A device for adjusting voltage value and voltage temperature coefficient and a voltage bias circuit

Abstract

This invention discloses a device and voltage bias circuit for adjusting voltage value and voltage temperature coefficient, comprising a reference current conversion module and a current adjustment module. Since the reference current conversion module converts the reference voltage (with a voltage temperature coefficient of 0) output from the bandgap reference circuit into a reference current, the current adjustment module can output a current with an adjustable magnitude and / or direction based on the reference current and a voltage temperature coefficient of 0. The non-inverting input of the low-dropout regulator circuit is connected to the output of the current adjustment module to achieve independent voltage value adjustment, and the inverting input of the low-dropout regulator circuit is connected to the output of the bandgap reference circuit (with a voltage temperature coefficient of non-zero) to achieve independent adjustment of the voltage temperature coefficient. Ultimately, this enables the voltage bias circuit to independently adjust both the voltage value and the voltage temperature coefficient.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit design, and in particular to a device and voltage biasing circuit for adjusting voltage value and voltage temperature coefficient. Background Technology

[0002] In integrated circuit design, many circuits require voltage bias circuits to provide a reference voltage. Therefore, the quality of the voltage bias circuit design directly affects the performance of the integrated circuit. Voltage bias circuits typically include bandgap reference circuits and low-dropout regulator circuits. The bandgap reference circuit provides a reference voltage with a defined voltage temperature coefficient, while the low-dropout regulator circuit provides a stable output voltage based on the reference voltage. However, because the reference voltage provided by the bandgap reference circuit is correlated with the voltage temperature coefficient—meaning the reference voltage changes with the voltage temperature coefficient—the output voltage of the low-dropout regulator circuit also changes with the voltage temperature coefficient. This results in the voltage value of the voltage bias circuit not being able to be independently adjusted along with the voltage temperature coefficient. Summary of the Invention

[0003] The purpose of this invention is to provide a device and voltage bias circuit for adjusting voltage value and voltage temperature coefficient, which can independently adjust the voltage value and voltage temperature coefficient of the output voltage of the voltage bias circuit.

[0004] To solve the above-mentioned technical problems, the present invention provides a device for adjusting voltage value and voltage temperature coefficient, applied to a voltage bias circuit including a bandgap reference circuit and a low-dropout voltage regulator circuit. The low-dropout voltage regulator circuit includes a first operational amplifier, a first PMOS, a first resistor, and a second resistor. The inverting input terminal of the first operational amplifier is connected to the voltage output terminal of the bandgap reference circuit where the voltage temperature coefficient is not zero. The first terminal of the first resistor is connected to the first terminal of the second resistor, and the common terminal of the connection is connected to the non-inverting input terminal of the first operational amplifier. The output terminal of the first operational amplifier is connected to the gate of the first PMOS. The source of the first PMOS is connected to a power supply. The drain of the first PMOS is connected to the second terminal of the first resistor, and the common terminal of the connection serves as the output terminal of the low-dropout voltage regulator circuit. The second terminal of the second resistor is grounded. The device includes:

[0005] A reference current conversion module is used to convert the reference voltage output from the first voltage output terminal of the bandgap reference circuit, which has a voltage temperature coefficient of 0, into a reference current, wherein the reference current is positively correlated with the reference voltage.

[0006] A current regulation module, wherein the input terminal of the current regulation module is connected to the output terminal of the reference current conversion module, and the output terminal is connected to the non-inverting input terminal of the first operational amplifier and the first terminal of the first resistor, respectively, for adjusting the magnitude and / or direction of the output current based on the current regulation command and the reference current, so as to regulate the output voltage of the low dropout voltage regulator circuit.

[0007] Preferably, the current adjustment command includes a first current adjustment command and / or a second current adjustment command;

[0008] The current regulation module includes a positive current regulation module and a negative current regulation module. The output terminals of both the positive and negative current regulation modules are connected to the non-inverting input terminal of the first operational amplifier and the first terminal of the first resistor.

[0009] A forward current regulation module is used to adjust the magnitude of the forward output current based on the first current regulation command and the reference current when the first current regulation command is received. The direction of the forward output current is from the output terminal of the low dropout voltage regulator circuit to the output terminal of the forward regulation module, so as to increase the magnitude of the output voltage of the low dropout voltage regulator circuit.

[0010] A negative current regulation module is used to adjust the magnitude of the negative output current based on the second current regulation command and the reference current when the second current regulation command is received. The direction of the negative output current is from the output terminal of the negative regulation module to the output terminal of the low dropout voltage regulator circuit, so as to reduce the magnitude of the output voltage of the low dropout voltage regulator circuit.

[0011] The output current is the sum of the positive output current and the negative output current.

[0012] Preferably, the reference current conversion module includes a second operational amplifier, a second PMOS, and a third resistor;

[0013] The inverting input terminal of the second operational amplifier is connected to the voltage output terminal of the bandgap reference circuit with a voltage temperature coefficient of 0; the non-inverting input terminal of the second operational amplifier is connected to the first terminal of the third resistor; the output terminal of the second operational amplifier is connected to the gate of the second PMOS; and the second terminal of the third resistor is grounded.

[0014] The source of the second PMOS is connected to the power supply, and the drain of the second PMOS is connected to the first end of the third resistor.

[0015] Preferably, the current regulation module further includes a third PMOS and a first NMOS;

[0016] The source of the third PMOS is connected to the power supply, the gate is connected to the gate of the second PMOS, the drain is connected to the drain and gate of the first NMOS, and the source of the first NMOS is grounded.

[0017] The forward current regulation module includes N fourth PMOS and N first controllable switches. The sources of the N fourth PMOS are all connected to the power supply, the gates of the N fourth PMOS are all connected to the gates of the third PMOS, the drains of the N fourth PMOS are respectively connected to the first terminals of the N first controllable switches, and the common terminal of the N first controllable switches is connected to the second terminals and serves as the output terminal of the forward current regulation module. N is a positive integer.

[0018] The negative current regulation module includes N second NMOS and N second controllable switches. The gates of the N second NMOS are all connected to the gates of the first NMOS, the sources of the N second NMOS are all grounded, and the sources of the N second NMOS are respectively connected to the first terminals of the N second controllable switches one by one. The common terminal of the connection of the second terminals of the N second controllable switches serves as the output terminal of the negative current regulation module.

[0019] Preferably, the aspect ratio of the second PMOS is the same as that of the third PMOS.

[0020] Preferably, the aspect ratio of the third PMOS is the same as that of each of the fourth PMOS, and the aspect ratio of the first NMOS is the same as that of each of the second NMOS.

[0021] The present invention also provides a voltage bias circuit, including a bandgap reference circuit and a low dropout voltage regulator circuit, and further including the above-mentioned device for adjusting the voltage value and voltage temperature coefficient.

[0022] Preferably, the low dropout voltage regulator circuit includes a first operational amplifier, a first PMOS, a first resistor, and a second resistor. The inverting input terminal of the first operational amplifier is connected to the voltage output terminal of the bandgap reference circuit where the voltage temperature coefficient is not zero. The first terminal of the first resistor is connected to the first terminal of the second resistor, and the common terminal of the connection is connected to the non-inverting input terminal of the first operational amplifier. The output terminal of the first operational amplifier is connected to the gate of the first PMOS. The source of the first PMOS is connected to the power supply. The drain of the first PMOS is connected to the second terminal of the first resistor, and the common terminal of the connection serves as the output terminal of the low dropout voltage regulator circuit. The second terminal of the second resistor is grounded.

[0023] Preferably, the bandgap reference circuit includes: a third operational amplifier, a fifth PMOS, a sixth PMOS, a first diode, a second diode, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a ninth resistor;

[0024] The source of the fifth PMOS and the source of the sixth PMOS are both connected to the power supply. The gate of the fifth PMOS and the gate of the sixth PMOS are connected, and their common terminal is connected to the output terminal of the third operational amplifier. The drain of the fifth PMOS is connected to the first terminal of the fourth resistor, and the drain of the sixth PMOS is connected to the first terminal of the fifth resistor.

[0025] The inverting input terminal of the third operational amplifier is connected to the second terminal of the fourth resistor, and the common terminal of the connection is connected to the positive terminal of the first diode. The non-inverting input terminal of the third operational amplifier is connected to the second terminal of the eighth resistor and the first terminal of the ninth resistor.

[0026] The negative terminals of the first diode and the second diode are both grounded, and the second terminal of the ninth resistor is connected to the positive terminal of the second diode;

[0027] The fifth resistor, the sixth resistor, the seventh resistor, and the eighth resistor are connected in sequence. The common terminal of the fifth resistor and the sixth resistor is the second voltage output terminal of the bandgap reference circuit. The common terminal of the sixth resistor and the seventh resistor is the first voltage output terminal of the bandgap reference circuit. The common terminal of the seventh resistor and the eighth resistor is the third voltage output terminal of the bandgap reference circuit. The voltage temperature coefficient of the first voltage output terminal is 0, the voltage temperature coefficient of the second voltage output terminal is positive, and the voltage temperature coefficient of the third voltage output terminal is negative.

[0028] This invention provides a device and voltage bias circuit for adjusting voltage value and voltage temperature coefficient, comprising a reference current conversion module and a current adjustment module. Since the reference current conversion module converts the reference voltage (with a voltage temperature coefficient of 0) output from the bandgap reference circuit into a reference current, the current adjustment module can output a current with an adjustable magnitude and / or direction based on the reference current and a voltage temperature coefficient of 0. The non-inverting input of the low-dropout regulator circuit is connected to the output of the current adjustment module to achieve independent voltage value adjustment, and the inverting input of the low-dropout regulator circuit is connected to the output of the bandgap reference circuit (with a voltage temperature coefficient of non-zero) to achieve independent adjustment of the voltage temperature coefficient. Ultimately, this enables the voltage bias circuit to independently adjust both the voltage value and the voltage temperature coefficient. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 A structural diagram of a device for adjusting voltage value and voltage temperature coefficient provided by the present invention;

[0031] Figure 2 A detailed structural diagram of a device for adjusting voltage value and voltage temperature coefficient provided by the present invention;

[0032] Figure 3 The present invention provides a structural diagram of a voltage biasing circuit. Detailed Implementation

[0033] The core of this invention is to provide a device and voltage bias circuit for adjusting voltage value and voltage temperature coefficient, which can independently adjust the voltage value and voltage temperature coefficient of the output voltage of the voltage bias circuit.

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0035] Please refer to Figure 1 , Figure 1 The present invention provides a structural diagram of a device for adjusting voltage value and voltage temperature coefficient, applied to a voltage bias circuit including a bandgap reference circuit and a low-dropout voltage regulator circuit. The low-dropout voltage regulator circuit includes a first operational amplifier, a first PMOS, a first resistor, and a second resistor. The inverting input terminal of the first operational amplifier is connected to the voltage output terminal of the bandgap reference circuit where the voltage temperature coefficient is not zero. The first terminal of the first resistor is connected to the first terminal of the second resistor, and the common terminal of the connection is connected to the non-inverting input terminal of the first operational amplifier. The output terminal of the first operational amplifier is connected to the gate of the first PMOS. The source of the first PMOS is connected to a power supply. The drain of the first PMOS is connected to the second terminal of the first resistor, and the common terminal of the connection serves as the output terminal of the low-dropout voltage regulator circuit. The second terminal of the second resistor is grounded. The device includes:

[0036] The reference current conversion module 1 is used to convert the reference voltage output from the first voltage output terminal of the bandgap reference circuit, which has a voltage temperature coefficient of 0, into a reference current. The reference current is positively correlated with the reference voltage.

[0037] The current adjustment module 2 has its input terminal connected to the output terminal of the reference current conversion module 1, and its output terminal connected to the non-inverting input terminal of the first operational amplifier and the first terminal of the first resistor, respectively. It is used to adjust the magnitude and / or direction of the output current based on the current adjustment command and the reference current, so as to adjust the output voltage of the low dropout voltage regulator circuit.

[0038] Many circuits require voltage biasing circuits to provide a reference voltage. The voltage temperature coefficient of the output voltage of a bandgap reference circuit within a voltage biasing circuit is fixed. For example, the voltage at the first voltage output terminal of a bandgap reference circuit is V. BG_TC0 , V BG_TC0 The voltage is 1.2V, with a voltage temperature coefficient of 0; the voltage at the second voltage output terminal is V. BG_TCP , V BG_TCP The voltage is greater than 1.2V, and the voltage temperature coefficient is positive; the voltage at the third voltage output terminal is V. BG_TCN , V BG_TCN The voltage is less than 1.2V, and the voltage temperature coefficient is negative. In existing low-dropout voltage regulator circuits, the inverting input V of the first operational amplifier... BG_TC The voltage value V at the output terminal of the low dropout voltage regulator circuit is connected to the first, second, or third voltage output terminal. LDO =V BG_TC (1+R1 / R2), where R1 is the first resistor and R2 is the second resistor. It is evident that current technology cannot independently adjust the output voltage V of a low-dropout voltage regulator circuit. LDO The voltage temperature coefficient of the output voltage of a low-dropout voltage regulator circuit.

[0039] To solve the above-mentioned technical problems, this invention provides a reference current conversion module 1 and a current adjustment module 2. The reference current conversion module 1 is connected to the first voltage output terminal of the bandgap reference circuit, where the voltage temperature coefficient is 0. Therefore, the voltage temperature coefficient of the reference current output by the reference current conversion module 1 is 0. The input terminal of the current adjustment module 2 is connected to the output terminal of the reference current conversion module 1, so the voltage temperature coefficient of the output current of the current adjustment module 2 is also 0. The output terminal of the current adjustment module 2 is connected to the non-inverting input terminal of the first operational amplifier and the first end of the first resistor R1. If the output current of the current adjustment module 2 is I, then V in this application... LDO =V BG_TC (1+R1 / R2)+IR1, it can be seen that by changing V BG_TC Adjust V LDOThe voltage temperature coefficient of IR1 is 0, while that of IR2 is 0. Therefore, V can be adjusted by changing the magnitude and / or direction of I. LDO The voltage value. The magnitude and / or direction of I can be adjusted based on current regulation commands and reference current.

[0040] In summary, the present invention provides a device for adjusting voltage value and voltage temperature coefficient, comprising a reference current conversion module 1 and a current adjustment module 2. Since the reference current conversion module 1 converts the reference voltage (with a voltage temperature coefficient of 0) output from the bandgap reference circuit into a reference current, the current adjustment module 2 can output a current with an adjustable magnitude and / or direction based on the reference current and a voltage temperature coefficient of 0. The non-inverting input terminal of the low-dropout regulator circuit is connected to the output terminal of the current adjustment module 2 to achieve independent voltage value adjustment, and the inverting input terminal of the low-dropout regulator circuit is connected to the output terminal of the bandgap reference circuit (with a voltage temperature coefficient of non-zero) to achieve independent voltage temperature coefficient adjustment. Ultimately, this enables the voltage bias circuit to independently adjust both the voltage value and the voltage temperature coefficient.

[0041] Based on the above embodiment:

[0042] In a preferred embodiment, the current regulation command includes a first current regulation command and / or a second current regulation command;

[0043] The current regulation module 2 includes a positive current regulation module 2 and a negative current regulation module 2. The output terminals of both the positive and negative current regulation modules 2 are connected to the non-inverting input terminal of the first operational amplifier and the first terminal of the first resistor.

[0044] The forward current regulation module 2 is used to adjust the magnitude of the forward output current based on the first current regulation command and the reference current when the first current regulation command is received. The direction of the forward output current is from the output terminal of the low dropout voltage regulator circuit to the output terminal of the forward regulation module, so as to increase the magnitude of the output voltage of the low dropout voltage regulator circuit.

[0045] The negative current regulation module 2 is used to adjust the magnitude of the negative output current based on the second current regulation command and the reference current when the second current regulation command is received. The direction of the negative output current is from the output terminal of the negative regulation module to the output terminal of the low dropout voltage regulator circuit, so as to reduce the magnitude of the output voltage of the low dropout voltage regulator circuit.

[0046] The output current is the sum of the positive output current and the negative output current.

[0047] In this embodiment, the current regulation module 2 includes a positive current regulation module 2 and a negative current regulation module 2. Since current in the external circuit always flows from a high potential to a low potential, the direction of the positive output current of the positive current regulation module 2 is set from the output terminal of the low-dropout voltage regulator circuit to the output terminal of the positive regulation module, so as to raise the potential of the output voltage of the low-dropout voltage regulator circuit and achieve the purpose of increasing the output voltage; the direction of the negative output current of the negative current regulation module 2 is set from the output terminal of the negative regulation module to the output terminal of the low-dropout voltage regulator circuit, so as to lower the potential of the output voltage of the low-dropout voltage regulator circuit and achieve the purpose of decreasing the output voltage.

[0048] The magnitude of the positive output current is adjusted based on the first current adjustment command and the reference current, while the magnitude of the negative output current is adjusted based on the second current adjustment command and the reference current. If the positive output current is I... P The negative output current is I N The output current I of the circuit adjustment module is I P with I N The vector sum of V LDO =V BG_TC (1+R1 / R2)+(I P +I N R1. The current adjustment command may include only the first current adjustment command to increase the output voltage of the low-dropout regulator circuit, or only the second current adjustment command to decrease the output voltage of the low-dropout regulator circuit, or both the first and second current adjustment commands.

[0049] In summary, this application provides a positive current adjustment module 2 and a negative current adjustment module 2, which can increase or decrease the output voltage of the low dropout voltage regulator circuit according to actual circuit requirements without changing the temperature coefficient of the output voltage of the low dropout voltage regulator circuit.

[0050] In a preferred embodiment, the reference current conversion module 1 includes a second operational amplifier, a second PMOS, and a third resistor;

[0051] The inverting input of the second operational amplifier is connected to the voltage output of the bandgap reference circuit with a voltage temperature coefficient of 0. The non-inverting input of the second operational amplifier is connected to the first end of the third resistor. The output of the second operational amplifier is connected to the gate of the second PMOS. The second end of the third resistor is grounded.

[0052] The source of the second PMOS is connected to the power supply, and the drain of the second PMOS is connected to the first end of the third resistor.

[0053] In this embodiment, the reference current conversion module 1 includes a second operational amplifier, a second PMOS, and a third resistor, capable of converting the reference voltage output from the first voltage output terminal of the bandgap reference circuit, which has a voltage temperature coefficient of 0, into a reference current. If the voltage at the first voltage output terminal, i.e., the reference voltage, is V... BG_TC0 The voltage at the non-inverting input of the second operational amplifier is U. + The voltage at the inverting input of the second operational amplifier is U. - U + =U - =V BG_TC0 The current at the common terminal connecting the non-inverting input of the second operational amplifier and the first terminal of the third resistor is V. BG_TC0 / R3, then the reference current I0 = V BG_TC0 / R3, it can be seen that the voltage temperature coefficient of I0 is 0, so that the current adjustment module 2 can adjust the output voltage of the low dropout voltage regulator circuit based on I0, where R3 is the resistance value of the third resistor.

[0054] It should be noted that, due to the negative feedback effect of the second PMOS, the voltage U at the non-inverting input of the second operational amplifier is... + The voltage U at the inverting input terminal - They are always approximately equal. + with U - The initial size relationship includes U + >U - U + ≈U - And U + - U here + with U - The initial size relationship is U + >U - Taking the second PMOS as an example, we will explain its negative feedback effect. The voltage at the output of the second operational amplifier is U. Δ =U + -U - =(U + -V BG_TC0 )A, where U + >U - The second A is the amplification factor of the operational amplifier, and A is a positive number, so U Δ The voltage value is positive and increases with U + The voltage increases with the increase of [the voltage]. The source of the second PMOS is connected to the power supply, so the source voltage V of the second PMOS increases. S The voltage remains unchanged, while the gate voltage V of the second PMOS remains unchanged. G =U Δ U Δ Enlarging leads to V G ​Increase, making V GS This reduces the current I after the second PMOS is turned on. 2p Decrease, leading to U + =R3I 2p Decrease, and the above process continues until U + ≈U - Therefore, the voltage U at the non-inverting input of the second operational amplifier + Voltage U at the inverting input terminal - They are always approximately equal.

[0055] In summary, the reference current conversion module 1 provided in this application can convert the reference voltage of the first voltage output terminal of the bandgap reference circuit, which has a voltage temperature coefficient of 0, into a reference current, and the circuit structure is simple and reliable.

[0056] In a preferred embodiment, the current regulation module 2 further includes a third PMOS and a first NMOS;

[0057] The source of the third PMOS is connected to the power supply, the gate is connected to the gate of the second PMOS, the drain is connected to the drain and gate of the first NMOS, and the source of the first NMOS is grounded.

[0058] The forward current regulation module 2 includes N fourth PMOS and N first controllable switches. The sources of the N fourth PMOS are all connected to the power supply, the gates of the N fourth PMOS are all connected to the gates of the third PMOS, the drains of the N fourth PMOS are respectively connected to the first terminals of the N first controllable switches, and the second terminals of the N first controllable switches are connected together, and the common terminal of the connection is used as the output terminal of the forward current regulation module 2. N is a positive integer.

[0059] The negative current regulation module 2 includes N second NMOS and N second controllable switches. The gates of the N second NMOS are all connected to the gates of the first NMOS, the sources of the N second NMOS are all grounded, and the sources of the N second NMOS are respectively connected to the first terminals of the N second controllable switches one by one. The second terminals of the N second controllable switches are connected and the common terminal of the connection is used as the output terminal of the negative current regulation module 2.

[0060] Please refer to Figure 2 , Figure 2 A detailed structural diagram of a device for adjusting voltage value and voltage temperature coefficient provided by the present invention.

[0061] The current after the MOSFET is turned on is (V GS -V TH ) 2 (W / L), where V GS V is the turn-on voltage of the MOSFET. THWhere V is the threshold voltage of the MOSFET, and W / L is the width-to-length ratio of the MOSFET. If the V of each MOSFET... GS and V TH If they are the same, then the ratio of the currents after each MOSFET is turned on is equal to the ratio of the width-to-length ratio of each MOSFET.

[0062] Based on the above principle, in this embodiment, the source of the third PMOS is connected to the power supply, and its gate is connected to the gate of the second PMOS. If the ratio of the width-to-length ratio of the second PMOS to that of the third PMOS is B1, the current after the second PMOS is turned on is I. 2p Then the current I after the third PMOS is turned on 3p =B1I 2p The current in the branch formed by the third PMOS and the first NMOS is also I. 3p .

[0063] Since the sources of all N fourth PMOS transistors in the forward current regulation module 2 are connected to the power supply, and the gates of all N fourth PMOS transistors are connected to the gates of the third PMOS transistors, the current after each fourth PMOS transistor is turned on is I. 3p Multiplying by the ratio of the width-to-length ratio of each fourth PMOS to that of the third PMOS, the number of fourth PMOS transistors turned on among the N fourth PMOS transistors can be controlled based on the first current adjustment command. Since the gates of all N second NMOS transistors in the negative current adjustment module 2 are connected to the gates of the first NMOS transistors, and the sources of all N second NMOS transistors are grounded, the current after each second NMOS transistor is turned on is I. 3p By multiplying the width-to-length ratio of each second NMOS by the ratio of the width-to-length ratio of the first NMOS, the number of second NMOS turned on among the N second NMOS can be controlled based on the second current adjustment command.

[0064] In summary, the positive current regulation module 2 and negative current regulation module 2 provided in this application can increase or decrease the output voltage of the low dropout voltage regulator circuit according to the actual circuit requirements without changing the temperature coefficient of the output voltage of the low dropout voltage regulator circuit. Moreover, the circuit structure is simple and easy to implement.

[0065] In a preferred embodiment, the width-to-length ratio of the second PMOS is the same as that of the third PMOS.

[0066] The current after the MOSFET is turned on is (V GS -V TH ) 2 (W / L), where V GS V is the turn-on voltage of the MOSFET. TH Where V is the threshold voltage of the MOSFET, and W / L is the width-to-length ratio of the MOSFET. If the V of each MOSFET... GSand V TH If the width and length ratios are the same, then the ratio of the currents after each MOS transistor is turned on is equal to the ratio of the width and length ratios of each MOS transistor. Based on the above principle, in this embodiment, a second PMOS and a third PMOS with the same width and length ratio are selected. Therefore, the current after the second PMOS is turned on is equal to the current after the third PMOS is turned on, making it more intuitive and simple to adjust the output current of the current adjustment module 2, and the circuit structure is simple and easy to implement.

[0067] In a preferred embodiment, the aspect ratio of the third PMOS is the same as that of each of the fourth PMOS, and the aspect ratio of the first NMOS is the same as that of each of the second NMOS.

[0068] The current after the MOSFET is turned on is (V GS -V TH ) 2 (W / L), where V GS V is the turn-on voltage of the MOSFET. TH Where V is the threshold voltage of the MOSFET, and W / L is the width-to-length ratio of the MOSFET. If the V of each MOSFET... GS and V TH If the width-to-length ratios of the MOSFETs are the same, then the ratio of the currents after each MOSFET is turned on is equal to the ratio of the width-to-length ratios of the MOSFETs. Based on the above principle, in this embodiment, a fourth PMOS with the same width-to-length ratio as the third PMOS and a second NMOS with the same width-to-length ratio as the first NMOS are selected. For example, if X fourth PMOS transistors are turned on based on a first current adjustment command, and Y second NMOS transistors are turned on based on a second current adjustment command, the current after the third PMOS is turned on is I. 3p Then the output current of current regulating module 2 is (YX)I 3p The output voltage V of the low dropout voltage regulator circuit LDO =V BG_TC (1+R1 / R2)+(YX)I 3p R1 further makes adjusting the output current of the current adjustment module 2 more intuitive and simple, and the circuit structure is simple and easy to implement.

[0069] Please refer to Figure 3 , Figure 3 The present invention provides a structural diagram of a voltage bias circuit, which includes a bandgap reference circuit 31 and a low dropout voltage regulator circuit 32, and also includes the aforementioned device for adjusting the voltage value and voltage temperature coefficient.

[0070] For a detailed description of the voltage bias circuit provided by this invention, please refer to the above description of the device for adjusting voltage value and voltage temperature coefficient, which will not be repeated here.

[0071] Figure 3Taking the connection of the non-inverting input terminal of the first operational amplifier in the low-dropout voltage regulator circuit 32 to the second voltage output terminal of the bandgap reference circuit as an example, the second voltage output terminal is the common terminal connected by the fifth resistor R5 and the sixth resistor R6. In fact, the non-inverting input terminal of the first operational amplifier in the low-dropout voltage regulator circuit 32 can also be connected to the third voltage output terminal of the bandgap reference circuit. The third voltage output terminal is the common terminal connected by the seventh resistor R7 and the eighth resistor R8. This application does not make any special limitation on this.

[0072] Based on the above embodiment:

[0073] In a preferred embodiment, the low dropout voltage regulator circuit 32 includes a first operational amplifier, a first PMOS, a first resistor, and a second resistor. The inverting input terminal of the first operational amplifier is connected to the voltage output terminal of the bandgap reference circuit 31 where the voltage temperature coefficient is not zero. The first terminal of the first resistor is connected to the first terminal of the second resistor, and the common terminal of the connection is connected to the non-inverting input terminal of the first operational amplifier. The output terminal of the first operational amplifier is connected to the gate of the first PMOS. The source of the first PMOS is connected to the power supply. The drain of the first PMOS is connected to the second terminal of the first resistor, and the common terminal of the connection serves as the output terminal of the low dropout voltage regulator circuit 32. The second terminal of the second resistor is grounded.

[0074] For a detailed description of the voltage bias circuit provided by this invention, please refer to the above description of the device for adjusting voltage value and voltage temperature coefficient, which will not be repeated here.

[0075] In a preferred embodiment, the bandgap reference circuit 31 includes: a third operational amplifier, a fifth PMOS, a sixth PMOS, a first diode, a second diode, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a ninth resistor;

[0076] The source of the fifth PMOS and the source of the sixth PMOS are both connected to the power supply. The gate of the fifth PMOS and the gate of the sixth PMOS are connected, and the common terminal of the connection is connected to the output terminal of the third operational amplifier. The drain of the fifth PMOS is connected to the first terminal of the fourth resistor, and the drain of the sixth PMOS is connected to the first terminal of the fifth resistor.

[0077] The inverting input of the third operational amplifier is connected to the second terminal of the fourth resistor, and the common terminal of the connection is connected to the positive terminal of the first diode. The non-inverting input of the third operational amplifier is connected to the second terminal of the eighth resistor and the first terminal of the ninth resistor.

[0078] The negative terminals of the first diode and the second diode are both grounded, and the second terminal of the ninth resistor is connected to the positive terminal of the second diode.

[0079] The fifth, sixth, seventh, and eighth resistors are connected in sequence. The common terminal of the fifth and sixth resistors is the second voltage output terminal of the bandgap reference circuit 31. The common terminal of the sixth and seventh resistors is the first voltage output terminal of the bandgap reference circuit 31. The common terminal of the seventh and eighth resistors is the third voltage output terminal of the bandgap reference circuit 31. The voltage temperature coefficient of the first voltage output terminal is 0, the voltage temperature coefficient of the second voltage output terminal is positive, and the voltage temperature coefficient of the third voltage output terminal is negative.

[0080] For a detailed description of the voltage bias circuit provided by this invention, please refer to the above description of the device for adjusting voltage value and voltage temperature coefficient, which will not be repeated here.

[0081] It should be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0082] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A device for adjusting voltage value and voltage temperature coefficient, applied to a voltage biasing circuit including a bandgap reference circuit and a low-dropout voltage regulator circuit, characterized in that, The low-dropout voltage regulator circuit includes a first operational amplifier, a first PMOS, a first resistor, and a second resistor. The inverting input terminal of the first operational amplifier is connected to the voltage output terminal of the bandgap reference circuit where the voltage temperature coefficient is not zero. The first terminal of the first resistor is connected to the first terminal of the second resistor, and their common terminal is connected to the non-inverting input terminal of the first operational amplifier. The output terminal of the first operational amplifier is connected to the gate of the first PMOS. The source of the first PMOS is connected to a power supply. The drain of the first PMOS is connected to the second terminal of the first resistor, and their common terminal serves as the output terminal of the low-dropout voltage regulator circuit. The second terminal of the second resistor is grounded. The device includes: A reference current conversion module is used to convert the reference voltage output from the first voltage output terminal of the bandgap reference circuit, which has a voltage temperature coefficient of 0, into a reference current, wherein the reference current is positively correlated with the reference voltage. A current regulation module, wherein the input terminal of the current regulation module is connected to the output terminal of the reference current conversion module, and the output terminal is connected to the non-inverting input terminal of the first operational amplifier and the first terminal of the first resistor, respectively, for adjusting the magnitude and / or direction of the output current based on the current regulation command and the reference current, so as to regulate the output voltage of the low dropout voltage regulator circuit.

2. The device for adjusting voltage value and voltage temperature coefficient as described in claim 1, characterized in that, The current regulation command includes a first current regulation command and / or a second current regulation command; The current regulation module includes a positive current regulation module and a negative current regulation module. The output terminals of both the positive and negative current regulation modules are connected to the non-inverting input terminal of the first operational amplifier and the first terminal of the first resistor. A forward current regulation module is used to adjust the magnitude of the forward output current based on the first current regulation command and the reference current when the first current regulation command is received. The direction of the forward output current is from the output terminal of the low dropout voltage regulator circuit to the output terminal of the forward current regulation module, so as to increase the magnitude of the output voltage of the low dropout voltage regulator circuit. A negative current regulation module is used to adjust the magnitude of the negative output current based on the second current regulation command and the reference current when the second current regulation command is received. The direction of the negative output current is from the output terminal of the negative current regulation module to the output terminal of the low dropout voltage regulator circuit, so as to reduce the magnitude of the output voltage of the low dropout voltage regulator circuit. The output current is the sum of the positive output current and the negative output current.

3. The device for adjusting voltage value and voltage temperature coefficient as described in claim 2, characterized in that, The reference current conversion module includes a second operational amplifier, a second PMOS, and a third resistor; The inverting input terminal of the second operational amplifier is connected to the voltage output terminal of the bandgap reference circuit with a voltage temperature coefficient of 0; the non-inverting input terminal of the second operational amplifier is connected to the first terminal of the third resistor; the output terminal of the second operational amplifier is connected to the gate of the second PMOS; and the second terminal of the third resistor is grounded. The source of the second PMOS is connected to the power supply, and the drain of the second PMOS is connected to the first end of the third resistor.

4. The device for adjusting voltage value and voltage temperature coefficient as described in claim 3, characterized in that, The current regulation module also includes a third PMOS and a first NMOS; The source of the third PMOS is connected to the power supply, the gate is connected to the gate of the second PMOS, the drain is connected to the drain and gate of the first NMOS, and the source of the first NMOS is grounded. The forward current regulation module includes N fourth PMOS and N first controllable switches. The sources of the N fourth PMOS are all connected to the power supply, the gates of the N fourth PMOS are all connected to the gates of the third PMOS, the drains of the N fourth PMOS are respectively connected to the first terminals of the N first controllable switches, and the common terminal of the N first controllable switches is connected to the second terminals and serves as the output terminal of the forward current regulation module. N is a positive integer. The negative current regulation module includes N second NMOS and N second controllable switches. The gates of the N second NMOS are all connected to the gates of the first NMOS, the sources of the N second NMOS are all grounded, and the sources of the N second NMOS are respectively connected to the first terminals of the N second controllable switches one by one. The common terminal of the connection of the second terminals of the N second controllable switches serves as the output terminal of the negative current regulation module.

5. The device for adjusting voltage value and voltage temperature coefficient as described in claim 4, characterized in that, The width-to-length ratio of the second PMOS is the same as that of the third PMOS.

6. The device for adjusting voltage value and voltage temperature coefficient as described in claim 4, characterized in that, The aspect ratio of the third PMOS is the same as that of each of the fourth PMOS, and the aspect ratio of the first NMOS is the same as that of each of the second NMOS.

7. A voltage biasing circuit, characterized in that, It includes a bandgap reference circuit and a low-dropout voltage regulator circuit, and also includes the means for adjusting the voltage value and voltage temperature coefficient as described in any one of claims 1 to 6.

8. The voltage biasing circuit as described in claim 7, characterized in that, The low dropout voltage regulator circuit includes a first operational amplifier, a first PMOS, a first resistor, and a second resistor. The inverting input terminal of the first operational amplifier is connected to the voltage output terminal of the bandgap reference circuit where the voltage temperature coefficient is not zero. The first terminal of the first resistor is connected to the first terminal of the second resistor, and the common terminal of the connection is connected to the non-inverting input terminal of the first operational amplifier. The output terminal of the first operational amplifier is connected to the gate of the first PMOS. The source of the first PMOS is connected to the power supply. The drain of the first PMOS is connected to the second terminal of the first resistor, and the common terminal of the connection serves as the output terminal of the low dropout voltage regulator circuit. The second terminal of the second resistor is grounded.

9. The voltage biasing circuit as described in claim 7, characterized in that, The bandgap reference circuit includes: a third operational amplifier, a fifth PMOS, a sixth PMOS, a first diode, a second diode, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a ninth resistor; The source of the fifth PMOS and the source of the sixth PMOS are both connected to the power supply. The gate of the fifth PMOS and the gate of the sixth PMOS are connected, and their common terminal is connected to the output terminal of the third operational amplifier. The drain of the fifth PMOS is connected to the first terminal of the fourth resistor, and the drain of the sixth PMOS is connected to the first terminal of the fifth resistor. The inverting input terminal of the third operational amplifier is connected to the second terminal of the fourth resistor, and the common terminal of the connection is connected to the positive terminal of the first diode. The non-inverting input terminal of the third operational amplifier is connected to the second terminal of the eighth resistor and the first terminal of the ninth resistor. The negative terminals of the first diode and the second diode are both grounded, and the second terminal of the ninth resistor is connected to the positive terminal of the second diode; The fifth resistor, the sixth resistor, the seventh resistor, and the eighth resistor are connected in sequence. The common terminal of the fifth resistor and the sixth resistor is the second voltage output terminal of the bandgap reference circuit. The common terminal of the sixth resistor and the seventh resistor is the first voltage output terminal of the bandgap reference circuit. The common terminal of the seventh resistor and the eighth resistor is the third voltage output terminal of the bandgap reference circuit. The voltage temperature coefficient of the first voltage output terminal is 0, the voltage temperature coefficient of the second voltage output terminal is positive, and the voltage temperature coefficient of the third voltage output terminal is negative.

Images