CN114879801A

CN114879801A - Current generation circuit with adjustable temperature coefficient

Info

Publication number: CN114879801A
Application number: CN202210619911.7A
Authority: CN
Inventors: 宋佳音; 杨中; 付江铎; 陈文亚; 黄一斌
Original assignee: Jiangsu Jicui Intelligent Integrated Circuit Design Technology Research Institute Co ltd
Current assignee: Jiangsu Jicui Intelligent Integrated Circuit Design Technology Research Institute Co ltd
Priority date: 2022-06-02
Filing date: 2022-06-02
Publication date: 2022-08-09

Abstract

The invention discloses a temperature coefficient adjustable current generating circuit, which has a larger current temperature coefficient adjusting range and can improve the accuracy of the generated current, and comprises a voltage-to-current module and a temperature coefficient adjusting module, wherein one end of the voltage-to-current module is connected with a band gap reference voltage source, the other end of the voltage-to-current module is connected with one end of the temperature coefficient adjusting module, and the other end of the temperature coefficient adjusting module is a current output end; the voltage-to-current module is used for converting the voltage of the band-gap reference voltage source into a first temperature coefficient current and carrying out primary adjustment on the magnitude of the first temperature coefficient current to obtain a primary adjustment current; the temperature coefficient adjusting module is used for adjusting the temperature coefficient of the primary adjusting current and compensating the size of the primary adjusting current; and the other end of the temperature coefficient adjusting module outputs a second temperature coefficient current after the temperature coefficient is adjusted and the current magnitude is compensated.

Description

Current generation circuit with adjustable temperature coefficient

Technical Field

The invention relates to the technical field of integrated circuits, in particular to a temperature coefficient adjustable current generation circuit.

Background

In the chip design process, the circuit is susceptible to PVT variation, which mainly refers to variation of chip process, voltage and temperature, and in the conventional bias current generation circuit, PVT variation not only causes variation of the temperature coefficient and magnitude of the bias current, but also easily causes deterioration of the gain and linearity of the bias current circuit, thereby affecting the stability of the performance of the related circuit. The wide temperature range circuit is typically: the electrical performance of the amplifier, especially the dynamic amplifier, varies greatly with temperature under advanced process conditions, and the variation of the chip temperature can cause the deterioration of the electrical performance (such as the working stability of the chip and the accuracy of the current magnitude).

The currently common way to reduce the effect of PVT variations on the circuit is: the temperature change is adapted through the adjustment of the temperature coefficient of the bias current, but when the temperature coefficient of the current is adjusted in the prior art, the current magnitude can be amplified or reduced in equal proportion along with the change of the temperature coefficient of the current, so that the stability and the accuracy of the current output by the bias current generating circuit are reduced, and the working stability of the whole chip is influenced. In order to prevent the circuit stability from being reduced due to large current size change, the adjustment range of the current temperature coefficient cannot be too large, but the application range of the whole current generation circuit is narrow due to the limited adjustment range of the current temperature coefficient, and the application requirement of a wide temperature range circuit (such as a dynamic amplifier under an advanced process) cannot be met.

Disclosure of Invention

The invention provides a temperature coefficient adjustable current generation circuit, which can enlarge the adjustment range of a current temperature coefficient and improve the accuracy of the generated current.

In order to achieve the purpose, the invention adopts the following technical scheme:

a temperature coefficient adjustable current generation circuit comprises a voltage-to-current module and a temperature coefficient adjusting module, wherein one end of the voltage-to-current module is connected with a band gap reference voltage source, the other end of the voltage-to-current module is connected with one end of the temperature coefficient adjusting module, and the other end of the temperature coefficient adjusting module is a current output end;

the voltage-to-current module is used for converting the voltage of the band-gap reference voltage source into a first temperature coefficient current and carrying out primary adjustment on the magnitude of the first temperature coefficient current to obtain a primary adjustment current;

the temperature coefficient adjusting module is used for adjusting the temperature coefficient of the primary adjusting current and compensating the size of the primary adjusting current;

and the other end of the temperature coefficient adjusting module outputs a second temperature coefficient current after the temperature coefficient is adjusted and the current magnitude is compensated.

It is further characterized in that the method further comprises the steps of,

the voltage-to-current module comprises an operational amplifier, a first switch control unit and a current temperature coefficient adjusting unit, wherein the forward input end of the operational amplifier is connected with a band gap reference voltage source, the voltage of the band gap reference voltage source is zero temperature coefficient voltage, the reverse input end of the operational amplifier is connected with one end of the current temperature coefficient adjusting unit, one end of the first switch control unit and the other end of the current temperature coefficient adjusting unit are connected with one end of the temperature coefficient adjusting module, the operational amplifier and the current temperature coefficient adjusting unit are used for generating first temperature coefficient current relevant to temperature coefficient, the first switch control unit is used for adjusting the current of the first temperature coefficient current at one time, the first switch control unit comprises a plurality of switches, and the switches are respectively connected with a power supply through a control voltage VBP, Control word TA < n:1> control;

the first switch control unit comprises N MOS tubes MP3 and N MOS tubes MP4, wherein N is a positive integer, the current temperature coefficient adjusting unit comprises MOS tubes MP1 and a resistor R1, the output end of the operational amplifier is respectively connected with one end of the resistor R1 and a gate of the MOS tube MP1, the drain of the MOS tube MP1 is connected with the drain and the gate of the MOS tube MP2 in the temperature coefficient adjusting module, the source of the MOS tube MP2 is respectively connected with the source of the N MOS tubes MP3 and the gate of the MOS tube MP5 in the temperature coefficient adjusting module, the gates of the N MOS tubes MP4 are controlled by a control voltage VBP, the drains of the N MOS tubes MP4 are correspondingly connected with the drains of the N MOS tubes MP3 one by one, the gate of the MOS tube MP3 is controlled by a control word TA < N:1>, and the source of the MOS tube MP4 is connected with the source of the MOS tubes MP5 and the MOS tubes MP7, the source of the MOS tubes MP9 and the MP11 in the temperature coefficient adjusting module;

the MOS tubes MP 1-MP 4 are PMOS tubes;

the temperature coefficient adjusting module comprises first to fourth current mirrors, a second switch control unit and a third switch control unit, the first current mirror is used for copying the first temperature coefficient current output by the power supply current conversion module according to proportions K1 and K2, the second current mirror and the third current mirror are used for copying the current passing through the first current mirror according to proportion K5, one ends of the first current mirror, the second switch control unit and the second current mirror are sequentially connected to form a first current branch, one end of the third current mirror, one end of the third switch control unit and one end of the fourth current mirror are sequentially connected to form a second current branch, the other end of the second current mirror is connected with the other end of the third current mirror, the conduction or the closing of the first current branch is controlled through the second switch control unit, and the conduction or the closing of the second current branch is controlled through the third switch control unit, the other end of the fourth current mirror is the current output end and is used for outputting the second temperature coefficient current after temperature coefficient adjustment and current magnitude compensation, a plurality of switches in the second switch control unit are controlled by control words TC1< n:1>, a plurality of switches in the third switch unit are respectively controlled by control words TC1< n:1>, control voltages VBN1 and VBN2, the temperature coefficient adjustment of the primary adjustment current is realized by controlling the switches in the second switch control unit by the control words TC1< n:1>, and the current magnitude compensation of the primary adjustment current is realized by controlling the switches in the third switch unit by the control words TC1< n:1>, the control voltages VBN1 and VBN 2;

the first current mirror comprises MOS tubes MP2, MP5 and MP7, the second current mirror branch comprises MOS tubes MN 1-MN 4, the third current mirror branch comprises MOS tubes MP 8-MP 11, the fourth current mirror branch comprises MOS tubes MN 11-MN 11, the second switch control unit comprises N MOS tubes MP11, the third switch control unit comprises M MOS tubes MP11, M MOS tubes MN11 and M MOS tubes MN11, wherein M is a positive integer, the sources of the MOS tubes MP11 are respectively connected with the sources of the MOS tubes MP11, the drains of the MOS tubes MP11 are respectively connected with the drains of the MOS tubes MN11, the gates of the MOS tubes MN11 and the MOS tubes MN11, the sources of the MOS tubes MN11 are respectively connected with the gates of the MOS tubes MN11, the sources of the MOS tubes MP11, the drain of the MOS tubes MP11 are respectively connected with the sources of the MOS tubes MN11, the sources of the MOS tubes MP11 and the drain of the MOS tubes MP11 and the MOS tubes MN11, and the drain of the MOS tubes MP11 are respectively connected with the gates of the MOS tubes MN11, and the sources of the MOS tubes MP11, the drain of the MOS tubes MP11, and the drain of the MOS tubes MP11 are respectively connected with the gates of the MOS tubes MN11, and the drain of the MOS tubes MN11, and the MOS tubes MP11, and the drain of the MOS tubes MP11, and the drain of the MOS tubes MP11 and the MOS tubes MP11, and the drain of the MOS tubes MP11 are respectively, MOS pipe MP10 grid, MOS pipe MN3 source, MOS pipe MN3 drain-electrode is connected MOS pipe MN4 drain-electrode, MOS pipe MN2 source-electrode is connected respectively MOS pipe MN4 source-electrode, MOS pipe MN6, MN8, MN10 source-electrode, MOS pipe MP11 drain-electrode is connected MOS pipe MP10 drain-electrode, M MOS pipe MP10 source-electrode is connected M MOS pipe MP24 source-electrode, MOS pipe MN7 source-electrode, grid and MOS pipe MN9 grid, MOS pipe MP24 drain-electrode is established ties in proper order MOS pipe MN5, MN6, M MOS pipe MP6 grid-electrode is through control word TC1< n:1> control, the grid of the MOS tube MP24 is controlled by a control word TC1< n:1 is greater than control, M MOS tubes MN5 are controlled by a control voltage VBN1, M MOS tubes MN6 are controlled by a control power supply VBN2, drains of the MOS tubes MN7 are respectively connected with drains and gates of MOS tubes MN8 and MN10, drains of the MOS tubes MN10 are connected with drains of the MOS tubes MN9, and sources of the MOS tubes MN9 are current output ends;

the MOS tubes MP 5-MP 11 and the MOS tube MP24 are PMOS tubes, and the MOS tubes MN 1-MN 10 are NMOS tubes.

A voltage-to-current method is applied to the voltage-to-current module, and is characterized in that the step of converting the zero temperature coefficient voltage of a bandgap reference voltage source into current by using the voltage-to-current module comprises the following steps: a1, amplifying the zero temperature coefficient voltage by an operational amplifier to obtain an amplified current;

a2, converting the amplified current through a current temperature coefficient adjusting unit to obtain a first temperature coefficient current;

a3, controlling the switch in the first switch control unit by control voltage VBP and control word TA < n:1> to realize the primary adjustment of the current of the first temperature coefficient current, and obtaining the primary adjustment current.

It is further characterized in that the method further comprises the steps of,

in step a2, the amplified current is compensated by the MOS transistor MP1 and the resistor R1 in the current temperature coefficient adjustment unit, and a first temperature coefficient current related to the temperature coefficient of the resistor R1 is generated;

in step a3, the N MOS transistors MP4 and N MOS transistors MP3 in the first switch control unit are respectively controlled by the control voltage VBP and the control word TA < N:1>, and the specific steps of the first switch control unit adjusting the first temperature coefficient current include: when the first temperature coefficient current flows through the MOS tube MP4, the grid electrode of the N MOS tubes MP4 is controlled by the control voltage VBP, meanwhile, the grid electrode of the N MOS tubes MP3 is controlled by the control word TA < N:1>, and the current magnitude of the first temperature coefficient current is adjusted for one time;

the specific steps of controlling the gate of the MOS transistor MP3 by the control word TA < n:1> include: a321, when n is 0 and TA < n:1> is 0, the MOS tube MP3 at the corresponding position is closed, the current of the MOS tube MP4 at the corresponding position enters the branch of the MOS tube MP1 through the MOS tube MP3, and the addition of the current of the MOS tube MP1 and the current of the MOS tube MP2 is realized; a322, when n is 1 and TA < n:1> is 1, the MOS tube MP3 is turned off, and the current from the branch of the MOS tube MP4 to the branch of the MOS tube MP1 is turned off through the MOS tube MP3, so that the current magnitude adjustment of the first temperature coefficient current is realized, and the current with the positive temperature coefficient is obtained.

The voltage at the reverse input end of the operational amplifier is feedback voltage, the feedback voltage is equal to the control voltage VBG and is zero temperature coefficient voltage, the feedback voltage passes through a grounded resistor R1, and the resistor R1 has negative temperature coefficient characteristics, so that a current branch where the resistor R1 is located has positive temperature coefficient current. The current Imp2 passing through the MOS transistor MP2 is Imp1-Imp4, and the current Imp1 is Ir1, so that the current passing through the MOS transistor MP4 and the MOS transistor MP3 is adjusted, the current Imp2 passing through the MOS transistor MP2 can be directly changed, the current of the MOS transistor MP4 and the current of the MOS transistor MP3 are controlled by a control word, and therefore, the current of the MOS transistor MP4 and the current of the MOS transistor MP3 are adjusted by the control word TA < n:1>, and the current magnitude adjustment of the first temperature coefficient current can be realized.

A current temperature coefficient adjusting method applies the temperature coefficient adjusting module, and is characterized in that the step of adjusting the temperature coefficient of the current by using the temperature coefficient adjusting module comprises the following steps: b1, the first current branch is conducted under the control of the second switch control unit;

b2, copying the first positive temperature coefficient current proportion K1 and K2 through a first current mirror;

b3, controlling the switch in the third switch control unit through a control word TC1< m:1> and control voltages VBN1 and VBN2, and realizing the compensation of the current after the temperature coefficient adjustment;

and B4, copying the compensated current through a fourth current mirror, and outputting a second temperature coefficient current at the current output end.

It is further characterized in that the method further comprises the steps of,

the size ratio of the MOS transistor MP5 to the MOS transistor MP2 is K1, and the ratio of the current passing through the MOS transistor MP5 to the current passing through the MOS transistor MP2 is K1, that is, Imp5 is K1 × Imp 2;

the size ratio of the MOS transistor MP7 to the MOS transistor MP2 is K1, and the ratio of the current passing through the MOS transistor MP7 to the current passing through the MOS transistor MP2 is K2, that is, Imp7 is K2 × Imp 2;

in step B2, the current flowing through the MOS transistor MP2 is copied by the MOS transistors MP5 and MP7 in the first current mirror according to the ratios K1 and K2, respectively;

in step B2, the current flowing through the MOS transistor MP2 in the first current mirror is a primary adjustment current obtained by conversion by the voltage-to-current module, and the temperature coefficient of the primary adjustment current is TC1, the temperature coefficient of the current flowing through the MOS transistor MP2 is TC1 × T, where T represents temperature, so as to implement primary adjustment of the temperature coefficient of the primary adjustment current;

in step B2, the current flowing through the MOS transistor MN1 in the first current branch is Imn1 ═ Imp5+ mtc ═ Imp6 to 7 ═ K1 ═ Imp2+ mtc × K2 × Imp2,

wherein Imp5 represents the current flowing through the MOS transistor MP5, Imp 6-7 represents the current flowing through the MOS transistors MP6 and MP7, Imp2 represents the current flowing through the MOS transistor MP2, mtc represents the number of transistors of the MOS transistor MP7 or the MOS transistor MP6 which are in conductive connection with the MOS transistor MN1, namely the number of closed and conductive MOS transistors MP6 at the corresponding position under the control action of a control word TC1< n:1>, m is more than or equal to mtc and more than or equal to 0, and the temperature coefficient of the current flowing through the MOS transistors MN5 and MN6 is K1+ mtc × K2;

in step B3, the MOS transistors MN5 and MN6 are controlled by the control voltages VBN1 and VBN2 of the gates thereof, and the control voltages VBN1 and VBN2 are zero temperature coefficient voltages;

in step B3, the control word TC1< m:1> is used to control the corresponding MOS transistor MP24, so as to adjust the current flowing through the MOS transistors MN5 and MN6, thereby meeting the current compensation requirement.

By adopting the structure of the invention, the following beneficial effects can be achieved: the temperature coefficient adjustable current generation circuit comprises a voltage-to-current module and a temperature coefficient adjusting module, wherein the voltage-to-current module converts the voltage of a band gap reference voltage source into a first temperature coefficient current with a certain temperature coefficient, and adjusts the current magnitude of the first temperature coefficient current once, and the temperature coefficient adjusting module adjusts the temperature coefficient of the once adjusted current once again, so that the current temperature coefficient adjusting range is expanded, and the application requirement of a wide bias current temperature coefficient is met. The temperature coefficient adjusting module has a current size compensating function, can compensate the current size after the temperature coefficient is adjusted, avoids the problem that the accuracy of the current size is reduced due to the change of the current temperature coefficient, and improves the accuracy of the current size generated by the current generating circuit.

Drawings

FIG. 1 is a block diagram of the circuit configuration of the present invention;

FIG. 2 is a schematic diagram of the circuit of the present invention;

fig. 3 is a schematic diagram of an array structure in which N MOS transistors MP3 and N MOS transistors MP4 are connected according to the present invention;

fig. 4 is a simulation diagram of the current temperature coefficient obtained by the adjustment of the current temperature coefficient adjusting module according to the present invention.

Detailed Description

For a better understanding of the present invention, and for the purpose of promoting an understanding thereof, reference will now be made to the embodiments of the present invention which are illustrated in the accompanying drawings and described below, wherein the terms "include" and "have" and any variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, apparatus, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The invention provides a specific embodiment of a temperature coefficient adjustable current generation circuit, aiming at the problems that the adjustable range of a bias current temperature coefficient adjusting circuit is smaller and the accuracy of the current size is reduced due to the change of a current temperature coefficient in the prior art.

Referring to fig. 1, a temperature coefficient adjustable current generation circuit includes a voltage-to-current module 1 and a temperature coefficient adjustment module 2, wherein one end of the voltage-to-current module 1 is connected to a bandgap reference voltage source, the other end of the voltage-to-current module 1 is connected to one end of the temperature coefficient adjustment module, and the other end of the temperature coefficient adjustment module 2 is a current output end; the voltage-to-current module 1 is used for converting the voltage of the band-gap reference voltage source into a first temperature coefficient current, and performing primary adjustment on the magnitude of the first temperature coefficient current to obtain a primary adjustment current; the temperature coefficient adjusting module 2 is used for adjusting the temperature coefficient of the primary adjusting current and compensating the size of the primary adjusting current; and a current output end IPTAT at the other end of the temperature coefficient adjusting module 2 outputs a second temperature coefficient current after temperature coefficient adjustment and current magnitude compensation.

Referring to fig. 2, the voltage-to-current module 1 includes an operational amplifier 11, a first switch control unit 12, and a current temperature coefficient adjustment unit 13, a forward input end of the operational amplifier 11 is connected to a bandgap reference voltage source, a voltage of the bandgap reference voltage source is zero temperature coefficient voltage, a reverse input end of the operational amplifier 11 is respectively connected to one end of the first switch control unit 12 and one end of the current temperature coefficient adjustment unit 13, the other end of the first switch control unit 12 and the other end of the current temperature coefficient adjustment unit 13 are both connected to one end of the temperature coefficient adjustment module 2, the operational amplifier 11 and the current temperature coefficient adjustment unit 13 are configured to generate a first temperature coefficient current related to a temperature coefficient, the first switch control unit 12 is configured to perform primary adjustment on a current magnitude of the first temperature coefficient current, the first switch control unit 12 includes a plurality of switches, and the switches are respectively controlled by a control voltage VBP, Control word TA < n:1> control.

The specific circuit structure of the voltage-to-current module 2 is as follows: the first switch control unit 12 includes N MOS transistors MP3 and N MOS transistors MP4, where N is a positive integer, a circuit structure in which the N MOS transistors MP3 and the N MOS transistors MP4 are connected is shown in fig. 3, the current temperature coefficient adjustment unit includes a MOS transistor MP1 and a resistor R1, an output end of the operational amplifier is connected to one end of the resistor R1 and a drain of the MOS transistor MP1, a source of the MOS transistor MP1 is connected to a drain of the MOS transistor MP2 and a gate of the temperature coefficient adjustment module, a source of the MOS transistor MP2 is connected to a source of the N MOS transistor MP4 and the temperature coefficient adjustment module, gates of the MOS transistors MP4 and MP4 are controlled by a control voltage VBP, drains of the N MOS transistors MP4 and sources of the N transistors MP3 are connected in one-to-one correspondence, a gate of the MOS transistor MP3 is controlled by a control word TA < N:1>, and drains of the MOS transistors MP3 are connected to gates of the MOS transistors MP2 and MP 5; in this embodiment, the MOS transistors MP 1-MP 4 are all PMOS transistors.

The step of converting the zero temperature coefficient voltage of the band-gap reference voltage source into the current by applying the voltage-to-current module comprises the following steps: a1, amplifying the zero temperature coefficient voltage generated by the band-gap reference voltage source by the operational amplifier 11 to obtain an amplified current; the band-gap reference voltage source is generated by a band-gap reference voltage circuit.

A2, converting the amplified current through a current temperature coefficient adjusting unit 13 to obtain a first temperature coefficient current;

a3, the switch in the first switch control unit 12 is controlled by the control voltage VBP and the control word TA < n:1>, so as to realize the primary adjustment of the current magnitude of the first temperature coefficient current and obtain the primary adjustment current.

The specific way of generating the current with a certain temperature coefficient by the zero temperature coefficient voltage through the steps a1, a2 and A3 is as follows: the zero temperature coefficient voltage generated by the band gap reference source passes through the MOS transistor MP1 and the operational amplifier OPA in the current temperature coefficient adjusting unit and the resistor R1 to generate a first temperature coefficient current related to the temperature coefficient of the resistor R1, and the resistor R1 is a positive temperature coefficient resistor, so that the generated first temperature coefficient current has a positive temperature coefficient.

N MOS transistors MP4 (indicated by MP4< N:1> in fig. 2) in the first switch control unit 12 are controlled by the control power VBP, and function to adjust the magnitude of the first temperature coefficient current, since Imp2+ Imp4 or Imp3 is Imp1+ Ir1, where Imp2 represents the current of the MOS transistor MP2, Imp4 represents the current of the MOS transistor MP4, Imp3 represents the current of the MOS transistor MP3, Imp1 represents the current of the MOS transistor MP1, and Ir1 represents the current of the resistor R1, the adjustment of the control word TA < N:1> can realize the adjustment of the on or off of the current of the branch where the MP4 is located, so as to realize the primary adjustment of the magnitude of the output current of the voltage-to-current module, that is when a certain MOS transistor MP 3628 in the control word is switched on, that a corresponding transistor MP3 is switched on, that when a corresponding transistor MP 466 is switched on the corresponding transistor MP1, the voltage-to-current module can adjust the output positive temperature coefficient current of the voltage-to-current module, the positive temperature coefficient current is determined by a resistor R1, and the current size is determined by the size ratio of the MOS tube MP5 to the MOS tube MP 2.

The temperature coefficient adjusting module 2 comprises a first current mirror 21 to a fourth current mirror 24, a second switch control unit 25 and a third switch control unit 26, wherein the first current mirror 21 is used for copying a first temperature coefficient current output by the power supply current conversion module according to proportions K1 and K2, the second current mirror 22 and the third current mirror 23 are used for copying a current passing through the first current mirror 21 according to a proportion K5, one ends of the first current mirror 21, the second switch control unit and the second current mirror are sequentially connected to form a first current branch, one ends of the third current mirror, the third switch control unit and the fourth current mirror are sequentially connected to form a second current branch, the other end of the second current mirror is connected with the other end of the third current mirror, the second switch control unit is used for controlling the connection or the disconnection of the first current branch, the third switch control unit is used for controlling the connection or the disconnection of the second current branch, the other end of the fourth current mirror is a current output end and is used for outputting second temperature coefficient current after temperature coefficient adjustment and current magnitude compensation, a plurality of switches in the second switch control unit are controlled through control words TC1< n:1>, a plurality of switches in the third switch unit are controlled through control words TC1< n:1>, control voltages VBN1 and VBN2 respectively, the switches in the second switch control unit are controlled through control words TC1< n:1> to achieve temperature coefficient adjustment of primary adjustment current, and the switches in the third switch unit are controlled through control words TC1< n:1>, control voltages VBN1 and VBN2 to achieve current magnitude compensation of the primary adjustment current.

The specific circuit structure of the temperature coefficient adjusting module is as follows: the first current mirror comprises MOS tubes MP, MP and MP, the second current mirror branch comprises MOS tubes MN-MN, the third current mirror branch comprises MOS tubes MP-MP, the fourth current mirror branch comprises MOS tubes MN-MN, the second switch control unit comprises N MOS tubes MP, the third switch control unit comprises M MOS tubes MP, M MOS tubes MN and M MOS tubes MN, wherein M is a positive integer, the source electrode of the MOS tube MP is respectively connected with the source electrodes of the MOS tubes MP, MP and MP, the drain electrode of the MOS tube MP is respectively connected with the drain electrode of the MOS tube MN, grid electrode and gate electrode of the MOS tube MN, the source electrode of the MOS tube MN is respectively connected with the grid electrode of the MOS tube MN, source electrode of the MOS tube MP is respectively connected with the grid electrode of the MOS tube MP, the drain electrode of the MOS tube MP is respectively connected with the source electrode of the MOS tube MP, the drain electrode of the MOS tube MP is respectively connected with the drain electrode of the MOS tube MN, and the source electrode of the MOS tube MN is respectively connected with the source electrode of the MOS tube MN, MOS pipe MN6, MN8, MN10 source electrode, MOS pipe MP11 drain electrode connection MOS pipe MP10 drain electrode, MOS pipe MP10 source electrode connection M MOS pipe MP24 source electrode, MOS pipe MN7 source electrode, grid and MOS pipe MN9 grid, MOS pipe MP24 drain electrode is the series connection MOS pipe MN5, MN6 in proper order, M MOS pipe MP6 grid is through control word TC1< n:1 is more than control, the grid of the MOS tube MP24 is controlled by a control word TC1< n:1> control, M MOS pipe MN5 is through control voltage VBN1 control, M MOS pipe MN6 is through control power VBN2 control, MOS pipe MN7 drain-electrode is connected MOS pipe MN8 drain-electrode, grid and MOS pipe MN10 grid respectively, MOS pipe MN10 drain-electrode is connected MOS pipe MN9 drain-electrode, MOS pipe MN9 source-electrode is current output end IPTAT.

In this embodiment, the MOS transistors MP5 to MP11 and the MOS transistor MP24 are PMOS transistors, and the MOS transistors MN1 to MN10 are NMOS transistors. The size ratio of the MOS transistor MP5 to the MOS transistor MP2 is K1, and the ratio of the current passing through the MOS transistor MP5 to the current passing through the MOS transistor MP2 is K1, that is, Imp5 is K1 × Imp 2; the size ratio of the MOS transistor MP7 to the MOS transistor MP2 is K1, the ratio of the current passing through the MOS transistor MP7 to the current passing through the MOS transistor MP2 is K2, that is, Imp7 is K2 × Imp2, wherein the current of the MOS transistor MP7 is Imp7, and the current of the MOS transistor MP2 is Imp 2.

The step of adjusting the temperature coefficient of the primary adjustment current by using the temperature coefficient adjusting module comprises the following steps: b1, the first current branch is conducted under the control of the second switch control unit;

and B4, copying the compensated current through a fourth current mirror, and outputting a second temperature coefficient current at a current output end.

The specific way of generating the current with a certain temperature coefficient through the steps B1-B4 is as follows: the current flowing through the MOS tube MP2 is respectively copied according to the proportions of K1 and K2 through MOS tubes MP5 and MP7 in the first current mirror; the current flowing through the MOS transistor MP2 in the first current mirror is the primary regulating current obtained by conversion of the voltage-to-current module, and the temperature coefficient of the primary regulating current is TC1, that is, Imp2 is TC1 × T, where T represents temperature. Therefore, the current flowing through the branch where the MOS transistor MN1 is located is:

Imn1＝Imp5+mtc*Imp6～7＝K1*Imp2+mtc*K2*Imp2，

wherein Imp5 represents the current flowing through the MOS transistor MP5, Imp 6-7 represents the current flowing through the MOS transistors MP6 and MP7, Imp2 represents the current flowing through the MOS transistor MP2, mtc represents the number of transistors of the MOS transistor MP7 or the MOS transistor MP6 which are in conductive connection with the MOS transistor MN1, namely the number of closed and conductive MOS transistors MP6 at the corresponding position under the control action of a control word TC1< n:1>, and m is more than or equal to mtc and more than or equal to 0; therefore, the temperature coefficient of the current flowing through the MOS tubes MN5 and MN6 is K1+ mtc × K2;

in step B3, the MOS transistors MN5 and MN6 are controlled by the control voltages VBN1 and VBN2 of their gates, and the control voltages VBN1 and VBN2 are zero temperature coefficient voltages. The corresponding MOS tube MP24 is controlled by the control word TC1< m:1>, so that the adjustment of the current flowing through the MOS tubes MN5 and MN6 is realized, and the current compensation requirement is met. When a certain bit m is 0 and TC1 is 0, the corresponding bit of MOS transistor MP6 is closed, the corresponding current of MOS transistor MP7 is connected to the current of MOS transistor MN1 through MOS transistor MP6, and the current is added to the current of MOS transistor MP5, when a certain bit m is 1 and TC1 is 1, the corresponding bit of MOS transistor MP6 is closed, and the corresponding current of MOS transistor MP7 is turned off through MOS transistor MP6, so that the corresponding TC1 at position mtc is set to 0, and a current of a corresponding K1+ mtc × K2 temperature coefficient can be obtained, thereby realizing the adjustment of the current temperature coefficient and expanding the adjustment range of the current temperature coefficient.

However, since the magnitude of the current flowing through the MOS transistors MN5 and MN6 also changes according to the above formula, the current Imn 1-2 passing through the MOS transistors MN1 and MN2 is copied in equal proportion by the second current mirror and the third current mirror of equal size proportion passing through the MOS transistors MN 1-MN 4 and the MOS transistors MP 8-MP 11. For circuit analysis it is possible to obtain:

mtc*Imp24 or Imn5～6+Imn7～8＝Imn10～11＝Imp8～9＝Imn3～4＝Imn1～2；

wherein, Imp24 represents the current flowing through MOS tube MP24, Imn 5-6 represents the current flowing through MOS tubes MN5 and MN6, Imn 7-8 represents the current flowing through MOS tubes MN7 and MN8, Imn 10-11 represents the current flowing through MOS tubes MN10 and MN11, Imp 8-9 represents the current flowing through MOS tubes MP8 and MP9, Imn 3-4 represents the current flowing through MOS tubes MN3 and MN4, and Imn 1-2 represents the current flowing through MOS tubes MN1 and MN 2. Since the control word for controlling the MOS transistor MP24 is equal to the control word for controlling the temperature coefficient adjustment of the MOS transistor MP6, therefore:

Imn7～8＝Imn1～2-mtc*Imp24 or Imn5～6＝Imp5+mtc*Imp6～7-mtc*Imp24 or Imn5～6；

the current flowing through the MOS transistors MN5 and MN6 is controlled by the gate voltages VBN1 and VBN2, and the voltage is zero temperature coefficient voltage, so that the temperature coefficient of the current flowing through the MOS transistor MP24 or the MOS transistors MN5 and MN6 is not changed, but the current Imp5 is still the basic current, but the temperature coefficient is still K1+ mtc × K2, so that the current temperature coefficient is adjusted, the current size compensation is realized, and the problem of current size reduction caused by temperature change or current temperature coefficient change in the circuit is solved. Therefore, the temperature coefficient adjusting module can output a positive temperature coefficient current with a temperature coefficient of K1+ mtc × K2, and under the normal-temperature working condition, no matter how the magnitude of the current temperature coefficient is adjusted, the magnitudes of the currents of the output second temperature coefficient currents, namely, the magnitudes of the currents flowing through the MOS transistors MN7 to MN8, are set Imp5 values, so that the accuracy of the output current of the current generating circuit is improved by the arrangement of the third switch in the current temperature coefficient compensation module, and the second temperature coefficient current with stable current magnitude is provided for other subsequent circuit modules.

In summary, the current generation circuit of the present application, aiming at PVT variations in the circuit, compensates the current temperature coefficient in advance through the voltage-to-current module, that is, generates a first temperature coefficient current, which is a positive temperature coefficient current, and adjusts the current magnitude of the first temperature coefficient current for the first time, and then compensates the current temperature coefficient of the once adjusted current for the second time through the current temperature coefficient adjustment module, so as to obtain a larger current temperature coefficient, so as to meet the requirements of a higher temperature circuit, and adjusts (compensates) the current magnitude after the current temperature coefficient adjustment for the second time, so as to provide a larger current, so as to avoid the current magnitude deviation caused by the circuit gain or linearity in the working temperature range.

Fig. 4 shows a current temperature coefficient adjustment function simulated by the current generation circuit. In fig. 4, the horizontal axis represents the temperature of the circuit, the vertical axis represents the current magnitude, the mta is controlled to be consistent, the change of the temperature coefficient of the output current under the same current can be obtained, namely, the working temperature range temp of the circuit is in the range of-40 ℃ to 125 ℃, the change of the temperature coefficient of the current from 337 nA/DEG C to 640 nA/DEG C can be obtained for each adjustment mtc, and at the mark V2, namely, the normal working temperature of the chip, the current magnitude of each current line can be obviously kept consistent at the position because the vertical axis is the current and the horizontal axis is the temperature, the current magnitude is ensured to be unchanged and the temperature coefficient of the current is changed for each adjustment mtc, and the stability of the current magnitude is ensured while the requirement of the wide temperature range of the chip is met.

The above is only a preferred embodiment of the present application, and the present invention is not limited to the above embodiments. It is to be understood that other modifications and variations directly derived or suggested to those skilled in the art without departing from the spirit and scope of the invention are to be considered as included within the scope of the invention.

Claims

1. A temperature coefficient adjustable current generation circuit comprises a voltage-to-current module and a temperature coefficient adjusting module, wherein one end of the voltage-to-current module is connected with a band gap reference voltage source, the other end of the voltage-to-current module is connected with one end of the temperature coefficient adjusting module, and the other end of the temperature coefficient adjusting module is a current output end;

2. The temperature coefficient adjustable current generating circuit according to claim 1, wherein the voltage-to-current module comprises an operational amplifier, a first switch control unit, and a current temperature coefficient adjusting unit, a forward input end of the operational amplifier is connected to the bandgap reference voltage source, a voltage of the bandgap reference voltage source is zero temperature coefficient voltage, a reverse input end of the operational amplifier is respectively connected to one end of the first switch control unit and one end of the current temperature coefficient adjusting unit, the other end of the first switch control unit and the other end of the current temperature coefficient adjusting unit are both connected to one end of the temperature coefficient adjusting module, the operational amplifier and the current temperature coefficient adjusting unit are configured to generate a first temperature coefficient current related to a temperature coefficient, and the first switch control unit is configured to adjust a current magnitude of the first temperature coefficient current once, the first switch control unit comprises a plurality of switches which are respectively controlled by a control voltage VBP and a control word TA < n:1 >.

3. The temperature coefficient adjustable current generation circuit according to claim 2, wherein the first switch control unit includes N MOS transistors MP3 and N MOS transistors MP4, where N is a positive integer, the current temperature coefficient adjustment unit includes a MOS transistor MP1 and a resistor R1, the output end of the operational amplifier is connected to one end of the resistor R1 and the gate of the MOS transistor MP1, the drain of the MOS transistor MP1 is connected to the drain and the gate of the MOS transistor MP2 in the temperature coefficient adjustment module, the source of the MOS transistor MP2 is connected to the source of N MOS transistors MP3 and the gate of the MOS transistor MP5 in the temperature coefficient adjustment module, the gates of N MOS transistors MP4 are controlled by the control voltage VBP, the drains of N MOS transistors MP4 and N MOS transistors MP3 are connected in one-to-one correspondence, the gate of the MOS transistor MP3 is controlled by the control word TA < N:1>, and the source of the MOS transistor MP4 is connected to the drain of the MOS transistor MP5, And sources of MOS tubes MP7, MP9 and MP11 in the temperature coefficient adjusting module.

4. The adjustable-temperature-coefficient current generating circuit of claim 3, wherein the step of converting the zero-temperature-coefficient voltage of the bandgap reference voltage source into a current by using the voltage-to-current module comprises: a1, amplifying the zero temperature coefficient voltage by an operational amplifier to obtain an amplified current;

5. The temperature coefficient adjustable current generating circuit of claim 4, wherein in the step A2, the amplifying current is compensated by the MOS transistor MP1 and the resistor R1 in the current temperature coefficient adjusting unit, and a first temperature coefficient current related to the temperature coefficient of the resistor R1 is generated.

6. The temperature-coefficient-adjustable current generating circuit of claim 5, wherein in the step A3, the N MOS transistors MP4 and MP3 in the first switch control unit are controlled by the control voltage VBP and the control word TA < N:1>, and the specific step of adjusting the first temperature coefficient current by the first switch control unit comprises: when the first temperature coefficient current flows through the MOS transistor MP4, the gate of the N MOS transistors MP4 is controlled by the control voltage VBP, and the gate of the N MOS transistors MP3 is controlled by the control word TA < N:1> to adjust the current magnitude of the first temperature coefficient current at one time, which specifically includes: a321, when n is 0 and TA < n:1> is 0, the MOS tube MP3 at the corresponding position is closed, the current of the MOS tube MP4 at the corresponding position enters the branch of the MOS tube MP1 through the MOS tube MP3, and the addition of the current of the MOS tube MP1 and the current of the MOS tube MP2 is realized; a322, when n is 1 and TA < n:1> is 1, the MOS tube MP3 is turned off, the current from the branch of the MOS tube MP4 to the branch of the MOS tube MP1 is turned off through the MOS tube MP3, and the current with positive temperature coefficient is output.

7. The circuit according to claim 1 or 6, wherein the temperature coefficient adjusting module comprises a first current mirror, a second switch control unit, and a third switch control unit, the first current mirror is used to copy the first temperature coefficient current outputted by the power conversion module according to the ratios K1 and K2, the second current mirror and the third current mirror are used to copy the current passing through the first current mirror according to the ratio K5, one end of the first current mirror, one end of the second switch control unit, and one end of the second current mirror are sequentially connected to form a first current branch, one end of the third current mirror, one end of the third switch control unit, and one end of the fourth current mirror are sequentially connected to form a second current branch, the other end of the second current mirror is connected to the other end of the third current mirror, and the second switch control unit is used to control the on/off of the first current branch, the third switch control unit is used for controlling the conduction or the closing of the second current branch, the other end of the fourth current mirror is a current output end and is used for outputting the second temperature coefficient current after temperature coefficient adjustment and current magnitude compensation, a plurality of switches in the second switch control unit are controlled through a control word TC1< n:1>, a plurality of switches in the third switch unit are respectively controlled through a control word TC1< n:1>, a control voltage VBN1 and a control voltage VBN2, the control word TC1< n:1> is used for controlling the switches in the second switch control unit to realize the temperature coefficient adjustment of primary adjustment current, and the control word TC1< n:1>, the control voltage VBN1 and the control voltage VBN2 are used for controlling the switches in the third switch unit to realize the current magnitude compensation of primary adjustment current.

8. The temperature coefficient adjustable current generation circuit according to claim 7, wherein the first current mirror comprises a MOS transistor MP2, a MOS transistor MP5, and MP7, the second current mirror branch comprises MOS transistors MN 1-MN 4, the third current mirror branch comprises MOS transistors MP 8-MP 11, the fourth current mirror branch comprises MOS transistors MN 7-MN 10, the second switch control unit comprises M MOS transistors MP6, the third switch control unit comprises M MOS transistors MP24, M MOS transistors MN5, and M MOS transistors MN6, wherein M is a positive integer, the drain of the MOS transistor MP5 is connected to the drain of the MOS transistor MN1, the gate of the MOS transistor MN3, the source of the MOS transistor MN1 is connected to the gate of the MOS transistor MN2, the source of the MOS transistor MN4, the drain of the MOS transistor MP9 is connected to the gate of the MOS transistors MP9, the drain of the MOS transistors MP 468, the drain of the MOS transistors MP 5475, and the drain of the MOS transistors MP8 are connected to the drain of the MOS transistors MP8 and MP8, A gate of the MOS transistor MP10, a source of the MOS transistor MN3, a drain of the MOS transistor MN3 is connected with a drain of the MOS transistor MN4, the source electrode of the MOS transistor MN2 is respectively connected with the source electrode of the MOS transistor MN4, the source electrodes of the MOS transistors MN6, MN8 and MN10, the drain electrode of the MOS tube MP11 is connected with the drain electrode of the MOS tube MP10, the source electrode of the MOS tube MP10 is connected with the source electrodes of M MOS tubes MP24, the source electrode of the MOS tube MN7, the grid electrode and the grid electrode of the MOS tube MN9, the drain of the MOS transistor MP24 is sequentially connected in series with the MOS transistors MN5 and MN6, and the gates of the M MOS transistors MP6 are connected in series with the gate of the MOS transistor MP 1< n:1> the control of the operation of the motor, the gate of the MOS transistor MP24 is controlled by a control word TC1< n:1>, M MOS tubes MN5 are controlled by a control voltage VBN1, M MOS tubes MN6 are controlled by a control power supply VBN2, the drain electrode of the MOS transistor MN7 is respectively connected with the drain electrode and the grid electrode of the MOS transistor MN8 and the grid electrode of the MOS transistor MN10, the drain electrode of the MOS transistor MN10 is connected with the drain electrode of the MOS transistor MN9, and the source electrode of the MOS transistor MN9 is the current output end.

9. The adjustable temperature coefficient current generating circuit of claim 8, wherein the step of adjusting the temperature coefficient of the current using the temperature coefficient adjustment module comprises: b1, the first current branch is conducted under the control of the second switch control unit;

10. The temperature coefficient adjustable current generating circuit according to claim 8, wherein the size ratio of the MOS transistor MP5 to the MOS transistor MP2 is K1, and the ratio of the current passing through the MOS transistor MP5 to the current passing through the MOS transistor MP2 is K1, i.e. Imp5 is K1 is Imp 2; the size ratio of the MOS transistor MP7 to the MOS transistor MP2 is K1, the ratio of the current passing through the MOS transistor MP7 to the current passing through the MOS transistor MP2 is K2, namely Imp7 is K2 and Imp 2; in step B2, the current flowing through the MOS transistor MP2 is duplicated by the MOS transistors MP5 and MP7 in the first current mirror according to the ratios K1 and K2, respectively.