mirror. The current ratio flowing through the first branch and the second branch can be set by adjusting the width-to-length ratio (W / L) of transistors P9 and P10, for example, 1:1 or 1:N. The output voltage of the comparator module 200 is compared with the gates of transistors P9 and P10, thereby dynamically controlling the output current of the current mirror until the feedback loop is balanced.
[0053] like Figure 3 As shown, the reference transistor 600 of this application is preferably an NMOS transistor, such as... Figure 3 The Nx transistor has its gate as the control terminal, used to connect to the voltage divider node, and its first current terminal as the drain, used to connect to the resistor R. 2b Its second current terminal is the source, used for grounding, and the final gate voltage depends on R. 2a and R 2b The resistance value, and the drain voltage depends on R. 2a and R 2b The voltage drop helps to adjust the drain voltage, which can reduce static power consumption to the microwatt level. In addition, Nx transistors can also be used in the form of multiple NMOS transistors connected in series, that is, the source and drain of adjacent NMOS transistors are connected together, and the gates are connected together on the voltage divider node.
[0054] like Figure 3 As shown, the bias module 100 of this application uses a current mirror composed of PMOS transistors (P5 and P6). The drain and gate of P5 are connected, and the drain is also connected to N1 and resistor R in sequence. B Through resistor R B And N1 to generate bias voltage Vbias .
[0055] This application discloses an integrated circuit chip, including the aforementioned reference voltage generation circuit.
[0056] The integrated circuit chip in this embodiment is manufactured using standard CMOS technology, such as 0.18μm or 40nm. The reference voltage generation circuit is integrated into the analog power supply module of the chip. The chip also integrates auxiliary circuits required for the bandgap reference, such as trimming logic and test interface.
[0057] This application discloses an electronic device, including the aforementioned integrated circuit chip, which is a quantum computer control device, a deep space probe, or a low-temperature physics experimental instrument.
[0058] In quantum computer control devices, the electronic device operates within a dilution refrigerator at an ambient temperature close to 4K. The chip in this application is used to provide a low-noise reference voltage for the quantum bit readout circuit. In deep space probe devices, the device needs to withstand temperature changes from room temperature at launch to extremely low temperatures in outer space, such as below -200°C. This ensures that the electronic device does not power-on and reset across the entire temperature range, and the low-power characteristics extend battery life.
[0059] This embodiment is a supplement to the above embodiments. Although the above embodiments describe an NMOS transistor as the reference transistor 600, in this embodiment, the reference transistor 600 can also be replaced by a depletion-mode MOS transistor or a junction field-effect transistor (JFET). These devices have better noise performance under certain processes. As long as its control terminal is connected to the voltage divider node and the source is grounded, the voltage difference generated by the voltage divider to reduce the drain-source voltage falls within the protection scope of this application.
[0060] In this embodiment, a closed-loop system consisting of a current source, a first branch, a second branch, and a comparison module 200 connects the control terminal of the reference transistor 600 to the voltage divider node of the voltage divider module 500, thereby realizing the first current terminal voltage V. ds_ZTC With control terminal voltage V gs_ZTC Decoupling control. Not only does it utilize complementary first resistor unit R1_P and second resistor unit R1_C to achieve wide-temperature compensation, but it also forcibly reduces the voltage V at the first current terminal. ds_ZTC This solves the problem of achieving high precision and low power consumption at the microwatt level in extremely low temperature environments.
[0061] The above description is merely a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the inventive concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.
Claims
1. A reference voltage generating circuit, characterized in that, include: The bias module is used to provide bias voltage; A comparison module, electrically connected to the bias module, is used to obtain the bias voltage, compare the voltage difference between its two input terminals, and output a control signal. A current source module is electrically connected to the output terminal of the comparison module. The current source module is controlled by the control signal and provides current to the first branch and the second branch, respectively. A temperature compensation module is connected in series on the first branch, and its first feedback node is electrically connected to the first input terminal of the comparison module. The temperature compensation module has a complementary temperature coefficient. A voltage divider module is connected in series on the second branch, and its second feedback node is electrically connected to the second input terminal of the comparator module. The voltage divider module has a reference voltage output. A reference transistor is connected in series in the second branch, its control terminal is connected to the voltage divider node of the voltage divider module, and its first current terminal is connected to the current source module through the voltage divider module.
2. The reference voltage generating circuit as described in claim 1, characterized in that, The temperature compensation module includes: The first resistor unit has one end electrically connected to the current source module and also electrically connected to the first input terminal of the comparison module; The second resistor unit has one end electrically connected to the first resistor unit and the other end grounded. The first resistor unit has a positive temperature coefficient, and the second resistor unit has a negative temperature coefficient; The first resistor unit and the second resistor unit generate reference voltages at the first feedback node and the second feedback node, respectively. The reference voltages are used to compensate for the voltage temperature drift at the control terminal of the reference transistor.
3. The reference voltage generating circuit as described in claim 2, characterized in that, The first resistor unit is an N-well diffusion resistor, and the second resistor unit is a P-type polysilicon resistor.
4. The reference voltage generating circuit as described in claim 1, characterized in that, The voltage divider module includes: The first impedance element has one end electrically connected to the current source module and another end electrically connected to the second input terminal of the comparator module to form the voltage divider node. The second impedance element has one end electrically connected to the first impedance element and the other end electrically connected to the first current terminal of the reference transistor. The reference voltage is led out between the first impedance element and the second impedance element; The control terminal of the reference transistor is connected to the voltage divider node, so that the voltage at the first current terminal of the reference transistor is lower than the voltage at its control terminal.
5. The reference voltage generating circuit as described in claim 4, characterized in that, The first impedance element is an adjustable resistor, which is used to adjust the voltage difference between the voltage divider node and the first current terminal of the reference transistor, so as to compress the voltage at the first current terminal of the reference transistor to a predetermined threshold.
6. The reference voltage generating circuit as described in claim 1, characterized in that, Also includes: The first compensation module has one end electrically connected to the first input terminal of the comparison module and the other end grounded. The second compensation module has one end electrically connected to the second input terminal of the comparison module, and the other end grounded. The first compensation module and the second compensation module are respectively used to balance the AC impedance of the first input terminal and the second input terminal of the comparison module.
7. The reference voltage generating circuit as described in claim 6, characterized in that, The first compensation module includes a compensation resistor and a compensation capacitor. The second compensation module has the same components as the first compensation module; One end of the compensation resistor is electrically connected to the input terminal of the comparator module, and the other end of the compensation resistor is electrically connected to one end of the compensation capacitor. The other end of the compensation capacitor is grounded.
8. The reference voltage generating circuit as described in claim 1, characterized in that, The current source module includes a first transistor and a second transistor; the source of the first transistor and the source of the second transistor are connected to the power supply voltage, and the gates of the first transistor and the second transistor share a common connection point with the output terminal of the comparison module to form a controlled current mirror. The drain of the first transistor is connected to the first branch. The drain of the second transistor is connected to the second branch.
9. An integrated circuit chip, characterized in that, Includes a reference voltage generating circuit as described in any one of claims 1 to 8.
10. An electronic device, characterized in that, Including the integrated circuit chip as described in claim 9, the electronic device is a quantum computer control device, a deep space probe, or a low-temperature physics experimental instrument.