CN112803906A - Front gain amplifier - Google Patents
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- CN112803906A CN112803906A CN202110144206.1A CN202110144206A CN112803906A CN 112803906 A CN112803906 A CN 112803906A CN 202110144206 A CN202110144206 A CN 202110144206A CN 112803906 A CN112803906 A CN 112803906A
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- 101100180304 Arabidopsis thaliana ISS1 gene Proteins 0.000 description 5
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
- H03F3/45—Differential amplifiers
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- H—ELECTRICITY
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- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers
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Abstract
The invention relates to the technical field of integrated circuit design, and particularly discloses a pre-gain amplifier, which comprises: the current source circuit is connected with the transconductance amplifier module, and the transconductance amplifier module is connected with the differential operational amplifier module; the current source circuit can output current to the transconductance amplifier module; the transconductance amplifier module can generate transconductance according to input current, amplify the input temperature signal, and the transconductance is irrelevant to the temperature signal, the power supply voltage and the process parameter, and the transconductance can adjust the multiple of the pre-gain amplifier; the differential operational amplifier module can process and output the temperature signal amplified by the transconductance amplifier module. The pre-gain amplifier provided by the invention can realize high precision when being applied to a temperature system and is not influenced by temperature and power supply voltage.
Description
Technical Field
The invention relates to the technical field of integrated circuit design, in particular to a pre-gain amplifier.
Background
With the development and popularization of the internet of things, more and more application scenes need to precisely sense parameters of the physical world, such as temperature, humidity, pressure and the like, through various sensors, weak electric signals obtained by the sensors are processed and converted into digital signals, and therefore analog-to-digital converters (ADCs) are needed to process and convert the signals of the real world. In a high-precision temperature measurement system, since the temperature signal changes slowly and the signal amplitude is very small, a high-resolution analog-to-digital converter (ADC) is required for processing, but the design difficulty and complexity of the ADC are greatly increased. Therefore, a pre-gain amplifier (VGA) is usually introduced in the front end of the ADC to amplify the signal, so as to reduce the performance requirement of the ADC. For a conventional preamplifier structure, the performance is easily affected by parameters such as temperature, voltage, and process.
Therefore, how to provide a high-precision pre-gain amplifier in a thermometry system without being affected by temperature and power supply voltage is a technical problem to be solved by those skilled in the art.
Disclosure of Invention
The invention provides a pre-gain amplifier, which solves the problem that the prior art lacks a high-precision pre-gain amplifier which is not influenced by temperature and power supply voltage.
As an aspect of the present invention, there is provided a pre-gain amplifier, comprising: the current source circuit is connected with the transconductance amplifier module, and the transconductance amplifier module is connected with the differential operational amplifier module;
the current source circuit is capable of outputting current to the transconductance amplifier module;
the transconductance amplifier module can generate transconductance according to input current, amplify an input temperature signal and adjust the multiple of the pre-gain amplifier through the transconductance amplifier module, wherein the transconductance amplifier module is unrelated to the temperature signal, the power supply voltage and the process parameter;
the differential operational amplifier module can process and output the temperature signal amplified by the transconductance amplifier module.
Further, the current source circuit includes: a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a fifth switch tube, a sixth switch tube, a seventh switch tube, an eighth switch tube and a first resistor,
one end of the first resistor is connected with a power supply end, the other end of the first resistor is connected with the source electrode of the first switch tube,
the source electrode of the eighth switching tube is connected with the power supply end, the grid electrode of the seventh switching tube is connected with the grid electrode of the eighth switching tube, and the grid electrode of the seventh switching tube and the grid electrode of the eighth switching tube are both connected to the drain electrode of the sixth switching tube;
the grid electrode of the sixth switching tube is connected with the grid electrode of the fifth switching tube, the grid electrode of the sixth switching tube and the grid electrode of the fifth switching tube are both connected with a first external bias voltage for inputting the first bias voltage,
the source electrode of the sixth switching tube is connected with the drain electrode of the eighth switching tube, and the source electrode of the fifth switching tube is connected with the drain electrode of the seventh switching tube;
the grid electrode of the third switching tube is connected with the grid electrode of the fourth switching tube, the grid electrode of the third switching tube and the grid electrode of the fourth switching tube are both connected with a second external bias voltage for inputting a second bias voltage,
the grid electrode of the first switch tube is connected with the grid electrode of the second switch tube, the grid electrode of the first switch tube and the grid electrode of the second switch tube are both connected with the drain electrode of the third switch tube, the drain electrode of the third switch tube is connected with the drain electrode of the fifth switch tube, the source electrode of the third switch tube is connected with the drain electrode of the first switch tube, the drain electrode of the third switch tube and the drain electrode of the fifth switch tube are both connected with the output end for outputting current,
the drain electrode of the fourth switching tube is connected with the drain electrode of the sixth switching tube, the source electrode of the fourth switching tube is connected with the drain electrode of the second switching tube,
the source electrode of the first switch tube and the source electrode of the second switch tube are both connected with a power ground.
Further, the first switch tube, the second switch tube, the third switch tube and the fourth switch tube all include N-type switch tubes, and the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube all include P-type switch tubes.
Further, the transconductance amplifier module comprises: a current source, a second resistor, a third resistor, a first switch, a second switch, a ninth switch tube, a tenth switch tube, an eleventh switch tube and a twelfth switch tube,
one end of the current source is connected with a power supply end, the other end of the current source is respectively connected with one end of the second resistor and one end of the third resistor, the first switch is connected with the second resistor in parallel, the second switch is connected with the third resistor in parallel,
the other end of the second resistor is connected with the source electrode of the ninth switching tube, the other end of the third resistor is connected with the source electrode of the tenth switching tube,
the grid electrode of the ninth switching tube is connected with the positive electrode of the input voltage, the drain electrode of the ninth switching tube is connected with the drain electrode of the eleventh switching tube,
the grid electrode of the tenth switching tube is connected with the negative electrode of the input voltage, the drain electrode of the tenth switching tube is connected with the drain electrode of the twelfth switching tube,
the grid electrode of the eleventh switching tube is connected with the grid electrode of the twelfth switching tube, and the grid electrode of the eleventh switching tube and the grid electrode of the twelfth switching tube are both connected with a third external bias voltage for inputting a third bias voltage,
the source electrode of the eleventh switch tube and the source electrode of the twelfth switch tube are both connected with the power ground,
and the drain electrode of the eleventh switching tube and the drain electrode of the twelfth switching tube are both used for outputting the amplified temperature signal to the differential operational amplifier.
Further, the ninth switching tube and the tenth switching tube each include a P-type switching tube, and the eleventh switching tube and the twelfth switching tube each include an N-type switching tube.
Further, the resistance value of the second resistor is the same as the resistance value of the third resistor.
Further, the differential operational amplifier module includes: a first amplifier, a second amplifier, a third amplifier, a fourth resistor, a fifth resistor, a thirteenth switch tube, a fourteenth switch tube, a fifteenth switch tube, a sixteenth switch tube, a seventeenth switch tube, an eighteenth switch tube, a nineteenth switch tube, a twentieth switch tube, a twenty-first switch tube, a twenty-second switch tube, a twentieth switch tube and a twenty-fourth switch tube,
the source electrode of the thirteenth switching tube, the source electrode of the fourteenth switching tube, the source electrode of the twenty-first switching tube and the source electrode of the twenty-second switching tube are all connected with a power supply end,
the drain electrode of the thirteenth switching tube is respectively connected with the source electrode of the fifteenth switching tube and the inverting input end of the first amplifier, the grid electrode of the thirteenth switching tube is respectively connected with the drain electrode of the fifteenth switching tube, the drain electrode of the seventeenth switching tube and the grid electrode of the twenty-first switching tube,
the drain electrode of the fourteenth switching tube is respectively connected with the source electrode of the sixteenth switching tube and the positive input end of the first amplifier, the grid electrode of the fourteenth switching tube is respectively connected with the drain electrode of the sixteenth switching tube, the drain electrode of the eighteenth switching tube and the grid electrode of the twenty second switching tube,
the grid electrode of the fifteenth switching tube is connected with the positive output end of the first amplifier, the grid electrode of the sixteenth switching tube is connected with the negative output end of the first amplifier,
the grid electrode of the seventeenth switching tube is connected with the positive output end of the second amplifier, the source electrode of the seventeenth switching tube is respectively connected with the drain electrode of the nineteenth switching tube and the reverse input end of the second amplifier,
the grid electrode of the eighteenth switching tube is connected with the reverse output end of the second amplifier, the source electrode of the eighteenth switching tube is respectively connected with the drain electrode of the twentieth switching tube and the positive input end of the second amplifier,
the grid electrode of the nineteenth switching tube is connected with the grid electrode of the twentieth switching tube, and both are connected with a third external bias voltage for inputting a third bias voltage, the source electrode of the nineteenth switching tube and the source electrode of the twentieth switching tube are connected with the power ground,
the drain electrode of the twenty-first switching tube is respectively connected with the reverse input end of the third amplifier and the source electrode of the twenty-third switching tube,
the drain electrode of the twenty-second switching tube is respectively connected with the positive input end of the third amplifier and the source electrode of the twenty-fourth switching tube,
the grid electrode of the twentieth three-switch tube is connected with the positive output end of the third amplifier, the drain electrode of the twentieth three-switch tube is connected with one end of the fourth resistor, the drain electrode of the twentieth three-switch tube is the negative end of the output voltage,
the grid electrode of the twenty-fourth switching tube is connected with the inverted output end of the third amplifier, the drain electrode of the twenty-fourth switching tube is connected with one end of the fifth resistor, the drain electrode of the twenty-fourth switching tube is the positive end of the output voltage,
the other end of the fourth resistor and the other end of the fifth resistor are both connected with a power ground.
Further, the thirteenth switching tube, the fourteenth switching tube, the fifteenth switching tube, the sixteenth switching tube, the twenty-first switching tube, the twenty-second switching tube, the twenty-third switching tube and the twenty-fourteenth switching tube all include P-type switching tubes, and the seventeenth switching tube, the eighteenth switching tube, the nineteenth switching tube and the twentieth switching tube all include N-type switching tubes.
Further, the resistance value of the fifth resistor is the same as the resistance value of the sixth resistor.
The pre-gain amplifier provided by the invention adopts the current source circuit irrelevant to the power supply to provide current for the transconductance amplifier module, the current is input to the transconductance amplifier to obtain a transconductance value without power supply voltage and process parameters, and the gain is adjusted by changing the transconductance value, so that the whole pre-gain amplifier obtains the gain irrelevant to the temperature power supply voltage and the process parameters. The pre-gain amplifier can realize high precision when applied to a temperature system and is not influenced by temperature and power supply voltage.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.
Fig. 1 is a schematic circuit diagram of a pre-gain amplifier according to the present invention.
Fig. 2 is a schematic circuit diagram of a current source circuit according to the present invention.
Fig. 3 is a schematic circuit diagram of a transconductance amplifier module and a differential operational amplifier module according to the present invention.
Detailed Description
It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.
In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged under appropriate circumstances in order to facilitate the description of the embodiments of the invention herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, 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.
In this embodiment, a pre-gain amplifier is provided, and fig. 1 is a schematic circuit diagram of a pre-gain amplifier provided according to an embodiment of the present invention, as shown in fig. 1, including: the current source circuit ISS1, the transconductance amplifier module OTA and the differential operational amplifier module OPA, wherein the current source circuit ISS1 is connected with the transconductance amplifier module OTA, and the transconductance amplifier module OTA is connected with the differential operational amplifier module OPA;
the current source circuit ISS1 is capable of outputting a current to the transconductance amplifier module OTA;
the transconductance amplifier module OTA can generate transconductance according to input current, amplify input temperature signals and adjust the multiple of the pre-gain amplifier through the transconductance amplifier module OTA, wherein the transconductance is irrelevant to the temperature signals, the power supply voltage and the process parameters;
the differential operational amplifier module OPA can process the temperature signal amplified by the transconductance amplifier module and then output the temperature signal.
The pre-gain amplifier provided by the embodiment of the invention adopts the current source circuit irrelevant to the power supply to provide the current for the transconductance amplifier module, inputs the current to the transconductance amplifier to obtain a transconductance value without power supply voltage and process parameters, and adjusts the gain by changing the transconductance value, so that the whole pre-gain amplifier obtains the gain irrelevant to the temperature power supply voltage and the process parameters. The pre-gain amplifier can realize high precision when applied to a temperature system and is not influenced by temperature and power supply voltage.
Specifically, as shown in fig. 2, the current source circuit includes: a first switch tube M1, a second switch tube M2, a third switch tube M3, a fourth switch tube M4, a fifth switch tube M5, a sixth switch tube M6, a seventh switch tube M7, an eighth switch tube M8 and a first resistor R1,
one end of the first resistor R1 is connected to a power supply terminal VDD, the other end of the first resistor R1 is connected to the source of the first switch transistor M1,
the source of the eighth switch transistor M8 is connected to the power supply terminal VDD, the gate of the seventh switch transistor M7 is connected to the gate of the eighth switch transistor M8, and the gate of the seventh switch transistor M7 and the gate of the eighth switch transistor M8 are both connected to the drain of the sixth switch transistor M6;
the grid electrode of the sixth switching tube M6 is connected with the grid electrode of the fifth switching tube M5, the grid electrode of the sixth switching tube M6 and the grid electrode of the fifth switching tube M5 are both connected with a first external bias voltage for inputting a first bias voltage Vb1,
the source electrode of the sixth switching tube M6 is connected to the drain electrode of the eighth switching tube M8, and the source electrode of the fifth switching tube M5 is connected to the drain electrode of the seventh switching tube M7;
the grid electrode of the third switching tube M3 and the grid electrode of the fourth switching tube M4 are connected, and the grid electrode of the third switching tube M3 and the grid electrode of the fourth switching tube M4 are both connected with a second external bias voltage for inputting a second bias voltage Vb2,
the grid of the first switch tube M1 is connected with the grid of the second switch tube M2, the grid of the first switch tube M1 and the grid of the second switch tube M2 are both connected with the drain of the third switch tube M3, the drain of the third switch tube M3 is connected with the drain of the fifth switch tube M5, the source of the third switch tube M3 is connected with the drain of the first switch tube M1, the drain of the third switch tube M3 and the drain of the fifth switch tube M5 are both connected with the output end for outputting current,
the drain of the fourth switching tube M4 is connected to the drain of the sixth switching tube M6, the source of the fourth switching tube M4 is connected to the drain of the second switching tube M2,
the source electrode of the first switch tube M1 and the source electrode of the second switch tube M2 are both connected to the power ground.
In the embodiment of the present invention, the first switching tube M1, the second switching tube M2, the third switching tube M3 and the fourth switching tube M4 all include N-type switching tubes, and the fifth switching tube M5, the sixth switching tube M6, the seventh switching tube M7 and the eighth switching tube M8 all include P-type switching tubes.
As shown in fig. 3, the transconductance amplifier module includes: a current source, a second resistor R2, a third resistor R3, a first switch phi 1, a second switch phi 2, a ninth switch tube M9, a tenth switch tube M10, an eleventh switch tube M11 and a twelfth switch tube M12,
one end of the current source ISS1 is connected to a power supply terminal VDD, the other end of the current source ISS1 is respectively connected to one end of the second resistor R2 and one end of the third resistor R3, the first switch phi 1 is connected in parallel with the second resistor R2, the second switch phi 2 is connected in parallel with the third resistor R3,
the other end of the second resistor R2 is connected to the source of the ninth switch transistor M9, the other end of the third resistor R3 is connected to the source of the tenth switch transistor M10,
the gate of the ninth switching tube M9 is connected to the positive electrode Vin + of the input voltage, the drain of the ninth switching tube M9 is connected to the drain of the eleventh switching tube M11,
the grid electrode of the tenth switching tube M10 is connected to the negative Vin-of the input voltage, the drain electrode of the tenth switching tube M10 is connected to the drain electrode of the twelfth switching tube M12,
the grid electrode of the eleventh switch tube M11 is connected with the grid electrode of the twelfth switch tube M12, and the grid electrode of the eleventh switch tube M11 and the grid electrode of the twelfth switch tube M12 are both connected with a third external bias voltage for inputting a third bias voltage Vb3,
the source electrode of the eleventh switch tube M11 and the source electrode of the twelfth switch tube M12 are both connected to the power ground,
the drain of the eleventh switch tube M11 and the drain of the twelfth switch tube M12 are both used for outputting the amplified temperature signal to the differential operational amplifier.
In the embodiment of the present invention, the drain of the eleventh switch M11 is output to the drain of the nineteenth switch M19 in the differential operational amplifier module OPA module, and the drain of the twelfth switch M12 is output to the drain of the twentieth switch M20 in the differential operational amplifier module OPA module.
In the embodiment of the present invention, the ninth switching tube M9 and the tenth switching tube M10 each include a P-type switching tube, and the eleventh switching tube M11 and the twelfth switching tube M12 each include an N-type switching tube.
Preferably, the resistance of the second resistor R2 is the same as the resistance of the third resistor R3.
Specifically, as shown in fig. 3, the differential operational amplifier module includes: a first amplifier A1, a second amplifier A2, a third amplifier A3, a fourth resistor R4, a fifth resistor R5, a thirteenth switching tube M13, a fourteenth switching tube M14, a fifteenth switching tube M15, a sixteenth switching tube M16, a seventeenth switching tube M17, an eighteenth switching tube M18, a nineteenth switching tube M19, a twentieth switching tube M20, a twenty-first switching tube M21, a twenty-second switching tube M22, a twentieth switching tube M23 and a twenty-fourteenth switching tube M24,
the source electrode of the thirteenth switching tube M13, the source electrode of the fourteenth switching tube M14, the source electrode of the twenty-first switching tube M21 and the source electrode of the twenty-second switching tube M22 are all connected with a power supply terminal,
the drain of the thirteenth switching tube M13 is connected to the source of the fifteenth switching tube M15 and the inverting input terminal of the first amplifier a1, respectively, the gate of the thirteenth switching tube M13 is connected to the drain of the fifteenth switching tube M15, the drain of the seventeenth switching tube M17 and the gate of the twenty-first switching tube M21,
the drain of the fourteenth switching tube M14 is connected to the source of the sixteenth switching tube M16 and the positive input terminal of the first amplifier a1, respectively, the gate of the fourteenth switching tube M14 is connected to the drain of the sixteenth switching tube M16, the drain of the eighteenth switching tube M18 and the gate of the twenty second switching tube M22, respectively,
the gate of the fifteenth switching tube M15 is connected to the positive output terminal of the first amplifier A1, the gate of the sixteenth switching tube M16 is connected to the negative output terminal of the first amplifier A1,
the gate of the seventeenth switching tube M17 is connected to the forward output terminal of the second amplifier a2, the source of the seventeenth switching tube M17 is connected to the drain of the nineteenth switching tube M19 and the inverting input terminal of the second amplifier a2,
the grid electrode of the eighteenth switching tube M18 is connected with the inverted output end of the second amplifier A2, the source electrode of the eighteenth switching tube M18 is respectively connected with the drain electrode of the twentieth switching tube M20 and the positive input end of the second amplifier A2,
the grid electrode of the nineteenth switching tube M19 and the grid electrode of the twentieth switching tube M20 are connected, and are both connected with a third external bias voltage for inputting a third bias voltage Vb3, the source electrode of the nineteenth switching tube M19 and the source electrode of the twentieth switching tube M20 are both connected with the power ground,
the drain of the twenty-first switching tube M21 is respectively connected with the inverting input terminal of the third amplifier A3 and the source of the twenty-second switching tube M23,
the drain of the twenty-second switching tube M22 is respectively connected with the positive input end of the third amplifier A3 and the source of the twenty-fourth switching tube M24,
the gate of the twentieth switching tube M23 is connected to the positive output terminal of the third amplifier A3, the drain of the twentieth switching tube M23 is connected to one end of the fourth resistor R4, and the drain of the twentieth switching tube M23 is the negative output voltage terminal Vout-,
the grid electrode of the twenty-fourth switching tube M24 is connected with the inverted output end of the third amplifier A3, the drain electrode of the twenty-fourth switching tube M24 is connected with one end of the fifth resistor R5, the drain electrode of the twenty-fourth switching tube M24 is an output voltage positive end Vout +,
the other end of the fourth resistor R4 and the other end of the fifth resistor R5 are both connected with the power ground.
In the embodiment of the present invention, the thirteenth switching tube M13, the fourteenth switching tube M14, the fifteenth switching tube M15, the sixteenth switching tube M16, the twenty-first switching tube M21, the twenty-second switching tube M22, the twenty-third switching tube M23, and the twenty-fourth switching tube M24 all include P-type switching tubes, and the seventeenth switching tube M17, the eighteenth switching tube M18, the nineteenth switching tube M19, and the twentieth switching tube M20 all include N-type switching tubes.
Preferably, the resistance of the fifth resistor R5 is the same as the resistance of the sixth resistor R6.
It should be noted that, in the embodiment of the present invention, the output expression of the pre-gain amplifier is as follows:
Vout＝-GmRfVin，
the current source current adopts a cascode current mirror structure to reduce the influence of channel length modulation, external bias voltages Vb1 and Vb2 are reasonably selected to enable the switching tubes M1-M8 to work in a saturation region, the width-to-length ratio of the switching tubes M8 and M7 is 1/M, the difference of VTHs of the switching tubes M4 and M5 is reduced through a resistor R1 and the switching tubes M5 and M6, and the switching tubes M3 and M4 form a cascode structure, the channel length modulation effect is reduced, the current generated by the final bias current mirror is enabled to be closer to an ideal current irrelevant to the power supply voltage, and the output current Iout is as follows:
the current is input to the source ends of the switching tubes M9 and M10 of the transconductance amplifier module, the switching tubes M9, M10, M11 and M12 in the transconductance amplifier OTA form a negative feedback structure with a source, and the transconductance gm of the switching tubes M9 and M10 of the gate input signal can be obtained by a formula:
it can be seen that the gm formula obtained finally is independent of the power supply voltage and does not contain process parameters. When the switches phi 1 and phi 2 in the transconductance amplifier module are turned on, the resistors R2 and R3 are short-circuited, and the transconductance Gm of the transconductance amplifier OTA is:
when the switches phi 1 and phi 2 are turned off, the currents output by the current sources are respectively input to the source ends of the switching tubes M9 and M10 from the resistors R2 and R3, and the transconductance Gm of the transconductance amplifier OTA is:
the last-stage operational amplifier OPA module adopts a cascode gain improvement technology to improve output impedance, the switching tubes M13, M15 and M21 form a current mirror structure, OTA input signals are mirrored onto the final output resistor R4, and the switching tubes M14, M16 and M22 similarly mirror the OTA input signals onto the final output resistor R5.
At this time, when the switches phi 1 and phi 2 in the transconductance amplifier module OTA are turned on, the output gain of the overall circuit is:
when the switches phi 1 and phi 2 in the transconductance amplifier module OTA are turned off, the output gain of the overall circuit is as follows:
the formula shows that the gain of the whole pre-gain amplifier has no relation with the power supply voltage, the temperature and the process parameters, and the temperature weak current signal input from the front end can be accurately and precisely amplified.
To sum up, in the pre-gain amplifier provided in the embodiment of the present invention, the current source provides a current unrelated to the power supply voltage, the transconductance unrelated to the power supply voltage, the temperature and the process parameter is generated by the transconductance amplifier, the gain unrelated to the power supply voltage, the temperature and the process parameter is obtained by the operational amplifier, and the transconductance of the transconductance amplifier is changed by the switch circuit to obtain different gain values. Therefore, the pre-gain amplifier can accurately amplify and transmit the weak point signal input from the sensor without being influenced by temperature and process parameters.
It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.
Claims (9)
1. A pre-gain amplifier, comprising: the current source circuit is connected with the transconductance amplifier module, and the transconductance amplifier module is connected with the differential operational amplifier module;
the current source circuit is capable of outputting current to the transconductance amplifier module;
the transconductance amplifier module can generate transconductance according to input current, amplify an input temperature signal and adjust the multiple of the pre-gain amplifier through the transconductance amplifier module, wherein the transconductance amplifier module is unrelated to the temperature signal, the power supply voltage and the process parameter;
the differential operational amplifier module can process and output the temperature signal amplified by the transconductance amplifier module.
2. The pre-gain amplifier of claim 1, wherein the current source circuit comprises: a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a fifth switch tube, a sixth switch tube, a seventh switch tube, an eighth switch tube and a first resistor,
one end of the first resistor is connected with a power supply end, the other end of the first resistor is connected with the source electrode of the first switch tube,
the source electrode of the eighth switching tube is connected with the power supply end, the grid electrode of the seventh switching tube is connected with the grid electrode of the eighth switching tube, and the grid electrode of the seventh switching tube and the grid electrode of the eighth switching tube are both connected to the drain electrode of the sixth switching tube;
the grid electrode of the sixth switching tube is connected with the grid electrode of the fifth switching tube, the grid electrode of the sixth switching tube and the grid electrode of the fifth switching tube are both connected with a first external bias voltage for inputting the first bias voltage,
the source electrode of the sixth switching tube is connected with the drain electrode of the eighth switching tube, and the source electrode of the fifth switching tube is connected with the drain electrode of the seventh switching tube;
the grid electrode of the third switching tube is connected with the grid electrode of the fourth switching tube, the grid electrode of the third switching tube and the grid electrode of the fourth switching tube are both connected with a second external bias voltage for inputting a second bias voltage,
the grid electrode of the first switch tube is connected with the grid electrode of the second switch tube, the grid electrode of the first switch tube and the grid electrode of the second switch tube are both connected with the drain electrode of the third switch tube, the drain electrode of the third switch tube is connected with the drain electrode of the fifth switch tube, the source electrode of the third switch tube is connected with the drain electrode of the first switch tube, the drain electrode of the third switch tube and the drain electrode of the fifth switch tube are both connected with the output end for outputting current,
the drain electrode of the fourth switching tube is connected with the drain electrode of the sixth switching tube, the source electrode of the fourth switching tube is connected with the drain electrode of the second switching tube,
the source electrode of the first switch tube and the source electrode of the second switch tube are both connected with a power ground.
3. The pre-gain amplifier according to claim 2, wherein the first switch tube, the second switch tube, the third switch tube and the fourth switch tube each comprise an N-type switch tube, and the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube each comprise a P-type switch tube.
4. The pre-gain amplifier of claim 1, wherein the transconductance amplifier module comprises: a current source, a second resistor, a third resistor, a first switch, a second switch, a ninth switch tube, a tenth switch tube, an eleventh switch tube and a twelfth switch tube,
one end of the current source is connected with a power supply end, the other end of the current source is respectively connected with one end of the second resistor and one end of the third resistor, the first switch is connected with the second resistor in parallel, the second switch is connected with the third resistor in parallel,
the other end of the second resistor is connected with the source electrode of the ninth switching tube, the other end of the third resistor is connected with the source electrode of the tenth switching tube,
the grid electrode of the ninth switching tube is connected with the positive electrode of the input voltage, the drain electrode of the ninth switching tube is connected with the drain electrode of the eleventh switching tube,
the grid electrode of the tenth switching tube is connected with the negative electrode of the input voltage, the drain electrode of the tenth switching tube is connected with the drain electrode of the twelfth switching tube,
the grid electrode of the eleventh switching tube is connected with the grid electrode of the twelfth switching tube, and the grid electrode of the eleventh switching tube and the grid electrode of the twelfth switching tube are both connected with a third external bias voltage for inputting a third bias voltage,
the source electrode of the eleventh switch tube and the source electrode of the twelfth switch tube are both connected with the power ground,
and the drain electrode of the eleventh switching tube and the drain electrode of the twelfth switching tube are both used for outputting the amplified temperature signal to the differential operational amplifier.
5. The pre-gain amplifier according to claim 4, wherein the ninth switching tube and the tenth switching tube each comprise a P-type switching tube, and the eleventh switching tube and the twelfth switching tube each comprise an N-type switching tube.
6. The pre-gain amplifier of claim 4, wherein the second resistor has the same resistance as the third resistor.
7. The pre-gain amplifier of claim 1, wherein the differential operational amplifier module comprises: a first amplifier, a second amplifier, a third amplifier, a fourth resistor, a fifth resistor, a thirteenth switch tube, a fourteenth switch tube, a fifteenth switch tube, a sixteenth switch tube, a seventeenth switch tube, an eighteenth switch tube, a nineteenth switch tube, a twentieth switch tube, a twenty-first switch tube, a twenty-second switch tube, a twentieth switch tube and a twenty-fourth switch tube,
the source electrode of the thirteenth switching tube, the source electrode of the fourteenth switching tube, the source electrode of the twenty-first switching tube and the source electrode of the twenty-second switching tube are all connected with a power supply end,
the drain electrode of the thirteenth switching tube is respectively connected with the source electrode of the fifteenth switching tube and the inverting input end of the first amplifier, the grid electrode of the thirteenth switching tube is respectively connected with the drain electrode of the fifteenth switching tube, the drain electrode of the seventeenth switching tube and the grid electrode of the twenty-first switching tube,
the drain electrode of the fourteenth switching tube is respectively connected with the source electrode of the sixteenth switching tube and the positive input end of the first amplifier, the grid electrode of the fourteenth switching tube is respectively connected with the drain electrode of the sixteenth switching tube, the drain electrode of the eighteenth switching tube and the grid electrode of the twenty second switching tube,
the grid electrode of the fifteenth switching tube is connected with the positive output end of the first amplifier, the grid electrode of the sixteenth switching tube is connected with the negative output end of the first amplifier,
the grid electrode of the seventeenth switching tube is connected with the positive output end of the second amplifier, the source electrode of the seventeenth switching tube is respectively connected with the drain electrode of the nineteenth switching tube and the reverse input end of the second amplifier,
the grid electrode of the eighteenth switching tube is connected with the reverse output end of the second amplifier, the source electrode of the eighteenth switching tube is respectively connected with the drain electrode of the twentieth switching tube and the positive input end of the second amplifier,
the grid electrode of the nineteenth switching tube is connected with the grid electrode of the twentieth switching tube, and both are connected with a third external bias voltage for inputting a third bias voltage, the source electrode of the nineteenth switching tube and the source electrode of the twentieth switching tube are connected with the power ground,
the drain electrode of the twenty-first switching tube is respectively connected with the reverse input end of the third amplifier and the source electrode of the twenty-third switching tube,
the drain electrode of the twenty-second switching tube is respectively connected with the positive input end of the third amplifier and the source electrode of the twenty-fourth switching tube,
the grid electrode of the twentieth three-switch tube is connected with the positive output end of the third amplifier, the drain electrode of the twentieth three-switch tube is connected with one end of the fourth resistor, the drain electrode of the twentieth three-switch tube is the negative end of the output voltage,
the grid electrode of the twenty-fourth switching tube is connected with the inverted output end of the third amplifier, the drain electrode of the twenty-fourth switching tube is connected with one end of the fifth resistor, the drain electrode of the twenty-fourth switching tube is the positive end of the output voltage,
the other end of the fourth resistor and the other end of the fifth resistor are both connected with a power ground.
8. The pre-gain amplifier according to claim 7, wherein the thirteenth switching tube, the fourteenth switching tube, the fifteenth switching tube, the sixteenth switching tube, the twenty-first switching tube, the twenty-second switching tube, the twentieth switching tube and the twenty-fourteenth switching tube each comprise a P-type switching tube, and the seventeenth switching tube, the eighteenth switching tube, the nineteenth switching tube and the twentieth switching tube each comprise an N-type switching tube.
9. The pre-gain amplifier of claim 7, wherein the resistance of the fifth resistor is the same as the resistance of the sixth resistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110144206.1A CN112803906A (en) | 2021-02-02 | 2021-02-02 | Front gain amplifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110144206.1A CN112803906A (en) | 2021-02-02 | 2021-02-02 | Front gain amplifier |
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| CN112803906A true CN112803906A (en) | 2021-05-14 |
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|---|---|---|---|
| CN202110144206.1A Pending CN112803906A (en) | 2021-02-02 | 2021-02-02 | Front gain amplifier |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115951105A (en) * | 2023-03-09 | 2023-04-11 | 苏州联讯仪器股份有限公司 | Electric signal sampling channel device and sampling oscilloscope |
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2021
- 2021-02-02 CN CN202110144206.1A patent/CN112803906A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115951105A (en) * | 2023-03-09 | 2023-04-11 | 苏州联讯仪器股份有限公司 | Electric signal sampling channel device and sampling oscilloscope |
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