A pre-gain amplifier

Abstract

The present invention relates to the field of integrated circuit design technology and specifically discloses a pre-gain amplifier, comprising: a current source circuit, a transconductance amplifier module, and a differential operational amplifier module, wherein the current source circuit is connected to the transconductance amplifier module, which is in turn connected to the differential operational amplifier module; the current source circuit is capable of outputting current to the transconductance amplifier module; the transconductance amplifier module is capable of generating a transconductance based on the input current, and is capable of amplifying an input temperature signal; the transconductance is independent of the temperature signal, power supply voltage, and process parameters, and is capable of adjusting the multiplier of the pre-gain amplifier; and the differential operational amplifier module is capable of processing and outputting the temperature signal amplified by the transconductance amplifier module. The pre-gain amplifier provided by the present invention can achieve high precision when used in a temperature system and is unaffected by temperature and power supply voltage.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuit design, and in particular to a pre-gain amplifier. Background Art

[0002] With the development and widespread use of the Internet of Things (IoT), an increasing number of applications require precise sensing of physical parameters such as temperature, humidity, and pressure through various sensors. These weak electrical signals must be processed and converted into digital signals. This requires analog-to-digital converters (ADCs) to process and convert these real-world signals. In high-precision temperature measurement systems, since temperature signals vary slowly and have very small amplitudes, high-resolution analog-to-digital converters (ADCs) are required. However, this significantly increases the difficulty and complexity of ADC design. Therefore, a preamplifier (VGA) is often introduced before the ADC to amplify the signal and reduce ADC performance requirements. However, traditional preamplifier architectures are susceptible to performance degradation due to temperature, voltage, and process parameters.

[0003] Therefore, how to provide a high-precision pre-gain amplifier that is not affected by temperature and power supply voltage in a temperature measurement system has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0004] The present invention provides a pre-gain amplifier, which solves the problem in the related art of lacking a high-precision pre-gain amplifier that is not affected by temperature and power supply voltage.

[0005] As one aspect of the present invention, a pre-gain amplifier is provided, comprising: a current source circuit, a transconductance amplifier module, and a differential operational amplifier module, wherein the current source circuit is connected to the transconductance amplifier module, and the transconductance amplifier module is connected to the differential operational amplifier module;

[0006] The current source circuit is capable of outputting current to the transconductance amplifier module;

[0007] The transconductance amplifier module can generate transconductance according to the input current, and can amplify the input temperature signal. The transconductance is independent of the temperature signal, the power supply voltage and the process parameters. The transconductance can adjust the multiple of the pre-gain amplifier.

[0008] The differential operational amplifier module can process the temperature signal amplified by the transconductance amplifier module and then output it.

[0009] Furthermore, 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.

[0010] One end of the first resistor is connected to the power supply end, and the other end of the first resistor is connected to the source of the first switch tube.

[0011] The source of the eighth switch tube is connected to the power supply end, the gate of the seventh switch tube is connected to the gate of the eighth switch tube, and the gates of the seventh switch tube and the eighth switch tube are both connected to the drain of the sixth switch tube;

[0012] The gate of the sixth switch tube is connected to the gate of the fifth switch tube, and the gate of the sixth switch tube and the gate of the fifth switch tube are both connected to a first external bias voltage for inputting the first bias voltage.

[0013] The source of the sixth switch tube is connected to the drain of the eighth switch tube, and the source of the fifth switch tube is connected to the drain of the seventh switch tube;

[0014] The gate of the third switch tube is connected to the gate of the fourth switch tube, and the gate of the third switch tube and the gate of the fourth switch tube are both connected to a second external bias voltage for inputting a second bias voltage.

[0015] The gate of the first switching tube is connected to the gate of the second switching tube, and the gates of the first switching tube and the second switching tube are both connected to the drain of the third switching tube, the drain of the third switching tube is connected to the drain of the fifth switching tube, the source of the third switching tube is connected to the drain of the first switching tube, and the drain of the third switching tube and the drain of the fifth switching tube are both connected to the output end for outputting current.

[0016] The drain of the fourth switch tube is connected to the drain of the sixth switch tube, and the source of the fourth switch tube is connected to the drain of the second switch tube.

[0017] The source of the first switching tube and the source of the second switching tube are both connected to the power ground.

[0018] Furthermore, 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.

[0019] Furthermore, the transconductance amplifier module includes: 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,

[0020] One end of the current source is connected to the power supply end, and the other end of the current source is connected to one end of the second resistor and one end of the third resistor respectively. The first switch is connected in parallel with the second resistor, and the second switch is connected in parallel with the third resistor.

[0021] The other end of the second resistor is connected to the source of the ninth switch tube, and the other end of the third resistor is connected to the source of the tenth switch tube.

[0022] The gate of the ninth switch tube is connected to the positive electrode of the input voltage, and the drain of the ninth switch tube is connected to the drain of the eleventh switch tube.

[0023] The gate of the tenth switch tube is connected to the negative electrode of the input voltage, and the drain of the tenth switch tube is connected to the drain of the twelfth switch tube.

[0024] The gate of the eleventh switch tube is connected to the gate of the twelfth switch tube, and the gate of the eleventh switch tube and the gate of the twelfth switch tube are both connected to a third external bias voltage for inputting the third bias voltage.

[0025] The source of the eleventh switch tube and the source of the twelfth switch tube are both connected to the power ground.

[0026] The drain of the eleventh switching tube and the drain of the twelfth switching tube are both used to output the amplified temperature signal to the differential operational amplifier.

[0027] Furthermore, the ninth switch tube and the tenth switch tube both include P-type switch tubes, and the eleventh switch tube and the twelfth switch tube both include N-type switch tubes.

[0028] Furthermore, the resistance value of the second resistor is the same as the resistance value of the third resistor.

[0029] Furthermore, 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 twenty-third switch tube, and a twenty-fourth switch tube.

[0030] The source of the thirteenth switch tube, the source of the fourteenth switch tube, the source of the twenty-first switch tube and the source of the twenty-second switch tube are all connected to the power supply terminal.

[0031] The drain of the thirteenth switch tube is respectively connected to the source of the fifteenth switch tube and the inverting input terminal of the first amplifier, and the gate of the thirteenth switch tube is respectively connected to the drain of the fifteenth switch tube, the drain of the seventeenth switch tube, and the gate of the twenty-first switch tube.

[0032] The drain of the fourteenth switch tube is connected to the source of the sixteenth switch tube and the positive input terminal of the first amplifier respectively, and the gate of the fourteenth switch tube is connected to the drain of the sixteenth switch tube, the drain of the eighteenth switch tube and the gate of the twenty-second switch tube respectively.

[0033] The gate of the fifteenth switch tube is connected to the positive output terminal of the first amplifier, and the gate of the sixteenth switch tube is connected to the negative output terminal of the first amplifier.

[0034] The gate of the seventeenth switch tube is connected to the positive output terminal of the second amplifier, and the source of the seventeenth switch tube is connected to the drain of the nineteenth switch tube and the negative input terminal of the second amplifier respectively.

[0035] The gate of the eighteenth switch tube is connected to the inverting output terminal of the second amplifier, and the source of the eighteenth switch tube is connected to the drain of the twentieth switch tube and the positive input terminal of the second amplifier respectively.

[0036] The gate of the nineteenth switch tube and the gate of the twentieth switch tube are connected and are both connected to a third external bias voltage for inputting the third bias voltage. The source of the nineteenth switch tube and the source of the twentieth switch tube are both connected to a power ground.

[0037] The drain of the twenty-first switch tube is connected to the inverting input terminal of the third amplifier and the source of the twenty-third switch tube respectively.

[0038] The drain of the twenty-second switch tube is connected to the positive input terminal of the third amplifier and the source of the twenty-fourth switch tube respectively.

[0039] The gate of the twenty-third switch tube is connected to the positive output terminal of the third amplifier, the drain of the twenty-third switch tube is connected to one end of the fourth resistor, and the drain of the twenty-third switch tube is the negative end of the output voltage.

[0040] The gate of the twenty-fourth switch tube is connected to the inverting output terminal of the third amplifier, the drain of the twenty-fourth switch tube is connected to one end of the fifth resistor, and the drain of the twenty-fourth switch tube is the positive terminal of the output voltage.

[0041] The other end of the fourth resistor and the other end of the fifth resistor are both connected to the power ground.

[0042] Furthermore, the thirteenth switch tube, the fourteenth switch tube, the fifteenth switch tube, the sixteenth switch tube, the twenty-first switch tube, the twenty-second switch tube, the twenty-third switch tube and the twenty-fourth switch tube all include P-type switch tubes, and the seventeenth switch tube, the eighteenth switch tube, the nineteenth switch tube and the twentieth switch tube all include N-type switch tubes.

[0043] Furthermore, the resistance value of the fifth resistor is the same as the resistance value of the sixth resistor.

[0044] The pre-gain amplifier provided by the present invention uses a power-supply-independent current source circuit to supply current to a transconductance amplifier module. This current is then fed into the transconductance amplifier to obtain a transconductance value that is independent of the power supply voltage and process parameters. By adjusting the transconductance value, the gain of the entire pre-gain amplifier is adjusted, ultimately achieving a gain that is independent of temperature, power supply voltage, and process parameters. When used in a temperature system, this pre-gain amplifier can achieve high precision and is unaffected by temperature and power supply voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation of the present invention.

[0046] Figure 1 This is a schematic diagram of the circuit structure of the pre-gain amplifier provided by the present invention.

[0047] Figure 2 This is a circuit schematic diagram of the current source circuit provided by the present invention.

[0048] Figure 3 This is a circuit schematic diagram of the transconductance amplifier module and the differential operational amplifier module provided by the present invention. DETAILED DESCRIPTION

[0049] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0050] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0051] It should be noted that the terms "first," "second," and the like in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate for the embodiments of the present invention described herein. In addition, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or apparatuses.

[0052] In this embodiment, a pre-gain amplifier is provided. Figure 1 FIG. 1 is a schematic diagram of a circuit structure of a pre-gain amplifier according to an embodiment of the present invention. Figure 1 As shown, it includes: a current source circuit ISS1, a transconductance amplifier module OTA and a differential operational amplifier module OPA, the current source circuit ISS1 is connected to the transconductance amplifier module OTA, and the transconductance amplifier module OTA is connected to the differential operational amplifier module OPA;

[0053] The current source circuit ISS1 is capable of outputting current to the transconductance amplifier module OTA;

[0054] The transconductance amplifier module OTA can generate a transconductance according to the input current, and the transconductance amplifier module OTA can amplify the input temperature signal. The transconductance is independent of the temperature signal, the power supply voltage and the process parameters. The transconductance can adjust the multiple of the pre-gain amplifier;

[0055] The differential operational amplifier module OPA can process the temperature signal amplified by the transconductance amplifier module and then output it.

[0056] The pre-gain amplifier provided in an embodiment of the present invention uses a power-supply-independent current source circuit to supply current to a transconductance amplifier module. This current is then fed into the transconductance amplifier to obtain a transconductance value that is independent of the power supply voltage and process parameters. By adjusting the transconductance value, the gain of the entire pre-gain amplifier is adjusted, ultimately achieving a gain that is independent of temperature, power supply voltage, and process parameters. This pre-gain amplifier, when used in a temperature system, can achieve high precision and is unaffected by temperature and power supply voltage.

[0057] Specifically, if Figure 2 As shown, 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.

[0058] One end of the first resistor R1 is connected to the power supply terminal VDD, and the other end of the first resistor R1 is connected to the source of the first switch tube M1.

[0059] The source of the eighth switch tube M8 is connected to the power supply terminal VDD, the gate of the seventh switch tube M7 is connected to the gate of the eighth switch tube M8, and the gates of the seventh switch tube M7 and the eighth switch tube M8 are both connected to the drain of the sixth switch tube M6;

[0060] The gate of the sixth switch tube M6 is connected to the gate of the fifth switch tube M5, and the gate of the sixth switch tube M6 and the gate of the fifth switch tube M5 are both connected to a first external bias voltage for inputting a first bias voltage Vb1.

[0061] The source of the sixth switch tube M6 is connected to the drain of the eighth switch tube M8, and the source of the fifth switch tube M5 is connected to the drain of the seventh switch tube M7;

[0062] The gate of the third switch tube M3 is connected to the gate of the fourth switch tube M4, and the gate of the third switch tube M3 and the gate of the fourth switch tube M4 are both connected to a second external bias voltage for inputting a second bias voltage Vb2.

[0063] The gate of the first switch tube M1 is connected to the gate of the second switch tube M2, and the gates of the first switch tube M1 and the second switch tube M2 are both connected to the drain of the third switch tube M3, the drain of the third switch tube M3 is connected to the drain of the fifth switch tube M5, the source of the third switch tube M3 is connected to the drain of the first switch tube M1, and the drain of the third switch tube M3 and the drain of the fifth switch tube M5 are both connected to the output end for outputting current.

[0064] The drain of the fourth switch tube M4 is connected to the drain of the sixth switch tube M6, and the source of the fourth switch tube M4 is connected to the drain of the second switch tube M2.

[0065] The source of the first switch tube M1 and the source of the second switch tube M2 are both connected to the power ground.

[0066] In the embodiment of the present invention, the first switch tube M1, the second switch tube M2, the third switch tube M3 and the fourth switch tube M4 are all N-type switch tubes, and the fifth switch tube M5, the sixth switch tube M6, the seventh switch tube M7 and the eighth switch tube M8 are all P-type switch tubes.

[0067] like Figure 3As shown, the transconductance amplifier module includes: a current source, a second resistor R2, a third resistor R3, a first switch ф1, a second switch ф2, a ninth switch tube M9, a tenth switch tube M10, an eleventh switch tube M11 and a twelfth switch tube M12,

[0068] One end of the current source ISS1 is connected to the power supply terminal VDD, and the other end of the current source ISS1 is connected to one end of the second resistor R2 and one end of the third resistor R3 respectively. The first switch ф1 is connected in parallel with the second resistor R2, and the second switch ф2 is connected in parallel with the third resistor R3.

[0069] The other end of the second resistor R2 is connected to the source of the ninth switch tube M9, and the other end of the third resistor R3 is connected to the source of the tenth switch tube M10.

[0070] The gate of the ninth switch tube M9 is connected to the positive input voltage Vin+, and the drain of the ninth switch tube M9 is connected to the drain of the eleventh switch tube M11.

[0071] The gate of the tenth switch tube M10 is connected to the negative input voltage Vin-, and the drain of the tenth switch tube M10 is connected to the drain of the twelfth switch tube M12.

[0072] The gate of the eleventh switch tube M11 is connected to the gate of the twelfth switch tube M12, and the gate of the eleventh switch tube M11 and the gate of the twelfth switch tube M12 are both connected to a third external bias voltage for inputting a third bias voltage Vb3.

[0073] The source of the eleventh switch tube M11 and the source of the twelfth switch tube M12 are both connected to the power ground.

[0074] The drain of the eleventh switch tube M11 and the drain of the twelfth switch tube M12 are both used to output the amplified temperature signal to the differential operational amplifier.

[0075] In an embodiment of the present invention, the drain of the eleventh switch tube M11 is output to the drain end of the nineteenth switch tube M19 in the differential operational amplifier module OPA module, and the drain of the twelfth switch tube M12 is output to the drain end of the twentieth switch tube M20 in the differential operational amplifier module OPA module.

[0076] In the embodiment of the present invention, the ninth switch tube M9 and the tenth switch tube M10 both include P-type switch tubes, and the eleventh switch tube M11 and the twelfth switch tube M12 both include N-type switch tubes.

[0077] Preferably, the resistance of the second resistor R2 is the same as the resistance of the third resistor R3.

[0078] Specifically, if Figure 3 As shown, 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 switch tube M13, a fourteenth switch tube M14, a fifteenth switch tube M15, a sixteenth switch tube M16, a seventeenth switch tube M17, an eighteenth switch tube M18, a nineteenth switch tube M19, a twentieth switch tube M20, a twenty-first switch tube M21, a twenty-second switch tube M22, a twenty-third switch tube M23, and a twenty-fourth switch tube M24.

[0079] The source of the thirteenth switch tube M13, the source of the fourteenth switch tube M14, the source of the twenty-first switch tube M21 and the source of the twenty-second switch tube M22 are all connected to the power supply terminal.

[0080] The drain of the thirteenth switch tube M13 is connected to the source of the fifteenth switch tube M15 and the inverting input terminal of the first amplifier A1, and the gate of the thirteenth switch tube M13 is connected to the drain of the fifteenth switch tube M15, the drain of the seventeenth switch tube M17, and the gate of the twenty-first switch tube M21.

[0081] The drain of the fourteenth switch tube M14 is connected to the source of the sixteenth switch tube M16 and the positive input terminal of the first amplifier A1, and the gate of the fourteenth switch tube M14 is connected to the drain of the sixteenth switch tube M16, the drain of the eighteenth switch tube M18, and the gate of the twenty-second switch tube M22.

[0082] The gate of the fifteenth switch tube M15 is connected to the positive output terminal of the first amplifier A1, and the gate of the sixteenth switch tube M16 is connected to the negative output terminal of the first amplifier A1.

[0083] The gate of the seventeenth switch tube M17 is connected to the positive output terminal of the second amplifier A2, and the source of the seventeenth switch tube M17 is connected to the drain of the nineteenth switch tube M19 and the negative input terminal of the second amplifier A2 respectively.

[0084] The gate of the eighteenth switch tube M18 is connected to the inverting output terminal of the second amplifier A2, and the source of the eighteenth switch tube M18 is connected to the drain of the twentieth switch tube M20 and the positive input terminal of the second amplifier A2 respectively.

[0085] The gate of the nineteenth switch tube M19 and the gate of the twentieth switch tube M20 are connected and are both connected to a third external bias voltage for inputting a third bias voltage Vb3. The source of the nineteenth switch tube M19 and the source of the twentieth switch tube M20 are both connected to a power ground.

[0086] The drain of the twenty-first switch tube M21 is connected to the inverting input terminal of the third amplifier A3 and the source of the twenty-third switch tube M23 respectively.

[0087] The drain of the twenty-second switch tube M22 is connected to the positive input terminal of the third amplifier A3 and the source of the twenty-fourth switch tube M24 respectively.

[0088] The gate of the twenty-third switch tube M23 is connected to the positive output terminal of the third amplifier A3, the drain of the twenty-third switch tube M23 is connected to one end of the fourth resistor R4, and the drain of the twenty-third switch tube M23 is the output voltage negative terminal Vout-.

[0089] The gate of the twenty-fourth switch tube M24 is connected to the inverting output terminal of the third amplifier A3, the drain of the twenty-fourth switch tube M24 is connected to one end of the fifth resistor R5, and the drain of the twenty-fourth switch tube M24 is the output voltage positive terminal Vout+.

[0090] The other end of the fourth resistor R4 and the other end of the fifth resistor R5 are both connected to the power ground.

[0091] In the embodiment of the present invention, the thirteenth switch tube M13, the fourteenth switch tube M14, the fifteenth switch tube M15, the sixteenth switch tube M16, the twenty-first switch tube M21, the twenty-second switch tube M22, the twenty-third switch tube M23 and the twenty-fourth switch tube M24 all include P-type switch tubes, and the seventeenth switch tube M17, the eighteenth switch tube M18, the nineteenth switch tube M19 and the twentieth switch tube M20 all include N-type switch tubes.

[0092] Preferably, the resistance of the fifth resistor R5 is the same as the resistance of the sixth resistor R6.

[0093] It should be noted that, in the embodiment of the present invention, the output expression of the pre-gain amplifier is:

[0094] V out =-G m R f V in ,

[0095] The current source current uses a cascode current mirror structure to reduce the influence of channel length modulation. At the same time, the external bias voltages Vb1 and Vb2 are reasonably selected to make the switches M1 to M8 all operate in the saturation region. The width-to-length ratio of the switches M8 and M7 is 1 / m. The resistor R1 and the switches M5, M6, M3, and M4 form a cascode structure to reduce the difference in VTH between the switches M4 and M5 and the channel length modulation effect. As a result, the current generated by the bias current mirror is closer to the ideal current that is independent of the power supply voltage. Its output current Iout is:

[0096]

[0097] This current is input to the source terminals of the switches M9 and M10 in the transconductance amplifier module. The switches M9, M10, M11, and M12 in the transconductance amplifier OTA form a structure with source negative feedback. At this time, the transconductance gm of the switches M9 and M10 of the gate input signal can be obtained by the formula:

[0098]

[0099] It can be seen that the final gm formula is independent of the power supply voltage and does not include process parameters. When switches ф1 and ф2 in the transconductance amplifier module are turned on, resistors R2 and R3 are short-circuited. At this time, the transconductance Gm of the transconductance amplifier OTA is:

[0100]

[0101] When switches ф1 and ф2 are turned off, the current output by the current source is input to the source terminals of switches M9 and M10 from resistors R2 and R3 respectively. At this time, the transconductance Gm of the transconductance amplifier OTA is:

[0102]

[0103] The final operational amplifier (OPA) module uses cascode gain enhancement technology to increase output impedance. Switches M13, M15, and M21 form a current mirror structure, mirroring the OTA input signal to the final output resistor R4. Similarly, switches M14, M16, and M22 mirror the OTA input signal to the final output resistor R5.

[0104] At this time, when switches ф1 and ф2 in the transconductance amplifier module OTA are turned on, the output gain of the overall circuit is:

[0105]

[0106] When switches ф1 and ф2 in the transconductance amplifier module OTA are turned off, the output gain of the overall circuit is:

[0107]

[0108] It can be seen from the formula that the gain of the entire pre-gain amplifier has nothing to do with the power supply voltage, temperature and process parameters, and can accurately and highly precisely amplify the temperature weak current signal input from the front end.

[0109] In summary, the pre-gain amplifier provided by the embodiments of the present invention uses a current source to provide a current independent of the power supply voltage, a transconductance amplifier to generate a transconductance independent of the power supply voltage, temperature, and process parameters, an operational amplifier to achieve a gain independent of the power supply voltage, temperature, and process parameters, and a switching circuit to adjust the transconductance of the transconductance amplifier to achieve different gain values. Therefore, the pre-gain amplifier can accurately amplify and transmit weak signals input from sensors, regardless of temperature and process parameters.

[0110] It will be understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present invention, and the present invention is not limited thereto. Those skilled in the art will appreciate that various modifications and improvements can be made without departing from the spirit and substance of the present invention, and such modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A pre-gain amplifier, characterized in that: include: A current source circuit, a transconductance amplifier module, and a differential operational amplifier module, wherein the current source circuit is connected to the transconductance amplifier module, and the transconductance amplifier module is connected to 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 the input current, and can amplify the input temperature signal. The transconductance is independent of the temperature signal, the power supply voltage and the process parameters. The transconductance can adjust the multiple of the pre-gain amplifier. The differential operational amplifier module is capable of processing the temperature signal amplified by the transconductance amplifier module and then outputting the processed signal; 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 to the power supply end, and the other end of the first resistor is connected to the source of the first switch tube. The source of the eighth switch tube is connected to the power supply end, the gate of the seventh switch tube is connected to the gate of the eighth switch tube, and the gates of the seventh switch tube and the eighth switch tube are both connected to the drain of the sixth switch tube; The gate of the sixth switch tube is connected to the gate of the fifth switch tube, and the gate of the sixth switch tube and the gate of the fifth switch tube are both connected to a first external bias voltage for inputting the first bias voltage. The source of the sixth switch tube is connected to the drain of the eighth switch tube, and the source of the fifth switch tube is connected to the drain of the seventh switch tube; The gate of the third switch tube is connected to the gate of the fourth switch tube, and the gate of the third switch tube and the gate of the fourth switch tube are both connected to a second external bias voltage for inputting a second bias voltage. The gate of the first switching tube is connected to the gate of the second switching tube, and the gates of the first switching tube and the second switching tube are both connected to the drain of the third switching tube, the drain of the third switching tube is connected to the drain of the fifth switching tube, the source of the third switching tube is connected to the drain of the first switching tube, and the drain of the third switching tube and the drain of the fifth switching tube are both connected to the output end for outputting current. The drain of the fourth switch tube is connected to the drain of the sixth switch tube, and the source of the fourth switch tube is connected to the drain of the second switch tube. The source of the first switching tube and the source of the second switching tube are both connected to the power ground; The transconductance amplifier module includes: 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 to the power supply end, and the other end of the current source is connected to one end of the second resistor and one end of the third resistor respectively. The first switch is connected in parallel with the second resistor, and the second switch is connected in parallel with the third resistor. The other end of the second resistor is connected to the source of the ninth switch tube, and the other end of the third resistor is connected to the source of the tenth switch tube. The gate of the ninth switch tube is connected to the positive electrode of the input voltage, and the drain of the ninth switch tube is connected to the drain of the eleventh switch tube. The gate of the tenth switch tube is connected to the negative electrode of the input voltage, and the drain of the tenth switch tube is connected to the drain of the twelfth switch tube. The gate of the eleventh switch tube is connected to the gate of the twelfth switch tube, and the gate of the eleventh switch tube and the gate of the twelfth switch tube are both connected to a third external bias voltage for inputting the third bias voltage. The source of the eleventh switch tube and the source of the twelfth switch tube are both connected to the power ground. The drain of the eleventh switching tube and the drain of the twelfth switching tube are both used to output the amplified temperature signal to the differential operational amplifier; 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 twenty-third switch tube, and a twenty-fourth switch tube. The source of the thirteenth switch tube, the source of the fourteenth switch tube, the source of the twenty-first switch tube and the source of the twenty-second switch tube are all connected to the power supply terminal. The drain of the thirteenth switch tube is respectively connected to the source of the fifteenth switch tube and the inverting input terminal of the first amplifier, and the gate of the thirteenth switch tube is respectively connected to the drain of the fifteenth switch tube, the drain of the seventeenth switch tube, and the gate of the twenty-first switch tube. The drain of the fourteenth switch tube is connected to the source of the sixteenth switch tube and the positive input terminal of the first amplifier respectively, and the gate of the fourteenth switch tube is connected to the drain of the sixteenth switch tube, the drain of the eighteenth switch tube and the gate of the twenty-second switch tube respectively. The gate of the fifteenth switch tube is connected to the positive output terminal of the first amplifier, and the gate of the sixteenth switch tube is connected to the negative output terminal of the first amplifier. The gate of the seventeenth switch tube is connected to the positive output terminal of the second amplifier, and the source of the seventeenth switch tube is connected to the drain of the nineteenth switch tube and the negative input terminal of the second amplifier respectively. The gate of the eighteenth switch tube is connected to the inverting output terminal of the second amplifier, and the source of the eighteenth switch tube is connected to the drain of the twentieth switch tube and the positive input terminal of the second amplifier respectively. The gate of the nineteenth switch tube and the gate of the twentieth switch tube are connected and are both connected to a third external bias voltage for inputting the third bias voltage. The source of the nineteenth switch tube and the source of the twentieth switch tube are both connected to a power ground. The drain of the twenty-first switch tube is connected to the inverting input terminal of the third amplifier and the source of the twenty-third switch tube respectively. The drain of the twenty-second switch tube is connected to the positive input terminal of the third amplifier and the source of the twenty-fourth switch tube respectively. The gate of the twenty-third switch tube is connected to the positive output terminal of the third amplifier, the drain of the twenty-third switch tube is connected to one end of the fourth resistor, and the drain of the twenty-third switch tube is the negative end of the output voltage. The gate of the twenty-fourth switch tube is connected to the inverting output terminal of the third amplifier, the drain of the twenty-fourth switch tube is connected to one end of the fifth resistor, and the drain of the twenty-fourth switch tube is the positive terminal of the output voltage. The other end of the fourth resistor and the other end of the fifth resistor are both connected to the power ground.

2. The pre-gain amplifier according to claim 1, wherein: 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.

3. The pre-gain amplifier according to claim 1, wherein: The ninth switch tube and the tenth switch tube both include P-type switch tubes, and the eleventh switch tube and the twelfth switch tube both include N-type switch tubes.

4. The pre-gain amplifier according to claim 1, wherein: The resistance value of the second resistor is the same as the resistance value of the third resistor.

5. The pre-gain amplifier according to claim 1, wherein: The thirteenth switch tube, the fourteenth switch tube, the fifteenth switch tube, the sixteenth switch tube, the twenty-first switch tube, the twenty-second switch tube, the twenty-third switch tube and the twenty-fourth switch tube all include P-type switch tubes, and the seventeenth switch tube, the eighteenth switch tube, the nineteenth switch tube and the twentieth switch tube all include N-type switch tubes.

6. The pre-gain amplifier according to claim 1, wherein: The resistance value of the fifth resistor is the same as the resistance value of the fourth resistor.

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