Reference voltage generating circuit

Abstract

The embodiment of the invention provides a reference voltage generation circuit, which comprises a voltage generation circuit and a voltage amplification circuit, and is characterized in that the voltage generation circuit comprises a pull-up resistor module and a pull-down resistor module which are connected in series, and a transistor module which is connected with the pull-up resistor module or the pull-down resistor module in parallel; a connection point of the pull-up resistor module and the pull-down resistor module outputs a temperature control voltage, and the voltage generation circuit determines a temperature coefficient of the temperature control voltage at least based on a first parameter of the pull-up resistor module and a second parameter of the transistor module; wherein the first parameter comprises a first equivalent temperature coefficient, and the second parameter comprises a temperature coefficient of a threshold voltage of a switched-on transistor in the transistor module; the voltage amplification circuit is connected with the connection point and is used for amplifying the temperature control voltage according to the first control signal to obtain reference voltage; wherein the first control signal is used for representing the relationship between the preset gain of the voltage amplification circuit to the temperature control voltage and the temperature coefficient of the temperature control voltage.

Description

Technical Field

[0001] The present disclosure relates to the field of integrated circuits, and relates to but is not limited to a reference voltage generating circuit. Background Art

[0002] In the field of integrated circuits, such as dynamic random access memory (DRAM), some components in the circuit may have temperature-dependent characteristics. For example, the threshold voltage of a MOS transistor changes as the temperature increases or decreases. For components in an integrated circuit that have temperature-dependent characteristics, providing a reference voltage that changes with temperature can ensure the normal operation of the circuit or improve the performance of the integrated circuit. Summary of the invention

[0003] According to one aspect of the present disclosure, there is provided a reference voltage generating circuit, comprising:

[0004] A voltage generating circuit, comprising a pull-up resistor module and a pull-down resistor module connected in series, and a transistor module connected in parallel with the pull-up resistor module or the pull-down resistor module; a connection point between the pull-up resistor module and the pull-down resistor module outputs a temperature-controlled voltage, and the voltage generating circuit determines a temperature coefficient of the temperature-controlled voltage based at least on a first parameter of the pull-up resistor module and a second parameter of the transistor module; wherein the first parameter comprises a first equivalent temperature coefficient, and the second parameter comprises a temperature coefficient of a threshold voltage of a transistor turned on in the transistor module;

[0005] A voltage amplifier circuit is connected to the connection point and is used to amplify the temperature-controlled voltage according to a first control signal to obtain a reference voltage; wherein the first control signal is used to characterize the relationship between the preset gain of the voltage amplifier circuit for the temperature-controlled voltage and the temperature coefficient of the temperature-controlled voltage.

[0006] In the reference voltage generating circuit provided by the embodiment of the present disclosure, the temperature control coefficient of the temperature control voltage is at least related to the first equivalent temperature coefficient of the pull-up resistor module and the temperature coefficient of the threshold voltage of the transistor turned on in the transistor module. The voltage generating circuit can adjust at least one of the first equivalent temperature coefficient and the threshold voltage temperature coefficient of the transistor so that the temperature control voltage has different positive temperature coefficients or different negative temperature coefficients. That is, the voltage generating circuit provided by the embodiment of the present disclosure can provide temperature control voltages with a variety of different temperature coefficients, so as to select the temperature control voltage that best matches the temperature coefficient of the component to accurately control the component. Furthermore, in the present disclosure, the temperature control voltage is affected by the first equivalent temperature coefficient and the threshold voltage temperature coefficient, so that when the temperature coefficients of the first equivalent temperature coefficient and the threshold voltage are adjusted to produce a large change, the temperature coefficient of the temperature control voltage changes less, so that the adjustment of the temperature coefficient of the temperature control voltage is more precise and accurate, and it is easier to obtain a temperature control voltage that accurately matches the temperature coefficient of the component.

[0007] Furthermore, the voltage amplifier circuit provided in the embodiment of the present disclosure can select a preset gain of the voltage amplifier circuit for the temperature-controlled voltage according to the temperature coefficient of the temperature-controlled voltage, and amplify the temperature-controlled voltage based on the preset gain to obtain a reference voltage. The preset gain can make reference voltages with different temperature coefficients have a target voltage at the target temperature, thereby providing a variety of optional reference voltages for components to operate at the target temperature, and then a reference voltage with a temperature coefficient that best matches the temperature coefficient of the component can be selected from the multiple optional reference voltages, providing a basis for refined control of components and facilitating improved device performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A schematic diagram of a reference voltage generating circuit provided by an embodiment of the present disclosure;

[0009] Figure 2 A schematic diagram of a voltage generating circuit provided in an embodiment of the present disclosure;

[0010] Figure 3 A schematic diagram of another voltage generating circuit provided in an embodiment of the present disclosure;

[0011] Figure 4 A schematic diagram of another voltage generating circuit provided in an embodiment of the present disclosure;

[0012] Figure 5 A schematic diagram of another voltage generating circuit provided in an embodiment of the present disclosure;

[0013] Figure 6 A schematic diagram of another voltage generating circuit provided in an embodiment of the present disclosure;

[0014] Figure 7 for Figure 2 A schematic diagram of four temperature-controlled voltages provided by the voltage generating circuit shown;

[0015] Figure 8 A schematic diagram of a voltage amplification circuit provided by an embodiment of the present disclosure;

[0016] Fig. 9 A schematic diagram of another reference voltage generating circuit provided in an embodiment of the present disclosure;

[0017] Fig.10 for Fig. 9 A mapping relationship table corresponding to the reference voltage generating circuit shown;

[0018] Fig.11 for Fig. 9 A schematic diagram of four reference voltages provided by the reference voltage generating circuit shown;

[0019] Fig.12 A corresponding schematic diagram of another mapping relationship table and a first control signal and a second control signal provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0020] The technical solution of the present disclosure is described in detail below in conjunction with the accompanying drawings and specific embodiments of the specification. Although the exemplary implementation method of the present disclosure is shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the implementation methods described here. On the contrary, these implementation methods are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0021] The present disclosure is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the present disclosure will become clearer according to the following description and claims. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present disclosure. It should be noted that the technical solutions recorded in the embodiments of the present disclosure can be arbitrarily combined without conflict.

[0022] As the performance of dynamic random access memory (DRAM) continues to improve, more and more circuits require fine control to cope with temperature changes, such as transistors in storage cells and sensitive amplifiers. In the fine control of circuits, it is essential to use a reference voltage with a certain temperature coefficient. Taking the transistor in the storage cell as an example, its threshold voltage V th May increase as the temperature decreases. If the gate voltage V gs Keeping it constant, V gs -Vth The gate voltage of the control transistor needs to have a negative temperature coefficient to improve DRAM performance.

[0023] In the related art, a current I_PTAT with a positive temperature coefficient is usually used to flow through a circuit to generate a reference voltage with a positive temperature coefficient. The reference voltage can be expressed as I_PTAT×R. The voltage V between the base and emitter of the transistor is used. be and the current I_CTAT with a negative temperature coefficient together generate a reference voltage with a negative temperature coefficient, which can be expressed as: V be +I_CTAT×R.

[0024] This method of using currents I_PTAT and I_CTAT to generate reference voltages may encounter some problems in applications. For example, due to process reasons, the actual values ​​of I_PTAT (or I_CTAT) and R may differ greatly from the designed values, resulting in a larger range of variation of the value of I_PTAT×R (or I_CTAT×R), making it difficult for the reference voltage to obtain a more accurate voltage value range. For another example, the temperature coefficient of I_PTAT is too large, which leads to a large temperature coefficient of the reference voltage.

[0025] In view of this, an embodiment of the present disclosure provides a reference voltage generating circuit to provide a reference voltage with a relatively accurate voltage value range. Figure 1 A reference voltage generating circuit provided for the implementation of the present disclosure includes:

[0026] A voltage generating circuit 100 includes a pull-up resistor module 110 and a pull-down resistor module 120 connected in series, and a transistor module 130 connected in parallel with the pull-up resistor module 110; a connection point C of the pull-up resistor module 110 and the pull-down resistor module 120 outputs a temperature-controlled voltage Vt, and the voltage generating circuit 100 determines a temperature coefficient of the temperature-controlled voltage Vt based at least on a first parameter of the pull-up resistor module 110 and a second parameter of the transistor module 130; wherein the first parameter includes a first equivalent temperature coefficient TRC1, and the second parameter includes a temperature coefficient TRC3 of a threshold voltage Vth of a transistor turned on in the transistor module 130;

[0027] The voltage amplifier circuit 200 is connected to the connection point C, and is used to amplify the temperature-controlled voltage Vt according to the first control signal to obtain a reference voltage Vref; wherein the first control signal is used to characterize the relationship between the preset gain of the temperature-controlled voltage Vt of the voltage amplifier circuit 200 and the temperature coefficient of the temperature-controlled voltage Vt.

[0028] In the present disclosure, the pull-up resistor module 110 has a first equivalent resistance R1, and the first equivalent temperature coefficient TRC1 is used to indicate the rate of change of the first equivalent resistance R1 with temperature. The pull-down resistor module 120 has a second equivalent resistance R2, and the second equivalent temperature coefficient TRC2 is used to indicate the rate of change of the second equivalent resistance R2 with temperature. The value of the equivalent temperature coefficient can be: the ratio of the increase in the equivalent resistance to the original equivalent resistance when the temperature changes by 1°C.

[0029] The temperature coefficient TRC3 of the threshold voltage Vth of the transistor is used to indicate the rate of change of the threshold voltage Vth of the transistor with temperature. The threshold voltage temperature coefficient TRC3 may be: the ratio of the change in the threshold voltage to the original threshold voltage when the temperature changes by 1°C.

[0030] In some embodiments, the first parameter also includes a first equivalent resistance R1, and the second parameter also includes a ratio W / L of a channel width to a channel length of a transistor turned on in the transistor module 130 (hereinafter referred to as the channel width-to-length ratio W / L); the voltage generating circuit is also used to adjust at least one of the first equivalent temperature coefficient TRC1, the first equivalent resistance R1, the channel width-to-length ratio W / L of the turned-on transistor, and the temperature coefficient TRC3 of the threshold voltage of the turned-on transistor according to the second control signal to adjust the temperature coefficient of the temperature control voltage Vt.

[0031] It should be understood that after the chip is manufactured, the threshold voltage Vth, the temperature coefficient of the threshold voltage TRC3, and the channel width-to-length ratio W / L of the transistor are determined. Therefore, adjusting the threshold voltage temperature coefficient TRC3 of the transistor and / or the ratio of the channel width-to-length ratio W / L is essentially replacing or adding transistors of different specifications for conduction, or selecting different numbers of transistors for conduction, and cannot adjust a transistor itself. Similarly, after the resistor is manufactured, its temperature coefficient is determined. For an immutable resistor, its resistance is also determined. The equivalent resistance and equivalent temperature coefficient of the adjustment resistor module can be achieved by enabling resistors with different resistance values ​​and / or temperature coefficients and enabling different numbers of resistors.

[0032] In some embodiments, Figure 1 As shown, the other end of the pull-up resistor module 110 is connected to the bandgap reference voltage source for receiving the bandgap reference voltage Vbgr; the other end of the pull-down resistor module 120 is connected to the first voltage node, and the voltage of the first voltage node is less than the bandgap reference voltage Vbgr. For example, the first voltage node is the ground terminal Vss. In this circuit connection mode, the transistor module 130 may include a plurality of Pmos transistors.

[0033] Combine the following Figure 1 Temperature control voltage Vt at reference temperature int Combined with the temperature coefficient of Figure 1And Kirchhoff's current law:

[0034]

[0035] Among them, I d is the on-state current of the on-state transistor of the transistor module 130 .

[0036] According to formula (1), it can be transformed into:

[0037]

[0038] Among them, I d =0.5×μ×C OX (W / L)×(V gs -V th ) 2 , is the current calculation formula when the transistor is in the on state, C OX is the unit capacitance of the gate dielectric layer, μ is the average mobility of carriers in the channel, and Vgs is the gate-source voltage, that is, the voltage of the gate of the transistor relative to the source; Substituting this current calculation formula into formula (2) yields formula (3). In formula (4), β = 0.5 × μ × C OX (W / L), β is a positive number.

[0039] From formula (4), it can be seen that the temperature-controlled voltage Vt is a function related to the first equivalent resistance R1, the second equivalent resistance R2, the threshold voltage Vth of the on-state transistor, and the channel width-to-length ratio W / L of the on-state transistor. Furthermore, R1, R2, and Vth are all related to temperature, and the correlation can be expressed by the first equivalent temperature coefficient TRC1, the second equivalent temperature coefficient TRC2, and the threshold voltage temperature coefficient TRC3. Therefore, the temperature-controlled voltage Vt is related to temperature, and the temperature coefficient of the temperature-controlled voltage Vt is at least related to TRC1, TRC2, and TRC3. Explained by a formula:

[0040] When the temperature rises from the reference temperature to the current temperature, the temperature control voltage Vt at the current temperature can be expressed as:

[0041]

[0042] ΔT is the difference between the current temperature and the reference temperature, which may be -40°C or a normal temperature of 25°C.

[0043] From this formula, we can see that the temperature coefficient of the temperature control voltage Vt is related to R1, R2, V th, TRC1, TRC2, TRC3 and W / L (included in β). In other words, when the temperature changes ΔT, the value of the temperature-controlled voltage Vt depends on these parameters. Therefore, the voltage generating circuit 100 can at least adjust the first equivalent resistor R1, the second equivalent resistor R2, the first equivalent temperature coefficient TRC1, the second equivalent temperature coefficient TRC2, the transistor threshold voltage V th , threshold voltage temperature coefficient TRC3 and at least one of the channel width-to-length ratio W / L to adjust the temperature coefficient of the temperature control voltage Vt.

[0044] In some embodiments, the first equivalent temperature coefficient TRC1 may be equal to the second equivalent temperature coefficient TRC2. In this case, the temperature control voltage Vt at the current temperature may be expressed as:

[0045]

[0046] As shown in formula (5), the first equivalent temperature coefficient TRC1 is equal to the second equivalent temperature coefficient TRC2, which can reduce the variables in the calculation formula of the temperature control voltage Vt, thereby reducing the difficulty of adjustment.

[0047] In some embodiments, combined with formula (5), it can be seen that when the first equivalent temperature coefficient TRC1 is positive, the threshold voltage Vth is negative, and the temperature coefficient TRC3 of the threshold voltage is negative (that is, as the temperature increases, the absolute value of the threshold voltage decreases), the temperature control voltage Vt may have a positive temperature coefficient. It should be noted that from formula (5), it can be seen that Vt is a cubic function of ΔT, and ΔT 3 The coefficient is greater than zero. If the temperature control voltage Vt is to have a positive temperature coefficient, the relationship between the parameters in formula (5) should be constrained according to the relationship between the coefficients when the cubic function satisfies monotonically increasing or partially satisfies monotonically increasing, so that when the temperature is within the operating temperature range of the component, the function of the temperature control voltage Vt increases monotonically.

[0048] In other embodiments, when the first equivalent temperature coefficient TRC1 is a negative number, the threshold voltage Vth is a negative number, the temperature coefficient TRC3 of the threshold voltage is a positive number, and the temperature control voltage Vt may have a negative temperature coefficient. Similarly, it is also necessary to constrain the relationship between the parameters in formula (5) according to the relationship between the coefficients when the cubic function satisfies monotonically decreasing or partially satisfies monotonically decreasing, so that when the temperature is within the operating temperature range of the component, the function of the temperature control voltage Vt decreases monotonically.

[0049] It can be seen that the voltage regulating circuit 100 can at least adjust the first equivalent temperature coefficient TRC1 and the temperature coefficient TRC3 of the threshold voltage so that the temperature-controlled voltage Vt has a positive temperature coefficient or a negative temperature coefficient. Further, the voltage regulating circuit 100 can adjust R1, R1 / R2 (the ratio of the first equivalent resistance value to the second equivalent resistance value), V th , TRC1, TRC3 and W / L, so that the temperature control voltage Vt has different positive temperature coefficients and different negative temperature coefficients.

[0050] The present disclosure analyzes the temperature coefficient of the temperature control voltage Vt using two specific examples. In the first embodiment, let R1 = 1Ω, R2 = 5Ω, TCR1 = 0.03 / °C, Vth = -0.8V, Vgs = -2.5V, TCR3 = -0.01 / °C, β = 0.2, and substitute into formula (5) to obtain:

[0051]

[0052] The temperature-controlled voltage Vt shown in formula (6) has a positive temperature coefficient when ΔT is greater than -279°C. It can be basically considered that the temperature-controlled voltage Vt has a positive temperature coefficient within the temperature range of the components. Specifically, taking ΔT = 10 as an example, substituting into formula (6) the value of the temperature-controlled voltage Vt at the current temperature is 0.833Vbgr + 0.686, and taking ΔT = 50 as an example, the value of the temperature-controlled voltage Vt at the current temperature is 0.833Vbgr + 1.838, and taking ΔT = 100 as an example, the value of the temperature-controlled voltage Vt at the current temperature is 0.833Vbgr + 4.167, while the value of the temperature-controlled voltage Vt at the reference temperature is 0.833Vbgr + 0.482. It can be seen that as the temperature increases, the temperature-controlled voltage Vt also increases.

[0053] In the second embodiment, R1, R2, Vth, Vgs and β are kept unchanged, TCR1 = -0.02 / °C, TCR3 = 0.03 / °C, and substituting into formula (5) yields:

[0054]

[0055] The temperature control voltage Vt shown in formula (7) has a negative temperature coefficient within a certain temperature range. Specifically, taking ΔT=10 as an example, substituting into formula (7) the value of the temperature control voltage Vt at the current temperature is 0.833Vbgr+0.284, while the value of the temperature control voltage Vt at the reference temperature is 0.833Vbgr+0.482. It can be seen that as the temperature increases, the temperature control voltage Vt decreases.

[0056] In the manufacturing process of integrated circuits, due to process reasons, etc., it is difficult to accurately know what temperature characteristics these components require in the design stage, and it is often necessary to obtain them through testing after the device is prepared. This makes it impossible for the reference voltage to accurately follow the characteristics of the components, and the performance of the integrated circuit may be reduced. In the reference voltage generating circuit provided by the embodiment of the present disclosure, the temperature control coefficient of the temperature control voltage is at least related to the first equivalent temperature coefficient of the pull-up resistor module and the temperature coefficient of the threshold voltage of the transistor turned on in the transistor module. The voltage generating circuit can adjust at least one of the first equivalent temperature coefficient and the threshold voltage temperature coefficient of the transistor so that the temperature control voltage has different positive temperature coefficients or different negative temperature coefficients. That is, the voltage generating circuit provided by the embodiment of the present disclosure can provide a variety of temperature control voltages with different temperature coefficients, so as to select the temperature control voltage that best matches the temperature coefficient of the component to accurately control the component.

[0057] Furthermore, in the present disclosure, the temperature-controlled voltage is affected by adjusting the first equivalent temperature coefficient and the threshold voltage temperature coefficient, so that when the temperature coefficients of the first equivalent temperature coefficient and the threshold voltage are adjusted to produce larger changes, the temperature coefficient of the temperature-controlled voltage changes less, thereby making the adjustment of the temperature coefficient of the temperature-controlled voltage more precise and accurate, and it is easier to obtain a temperature-controlled voltage that accurately matches the temperature coefficient of components.

[0058] In some embodiments, the pull-up resistor module 110 may include a plurality of pull-up resistors connected in series, at least two ends of some of the pull-up resistors are connected in parallel with pull-up switches, and each pull-up switch enables or disables the corresponding pull-up resistor based on a second control signal.

[0059] Figure 2 Schematic diagram of another voltage generating circuit provided by an embodiment of the present disclosure. Figure 2 As shown, the pull-up resistor module 110 may include a first pull-up resistor 11, a second pull-up resistor 12, a third pull-up resistor 13 and a fourth pull-up resistor 14 connected in series, wherein the first pull-up switch S 12 The second pull-up switch S is connected in parallel with the second pull-up resistor 12, the third pull-up resistor 13 and the fourth pull-up resistor 14. 13 The first pull-up switch S is connected in parallel with the third pull-up resistor 13 and the fourth pull-up resistor 14; 12 , the second pull-up switch S 13 and the third pull-up switch S 14 The second pull-up resistor 12 , the third pull-up resistor 13 , and the fourth pull-up resistor 14 may be enabled or disabled.

[0060] It should be noted that the first pull-up resistor 11, the second pull-up resistor 12, the third pull-up resistor 13 and the fourth pull-up resistor 14 are all pull-up resistors. 12 , the second pull-up switch S13 and the third pull-up switch S 14 They are all pull-up switches. This application defines them as "pull-up" and does not limit them to being used to pull up the temperature control voltage Vt after being enabled. It is just because they are the side that receives the power signal - the bandgap reference voltage, and no other aspects are limited.

[0061] In some embodiments, if the first pull-up switch S 12 If the pull-up resistor module 110 only includes the first pull-up resistor 11, the first equivalent resistance R1 and the first equivalent temperature coefficient TRC1 of the pull-up resistor module 110 correspond to the resistance R of the first pull-up resistor 11. 11 and temperature coefficient TCR 11 .

[0062] In some embodiments, if the first pull-up switch S 12 The second pull-up switch S is disconnected 13 If the pull-up resistor module 110 is closed, the pull-up resistor module 110 includes a first pull-up resistor 11 and a second pull-up resistor 12 connected in series. The resistance of the second pull-up resistor 12 is R 12 , the temperature coefficient is TCR 12 The first equivalent temperature coefficient TCR1 of the pull-up resistor module 110 can be expressed as:

[0063]

[0064] Among them, ΔR 11 and ΔR 21 The resistance change of the first pull-up resistor 11 and the resistance change of the second pull-up resistor 12 when the temperature changes ΔT can be expressed as: ΔR 11 =R 11 ×TCR 11 , ΔR 12 =R 12 ×TCR 12 .

[0065] Combining formula (8), it can be seen that if the temperature coefficient TCR of the first pull-up resistor 11 is 11 The temperature coefficient TCR of the second pull-up resistor 12 12 Same (TCR 11 =TCR 12 ), then TCR1=TCR 11 , that is, the first equivalent coefficient T1 remains unchanged. However, the first equivalent resistance value changes from R 11 Change to R 11 +R 12 .

[0066] It can be deduced from this that if the temperature coefficients of multiple pull-up resistors connected in series are the same, enabling different pull-up resistors or enabling different numbers of pull-up resistors can change the first equivalent resistance, but will not affect the first equivalent temperature coefficient. Therefore, the voltage generating circuit can control the first switch based on the second control signal to adjust the first equivalent resistance, thereby changing the temperature coefficient of the temperature-controlled voltage Vt.

[0067] In this embodiment, Figure 2 As shown, the temperature coefficients of all pull-up resistors 11, 12, 13, and 14 are the same. In this way, it can be ensured that no matter how the pull-up switch S is configured, 12 , S 13 , S 14 , the first equivalent temperature coefficient TRC1 always remains unchanged.

[0068] In some embodiments, the pull-down resistor module 120 may include a plurality of pull-down resistors connected in series. Figure 2 As shown, the pull-down resistor module 120 may include a first pull-down resistor 21 , a second pull-down resistor 22 , a third pull-down resistor 23 and a fourth pull-down resistor 24 connected in series.

[0069] It should be noted that the first pull-down resistor 21, the second pull-down resistor 22, the third pull-down resistor 23 and the fourth pull-down resistor 24 are all pull-down resistors. The present application defines them as "pull-down" and does not limit them to being used to pull down the temperature control voltage Vt after being enabled. It is just because they are on one side of the ground terminal and no other aspects are limited.

[0070] In some embodiments, the pull-down resistor module 120 may not include a switch, so that the second equivalent resistance R2 and the second equivalent coefficient TRC2 remain unchanged. In some other embodiments, the two ends of some pull-down resistors may also be connected in parallel to the pull-down switch, and each pull-down switch enables or disables the corresponding pull-down resistor based on the second control signal. In this way, when the temperature coefficients of multiple pull-down resistors in series are the same, the voltage generating circuit can enable different pull-down resistors or enable different numbers of pull-down resistors to change the second equivalent resistance R2, but will not affect the second equivalent temperature coefficient TRC2. This ensures that no matter how the pull-down switch is configured, the first equivalent temperature coefficient TRC1 is always equal to the second equivalent temperature coefficient TRC2.

[0071] In addition, in some embodiments, when the temperature coefficients of multiple pull-up resistors connected in series are not exactly the same, and / or the temperature coefficients of multiple pull-down resistors connected in series are different, the voltage generating circuit may enable different pull-up resistors or enable different numbers of pull-up resistors to change the first equivalent resistance and / or the first equivalent temperature coefficient; and / or enable different pull-down resistors or enable different numbers of pull-down resistors to change the second equivalent resistance and / or the second equivalent temperature coefficient, thereby changing the temperature coefficient of the temperature-controlled voltage Vt.

[0072] In some embodiments, the pull-up resistor module 110 may include a plurality of pull-up resistors connected in parallel, some of the pull-up resistors are connected in series with pull-up switches, and each pull-up switch may enable or disable the corresponding pull-up resistor based on the second control signal.

[0073] Figure 3 A schematic diagram of another voltage generating circuit provided in an embodiment of the present disclosure is shown in FIG. Figure 3 As shown, the pull-up resistor module 110 may include a first pull-up resistor 11, a second pull-up resistor 12, a third pull-up resistor 13 and a fourth pull-up resistor 14 connected in parallel, and the second pull-up resistor 12 is connected in series with the first pull-up switch S 12 The third pull-up resistor 13 is connected in series with the second pull-up switch S 13 The fourth pull-up resistor 14 is connected in series with the third pull-up switch S 14 ; The first pull-up switch S 12 , the second pull-up switch S 13 and the third pull-up switch S 14 The corresponding second pull-up resistor 12 , third pull-up resistor 13 , and fourth pull-up resistor 14 may be enabled or disabled.

[0074] In some embodiments, if any one of the pull-up switches is closed and the other pull-up switches are open, for example, the first pull-up switch S 12 Close and the second pull-up switch S 13 and the third pull-up switch S 14 If disconnected, the pull-up resistor module 110 includes a first pull-up resistor 11 and a second pull-up resistor 12 connected in parallel, and a first equivalent temperature coefficient TCR1 of the pull-up resistor module 110 can be expressed as:

[0075]

[0076] Combining formula (9), it can be seen that if the temperature coefficient TCR of the first pull-up resistor 11 is 11 The temperature coefficient TCR of the second pull-up resistor 12 12 Same (TCR 11 =TCR 12 ), then TCR1=TCR 11 , that is, the first equivalent coefficient T1 remains unchanged. However, the first equivalent resistance value changes from R 11 Change to R 11 R 12 / (R 11 +R 12 ).

[0077] It can be deduced from this that when the temperature coefficients of multiple pull-up resistors connected in parallel are the same, enabling different pull-up resistors or enabling different numbers of pull-up resistors can change the first equivalent resistance, but will not affect the first equivalent temperature coefficient. Therefore, the voltage generating circuit can adjust the first equivalent resistance by controlling the pull-up switch based on the second control signal, thereby changing the temperature coefficient of the temperature-controlled voltage Vt.

[0078] In some embodiments, the pull-down resistor module 120 may include a plurality of pull-down resistors connected in parallel. Figure 3 As shown, the pull-down resistor module 120 may include a first pull-down resistor 21 , a second pull-down resistor 22 , a third pull-down resistor 23 and a fourth pull-down resistor 24 connected in parallel.

[0079] Continue to see Figure 3 The second pull-down resistor 22 can be connected in series with the first pull-down switch S 22 The third pull-down resistor 23 can be connected in series with the second pull-down switch S 23 The fourth pull-down resistor 14 can be connected in series with the third pull-down switch S 24 .

[0080] Based on the same analytical thinking as the above formula (9), it can be seen that if the temperature coefficients of multiple pull-down resistors are the same, the voltage generating circuit can enable different pull-down resistors or different numbers of pull-down resistors to adjust the second equivalent resistance value, but will not affect the second equivalent temperature coefficient. In this way, it can be ensured that no matter how the pull-down switch is configured, the first equivalent temperature coefficient is always equal to the second equivalent temperature coefficient.

[0081] In this embodiment, Figure 3 As shown, the temperature coefficients of all the pull-up resistors 11, 12, 13, 14 and all the pull-down resistors 21, 22, 23, 24 are the same, so that the pull-up switch S can be configured in any manner. 12 , S 13 , S 14 and pull-down switch S 22 , S 23 , S 24 , the first equivalent temperature coefficient TRC1 is always equal to the second equivalent temperature coefficient TRC2.

[0082] It should be understood that in some embodiments, the pull-up resistor module 110 may include multiple pull-up resistors connected in series, and the pull-down resistor module 120 may include multiple pull-down resistors connected in parallel. In other embodiments, the pull-up resistor module 110 may include multiple pull-up resistors connected in parallel, and the pull-down resistor module 120 may include multiple pull-down resistors connected in series. For example, the temperature coefficients of the pull-up resistors are the same, and the temperature coefficients of the pull-down resistors are the same and equal to the temperature coefficients of the pull-up resistors.

[0083] In some embodiments, the pull-up resistor may be one of the resistors commonly used in CMOS, such as a diffusion resistor, a polysilicon resistor, a metal resistor, a Well resistor, etc. The pull-down resistor may also be one of the resistors commonly used in CMOS, such as a diffusion resistor, a polysilicon resistor, a metal resistor, a Well resistor, etc.

[0084] In some embodiments, the transistor module may include a plurality of transistors connected in parallel, each transistor is connected in series with a control switch, and a source and a drain of each turned-on transistor are connected to two ends of the pull-up resistor module.

[0085] Continue to see Figure 2 The transistor module 130 may include a first transistor P16, a second transistor P8, a third transistor P4 and a fourth transistor P2 connected in parallel, and the transistors P16, P8, P4 and P2 are respectively connected in series with a first control switch S 31 , the second control switch S 32 , the third control switch S 33 , the fourth control switch S 44 The drain of each transistor is connected to the connection point C, and a control switch is connected in series between the source of the transistor and one end of the pull-up resistor module 110. When the control switch is turned on, the source of the corresponding transistor is electrically connected to one end of the pull-up resistor module 110, so that the turned-on transistor is connected in parallel at both ends of the pull-up resistor module 110.

[0086] The transistor has at least three parameters that will affect the temperature coefficient of the temperature-controlled voltage Vt, namely, the channel width-to-length ratio W / L, the threshold voltage Vth and the threshold voltage temperature coefficient TRC3.

[0087] In some embodiments, Figure 2 As shown, the channel width-to-length ratios W / L of the multiple transistors P16, P8, P4, and P2 can be made different from each other, for example, the channel width ratio W / L of P16 is 16, the channel width ratio W / L of P8 is 8, the channel width ratio W / L of Ps4 is 4, and the channel width ratio W / L of P2 is 2. The threshold voltage Vth and the threshold voltage temperature coefficient TRC3 of all transistors are the same, and the voltage generating circuit can adjust the channel width-to-length ratio W / L of the transistors turned on in the transistor module 130 by selecting different transistors for conduction. In the manufacturing process, adjusting the channel width-to-length ratio W / L of the transistor only requires changing the length and width of the channel region. However, adjusting the threshold voltage or the temperature coefficient of the threshold voltage of the transistor may require changing the gate, the gate dielectric layer composition, or using a back gate with different doping to achieve, which will increase the complexity and difficulty of the process. Therefore, the method of only adjusting the channel width-to-length ratio W / L of the transistor can relatively simplify the manufacturing process and has good compatibility with the existing process.

[0088] In other embodiments, the channel width ratio W / L and the threshold voltage Vth of all transistors may be the same, and the threshold voltage temperature coefficients TRC3 of different transistors may be different; or, the channel width ratio W / L and the threshold voltage temperature coefficients TRC3 of all transistors may be the same, and the threshold voltages Vth of different transistors may be different. In this way, when any one of the above three parameters remains unchanged, the other one can be adjusted, which can reduce the difficulty of adjusting the temperature-controlled voltage Vth.

[0089] In some other embodiments, the channel width ratios W / L of multiple transistors may not be all the same, the threshold voltage temperature coefficients TRC3 may not be all the same, and the threshold voltage Vth of all transistors may be the same. For example, in an example including four transistors, the channel width ratio W / L of the first transistor and the second transistor may be 16, but the threshold voltage temperature coefficients are -0.01 / °C and -0.03 / °C respectively; the channel width ratio W / L of the third transistor and the fourth transistor may be 8, but the threshold voltage temperature coefficients are -0.01 / °C and -0.03 / °C respectively, and the threshold voltage of all transistors is -0.8V. In this way, the voltage generating circuit can adjust the channel width-to-length ratio W / L and the threshold voltage temperature coefficient TRC3 of the transistors turned on in the transistor module 130 by selecting different transistors to conduct. That is, one of the three parameters may be kept unchanged and the other two may be adjusted; or all three parameters may be different and the temperature coefficient of the temperature-controlled voltage Vt may be changed by adjusting the three parameters.

[0090] In some embodiments, Figure 2 As shown, the gate of each transistor is connected to the connection point C of the pull-up resistor module 110 and the pull-down resistor module 120, that is, the gate and drain of the transistor are short-circuited, so that the transistor is in a diode connection mode.

[0091] Corresponding to the connection mode of the gate of the transistor in FIG. (2), the calculation formula of the temperature control voltage Vt at the reference temperature can be further transformed from formula (4) into:

[0092]

[0093] In some embodiments, when the first equivalent temperature coefficient is equal to the second equivalent temperature coefficient, and the first equivalent resistance R1 is much smaller than the second equivalent resistance R2, formula (10) can be further transformed into:

[0094] Vt int -V bgr =β×R1×(Vt int -V bgr -V th ) 2 (11)

[0095] Let Von = Vt int -Vbgr , then formula (11) can be simplified as: Von = β × R1 × (Von-V th ) 2 (12)

[0096] Formula (12) is a quadratic equation with one variable. Two roots can be obtained. Considering the actual situation, we can choose one of the roots, namely:

[0097]

[0098]

[0099]

[0100] According to formula (15), when the first equivalent resistance R1 of the pull-up resistor module has a positive temperature coefficient, the threshold voltage Vth of the transistor turned on in the transistor module is a negative number, and the temperature coefficient TRC3 of the threshold voltage is a negative number (that is, as the temperature increases, the absolute value of the threshold voltage decreases), the temperature-controlled voltage Vt may have a positive temperature coefficient. The positive temperature coefficient of the temperature-controlled voltage Vt can be changed by adjusting β or R1, where β is proportional to the channel width-to-length ratio W / L of the transistor; when β×R1 is large, it can also be understood that when the first equivalent temperature coefficient TRC1 of the pull-up resistor module is large, the temperature-controlled voltage Vt is approximately a linear function of temperature. When β×R1 is relatively small, the temperature-controlled voltage Vt presents a quadratic function of temperature under the joint action of the threshold voltage Vth and the first equivalent resistance R1. It is necessary to further constrain Vth and R1 so that when the temperature is within the operating temperature range of the component, the temperature-controlled voltage Vt is in the monotonically rising interval of the quadratic function.

[0101] Figure 4 yes Figure 2 The schematic diagram of a temperature-controlled voltage output by the voltage generating circuit shown in FIG. Figure 2 and Figure 4 The turned-on transistor and the pull-up resistor are connected in parallel, which clamps the temperature control voltage Vt. Figure 2 Taking the transistor P16 and the pull-up resistors 11 to 14 shown in parallel as an example, when the temperature-controlled voltage Vt has a positive temperature coefficient, when the temperature is lower than the lower limit temperature T1, the temperature-controlled voltage Vt decreases again, which will increase the gate-source voltage Vgs of the transistor P16, thereby increasing the on-current of the transistor P16 and limiting the further decrease of the temperature-controlled voltage Vt. The temperature-controlled voltage Vt no longer decreases linearly, but slows down, resulting in a clamping phenomenon.

[0102] Similarly, when the temperature is higher than the upper limit temperature T2, the temperature control voltage Vt increases further, which will reduce the gate-source voltage Vgs of the transistor P16, thereby causing the on-current of the transistor P16 to decrease, limiting the further increase of the temperature control voltage Vt. The temperature control voltage Vt no longer increases linearly, but increases very slowly, and becomes clamped. The temperature control voltage Vt gets closer and closer to the bandgap reference voltage Vbgr.

[0103] In some embodiments, even at low temperatures, if the reference voltage is too small, the driving capability is small, the anti-noise interference capability is weak, and there will be reliability issues. Even at high temperatures, if the reference voltage is too large, there will be reliability, power consumption, heat dissipation and other issues. Although it is hoped that the reference voltage provided can follow the changes in the requirements of components, if the reference voltage has upper and lower limits, the reliability of the device can be improved and power consumption can be saved. The temperature-controlled voltage provided by the voltage generating circuit provided in this embodiment can have a temperature coefficient that follows the component, and the temperature-controlled voltage has upper and lower limits for constraints, so that the reference voltage obtained based on the temperature-controlled voltage can inherit this characteristic, thereby providing device reliability.

[0104] Figure 5 Schematic diagram of another voltage generating circuit provided by an embodiment of the present disclosure. Figure 5 As shown, the pull-up resistor module 110 may include a first pull-up resistor 11, a second pull-up resistor 12, a third pull-up resistor 13 and a fourth pull-up resistor 14 connected in series, and the two ends of the second pull-up resistor 12 are connected in parallel with a first pull-up switch S 12 The two ends of the third pull-up resistor 13 are connected in parallel with a second pull-up switch S 13 The two ends of the fourth pull-up resistor 14 are connected in parallel with a third pull-up switch S 14 Based on the first pull-up switch S 12 , the second pull-up switch S 13 and the third pull-up switch S 14 The pull-up resistor module can obtain 6 different first equivalent resistance values, thereby increasing the diversity of the temperature coefficient of the temperature-controlled voltage Vt.

[0105] Continue to see Figure 5 The transistor module 130 in this embodiment includes a first transistor P16, a second transistor P8, a third transistor P4 and a fourth transistor P2 connected in parallel, and does not include a corresponding control switch. The source and drain of each transistor P16, P8, P4, P2 are connected in parallel to the two ends of the pull-up resistor module 110, and the second control signal is directly applied to the gate of the transistor P16, P8, P4, P2 to control the conduction or cutoff of the transistor P16, P8, P4, P2, thereby adjusting the parameters of the transistor that is turned on.

[0106] Compared to Figure 2The transistor module circuit shown in the embodiment can provide a gate voltage to the gate of each transistor adaptively, so that the gate-source voltage Vgs remains unchanged under different temperature conditions. In other embodiments, a gate voltage is provided to each transistor independently, that is, the gate voltage of each transistor can be the same or different.

[0107] Figure 6 Schematic diagram of another voltage generating circuit provided by an embodiment of the present disclosure. Figure 6 As shown, the transistor module 130 may also be connected in parallel with the pull-down resistor module 120. In this case, the transistor module 130 may include a plurality of NMOS transistors.

[0108] Combine the following Figure 6 Temperature control voltage Vt at reference temperature int Combined with the temperature coefficient of Figure 6 And Kirchhoff's current law:

[0109]

[0110] According to formula (16), it can be transformed into:

[0111]

[0112] From formula (17), it can be seen that the temperature-controlled voltage Vt is a function related to the first equivalent resistance R1, the second equivalent resistance R2, the threshold voltage Vth of the on-state transistor, and the channel width-to-length ratio W / L of the on-state transistor. Further, R1, R2, and Vth are all related to temperature, and the correlation can be expressed by the first equivalent temperature coefficient TRC1, the second equivalent temperature coefficient TRC2, and the threshold voltage temperature coefficient TRC3. Therefore, the temperature-controlled voltage Vt is related to temperature, and the temperature coefficient of the temperature-controlled voltage Vt is also related to TRC1, TRC2, and TRC3.

[0113] In some embodiments, the first equivalent temperature coefficient TRC1 may be equal to the second equivalent temperature coefficient TRC2. In this case, the temperature control voltage Vt at the current temperature may be expressed as:

[0114]

[0115] In some embodiments, combined with formula (18), when the first equivalent temperature coefficient TRC1 is positive, the threshold voltage Vth is positive, and the temperature coefficient TRC3 of the threshold voltage is negative (that is, as the temperature increases, the absolute value of the threshold voltage decreases), the temperature control voltage Vt may have a negative temperature coefficient. It should be noted that, as can be seen from formula (18), Vt is a cubic function of ΔT, and ΔT 3The coefficient is less than zero. If the temperature control voltage Vt is to have a negative temperature coefficient, the relationship between the parameters in formula (18) should be constrained according to the relationship between the coefficients when the cubic function satisfies monotonically decreasing or partially satisfies monotonically decreasing, so that when the temperature is within the operating temperature range of the component, the function of the temperature control voltage Vt decreases monotonically. For example, based on the cubic function formula, a maximum point of the function is obtained at According to the threshold voltage Vth, threshold voltage temperature coefficient TRC3, and gate-source voltage Vgs of the commonly used transistor, ΔT is a negative number with a large absolute value. Therefore, the temperature-controlled voltage has a negative temperature coefficient in a commonly used temperature range (for example, greater than -40°C). For example, when (V gs -V th )TRC1=-V th At TRC3, the temperature control voltage Vt always has a negative temperature coefficient.

[0116] The temperature coefficient of the temperature control voltage Vt is analyzed in a specific embodiment. In this embodiment, let R1 = 1Ω, R2 = 5Ω, TCR1 = 0.03 / °C, Vth = 0.8V, Vgs = 2.5V, TCR3 = -0.01 / °C, β = 0.2, and substitute into formula (18) to obtain:

[0117]

[0118] The temperature-controlled voltage Vt shown in formula (19) has a negative temperature coefficient when ΔT is greater than -279°C. It can be basically considered that the temperature-controlled voltage Vt has a negative temperature coefficient within the temperature range of the components. Specifically, taking ΔT = 10 as an example, substituting into formula (19) the value of the temperature-controlled voltage Vt at the current temperature is 0.833Vbgr-0.686, and taking ΔT = 50 as an example, the value of the temperature-controlled voltage Vt at the current temperature is 0.833Vbgr-1.838, while the value of the temperature-controlled voltage Vt at the reference temperature is 0.833Vbgr-0.482. It can be seen that as the temperature increases, the temperature-controlled voltage Vt decreases.

[0119] Similarly, when the first equivalent temperature coefficient TRC1 is a negative number, the threshold voltage Vth is a positive number, and the temperature coefficient TRC3 of the threshold voltage is a positive number, the temperature control voltage Vt may have a positive temperature coefficient.

[0120] It can be seen from this that Figure 6 The voltage regulating circuit 100 shown can at least adjust the first equivalent temperature coefficient TRC1 and the temperature coefficient TRC3 of the threshold voltage so that the temperature-controlled voltage Vt has a negative temperature coefficient or a positive temperature coefficient. Further, the voltage regulating circuit 100 can adjust R1, R1 / R2 (the ratio of the first equivalent resistance value to the second equivalent resistance value), V th, TRC1, TRC3 and W / L, so that the temperature control voltage Vt has a different negative temperature coefficient or a positive temperature coefficient.

[0121] In some embodiments, as shown in FIG. 6 , the pull-up resistor module 110 may have Figure 2 The pull-down resistor module 120 may include a first pull-down resistor 21, a second pull-down resistor 22, a third pull-down resistor 23, and a fourth pull-down resistor 24 connected in series, wherein the first pull-down switch S 22 The second pull-down switch S is connected in parallel with the second pull-down resistor 22, the third pull-down resistor 23 and the fourth pull-down resistor 24. 23 The third pull-down resistor 23 and the fourth pull-down resistor 24 are connected in parallel. By controlling the first pull-down switch S 22 , the second pull-down switch S 23 and the third pull-down switch S 24 Different numbers of pull-down resistors may be enabled or disabled, thereby changing the second equivalent resistance R2 of the pull-down resistor module 120 and further changing the temperature coefficient Vt of the temperature control voltage.

[0122] In some embodiments, Figure 6 As shown, the transistor module may include a first transistor N16, a second transistor N8, a third transistor N4 and a fourth transistor N2 connected in parallel, and the transistors N16, N8, N4 and N2 are respectively connected in series with a first control switch S 31 , the second control switch S 32 , the third control switch S 33 , the fourth control switch S 44 The drain of each transistor is connected to the connection point C, and a control switch is connected in series between the source of the transistor and one end of the pull-down resistor module 110. When the control switch is turned on, the source of the corresponding transistor is electrically connected to one end of the pull-down resistor module 110, so that the turned-on transistor is connected in parallel at both ends of the pull-down resistor module 110.

[0123] In some embodiments, the gate of each transistor is connected to the connection point C of the pull-up resistor module 110 and the pull-down resistor module 120, that is, the gate and drain of the transistor are short-circuited, so that the transistor is connected in a diode manner, thereby clamping the temperature control voltage Vt.

[0124] In some embodiments, the channel width-to-length ratios W / L of the plurality of transistors N16, N8, N4, and N2 may be different from each other, for example, their channel width ratios W / L are 16, 8, 4, and 2, respectively. The threshold voltage Vth and the threshold voltage temperature coefficient TRC3 of all transistors are the same, and the voltage generating circuit may adjust the channel width-to-length ratios W / L of the transistors turned on in the transistor module 130 by selecting different transistors to be turned on, thereby adjusting the temperature coefficient Vt of the temperature control voltage.

[0125] In summary, the voltage generating circuit provided in the embodiment of the present disclosure can adjust the first equivalent resistance R1, the ratio of the first equivalent resistance to the second equivalent resistance R1 / R2, the first equivalent temperature coefficient TRC1, the threshold voltage V th , the temperature coefficient of the threshold voltage TRC3 and at least one of the channel width and length W / L of the transistor, so that the temperature-controlled voltage Vt has different positive temperature coefficients or negative temperature coefficients.

[0126] Figure 7 for Figure 2 The schematic diagram of the voltage generating circuit shown in FIG. 1 is a schematic diagram of four temperature control voltages provided by the voltage generating circuit shown in FIG. 31 Close and pull up switch S 12 , S 13 , S 14 When disconnected, the first transistor P16 and the pull-up resistors 11, 12, 13, and 14 are connected in parallel, and the image of the output first temperature-controlled voltage Vt1 is a first straight line Vt1. 32 Closed, the first pull-up switch S 12 and the second pull-up switch S 13 Disconnect, the fourth pull-up switch S 14 When the third control switch S is closed, the second transistor P8 and the pull-up resistors 11, 12, and 13 are connected in parallel, and the image of the output second temperature-controlled voltage Vt2 is a second straight line Vt2. 33 Closed, the first pull-up switch S 12 The second pull-up switch S is disconnected 13 When the third transistor P4 is closed, the pull-up resistors 11 and 12 are connected in parallel, and the image of the output third temperature-controlled voltage Vt3 is a second straight line Vt3. 34 Closed, the first pull-up switch S 12 When closed, the fourth transistor P2 is connected in parallel with the first pull-up resistor 11, and the image of the output fourth temperature-controlled voltage Vt4 is a second straight line Vt4. Here, the control switch not mentioned in each case is in an open state.

[0127] For example, Figure 2In the embodiment, the resistance value of each pull-up resistor is equal and the temperature coefficient is the same, the channel width-to-length ratios of transistors P16, P8, P4 and P2 are 16, 8, 4 and 2 respectively, and the threshold voltages and threshold voltage temperature coefficients of these transistors are equal to each other. Based on formula (15), it can be seen that the temperature coefficients of the first temperature-controlled voltage Vt1, the second temperature-controlled voltage Vt2, the third temperature-controlled voltage Vt3 and the fourth temperature-controlled voltage Vt4 increase in sequence.

[0128] It should be noted that, in theory, the function corresponding to the temperature control voltage Vt is formula (15), but since the temperature coefficient TRC1 of the first equivalent resistance R1 and the temperature coefficient TRC3 of the threshold voltage Vth are very small, the temperature coefficient of the temperature control voltage Vt is also small. In the temperature range commonly used by components, it can be basically regarded that the temperature control voltage changes linearly with temperature, that is, the image of the temperature control voltage is a straight line, so it can be expressed by the formula Vt = a × ΔT + b. In this formula, ΔT = TT int , T int is the reference temperature, for example -40°C, and a and b can be obtained by fitting by measuring multiple sets of (T, Vt) values.

[0129] like Figure 7 As shown, when the temperature-controlled voltage has different temperature coefficients, the straight lines corresponding to the temperature-controlled voltage have different slopes, which may result in different voltage values ​​of the temperature-controlled voltages with different temperature coefficients at the target temperature (e.g., 85°C). For example, the voltage value of the first straight line Vt1 at 85°C may be 1.037V, the voltage value of the second straight line Vt2 at 85°C may be 1.014V, the voltage value of the third straight line Vt3 at 85°C may be 0.991V, and the voltage value of the fourth straight line Vt4 at 85°C may be 0.970V.

[0130] It should be understood that providing a suitable reference voltage Vref to components can ensure that the components work normally or are in the best working state at the target temperature. Here, the voltage required for the components to work normally or in the best working state at the target temperature can be defined as the target voltage. For example, the target voltage for the components to work in the best state at 85°C is 1.0V±10mV. Figure 7 As shown, the voltage values ​​of temperature control voltages with different temperature coefficients at 85°C are not all within the target voltage range (approximately in the range of 0.96 to 1.04V), which may cause components to fail to work normally at the target temperature when using a certain temperature control voltage (for example, the first temperature control voltage Vt1, the second temperature control voltage Vt2 and the fourth temperature control voltage Vt4).

[0131] Therefore, if Figure 1As shown, the present disclosure sets a voltage amplifier circuit 200 in a reference voltage generating circuit, which is used to amplify the temperature-controlled voltage Vt according to a first control signal to obtain a reference voltage Vref; wherein the first control signal is used to characterize the correspondence between the preset gain of the temperature-controlled voltage Vt of the voltage amplifier circuit 200 and the temperature coefficient of the temperature-controlled voltage Vt, and the obtained reference voltage Vref has a target voltage at a target temperature, which can meet the requirements for component use.

[0132] It should be understood that the "preset gain" in the present disclosure can be a value greater than 1, so that the reference voltage is greater than the temperature control voltage; it can also be a value greater than 0 and less than 1, so that the reference voltage is less than the temperature control voltage; or it can also be a value equal to 1.

[0133] Figure 8 A circuit diagram of a voltage amplifier circuit provided by an embodiment of the present disclosure is shown in FIG. Figure 8 As shown, the first input terminal of the voltage amplifier circuit 200 is connected to the connection point of the pull-up resistor module and the pull-down resistor module, and is used to receive the temperature-controlled voltage Vt. The first adjustment resistor 31 is connected in series between the second input terminal and the output terminal, and the second adjustment resistor 32 is connected in series between the second input terminal and the second voltage node.

[0134] The voltage amplifier circuit 200 includes a circuit for adjusting the resistance of the first adjustment resistor 31 and / or the resistance of the second adjustment resistor 32 according to the first control signal, so as to adjust the gain of the voltage amplifier circuit 200 to the temperature-controlled voltage Vt to a preset gain.

[0135] By way of example, the second voltage node may be a ground terminal.

[0136] In some embodiments, the first regulating resistor 31 and the second regulating resistor 32 may be variable resistors. In some other embodiments, the first regulating resistor 31 and the second regulating resistor 32 may be MOS transistors, which are used as variable resistors by controlling the gate voltage of the MOS transistor to make the MOS transistor in the linear region.

[0137] Fig. 9 A circuit diagram of another reference voltage generating circuit provided in an embodiment of the present disclosure should be understood as follows: Fig. 9 The voltage generating circuit in can be Figures 2 to 6 Any of the voltage generating circuits shown in the present embodiment, with Figure 2 The voltage generating circuit shown is used as an example for explanation.

[0138] In some embodiments, Fig. 9 As shown, the voltage amplification circuit 200 may include: an adjustment resistance module 210 and a first selector 220;

[0139] One end of the regulating resistor module 210 is connected to the output end of the voltage amplifier circuit, and the other end is connected to the second voltage node (e.g., the ground end Vss); the regulating resistor module 210 includes a plurality of sub-regulating resistors (e.g., a first sub-regulating resistor 41, a second sub-regulating resistor 42 ... an Nth sub-regulating resistor 4n) connected in series, and a voltage dividing point is provided between each two adjacent sub-regulating resistors;

[0140] The multiple input terminals of the first selector 220 are correspondingly connected to the multiple voltage dividing points of the regulating resistor module 210, and the output terminal of the first selector 220 is connected to the second input terminal of the voltage amplifier circuit; the first selector 220 is used to conduct the specified voltage dividing point with the second input terminal of the voltage amplifier circuit according to the first control signal; wherein, the multiple sub-regulating resistors between the specified voltage dividing point and the output terminal of the voltage amplifier circuit are equivalent to the first regulating resistor 31, and the multiple sub-regulating resistors between the specified voltage dividing point and the second voltage node (for example, the ground terminal) are equivalent to the second regulating resistor 32. The first selector 220 changes the resistance value of the first regulating resistor 31 and the resistance value of the second regulating resistor 32 by selecting different voltage dividing points to conduct with the second input terminal of the voltage amplifier circuit, thereby changing the gain of the voltage amplifier circuit 200 to the temperature control voltage Vt.

[0141] In some embodiments, Figure 8 and Fig. 9 As shown, the voltage amplification circuit 200 further includes:

[0142] An amplifier 230, wherein the inverting input terminal of the amplifier 230 is the first input terminal of the voltage amplifier circuit 200 and is connected to the connection point of the pull-up resistor module and the pull-down resistor module, and the non-inverting input terminal of the amplifier 230 is the second input terminal of the voltage amplifier circuit 200 and is connected to the output terminal of the first selector 220;

[0143] The load tube 240 has a gate connected to the output end of the amplifier 230, a source connected to the third voltage node, and is used to receive the power supply voltage Vdd. The drain is connected to the regulating resistor module 210 (that is, connected to the output end of the voltage amplifier circuit 200). The connection point between the drain of the load tube 240 and the regulating resistor module 210 outputs the reference voltage Vref. Here, the load tube 240 is a PMOS transistor, and the power supply voltage Vdd of the third voltage node is greater than the voltage of the second voltage node.

[0144] As shown above, the voltage generating circuit controls the pull-up switch and / or the control switch based on the second control signal to adjust the temperature coefficient of the temperature-controlled voltage Vt. After the temperature coefficient is determined, it is necessary to adjust the first adjustment resistor 31 and the second adjustment resistor 32 so that the voltage amplifier circuit 200 obtains a preset gain, and amplifies the temperature-controlled voltage Vt based on the preset gain, so as to achieve a target voltage at the target temperature for the reference voltage Vref. It can be seen that there should be a certain corresponding relationship between the preset gain and the pull-up switch state and / or the control switch state, that is, there should be a certain mapping relationship between the pull-up switch state and / or the control switch state and the resistance value of the first adjustment resistor and the second adjustment resistor; and the first control signal and the second control signal are provided based on the mapping relationship to achieve the target voltage at the target temperature for the reference voltage Vref.

[0145] In some embodiments, if Figure 8 In the voltage amplifier circuit shown, the first regulating resistor and the second regulating resistor are MOS tubes, and the entries of the mapping relationship may include: the state of the control switch and / or the state of the pull-up switch, the gate voltage of the first MOS tube (equivalent to the first regulating resistor 31) and the gate voltage of the second MOS tube (equivalent to the second regulating resistor 32). The second control signal is used to control the pull-up switch to be in a closed or open state, and / or to control the control switch to be in a closed or open state. The second control signal is used to provide a suitable gate voltage to the gate of the first MOS tube and the gate of the second MOS tube.

[0146] In some embodiments, Fig. 9 Taking the voltage amplifier circuit shown in FIG. 1 as an example, the entries of the mapping relationship may include: the state of the pull-up switch and / or the state of the control switch, and the state of the first selector. For example, Fig. 9 The medium voltage generating circuit includes a first pull-up switch S 12 To the third pull-up switch S 14 , and the first control switch S 31 To the fourth control switch S 34 , the voltage generating circuit can generate 16 temperature-controlled voltages with different temperature coefficients.

[0147] In this embodiment, taking the first temperature-controlled voltage Vt1, the second temperature-controlled voltage Vt2, the third temperature-controlled voltage Vt3 and the fourth temperature-controlled voltage Vt4 output by the voltage generating circuit as described above as an example, correspondingly, the regulating resistor module 210 may include 5 first sub-regulating resistors 41, the second sub-regulating resistors 42, the third sub-regulating resistors 43, the fourth sub-regulating resistors 44 and the fifth sub-regulating resistors 45 connected in series, wherein the fifth sub-regulating resistor 45 is closer to the second voltage node (ground terminal Vss). There are first, second, third and fourth voltage dividing points between these sub-regulating resistors in sequence. The first selector 220 may have four input terminals, for example, the first input terminal, the second input terminal, the third input terminal and the fourth input terminal of the first selector are sequentially connected to the first voltage dividing point, the second voltage dividing point, the third voltage dividing point and the fourth voltage dividing point, so as to adjust the voltage values ​​of the temperature-controlled voltages with four different positive temperature coefficients to be 1V at 85°C.

[0148] Fig.10 for Fig. 9 A mapping relationship table of the reference voltage generating circuit shown in FIG. Fig.11 for Fig. 9 The reference voltage generation circuit shown is a schematic diagram of four reference voltages provided. The reference voltage generation circuit can generate a first reference voltage Vref1, a second reference voltage Vref2, a third reference voltage Vref3 and a fourth reference voltage Vref4, which are obtained by amplifying four temperature-controlled voltages Vt1, Vt2, Vt3 and Vt4 respectively, and the voltage values ​​are all 1V at 85°C.

[0149] like Fig.10 As shown, taking the fourth reference voltage Vref4 as an example, when the voltage generating circuit outputs the fourth temperature-controlled voltage Vt4, the first input terminal and the output terminal of the first selector 220 can be turned on to select the first sub-adjusting resistor 41 as the first adjusting resistor, and the remaining sub-adjusting resistors as the second adjusting resistors, so that the voltage value of the first reference voltage Vref1 at 85°C can be achieved to be 1V.

[0150] In some embodiments, at the target temperature, the greater the difference between the voltage value of the temperature control voltage Vt and the target voltage, the greater the required gain. For example, Fig. 9 In the circuit shown, the greater the ratio of (first adjustment resistor+second adjustment resistor) / second adjustment resistor, the greater the gain of the voltage amplifier circuit.

[0151] Taking the first reference voltage Vref1 as an example, when the voltage generating circuit outputs the first temperature control voltage Vt1, Figure 7As shown, the voltage value of the first temperature-controlled voltage Vt1 at 85°C is smaller, so a larger gain is required. At this time, the fourth input terminal and the output terminal of the first selector 220 can be turned on to select the sub-adjusting resistors 41, 42, 43, and 44 as the first adjusting resistors, and the sub-adjusting resistor 45 as the second adjusting resistor, so that the voltage amplifier circuit 200 obtains a larger gain, thereby achieving a voltage value of 1V for the second reference voltage Vref2 at 85°C.

[0152] Similarly, when the voltage generating circuit outputs the second temperature-controlled voltage Vt2, the third input terminal and the output terminal of the first selector can be turned on. When the voltage generating circuit outputs the third temperature-controlled voltage Vt3, the second input terminal and the output terminal of the first selector can be turned on.

[0153] In some embodiments, the voltage amplifier circuit 200 does not substantially change the temperature coefficient of the temperature control voltage. Therefore, based on the temperature coefficients of the first temperature control voltage Vt1 to the fourth temperature control voltage Vt2, it can be seen that in this embodiment, Fig.10 As shown, the temperature coefficients of the first reference voltage Vref1, the third reference voltage Vref3, the second reference voltage Vref2 and the fourth reference voltage Vref4 decrease in this order.

[0154] In some embodiments, the number of states of the second control signal is the same as the number of states of the first control signal. Fig. 9 As shown, the second control signal needs at least 2 bits to control the pull-up switch and the control switch to output four temperature-controlled voltages. For example, the second control signal controls the switch based on the four states of 00, 01, 10 and 11. Fig.10 The first control signal needs 2 bits to control the first selector 220 to select different input terminals to be connected to the output terminals. For example, the first control signal can control the first selector 220 based on four states: 00, 01, 10, and 11.

[0155] In some embodiments, when the first control signal and the second control signal have the same state, the preset gain obtained based on the first control signal and the temperature-controlled voltage generated based on the second control signal can satisfy that the reference voltage has a target voltage at the target temperature. Fig.10 The mapping relationship table shown in FIG. 1 configures the first control signal and the second control signal to be both in the 00 state, thereby generating the first reference voltage Vref1. Specifically, the voltage generating circuit closes the switch S based on the 00 state of the first control signal. 31 And turn off switch S 12 , S 13 , S 14, outputs a first temperature-controlled voltage Vt1; at the same time, the voltage amplifying circuit turns on the fourth input terminal and the output terminal of the first selector based on the 00 state of the second control signal to obtain a preset gain, and amplifies the first temperature-controlled voltage Vt1 to obtain a first reference voltage Vref1.

[0156] Similarly, the first control signal and the second control signal can be both in the 01 state, the 10 state and the 11 state, and the second reference voltage Vref2, the third reference voltage Vref3 and the fourth reference voltage Vref4 are generated accordingly.

[0157] In some embodiments, the first control signal and the second control signal may be the same signal and may be generated by a signal generation module. In other embodiments, the first control signal and the second control signal may also be different signals, but when configured to have the same state, generate a reference voltage having a target voltage at a target temperature.

[0158] In some embodiments, the second control signal can be converted into a plurality of sub-control signals, each of which is used to control a pull-up switch or a control switch, and each of which has two states, 0 or 1. By way of example, the semiconductor device further includes a plurality of control signal conversion modules, each of which is connected to a switch, and the control signal conversion module can be a circuit composed of logic gates such as a NAND gate, an OR gate, and a NOT gate, and is used to convert the second control signal into different sub-control signals. For example, when the second control signal is 00, the first control switch S 31 The connected control signal conversion module receives the signal 00 and outputs the signal 1 to control the first control switch S 31 Closed; at the same time, with the first pull-up switch S 12 The connected control signal conversion module receives the signal 00 and outputs the signal 0 to control the first pull-up switch S 12 Disconnect, so that different switches can be controlled to be opened or closed based on the same second control signal. For example, each sub-control signal can be transmitted to the corresponding switch through an independent line.

[0159] In some embodiments, when the first control signal and the second control signal have different states, the preset gain obtained based on the first control signal and the temperature-controlled voltage generated based on the second control signal can satisfy that the reference voltage has a target voltage at the target temperature. In this case, the first control signal and the second control signal can be two different signals generated by two signal generation modules.

[0160] For example, Fig.10As shown, the first control signal can be in the 00 state and the second control signal can be in the 11 state to generate a first reference voltage Vref1; the first control signal can be in the 01 state and the second control signal can be in the 10 state to generate a second reference voltage Vref2; the first control signal can be in the 10 state and the second control signal can be in the 00 state to generate a third reference voltage Vref3; the first control signal can be in the 11 state and the second control signal can be in the 01 state to generate a fourth reference voltage Vref4.

[0161] In some embodiments, the first control signal and the second control signal may be provided to the reference voltage generating circuit at the same time, or the first control signal may be provided before the second control signal, or the first control signal may be provided after the second control signal.

[0162] In some embodiments, the semiconductor device may be used at multiple target temperatures, and different target voltages are required at different target temperatures. Therefore, the mapping relationship should also indicate the corresponding relationship between the target temperature, the target voltage, the state of the pull-up switch and / or the state of the control switch, the resistance value of the first adjustment resistor, and the resistance value of the second adjustment resistor. According to the target voltage required by the device at the target temperature, the corresponding first control and second control signals can be selected based on the mapping relationship table and provided to the reference voltage generating circuit, so that the reference voltage with the required temperature coefficient and target voltage can be obtained, which can meet the needs of more diverse usage scenarios.

[0163] Fig.12 for Fig. 9 Schematic diagram of another mapping relationship of the reference voltage generating circuit and the first control signal and the second control signal. Fig.10 Compared with the two, the corresponding voltage generation circuits remain unchanged, but Fig.12 The corresponding voltage amplifier circuit's regulating resistor module includes a larger number of sub-regulating resistors to provide more different gains. Fig.12 As shown, the reference voltage generating circuit can provide Fig.10 The four reference voltages with different temperature coefficients that meet the target voltage of 1V at 85°C shown in the figure can also provide two reference voltages with different temperature coefficients that meet the target voltage of 1.5V at 60°C, and two reference voltages with different temperature coefficients that meet the target voltage of 0.8V at 60°C. It should be understood that Fig.12 The resistance configuration of the sub-regulator in the corresponding regulator module is different from Fig.10 The corresponding regulating resistor module, therefore, needs to reconfigure the connection relationship between the multiple input terminals of the first selector and the voltage dividing points in the regulating resistor module.

[0164] In some embodiments, Fig.12As shown, the number of states of the first control signal is greater than the number of states of the second control signal. The first control signal and the second control signal are different signals. For example, the second control signal requires a 2-bit width to provide four states of 00, 01, 10 and 11 to control the voltage generating circuit to generate four temperature-controlled voltages Vt with different temperature coefficients. The second control signal requires a 3-bit width to provide 8 states to select the gain of the voltage amplifier circuit. In some embodiments, the first selector may include a multi-stage sub-selector, for example, including two first-stage sub-selectors of four-selection and a second-stage sub-selector of two-selection, the input end of the first-stage sub-selector is connected to the voltage dividing point of the regulating resistor module, and the output end thereof is connected to the input end of the second-stage sub-selector, and the output end of the second-stage sub-selector is connected to the in-phase input end of the amplifier.

[0165] In some embodiments, the mapping relationship table can be stored in a test machine, and multiple first control signals and second control signals can be provided to the reference voltage during the test phase, thereby selecting a reference voltage that best matches the temperature coefficient of the component, thereby putting the component in a better working state and improving the performance of the device.

[0166] In some embodiments, the control signal conversion module may be located in a test machine to provide a plurality of sub-control signals and a first control signal to the reference voltage generating circuit during a test phase.

[0167] In some other embodiments, the semiconductor device may further include: a control circuit, the mapping relationship table is stored in the control circuit, and the control circuit may select a suitable first control signal and a second control signal according to an instruction of a host or a controller to provide to a reference voltage generating circuit to obtain a desired reference voltage. In this case, the reference voltage generating circuit may include a control signal conversion module. Also exemplarily, the control signal conversion module may be included in the control circuit so that the control circuit provides a plurality of sub-control signals and the first control signal to the reference voltage generating circuit.

[0168] In addition, in some embodiments, the control circuit may be further connected to a reference voltage generating circuit, and the control circuit may select the most matching reference voltage by trial and error based on the feedback of the reference voltage.

[0169] The voltage amplifier circuit provided in the embodiment of the present disclosure can amplify the temperature control voltage according to the required target voltage to obtain the reference voltage. The voltage amplifier circuit can improve the driving capability and anti-noise performance of the reference voltage.

[0170] The reference voltage generating circuit provided by the embodiment of the present disclosure can be applied to semiconductor devices and can improve the performance of memory. The semiconductor device can be a memory, and the memory includes but is not limited to DRAM, NAND memory, phase change memory, ferroelectric memory, etc.

[0171] The above embodiments are merely illustrative of the principles and effects of the present disclosure, and are not intended to limit the present disclosure. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present disclosure. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present disclosure shall still be covered by the claims of the present disclosure.

Claims

1. A reference voltage generating circuit, characterized in that: include: A voltage generating circuit, comprising a pull-up resistor module and a pull-down resistor module connected in series, and a transistor module connected in parallel with the pull-up resistor module or the pull-down resistor module; a connection point between the pull-up resistor module and the pull-down resistor module outputs a temperature-controlled voltage, and the voltage generating circuit determines a temperature coefficient of the temperature-controlled voltage based at least on a first parameter of the pull-up resistor module and a second parameter of the transistor module; wherein the first parameter comprises a first equivalent temperature coefficient, and the second parameter comprises a temperature coefficient of a threshold voltage of a transistor turned on in the transistor module; A voltage amplifier circuit is connected to the connection point and is used to amplify the temperature-controlled voltage according to a first control signal to obtain a reference voltage; wherein the first control signal is used to characterize the relationship between the preset gain of the voltage amplifier circuit for the temperature-controlled voltage and the temperature coefficient of the temperature-controlled voltage.

2. The reference voltage generating circuit according to claim 1, characterized in that: The first parameter further includes a first equivalent resistance, and the second parameter further includes a ratio of a channel width to a channel length of a transistor turned on in the transistor module; The voltage generating circuit is also used to adjust at least one of the first equivalent temperature coefficient, the first equivalent resistance, the ratio of the channel width to the channel length of the turned-on transistor, and the temperature coefficient of the threshold voltage of the turned-on transistor according to a second control signal to adjust the temperature coefficient of the temperature-controlled voltage.

3. The reference voltage generating circuit according to claim 2, characterized in that: The first equivalent temperature coefficient is equal to the second equivalent temperature coefficient of the pull-down resistor module.

4. The reference voltage generating circuit according to claim 3, characterized in that: The pull-up resistor module includes a plurality of pull-up resistors connected in series and / or in parallel, at least some of the pull-up resistors are correspondingly provided with pull-up switches, and each of the pull-up switches enables or disables the corresponding pull-up resistor based on the second control signal; The temperature coefficients of the multiple pull-up resistors are the same, and the voltage generating circuit is used to control the pull-up switch according to the second control signal to adjust the first equivalent resistance.

5. The reference voltage generating circuit according to claim 2, characterized in that: The transistor module comprises a plurality of transistors connected in parallel, each of the transistors is connected in series with a control switch, and the source and drain of each turned-on transistor are connected to two ends of the pull-up resistor module; Among them, the ratios of channel width to channel length of the multiple transistors are not all the same, and the voltage generating circuit is used to control the control switch according to the second control signal to adjust the ratio of channel width to channel length of the transistor turned on in the transistor module.

6. The reference voltage generating circuit according to claim 5, characterized in that: The temperature coefficient of the threshold voltage of each of the transistors is substantially the same.

7. The reference voltage generating circuit according to claim 5, characterized in that: The other end of the pull-up resistor module is used to receive the bandgap reference voltage, and the other end of the pull-down resistor module is connected to the ground end; Wherein, the transistor module connected in parallel with the pull-up resistor module includes a plurality of PMOS transistors connected in parallel; or, The transistor module connected in parallel with the pull-down resistor module includes a plurality of NMOS transistors connected in parallel.

8. The reference voltage generating circuit according to claim 5, characterized in that: A gate of each of the transistors is connected to a connection point between the pull-up resistor module and the pull-down resistor module.

9. The reference voltage generating circuit according to claim 2, characterized in that: The first input end of the voltage amplifier circuit is connected to the connection point of the pull-up resistor module and the pull-down resistor module, the first regulating resistor is connected in series between the second input end and the output end, and the second regulating resistor is connected in series between the second input end and the ground end; The voltage amplifier circuit is used to adjust the resistance value of the first adjustment resistor and the resistance value of the second adjustment resistor according to the first control signal, so as to adjust the gain of the voltage amplifier circuit to the temperature control voltage to a preset gain.

10. The reference voltage generating circuit according to claim 9, characterized in that: The pull-up resistor module includes a plurality of pull-up resistors and a plurality of pull-up switches, and the transistor module includes a plurality of transistors and a plurality of control switches; The reference voltage generating circuit further includes: a control circuit connected to the voltage generating circuit and the voltage amplifying circuit, wherein the control circuit stores a mapping relationship between the state of the pull-up switch, the state of the control switch, the resistance value of the first regulating resistor, and the resistance value of the second regulating resistor; The control circuit is used to generate the first control signal and the second control signal according to the mapping relationship, so that the reference voltage has a target voltage value at a target temperature.

11. The reference voltage generating circuit according to claim 10, characterized in that: The mapping relationship is also used to indicate the corresponding relationship between the target temperature, the target voltage, the state of the pull-up switch and / or the state of the control switch, the resistance value of the first regulating resistor, and the resistance value of the second regulating resistor.

Images