CN114362724B

CN114362724B - Ring oscillator with temperature compensation function

Info

Publication number: CN114362724B
Application number: CN202111624980.9A
Authority: CN
Inventors: 黄颋
Original assignee: Nanjing Niuxin Microelectronics Co ltd
Current assignee: Nanjing Niuxin Microelectronics Co ltd
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2023-10-10
Anticipated expiration: 2041-12-28
Also published as: CN114362724A

Abstract

The invention discloses a ring oscillator with temperature compensation function, comprising: the PAPT current generation module is used for outputting a VBG voltage signal to the ICON current generation module and outputting an IPTAT current signal to the compensation current synthesis module, wherein the VBG voltage signal does not change along with temperature, and the IPTAT current signal is in direct proportion to the temperature; the ICON current generation module is connected with the compensation current synthesis module and is used for outputting an ICON current signal to the compensation current synthesis module, wherein the ICON current signal does not change along with temperature; the compensation current synthesis module is connected with the ring oscillator and is used for outputting an ITAIL current signal to the ring oscillator, the ITAIL current signal is provided with temperature compensation, and frequency change caused by temperature change is compensated in the ring oscillator. In the invention, PTAT current and constant temperature coefficient current are adopted to synthesize and generate a current with a specific temperature coefficient, and the current is used as a current source of an oscillator, so that frequency change caused by temperature change can be effectively compensated.

Description

Ring oscillator with temperature compensation function

Technical Field

The invention relates to the technical field of analog current oscillators, in particular to a ring oscillator with a temperature compensation function.

Background

With the development of integrated circuit technology and the increasing demands of people on information processing capability, system SOC and data processing chip technology are becoming mainstream. As a clock source of the SOC and the data processing chip, the frequency stability characteristic directly influences the application performance of the whole chip. In recent years, the traditional three-stage ring vibration is widely applied to the SOC chip as a clock source, the oscillation frequency of the SOC chip has larger temperature drift, the frequency stability is greatly influenced by temperature, and meanwhile, the frequency stability is also greatly influenced by power supply voltage. Therefore, it is important to design an oscillator reasonably independent of the supply voltage and temperature.

Disclosure of Invention

The technical purpose is that: aiming at the defect that the oscillation frequency of an oscillator is influenced by power supply voltage and temperature in the prior art, the invention discloses a ring oscillator with a temperature compensation function.

The technical scheme is as follows: in order to achieve the technical purpose, the invention adopts the following technical scheme.

A ring oscillator with temperature compensation function comprises a PAPT current generation module, an ICON current generation module, a compensation current synthesis module and a ring oscillator;

the PAPT current generation module is connected with the ICON current generation module and the compensation current synthesis module, and is used for outputting a VBG voltage signal to the ICON current generation module and outputting an IPTAT current signal to the compensation current synthesis module, wherein the VBG voltage signal does not change along with temperature, and the IPTAT current signal is in direct proportion to the temperature; the ICON current generation module is connected with the compensation current synthesis module and is used for outputting an ICON current signal to the compensation current synthesis module, wherein the ICON current signal does not change along with temperature; the compensation current synthesis module is connected with the ring oscillator and is used for outputting an ITAIL current signal to the ring oscillator, wherein the ITAIL current signal is provided with temperature compensation, and frequency change caused by temperature change is compensated in the ring oscillator.

Preferably, the PAPT current generating module includes a first self-bias current generating circuit, a second self-bias current generating circuit, an amplifier driving circuit and an output circuit, the first self-bias current generating circuit outputs a first current, the second self-bias current generating circuit outputs a second current, the first self-bias current generating circuit and the second self-bias current generating circuit are connected with the amplifier driving circuit, the inputs of the amplifier driving circuit are the first current and the second current, and the outputs are a first driving signal and a second driving signal; the amplifier driving circuit is connected with the output circuit, the input of the output circuit is a first driving signal and a second driving signal, and the output is an IPTAT current signal and a VBG voltage signal.

Preferably, the first self-bias current generating circuit includes a MOS transistor MP0 and a resistor R0, where a drain of the MOS transistor MP0 is connected to one end of the resistor R0, and the other end of the resistor R0 is grounded, and after the drain of the MOS transistor MP0 is connected to the gate, the first current is output.

Preferably, the second self-bias current generating circuit includes a MOS transistor MP1 and a resistor R1, wherein a drain electrode of the MOS transistor MP1 is connected to one end of the resistor R1, and the other end of the resistor R1 is grounded, and the drain electrode of the MOS transistor MP1 is connected to the gate electrode and then outputs the second current.

Preferably, the amplifier driving circuit includes MOS transistors MP2 to MP6, MN0, MN1, Q0 and Q1, and the input of the amplifier driving circuit is a first current and a second current, and the output is a first driving signal and a second driving signal;

the grid electrode of the MOS tube MP2 and the grid electrode of the MOS tube MP3 are connected with a second current, the drain electrode of the MOS tube MP2 is connected with the collector electrode and the base electrode of the triode Q0, and is simultaneously connected with the grid electrode of the MOS tube MP5, the emitter electrode of the triode Q0 is connected with one end of a resistor R2, and the other end of the resistor R2 is grounded; the drain electrode of the MOS tube MP3 is connected with the collector electrode and the base electrode of the triode Q1, and is simultaneously connected with the grid electrode of the MOS tube MP6, the emitter electrode of the triode Q1 is connected with one end of a resistor R3, the emitter electrode of the triode Q1 outputs a second driving signal, and the other end of the resistor R3 is grounded;

the grid electrode of the MOS tube MP4 is connected with the first current, the drain electrode of the MOS tube MP4 is connected with the source electrode of the MOS tube MP5 and the source electrode of the MOS tube MP6, the drain electrode of the MOS tube MP5 is connected with the drain electrode and the grid electrode of the MOS tube MN0, and meanwhile, the drain electrode of the MOS tube MP4 is connected with the grid electrode of the MOS tube MN 1; the drain electrode of the MOS tube MP6 is connected with the drain electrode of the MOS tube MN1, the drain electrode of the MOS tube MP6 outputs a first driving signal, the source electrode of the MOS tube MN0 and the source electrode of the MOS tube MN1 are commonly connected with one end of a resistor R4, and the other end of the resistor R4 is grounded.

Preferably, the output circuit comprises MOS transistors MP7 to MP9, MN2 and Q3; the input of the output circuit is a first driving signal and a second driving signal, and the output is an IPTAT current signal and a VBG voltage signal;

the grid electrode of the MOS tube MN2 is connected with the first driving signal, the source electrode of the MOS tube MN2 is connected with the second driving signal, the drain electrode of the MOS tube MN2 is connected with the drain electrode and the grid electrode of the MOS tube MP7, the grid electrode of the MOS tube MP8 and the grid electrode of the MOS tube MP9 are connected, the source electrodes of the MOS tube MP7, the MOS tube MP8 and the MOS tube MP9 are connected with a power supply, the drain electrode of the MOS tube MP8 is connected with one end of a resistor R5, and a VBG voltage signal is output; the other end of the resistor R5 is connected with the base electrode and the collector electrode of the triode Q3, and the emitter electrode of the triode Q3 is grounded; the drain electrode of the MOS tube MP9 is connected with an output port IPTAT, the output port IPTAT outputs an IPTAT current signal, and the sources of the MOS tube MP0 and the MOS tube MP9 are connected with a power supply.

Preferably, the ICON current generating module comprises an operational amplifier OP, a MOS tube MN3, MOS tubes MP10-MP11 and a resistor R6, wherein the MOS tube MN3 is an NMOS tube, and the MOS tubes MP10-MP11 are PMOS tubes; the input of the ICON current generation module is a VBG voltage signal, and the output of the ICON current generation module is an ICON current signal;

the positive input end of the operational amplifier OP is connected with a VBG voltage signal, the negative input end of the operational amplifier OP is connected with one end of a resistor R6 and the source electrode of a MOS tube MN3, the other end of the resistor R6 is grounded, the output end of the operational amplifier OP is connected with the grid electrode of the MOS tube MN3, the drain electrode of the MOS tube MN3 is connected with the drain electrode and the grid electrode of a MOS tube MP10, and meanwhile, the grid electrode of the MOS tube MP11 is connected; the source electrode of the MOS tube MP10-MOS tube MP11 is commonly connected with a power supply, the drain electrode of the MOS tube MP11 is connected with an output port ICON, and the output port ICON outputs an ICON current signal.

Preferably, the compensation current synthesis module includes a switching signal SB with a B-bit number of bits, a first mirroring unit, a second mirroring unit and B temperature coefficient adjusting units, where the switching signal S is a binary control signal with a B-bit number of bits, the bit number of the switching signal SB is equal to the switching signal S, each of the switching signals SB is a control signal of the switching signal S, the first mirroring unit inputs an IPTAT current signal, the second mirroring unit inputs an ICON current signal, the second mirroring unit outputs an ICON current signal, the temperature coefficient adjusting units output an ICON current signal, the number of the temperature coefficient adjusting units is equal to the bit number of the switching signal S, the B-bit switching signal SB is equal to or less than B, the B-bit switching signal S is used for controlling whether the input IPTAT current signal is on, the B-bit switching signal SB is used for controlling whether the input ictn current signal is on, the temperature coefficient adjusting units output an ictn current signal, the temperature coefficient adjusting units output a temperature coefficient adjusting unit outputs an itl signal, and an itl, and the temperature coefficient adjusting unit outputs a common output port.

Preferably, the first mirror image unit and the second mirror image unit have the same structure, and current mirror image is realized through a pair of MOS tubes; each temperature coefficient adjusting unit comprises 4 MOS tubes, wherein the grid electrode of a first MOS tube is connected with an IPTAT current signal, the grid electrode of a second MOS tube is connected with an ICON current signal, the source electrode of the first MOS tube is connected with the source electrode of the second MOS tube, the drain electrode of the first MOS tube is connected with the source electrode of a third MOS tube, the grid electrode of the third MOS tube is connected with a one-bit signal of a switch signal S, the drain electrode of the third MOS tube is connected with an output port ITAIL, the drain electrode of the second MOS tube is connected with the source electrode of a fourth MOS tube, the grid electrode of the fourth MOS tube is connected with a one-bit signal of a switch signal SB, and the drain electrode of the fourth MOS tube is connected with the output port ITAIL. The on-off of the third MOS tube and the fourth MOS tube is controlled through the switch signal S and the switch signal SB, so that the temperature coefficient adjustment of the ITAIL current signal is realized; and the temperature coefficient adjustment of the ITAIL current signal is controlled by adjusting the width-to-length ratio between the first MOS tubes and the width-to-length ratio between the second MOS tubes of the B temperature coefficient adjustment units.

Preferably, the ring oscillator comprises an MOS tube MP12, an MOS tube MP13 and an odd number of inverter delay units, wherein the MOS tube MP12 and the MOS tube MP13 are PMOS tubes; the input of the ring oscillator is an ITAIL current signal;

the grid electrode and the drain electrode of the MOS tube MP12 are commonly connected with ITAIL current signals, and are simultaneously connected with the grid electrode of the MOS tube MP13, the drain electrode of the MOS tube MP13 outputs VRING signals, the VRING signals are connected with power supplies of all inverter delay units, and the odd number inverter delay units are connected in a tail-to-tail manner, namely, the output of one inverter delay unit is connected with the input of the next inverter delay unit, so that a ring structure is formed.

The beneficial effects are that: in the invention, PTAT current and constant temperature coefficient current are adopted to synthesize and generate a current with a specific temperature coefficient, and the current is used as a current source of the oscillator, so that frequency variation caused by temperature variation can be effectively compensated.

Drawings

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

fig. 2 is a circuit diagram of a PAPT current generating module according to an embodiment;

FIG. 3 is a circuit diagram of an ICON current generation module according to an embodiment;

FIG. 4 is a circuit diagram of a compensation current combining module according to an embodiment;

FIG. 5 is a circuit diagram of a ring oscillator in an embodiment;

fig. 6 is a simulated waveform diagram of the overall circuit in the embodiment.

Description of the embodiments

A ring oscillator with temperature compensation according to the present invention is further described and illustrated below with reference to the accompanying drawings and examples.

As shown in figure 1, the ring oscillator with the temperature compensation function comprises a PAPT current generation module, an ICON current generation module, a compensation current synthesis module and a ring oscillator;

In the invention, the IPTAT current signal output by the PAPT current generating module is in direct proportion to the temperature, the temperature coefficient is higher, and if the current with the fixed temperature coefficient is singly adopted as the current source of the ring oscillator, the overcompensation effect can occur. The temperature coefficient required for compensation does not need to be as large as that of IPTAT current, and therefore the temperature coefficient needs to be reduced. The ICON current signal output by the ICON current generating module is irrelevant to temperature, and if the current is simply used as a current source of the ring oscillator, the temperature compensation effect cannot be achieved. The ITAIL current signal output by the compensation current synthesis module is provided with temperature compensation, the temperature coefficient is moderate, and the temperature coefficient of the ITAIL current signal can be regulated by the proportion of IPTAT current and ICON current. The ring oscillator adopts the ITAIL current signal as a current source, so that temperature compensation can be effectively realized, and an overcompensation effect can not occur. The temperature coefficient referred to in the present invention means: the ratio of the amount of current change with temperature to the current at normal temperature.

Examples

As shown in fig. 2, the PAPT current generating module includes a first self-bias current generating circuit, a second self-bias current generating circuit, an amplifier driving circuit and an output circuit, where the first self-bias current generating circuit outputs a first current, the second self-bias current generating circuit outputs a second current, the first self-bias current generating circuit and the second self-bias current generating circuit are connected to the amplifier driving circuit, the inputs of the amplifier driving circuit are the first current and the second current, and the outputs are a first driving signal and a second driving signal; the amplifier driving circuit is connected with the output circuit, the input of the output circuit is a first driving signal and a second driving signal, and the output of the output circuit is an IPTAT current signal and a VBG voltage signal;

the first self-bias current generation circuit comprises a MOS tube MP0 and a resistor R0, wherein the source electrode of the MOS tube MP0 is connected with a power supply, the drain electrode of the MOS tube MP0 is connected with one end of the resistor R0, the other end of the resistor R0 is grounded, and the drain electrode of the MOS tube MP0 is connected with a grid electrode and then outputs a first current;

the second self-bias current generation circuit comprises a MOS tube MP1 and a resistor R1, wherein the source electrode of the MOS tube MP1 is connected with a power supply, the drain electrode of the MOS tube MP1 is connected with one end of the resistor R1, the other end of the resistor R1 is grounded, and the drain electrode of the MOS tube MP1 is connected with a grid electrode and then outputs a second current;

the amplifier driving circuit comprises MOS transistors MP2 to MP6, MOS transistor MN0, MOS transistor MN1, triode Q0 and triode Q1, wherein the input of the amplifier driving circuit is a first current and a second current, and the output of the amplifier driving circuit is a first driving signal and a second driving signal;

the grid electrode of the MOS tube MP2 and the grid electrode of the MOS tube MP3 are connected with a second current, namely connected with the grid electrode of the MOS tube MP1, the drain electrode of the MOS tube MP2 is connected with the collector electrode and the base electrode of the triode Q0, and simultaneously connected with the grid electrode of the MOS tube MP5, the emitter electrode of the triode Q0 is connected with one end of a resistor R2, and the other end of the resistor R2 is grounded; the drain electrode of the MOS transistor MP3 is connected with the collector electrode and the base electrode of the transistor Q1, and is simultaneously connected with the grid electrode of the MOS transistor MP6, the emitter electrode of the transistor Q1 is connected with one end of the resistor R3, the emitter electrode of the transistor Q1 outputs a second driving signal, namely, the emitter electrode of the transistor Q1 is connected with the source electrode of the MOS transistor MN2, and the other end of the resistor R3 is grounded;

the grid electrode of the MOS tube MP4 is connected with the first current, namely, the grid electrode of the MOS tube MP0, the drain electrode of the MOS tube MP4 is connected with the source electrode of the MOS tube MP5 and the source electrode of the MOS tube MP6, the drain electrode of the MOS tube MP5 is connected with the drain electrode and the grid electrode of the MOS tube MN0, and meanwhile, the grid electrode of the MOS tube MN1 is connected; the drain electrode of the MOS tube MP6 is connected with the drain electrode of the MOS tube MN1, the drain electrode of the MOS tube MP6 outputs a first driving signal, namely, the drain electrode of the MOS tube MP6 is connected with the grid electrode of the MOS tube MN2, the source electrode of the MOS tube MN0 and the source electrode of the MOS tube MN1 are commonly connected with one end of a resistor R4, and the other end of the resistor R4 is grounded;

the output circuit comprises MOS transistors MP7 to MP9, MOS transistor MN2 and triode Q3; the input of the output circuit is a first driving signal and a second driving signal, and the output is an IPTAT current signal and a VBG voltage signal;

the grid electrode of the MOS tube MN2 is connected with a first driving signal, namely the drain electrode of the MOS tube MP6, the source electrode of the MOS tube MN2 is connected with a second driving signal, namely the emitter electrode of the triode Q1, the drain electrode of the MOS tube MN2 is connected with the drain electrode and the grid electrode of the MOS tube MP7, and simultaneously connected with the grid electrode of the MOS tube MP8 and the grid electrode of the MOS tube MP9, the source electrodes of the MOS tube MP7, the MOS tube MP8 and the MOS tube MP9 are connected with a power supply, and the drain electrode of the MOS tube MP8 is connected with one end of a resistor R5 and simultaneously outputs a VBG voltage signal; the other end of the resistor R5 is connected with the base electrode and the collector electrode of the triode Q3, and the emitter electrode of the triode Q3 is grounded; the drain electrode of the MOS tube MP9 is connected with an output port IPTAT, the output port IPTAT outputs an IPTAT current signal, and the sources of the MOS tube MP0 and the MOS tube MP9 are connected with a power supply.

In the embodiment, the MOS transistors MP0-MP9 are PMOS transistors, the MOS transistors MN0-MN2 are NMOS transistors, and the triodes Q0-Q3 are NPN triodes; the sources of MOS transistors MP0-MP4 and MP7-MP9 are connected with power supply, and in some embodiments, the power supply voltage is 2.5V.

In this embodiment, the following is set: the relation of the width-to-length ratios of the MOS transistors MP1, MP2 and MP3 is 1:10:1, the area relationship of the triodes Q0, Q1, Q3 is 1:12:1.

MOS tube MP0 and resistor R0 form the first self-bias current generation circuit, this electric current is regarded as the mirror image current source of MOS tube MP4, namely provide the bias voltage for amplifier in the amplifier driving circuit; meanwhile, the MOS tube MP1 and the resistor R1 form a second self-bias current generating circuit which is used as a mirror current source of the MOS tube MP2 and the MOS tube MP3, namely, the mirror current source provides bias for other circuits in the amplifier driving circuit.

MOS tube MP4-MP6, MOS tube MN0-MN1 and resistor R4 form an amplifier, MOS tube MN2 in the output circuit is driven, the voltage of node A is the same as the voltage of node B under the stable operation of the amplifier, the voltage of node A is the grid power supply of MOS tube MP5, the voltage of node B is the grid power supply of MOS tube MP6, namely。

The voltage of the base and the emitter of the triode, and the VA voltage is +.>(triode Q0 +.>) And the sum of the voltage drops of the resistor R2, i.e. +.>The method comprises the steps of carrying out a first treatment on the surface of the The relation of the width-to-length ratio of the MOS transistors MP2 and MP3 is 10:1 assuming that the source-drain current of MP2 is +.>MP1 source drain current of +.>Then->Wherein->For PN junction reverse cut-off current, thermal voltage of triode Q0 +.>K is Boltzmann constant, T is temperature, and normal temperature (27 ℃) is 300k, < ->Is electron charge, and the thermal voltage has a value of about 26mV at normal temperature. The voltage drop of resistor R2 is +.>Thus, it is。

The circuit structure of the amplifier in the amplifier driving circuit (the amplifier is an operational amplifier) leads toThus->In addition, the voltage of node B +.>And is a +.o. of triode Q1>And the sum of the voltage drops of the resistor R3. Because the area of the triode Q1 is 12 times of that of the triode Q0, the size of the MOS tube MP3 is 1/10 of that of the MOS tube MP2, soThe voltage drop across resistor R3 is:the current through R3 is available according to ohm's law as: />According to KCL theorem (kirchhoff current theorem), the current flowing through the MOS transistor MN2 can be obtained, that is, the source-drain current of the MOS transistor MN2 is:because the source leakage current of the MOS transistor MN2 is equal to the source leakage current of the MOS transistor MP7, the MOS transistorThe source-drain current of MP7 is: />Wherein->Proportional to temperature, in particular, +.>The temperature increases proportionally with the increase in temperature. MOS tube MP7 and MOS tube MP9 are in mirror image relationship, MOS tube MP9 mirrors MOS tube MP7 current output to obtain current IPTAT which is in direct proportion with temperature, namely current IPTAT with positive temperature coefficient.

The voltage VBG which does not vary with temperature adopts the voltage with positive temperature coefficient and the voltage with negative temperature coefficient generated by the current IPTAT with positive temperature coefficient on the resistor R5Obtained by addition, i.e.Wherein->The source leakage current of the MOS transistor MP8 is a positive temperature coefficient current.

As shown in fig. 3, the ICON current generating module comprises an operational amplifier OP, a MOS transistor MN3, MOS transistors MP10-MP11, and a resistor R6, wherein the MOS transistor MN3 is an NMOS transistor, and the MOS transistors MP10-MP11 are PMOS transistors; the input of the ICON current generation module is a VBG voltage signal, and the output of the ICON current generation module is an ICON current signal;

The operational amplifier OP makes the voltage of the input pin VBG equal to the source voltage of the MOS transistor MN3, so that the source voltage of the MOS transistor MN3 does not change with temperature, and therefore, the current flowing through the resistor R6 does not change with temperature, the MOS transistor MP10 is mirrored with the MOS transistor MP11, the current flowing through the MOS transistor MP10 and the resistor R6 are equal, and the current of the drain mirror resistor R6 of the MOS transistor MP11 obtains an ICON current signal which does not change with temperature.

The compensation current synthesis module comprises a switching signal S, B-bit switching signal SB, a first mirror image unit, a second mirror image unit and B temperature coefficient regulating units, wherein the switching signal S is a binary control signal of the B-bit, the bit number of the switching signal SB is equal to that of the switching signal S, each bit control signal of the switching signal SB is the control signal of the switching signal S in an inverse manner, the first mirror image unit is input with an IPTAT current signal, the output of the first mirror image unit is an IPTAT current signal through a mirror image structure, the input of the second mirror image unit is an ICON current signal, the output of the second mirror image unit is an ICON current signal through a mirror image structure, the number of the temperature coefficient regulating units is equal to that of the switching signal S, the input of the B temperature coefficient regulating units is an IPTAT current signal, an ICON current signal, a B-bit switching signal S, a B-bit switching signal SB, a B-less than or-B, the B-bit switching signal S is used for controlling whether the input IPTAT current signal is conducted or not, the B-bit switching signal SB is used for controlling whether the input ICON current signal is conducted or not, the temperature coefficient regulating unit is used for controlling the input of the ICON current signal, the output of the switching signal S, the temperature coefficient regulating unit is connected with the output of the AIL signal, the AIL and the AIL signal is output through a common port.

The first mirror image unit and the second mirror image unit have the same structure, and realize current mirror image through a pair of MOS tubes; each temperature coefficient adjusting unit comprises 4 MOS tubes, wherein the grid electrode of a first MOS tube is connected with an IPTAT current signal, the grid electrode of a second MOS tube is connected with an ICON current signal, the source electrode of the first MOS tube is connected with the source electrode of the second MOS tube, the drain electrode of the first MOS tube is connected with the source electrode of a third MOS tube, the grid electrode of the third MOS tube is connected with a one-bit signal of a switch signal S, the drain electrode of the third MOS tube is connected with an output port ITAIL, the drain electrode of the second MOS tube is connected with the source electrode of a fourth MOS tube, the grid electrode of the fourth MOS tube is connected with a one-bit signal of a switch signal SB, and the drain electrode of the fourth MOS tube is connected with the output port ITAIL. And the on-off of the third MOS tube and the fourth MOS tube is controlled by the switch signal S and the switch signal SB, so that the temperature coefficient adjustment of the ITAIL current signal is realized. In addition, the temperature coefficient adjustment of the ITAIL current signal is controlled by adjusting the width-to-length ratio between the first MOS tubes and the width-to-length ratio between the second MOS tubes of the B temperature coefficient adjustment units.

As shown in fig. 4, in this embodiment, the compensation current synthesis module includes a switching signal S with 4 bits, a switching signal SB with 4 bits, a first mirror image unit, a second mirror image unit, and 4 temperature coefficient adjustment units, where the switching signal S <3:0> controls the gate of the MOS transistor MN 17-MN 20 (corresponding to the fourth MOS transistor in the 4 temperature coefficient adjustment units), controls the on/off of the gate, and the ratio of the width to length of the MOS transistor MN 5-MN 10 (MOS transistor MN5 corresponds to one MOS transistor in the first mirror image unit, and the ratio of the width to length of the MOS transistor MN 6-MN 9 corresponds to the first MOS transistor in the 4 temperature coefficient adjustment units) is 12:4:1:2:4:8. the switch signal SB <3:0> controls the grid electrode of the MOS tube MN24-MOS tube MN21 (corresponding to the third MOS tube in the 4 temperature coefficient adjusting units), controls the conduction and the closing of the grid electrode, and the width-length ratio of the MOS tube MN11-MOS tube MN16 (the MOS tube MN16 corresponds to one MOS tube in the first mirror image unit and the MOS tube MN15-MOS tube MN12 corresponds to the second MOS tube in the 4 temperature coefficient adjusting units) is 8:4:2:1:17:24.

in this embodiment, the current input to IPTAT is 8uA-16uA within the range of-40 to 125 degrees, the current at 40 degrees is 12uA, the current input to ICON is 24uA current which does not change with temperature,

when the switching signal S is 1000, itail=36 uA at a temperature of 40 °, itail=32 uA at a temperature of-40 °, and itail=40 uA at a temperature of 125 °.

When the switching signal S is 0000, itail=36 uA at a temperature of 40 °, itail=34.6 uA at a temperature of-40 °, and itail=37.3 uA at a temperature of 125 °.

When the switching signal S is 1111, itail=36 uA at a temperature of 40 °, itail=29.67 uA at a temperature of-40 °, and itail=42.33 uA at a temperature of 125 °.

The temperature coefficient of the final output current can be adjusted according to the simulation result or the value of the actual demand adjusting switch signal S <3:0>, and the requirements of different processes and different oscillation frequencies are met. The specific circuit design is not limited to the parameters, and a designer can adjust the size of input currents of IPTAT and ICON and the proportion of pipes according to different process characteristics and different oscillation frequencies, even increase the bit of a switch to adjust the temperature coefficient, so that the optimal design is achieved.

The ITAIL current signal realizes superposition of the IPTAT current signal and the ICON current signal, and the temperature coefficient of the output ITAIL current signal can be adjusted by the sum of the ICON current signal which does not change along with temperature and the IPTAT current signal with higher temperature coefficient so as to adapt to the compensation effect of the current-type oscillator and avoid the occurrence of the condition of overcompensation. The temperature compensation of the invention does not greatly increase the power consumption of the circuit.

The invention synthesizes IPTAT current with fixed temperature coefficient and ICON current irrelevant to temperature to generate ITAIL current with specific temperature coefficient, which is used as a current source of an oscillator, can effectively compensate frequency change caused by temperature change, has simple circuit structure, does not need to introduce an operational amplifier, and adopts current superposition to compensate, so that the frequency of the oscillator is not influenced by power supply voltage fluctuation.

The ring oscillator comprises MOS transistors MP12 and MP13, and an odd number of inverter delay units; the input of the ring oscillator is an ITAIL current signal; the grid electrode and the drain electrode of the MOS tube MP12 are commonly connected with ITAIL current signals, and are simultaneously connected with the grid electrode of the MOS tube MP13, the drain electrode of the MOS tube MP13 outputs VRING signals, the VRING signals are connected with power supplies of all inverter delay units, and the odd number inverter delay units are connected in a tail-to-tail manner, namely, the output of one inverter delay unit is connected with the input of the next inverter delay unit, so that a ring structure is formed. In some embodiments, as shown in fig. 5, the ring oscillator includes a MOS tube MP12, a MOS tube MP13, and three inverter delay units INV0 to INV2, where the MOS tube MP12 and the MOS tube MP13 are PMOS tubes; the ring oscillator adopts a current type ring oscillator, and the frequency deviation caused by the power supply voltage can be effectively reduced by adopting the current type ring oscillator. The input of the ring oscillator is an ITAIL current signal;

the grid electrode and the drain electrode of the MOS tube MP12 are commonly connected with ITAIL current signals, the grid electrode of the MOS tube MP13 is connected at the same time, the drain electrode of the MOS tube MP13 outputs VRING signals, the VRING signals are connected with power supplies of three inverter delay units, the output of the inverter INV0 is connected with the input of the inverter INV1, the output of the inverter INV1 is connected with the input of the inverter INV2, the output of the inverter INV2 is connected with the input of the inverter INV0, and the source electrodes of the MOS tubes MP 12-MP 13 are all connected with the power supplies.

The three inverters are cascaded into a ring to form a ring oscillator, the power supply of the inverters is VRING signal, and the MOS tube MP13 mirrors the input current of the MOS tube MP12, namely ITAIL current signal, and the ITAIL current signal is output to the three inverters. The oscillation frequency is mainly related to current, the current is completely mirrored and is not influenced by power supply voltage, when the source voltages of the MOS tube MP12 and the MOS tube MP13 are changed, the output current of the MOS tube MP13 is not influenced, and therefore the oscillation frequency is not influenced, that is, the current superposition is adopted for compensation, and the oscillator frequency is not influenced by the fluctuation of the power supply voltage.

The circuit designed by the invention is already applied to an optical transmitter SOC system, as shown in a figure 6, a simulation result of a specific circuit is given, the IPTAT current increases along with the increase of temperature, the range is 8-17 uA, the ICON does not change along with the temperature, the value is 24uA, after the two are added, the current does not change along with the temperature, but after the total current increases, the temperature coefficient of the current decreases, namely the temperature coefficient of the current of the ITAIL current decreases, and a designer can adjust the proportion of the IPTAT and the ICON through simulation according to the characteristics of transistors of different processes, so that the oscillation frequency which does not change along with the temperature is obtained. The actual test results showed that the temperature was in the range of-40-125 deg. and the frequency was varied by only 0.3%.

The foregoing is only a preferred embodiment of the invention, it being noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present invention, and such modifications and adaptations are intended to be comprehended within the scope of the invention.

Claims

1. A ring oscillator with temperature compensation function, characterized in that: the device comprises a PAPT current generation module, an ICON current generation module, a compensation current synthesis module and a ring oscillator;

the PAPT current generation module is connected with the ICON current generation module and the compensation current synthesis module, and is used for outputting a VBG voltage signal to the ICON current generation module and outputting an IPTAT current signal to the compensation current synthesis module, wherein the VBG voltage signal does not change along with temperature, and the IPTAT current signal is in direct proportion to the temperature; the ICON current generation module is connected with the compensation current synthesis module and is used for outputting an ICON current signal to the compensation current synthesis module, wherein the ICON current signal does not change along with temperature; the compensation current synthesis module is connected with the ring oscillator and is used for outputting an ITAIL current signal to the ring oscillator, the ITAIL current signal is provided with temperature compensation, and frequency change caused by temperature change is compensated in the ring oscillator;

the ICON current generation module comprises an operational amplifier OP, an MOS tube MN3, MOS tubes MP10-MP11 and a resistor R6, wherein the MOS tube MN3 is an NMOS tube, and the MOS tubes MP10-MP11 are PMOS tubes; the input of the ICON current generation module is a VBG voltage signal, and the output of the ICON current generation module is an ICON current signal;

the positive input end of the operational amplifier OP is connected with a VBG voltage signal, the negative input end of the operational amplifier OP is connected with one end of a resistor R6 and the source electrode of a MOS tube MN3, the other end of the resistor R6 is grounded, the output end of the operational amplifier OP is connected with the grid electrode of the MOS tube MN3, the drain electrode of the MOS tube MN3 is connected with the drain electrode and the grid electrode of a MOS tube MP10, and meanwhile, the grid electrode of the MOS tube MP11 is connected; the source electrode of the MOS tube MP10-MOS tube MP11 is commonly connected with a power supply, the drain electrode of the MOS tube MP11 is connected with an output port ICON, and the output port ICON outputs an ICON current signal;

the compensation current synthesis module comprises a switching signal SB with B bit number, a first mirror image unit, a second mirror image unit and B temperature coefficient regulating units, wherein the switching signal S is a binary control signal with B bit number, the bit number of the switching signal SB is equal to that of the switching signal S, each control signal of the switching signal SB is the control signal of the switching signal S and is inverted, the first mirror image unit is input into an IPTAT current signal, the output of the first mirror image unit is an IPTAT current signal through a mirror image structure, the input of the second mirror image unit is an ICON current signal, the output of the second mirror image unit is an ICON current signal through a mirror image structure, the number of the temperature coefficient regulating units is equal to that of the switching signal S, the input of the B temperature coefficient regulating units is an IPTAT current signal, an ICON current signal, a B bit switching signal S, a B bit switching signal SB, B bit number of the B is not less than or equal to B, B number of the B is not more than 1, B is used for controlling whether the input AT current signal is conducted or not, B bit switching signal SB is used for controlling whether the input ICON current signal is conducted or not, the temperature coefficient regulating unit is used for controlling the output of the switching signal SB signal to be connected with an AIL current port through the mirror image unit, the output of the AIL current regulating unit, the AIL current is connected with the AIL current regulating unit, and the AIL current is output through the output port.

2. A ring oscillator with temperature compensation as claimed in claim 1, wherein: the PAPT current generation module comprises a first self-bias current generation circuit, a second self-bias current generation circuit, an amplifier driving circuit and an output circuit, wherein the first self-bias current generation circuit outputs a first current, the second self-bias current generation circuit outputs a second current, the first self-bias current generation circuit and the second self-bias current generation circuit are connected with the amplifier driving circuit, the input of the amplifier driving circuit is the first current and the second current, and the output of the amplifier driving circuit is a first driving signal and a second driving signal; the amplifier driving circuit is connected with the output circuit, the input of the output circuit is a first driving signal and a second driving signal, and the output is an IPTAT current signal and a VBG voltage signal.

3. A ring oscillator with temperature compensation function as claimed in claim 2, wherein: the first self-bias current generation circuit comprises a MOS tube MP0 and a resistor R0, wherein the drain electrode of the MOS tube MP0 is connected with one end of the resistor R0, the other end of the resistor R0 is grounded, and the drain electrode of the MOS tube MP0 is connected with the grid electrode and then outputs a first current.

4. A ring oscillator with temperature compensation function as claimed in claim 2, wherein: the second self-bias current generation circuit comprises a MOS tube MP1 and a resistor R1, wherein the drain electrode of the MOS tube MP1 is connected with one end of the resistor R1, the other end of the resistor R1 is grounded, and the drain electrode of the MOS tube MP1 is connected with the grid electrode and then outputs a second current.

5. A ring oscillator with temperature compensation function as claimed in claim 2, wherein: the amplifier driving circuit comprises MOS transistors MP2 to MP6, MOS transistor MN0, MOS transistor MN1, triode Q0 and triode Q1, wherein the input of the amplifier driving circuit is a first current and a second current, and the output of the amplifier driving circuit is a first driving signal and a second driving signal;

6. A ring oscillator with temperature compensation function as claimed in claim 2, wherein: the output circuit comprises MOS transistors MP7 to MP9, MOS transistor MN2 and triode Q3; the input of the output circuit is a first driving signal and a second driving signal, and the output is an IPTAT current signal and a VBG voltage signal;

7. A ring oscillator with temperature compensation as claimed in claim 1, wherein: the first mirror image unit and the second mirror image unit have the same structure, and realize current mirror image through a pair of MOS tubes; each temperature coefficient adjusting unit comprises 4 MOS tubes, wherein the grid electrode of a first MOS tube is connected with an IPTAT current signal, the grid electrode of a second MOS tube is connected with an ICON current signal, the source electrode of the first MOS tube is connected with the source electrode of the second MOS tube, the drain electrode of the first MOS tube is connected with the source electrode of a third MOS tube, the grid electrode of the third MOS tube is connected with a one-bit signal of a switch signal S, the drain electrode of the third MOS tube is connected with an output port ITAIL, the drain electrode of the second MOS tube is connected with the source electrode of a fourth MOS tube, the grid electrode of the fourth MOS tube is connected with a one-bit signal of a switch signal SB, and the drain electrode of the fourth MOS tube is connected with the output port ITAIL; the on-off of the third MOS tube and the fourth MOS tube is controlled through the switch signal S and the switch signal SB, so that the temperature coefficient adjustment of the ITAIL current signal is realized; and the temperature coefficient adjustment of the ITAIL current signal is controlled by adjusting the width-to-length ratio between the first MOS tubes and the width-to-length ratio between the second MOS tubes of the B temperature coefficient adjustment units.

8. A ring oscillator with temperature compensation as claimed in claim 1, wherein: the ring oscillator comprises a MOS tube MP12, a MOS tube MP13 and an odd number of inverter delay units; the input of the ring oscillator is an ITAIL current signal;