Trimming circuit, trimming method and integrated circuit chip

Abstract

The application provides a trimming circuit, a trimming method and an integrated circuit chip. The trimming circuit comprises a reference source generation unit, a current mirror unit, a current trimming unit and a voltage clamping unit. A first input end of the voltage clamping unit is used for inputting a positive power supply voltage, a second input end of the voltage clamping unit is used for inputting a zero temperature voltage, and a third input end of the voltage clamping unit is used for inputting a feedback voltage. A first input end of the current trimming unit is connected with a first power supply, and a second input end of the current trimming unit is used for inputting the positive power supply voltage. A first input end of the current mirror unit is used for inputting the positive power supply voltage, a second input end of the current mirror unit is used for inputting a negative power supply voltage, and an output end of the current mirror unit is connected with the reference source generation unit. The voltage clamping unit is used for clamping the feedback voltage of the reference source generation unit, and the current trimming unit controls the reference current generated by the reference source generation unit to be the zero temperature current.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of integrated circuits, and in particular to a trimming circuit, a trimming method and an integrated circuit chip. BACKGROUND

[0002] Bandgap reference voltage can provide stable voltage or current that does not change with temperature, and is an indispensable important module in analog systems such as digital-to-analog converters, analog-to-digital converters and linear voltage stabilizers. The precision and stability of the bandgap reference voltage directly affect the precision of the entire system. The principle is to add a voltage with a negative temperature coefficient and a voltage with a positive temperature coefficient with appropriate weights to obtain a zero-temperature coefficient voltage.

[0003] In the process of conceiving and implementing the present application, the inventors found that in some schemes, a zero-temperature voltage is introduced to generate a current through an operational amplifier, and the absolute value of the output current can be trimmed by trimming the resistance connected to the negative input of the operational amplifier. However, since the resistance usually has a certain temperature coefficient, the output current also has a certain temperature coefficient, and a zero-temperature current cannot be completely obtained.

[0004] The foregoing discussion is presented to provide general background information, does not necessarily constitute prior art. SUMMARY

[0005] The present application provides a trimming circuit, a trimming method and an integrated circuit chip to solve the problem that some schemes cannot completely obtain a zero-temperature current.

[0006] In a first aspect, the present application provides a trimming circuit, comprising a reference source generation unit, a current mirror unit, a current trimming unit and a voltage clamping unit;

[0007] The first input terminal of the voltage clamping unit is used to input a positive power supply voltage, the second input terminal of the voltage clamping unit is used to input a zero-temperature voltage, the third input terminal of the voltage clamping unit is used to input a feedback voltage, the first output terminal of the voltage clamping unit and the second output terminal of the voltage clamping unit are connected with the current mirror unit, the first output terminal of the voltage clamping unit is used to output a first current, and the second output terminal of the voltage clamping unit is used to output a second current;

[0008] The first input terminal of the current trimming unit is connected with a first power supply, the second input terminal of the current trimming unit is used to input a positive power supply voltage, the first output terminal of the current trimming unit and the second output terminal of the current trimming unit are connected with the current mirror unit, the first output terminal of the current trimming unit is used to output a third current, and the second output terminal of the current trimming unit is used to output a fourth current;

[0009] The first input end of the current mirror unit is used for inputting a positive power voltage, the second input end of the current mirror unit is used for inputting a negative power voltage, the third input end of the current mirror unit is used for inputting a fifth current, the fourth input end of the current mirror unit is used for inputting a sixth current, and the output end of the current mirror unit is connected with the reference source generation unit; the fifth current is the sum of the first current and the third current, and the sixth current is the sum of the second current and the fourth current.

[0010] The reference source generation unit is used for generating a stable reference current, the voltage clamping unit is used for clamping the feedback voltage of the reference source generation unit, the current trimming unit is used for compensating the temperature characteristic, and the current mirror unit is used for controlling the fifth current and the sixth current to match.

[0011] In one of the embodiments, the trimming circuit further comprises a trimming proportion control unit, the second end of the current trimming unit is connected with the trimming proportion control unit, and the trimming proportion control unit is used for inputting the first voltage or the second voltage to the current trimming unit.

[0012] The first voltage and the second voltage have a voltage difference with a positive temperature coefficient or a negative temperature coefficient.

[0013] In one of the embodiments, the current trimming unit comprises a first switch tube, a second switch group and a third switch unit.

[0014] The first end of the first switch tube is connected with a first power supply, the control end of the first switch tube is used for inputting a positive power voltage, and the second end of the first switch tube is connected with the first end of the second switch group and the third switch unit.

[0015] The second end of the second switch group is connected with the fourth input end of the current mirror unit, and the control end of the second switch group is connected with the trimming proportion control unit.

[0016] The second end of the third switch unit is connected with the third input end of the current mirror unit, and the control end of the third switch unit is connected with the trimming proportion control unit.

[0017] In one of the embodiments, the second switch group comprises 2 n MOS tubes, the third switch unit comprises n groups of switch tubes, the i-th group of switch tubes comprises 2 i-1 MOS tubes, 1≤i≤n, and n is a positive integer.

[0018] The drain electrodes of all the MOS tubes in the second switch group are connected with the fourth input end of the current mirror unit, and the control ends of all the MOS tubes in the second switch group are connected at one end and connected with the trimming proportion control unit.

[0019] The drain electrodes of all the switch tubes in the third switch unit are connected with the third input end of the current mirror unit, and the control ends of all the switch tubes in the third switch unit are connected with the trimming proportion control unit.

[0020] In one of the embodiments, the trimming proportion control unit comprises a trimming register.

[0021] The trimming register stores a trimming instruction, which is used to control the current trimming unit to output one of the negative temperature current, the zero temperature current and the positive temperature current.

[0022] In one of the embodiments, the trimming instruction is used to control the voltage combination of the control terminals of the MOS tubes in the second switch group and the third switch unit.

[0023] In one of the embodiments, the current mirror unit comprises a fourth switch tube, a fifth switch tube, a sixth switch tube, a seventh switch tube, an eighth switch tube and a ninth switch tube.

[0024] The drain of the fourth switch tube is connected to the second output terminal of the voltage clamping unit and the second output terminal of the current trimming unit, the source of the fourth switch tube is grounded, and the control terminal of the fourth switch tube is connected to the control terminal of the fifth switch tube.

[0025] The drain of the fifth switch tube is connected to the first output terminal of the voltage clamping unit and the first output terminal of the current trimming unit, and the source of the fifth switch tube is grounded.

[0026] The source of the sixth switch tube is connected to the first power supply, the control terminal of the sixth switch tube is used to input the positive power supply voltage, and the drain of the sixth switch tube is connected to the drain of the eighth switch tube.

[0027] The source of the seventh switch tube is connected to the first power supply, the control terminal of the seventh switch tube is used to input the positive power supply voltage, and the drain of the seventh switch tube is connected to the drain of the ninth switch tube.

[0028] The control terminal of the eighth switch tube is used to input the negative power supply voltage, and the source of the eighth switch tube is connected to the drain of the fourth switch tube.

[0029] The control terminal of the ninth switch tube is used to input the negative power supply voltage, the source of the ninth switch tube is connected to the drain of the fifth switch tube, and the drain of the ninth switch tube is connected to the reference source generation unit.

[0030] The drain of the eighth switch tube is connected to the control terminal of the fourth switch tube.

[0031] In one of the embodiments, the width-length ratios of the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube, the eighth switch tube and the ninth switch tube are the same.

[0032] In one of the embodiments, the voltage clamping unit comprises a tenth switch tube, an eleventh switch tube and a twelfth switch tube.

[0033] The source of the tenth switch tube is connected with the first power supply, the control end of the tenth switch tube is used for inputting the positive power supply voltage, and the drain of the tenth switch tube is connected with the source of the first switch tube and the source of the sixth switch tube.

[0034] The control end of the twelfth switch tube is used for inputting the zero temperature voltage, and the drain of the twelfth switch tube is connected with the drain of the fourth switch tube.

[0035] The control end of the eleventh switch tube is connected with the reference source generating unit and is used for inputting the feedback voltage of the reference source generating unit, and the drain of the eleventh switch tube is connected with the drain of the fifth switch tube.

[0036] In one embodiment, the reference source generating unit comprises a thirteenth switch tube, a fourteenth switch tube, a fifteenth switch tube and a first resistor.

[0037] The source of the thirteenth switch tube is connected with the first power supply, the control end of the thirteenth switch tube is connected with the control end of the fourteenth switch tube, the control end of the thirteenth switch tube is connected with the drain of the thirteenth switch tube, and the drain of the thirteenth switch tube is connected with the drain of the fifteenth switch tube.

[0038] The source of the fifteenth switch tube is connected with the first end of the first resistor, and the control end of the fifteenth switch tube is connected with the drain of the ninth switch tube.

[0039] The first end of the first resistor is connected with the voltage clamping unit and is used for providing the feedback voltage to the voltage clamping unit, and the second end of the first resistor is grounded.

[0040] The source of the fourteenth switch tube is connected with the first power supply, and the drain of the fourteenth switch tube is used for outputting the zero temperature current.

[0041] In one embodiment, the first resistor is an adjustable resistor.

[0042] In one embodiment, the ratio of the aspect ratio of the first switch tube to the aspect ratio of the tenth switch tube is a first ratio, and the first ratio is used for adjusting the source current of the second switch group and the third switch unit to control the trimming accuracy.

[0043] In one embodiment, the trimming ratio control unit is used for controlling the trimming accuracy by adjusting the voltage difference between the first voltage and the second voltage.

[0044] In a second aspect, the present application provides an integrated circuit chip comprising the trimming circuit according to any one of the above.

[0045] In a third aspect, the present application provides a trimming method based on the trimming circuit according to any one of the above, and the trimming method comprises:

[0046] Trimming the current temperature characteristic according to the feedback voltage of the reference source generating unit.

[0047] After the current temperature characteristic trimming is completed, the absolute value of the current is trimmed.

[0048] In one embodiment, the current temperature characteristic trimming is performed according to the feedback voltage of the reference source generating unit, and specifically includes:

[0049] If the feedback voltage is a positive temperature voltage, the current trimming unit outputs a negative temperature current, so that the reference current output by the reference source generating unit is a zero temperature current; or

[0050] If the feedback voltage is a zero temperature voltage, the current trimming unit outputs a zero temperature current, so that the reference current output by the reference source generating unit is a zero temperature current; or

[0051] If the feedback voltage is a positive temperature voltage, the current trimming unit outputs a negative temperature current, so that the reference current output by the reference source generating unit is a zero temperature current.

[0052] The application provides a trimming circuit, which includes a reference source generating unit, a current mirror unit, a current trimming unit and a voltage clamping unit; a first input end of the voltage clamping unit is used for inputting a positive power voltage, a second input end of the voltage clamping unit is used for inputting a zero temperature voltage, a third input end of the voltage clamping unit is used for inputting a feedback voltage, a first output end of the voltage clamping unit and a second output end of the voltage clamping unit are connected with the current mirror unit, the first output end of the voltage clamping unit is used for outputting a first current, and the second output end of the voltage clamping unit is used for outputting a second current; a first input end of the current trimming unit is connected with a first power supply, a second input end of the current trimming unit is used for inputting the positive power voltage, a first output end of the current trimming unit and a second output end of the current trimming unit are connected with the current mirror unit, the first output end of the current trimming unit is used for outputting a third current, and the second output end of the current trimming unit is used for outputting a fourth current; a first input end of the current mirror unit is used for inputting the positive power voltage, a second input end of the current mirror unit is used for inputting a negative power voltage, a third input end of the current mirror unit is used for inputting a fifth current, a fourth input end of the current mirror unit is used for inputting a sixth current, and an output end of the current mirror unit is connected with the reference source generating unit; the fifth current is the sum of the first current and the third current, and the sixth current is the sum of the second current and the fourth current; the reference source generating unit is used for generating a stable reference current, the voltage clamping unit is used for clamping the feedback voltage of the reference source generating unit, the current trimming unit is used for compensating a temperature characteristic, and the current mirror unit is used for controlling the fifth current and the sixth current to be matched. The application realizes the compensation of the current temperature characteristic by introducing the current trimming unit, and controls the reference current generated by the reference source generating unit to be a zero temperature current. BRIEF DESCRIPTION OF DRAWINGS

[0053] The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate embodiments consistent with the application and, together with the description, further serve to explain the principles of the application.

[0054] Figure 1 Structure diagram of the trimming circuit provided for an embodiment of the application;

[0055] Figure 2 Structure diagram of the trimming circuit provided for an embodiment of the application;

[0056] Figure 3 Structure diagram of the trimming circuit provided for another embodiment of the application;

[0057] Figure 4 Structure diagram of the trimming circuit provided for an embodiment of the application;

[0058] Figure 5 Effect diagram of different combinations of temperature characteristics provided for an embodiment of the application;

[0059] Figure 6 Flow chart of the trimming method provided for an embodiment of the application.

[0060] Reference signs:

[0061] 304, reference source generating unit; 303, current mirror unit; 302, current trimming unit; 301, voltage clamping unit; 305, trimming proportional control unit; M1, first switch tube; M2, second switch group; M3, third switch unit; M4, fourth switch tube; M5, fifth switch tube; M6, sixth switch tube; M7, seventh switch tube; M8, eighth switch tube; M9, ninth switch tube; M10, tenth switch tube; M11, eleventh switch tube; M12, twelfth switch tube; M13, thirteenth switch tube; M14, fourteenth switch tube; M15, fifteenth switch tube; VBP, positive power voltage; VBG, zero temperature voltage; VBN, negative power voltage; R, first resistor.

[0062] The specific embodiments of the application have been shown and described above through the above-described drawings, and will be described in more detail hereinafter. These drawings and written descriptions are not intended to limit the scope of the concept of the application in any way, but to illustrate the concept of the application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0063] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0064] like Figure 1 As shown, Figure 1 The diagram below shows the structure of a trimming circuit provided in one embodiment. The positive terminal of the operational amplifier OPA is input with a zero-temperature voltage (VBG), which is generally achieved by a bandgap reference. The negative feedback formed by the operational amplifier clamps the far-ground end of the resistor. If the gain of the operational amplifier is high enough, the Vgs of the switching transistor Mc is approximately equal to VBG. Therefore, the current I in the branch where the switching transistor Mc is located is equal to VBG / R. Switches M9 and M10 are current mirrors, so the output current of the drain of the switching transistor M10 replicates the current I in the branch where the switching transistor Mc is located. However, the resistor R usually has a certain temperature coefficient, so the output current cannot be completely zero-temperature current.

[0065] Based on this, such as Figure 2 As shown, Figure 2 This is a schematic diagram of the structure of a trimming circuit provided in an embodiment of this application. The trimming circuit includes a reference source generation unit, a current mirror unit, and a voltage clamping unit. However, the absolute current value trimming and temperature characteristic trimming in this current structure affect each other, making it difficult to achieve accurate calibration.

[0066] exist Figure 2 Based on the embodiments, this application provides a schematic diagram of the structure of a trimming circuit, as shown in the example. Figure 3 As shown, the adjustment circuit includes a reference source generation unit 304, a current mirror unit 303, a current adjustment unit 302, and a voltage clamping unit 301. The first input terminal of the voltage clamping unit 301 is used to input a positive power supply voltage, the second input terminal is used to input a zero-temperature voltage, and the third input terminal is used to input a feedback voltage. The first and second output terminals of the voltage clamping unit 301 are connected to the current mirror unit 303. The first output terminal of the voltage clamping unit 301 is used to output a first current, and the second output terminal is used to output a second current.

[0067] The first input terminal of the current adjustment unit 302 is connected to the first power supply, the second input terminal of the current adjustment unit 302 is used to input the positive power supply voltage, the first output terminal and the second output terminal of the current adjustment unit 302 are connected to the current mirror unit 303, the first output terminal of the current adjustment unit 302 is used to output the third current, and the second output terminal of the current adjustment unit 302 is used to output the fourth current.

[0068] The first input terminal of the current mirror unit 303 is used to input a positive power supply voltage, the second input terminal is used to input a negative power supply voltage VBN, the third input terminal is used to input a fifth current, and the fourth input terminal is used to input a sixth current. The output terminal of the current mirror unit 303 is connected to the reference source generation unit 304. The fifth current is the sum of the first and third currents, and the sixth current is the sum of the second and fourth currents. The reference source generation unit 304 is used to generate a stable reference current. The voltage clamping unit 301 is used to clamp the feedback voltage of the reference source generation unit 304. The current adjustment unit 302 is used to compensate for temperature characteristics, and the current mirror unit 303 is used to control the matching of the fifth and sixth currents.

[0069] This application achieves current temperature characteristic compensation by introducing a current adjustment unit, and controls the reference current generated by the reference source generation unit 304 to be a zero-temperature current; secondly, the temperature adjustment and the absolute value resistance adjustment are separated, avoiding the problem of low accuracy caused by mutual interference between temperature characteristic adjustment and absolute value current adjustment.

[0070] In optional embodiments, such as Figure 4 As shown, Figure 4 This is a schematic diagram of the structure of a trimming circuit provided in an embodiment of the present application. The trimming circuit also includes a trimming ratio control unit 305. The second end of the current trimming unit 302 is connected to the trimming ratio control unit 305. The trimming ratio control unit 305 is used to input a first voltage V1 or a second voltage V2 to the current trimming unit 302.

[0071] There is a pressure difference ΔV between the first voltage V1 and the second voltage V2 with a positive or negative temperature coefficient.

[0072] In an optional embodiment, the current adjustment unit 302 includes a first switching transistor M1, a second switching group M2, and a third switching unit M3; the first end of the first switching transistor M1 is connected to a first power supply, the control end of the first switching transistor M1 is used to input a positive power supply voltage, and the second end of the first switching transistor M1 is connected to the first ends of the second switching group M2 and the third switching unit M3.

[0073] The second end of the second switch group M2 is connected to the fourth input end of the current mirror unit 303, and the control end of the second switch group M2 is connected to the trimming proportional control unit 305; the second end of the third switch group M3 is connected to the third input end of the current mirror unit 303, and the control end of the third switch group M3 is connected to the trimming proportional control unit 305.

[0074] In an optional embodiment, the current mirror unit 303 includes 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 ninth switch tube M9; the drain of the fourth switch tube M4 is connected to the second output end of the voltage clamping unit 301 and the second output end of the current trimming unit 302, the source of the fourth switch tube M4 is grounded, and the control end of the fourth switch tube M4 is connected to the control end of the fifth switch tube M5; the drain of the fifth switch tube M5 is connected to the first output end of the voltage clamping unit 301 and the first output end of the current trimming unit 302, and the source of the fifth switch tube M5 is grounded; the source of the sixth switch tube M6 is connected to the first power supply, the control end of the sixth switch tube M6 is used for inputting a positive power supply voltage, and the drain of the sixth switch tube M6 is connected to the drain of the eighth switch tube M8; the source of the seventh switch tube M7 is connected to the first power supply, the control end of the seventh switch tube M7 is used for inputting a positive power supply voltage, and the drain of the seventh switch tube M7 is connected to the drain of the ninth switch tube M9; the control end of the eighth switch tube M8 is used for inputting a negative power supply voltage VBN, and the source of the eighth switch tube M8 is connected to the drain of the fourth switch tube M4; the control end of the ninth switch tube M9 is used for inputting a negative power supply voltage VBN, the source of the ninth switch tube M9 is connected to the drain of the fifth switch tube M5, and the drain of the ninth switch tube M9 is connected to the reference source generation unit 304; wherein the drain of the eighth switch tube M8 is connected to the control end of the fourth switch tube M4.

[0075] The current mirror unit is a folded operational amplifier input pair, which is used for controlling the current matching of the input pair, that is, the input currents in the third input end and the fourth input end of the current mirror unit are matched with the fifth current and the sixth current, so that the fifth current is equal to the sixth current.

[0076] In one of the embodiments, the width-length ratios of the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube, the eighth switch tube, and the ninth switch tube are the same, which ensures that the fifth current and the sixth current of the current mirror unit are equal.

[0077] In an optional embodiment, the voltage clamping unit 301 includes a tenth switch tube M10, an eleventh switch tube M11, and a twelfth switch tube M12; the source of the tenth switch tube M10 is connected to the first power supply, the control end of the tenth switch tube M10 is used for inputting a positive power supply voltage, the drain of the tenth switch tube M10 is connected to the first output end of the voltage clamping unit 301 and the first output end of the current trimming unit 302, the source of the eleventh switch tube M11 is connected to the first power supply, the control end of the eleventh switch tube M11 is used for inputting a positive power supply voltage, and the drain of the eleventh switch tube M11 is connected to the second output end of the voltage clamping unit 301 and the second output end of the current trimming unit 302; the source of the twelfth switch tube M12 is connected to the first power supply, the control end of the twelfth switch tube M12 is used for inputting a positive power supply voltage, and the drain of the twelfth switch tube M12 is connected to the third output end of the voltage clamping unit 301 and the third output end of the current trimming unit 302.

[0078] The source of the first switch tube M1, the source of the sixth switch tube M6, the control end of the twelfth switch tube M12 is used for inputting zero temperature voltage, the drain of the twelfth switch tube M12 is connected with the drain of the fourth switch tube M4; the control end of the eleventh switch tube M11 is connected with the reference source generating unit 304, and is used for inputting the feedback voltage of the reference source generating unit 304; the drain of the eleventh switch tube M11 is connected with the drain of the fifth switch tube M5. The voltage clamping unit is a folded operational amplifier input pair tube, and the voltage clamping unit is used for clamping the feedback voltage VM of the reference source generating unit, so that the feedback voltage is stable.

[0079] In an optional embodiment, the reference source generating unit 304 comprises a thirteenth switch tube M13, a fourteenth switch tube M14, a fifteenth switch tube M15 and a first resistor R; the source of the thirteenth switch tube M13 is connected with the first power supply, the control end of the thirteenth switch tube M13 is connected with the control end of the fourteenth switch tube M14, the control end of the thirteenth switch tube M13 is connected with the drain of the thirteenth switch tube M13, the drain of the thirteenth switch tube M13 is connected with the drain of the fifteenth switch tube M15; the source of the fifteenth switch tube M15 is connected with the first end of the first resistor R, the control end of the fifteenth switch tube M15 is connected with the drain of the tenth switch tube M10; the first end of the first resistor R is connected with the voltage clamping unit 301, and is used for providing the feedback voltage to the voltage clamping unit 301; the second end of the first resistor R is grounded; the source of the fourteenth switch tube M14 is connected with the first power supply, and the drain of the fourteenth switch tube M14 is used for outputting zero temperature current, and the reference source generating unit is used for generating a stable reference current.

[0080] In an optional embodiment, the first resistor R is an adjustable resistor.

[0081] Optionally, the first switch tube M1, the tenth switch tube, the eleventh switch tube, all switch tubes in the second switch group M2, all switch tubes in the third switch unit M3, the twelfth switch tube, the seventh switch tube M7, the sixth switch tube, the thirteenth switch tube M13 and the fourteenth switch tube M14 are P-type switch tubes, and the eighth switch tube M8, the ninth switch tube M9, the fourth switch tube, the fifth switch tube and the fifteenth switch tube M15 are N-type switch tubes.

[0082] In an optional embodiment, the second switch group M2 comprises 2 n MOS tubes, the third switch unit M3 comprises n groups of switch tubes, the i group of switch tubes comprises 2 i-1 MOS tubes, 1≤i≤n, and n is a positive integer;

[0083] The drains of all MOS tubes in the second switch group M2 are connected with the drain of the fourth switch tube M4, and the control ends of all MOS tubes in the second switch group M2 are connected at one end and connected with the trimming ratio control unit 305.

[0084] The drain of all the MOS transistors in the third switch unit M3 is connected to the drain of the fifth MOS transistor M5, and the control end of all the MOS transistors in the third switch unit M3 is connected to the trimming proportion control unit 305.

[0085] Specifically, the control end of all the MOS transistors in the second switch unit M2 is connected to one end and connected to the trimming proportion control unit 305, and the trimming proportion control unit 305 is used to input the first voltage V1 or the second voltage V2 to the control end of all the MOS transistors in the second switch unit M2. It can be understood that the control end of all the MOS transistors in the second switch unit M2 simultaneously inputs the first voltage V1 or the control end of all the MOS transistors in the second switch unit M2 simultaneously inputs the second voltage V2.

[0086] The trimming proportion control unit 305 inputs the first voltage V1 or the second voltage V2 to the control end of all the MOS transistors in the third switch unit M3, that is, the voltage at the control end of the MOS transistors in the third switch unit M3 can be the same or different.

[0087] In an optional embodiment, the trimming proportion control unit 305 includes a trimming register; the trimming register stores a trimming instruction, and the trimming instruction is used to control the current trimming unit 302 to output one of the negative temperature current, the zero temperature current and the positive temperature current.

[0088] In an optional embodiment, the trimming instruction is used to control the voltage combination of the control end of the MOS transistors in the second switch unit M2 and the third switch unit M3.

[0089] Specifically, the multi-bit trimming register (TCTRIM) <n:0>, different settings of the register correspond to different M2 and M3 transistor gate voltage combinations (see Table 1, taking n = 4 as an example, the number of bits of the register is 4), the number of registers is 4, corresponding to a total of 15 MOS tubes in the second switch group M2, and a total of 4 groups of switches in the third switch unit M3, the number of MOS tubes in each group of switches is 1, 2, 4, and 8, respectively, corresponding to M2 gate voltage (V1 or V2), M3 gate voltage (V1, V0) combination mode 2 n One; the register can store the combination of MOS transistor gate voltages in the second switch group M2 and the third switch unit M3, and by selecting the best combination mode, the best temperature characteristic can be achieved. As shown in Figure 5 Figure 5 The temperature characteristic effect diagram of different combinations provided by an embodiment of the present application.

[0090] Table 1: 4-bit register corresponding M2 transistor and M3 transistor gate voltage combination.

[0091] TCTRIM<4:0 M2 gate voltage M3 gate voltage 00000 V0 15xV1 00001 V0 14xV1, 1xV0 00010 V0 13xV1, 2xV0 ……… ……… ……… 01111 V0 15xV0 10000 V1 15xV1 10001 V1 14xV1, 1xV0 ……… ……… ……… 11111 V1 15xV0

[0092] The circuit structure provided by the present application does not consider the temperature characteristic of the resistor R when performing the temperature characteristic adjustment process, at this time, the gate voltage of the MOS tube in the second switch group M2 is considered to be the first voltage V1, the gate voltage of the MOS tube in the third switch unit M3 is the first voltage V1, and the gate voltage of the remaining MOS tube is the second voltage V2, the drain current of the twelfth switch tube is the second current I a1 , the drain current of the second switch group M2 is the fourth current I b1 , the drain current of the fourth switch tube is the sixth current I c1 , the drain current of the eleventh switch tube is the first current I a0 , the drain current of the third switch unit M3 is the third current I b0 , the drain current of the fifth switch tube is the fifth current I c0 Since the fourth switch tube and the fifth switch tube are mirror images of each other, I c0 = I C1 According to the analysis of the circuit in Figure 4 , the following formula can be obtained:

[0093] I c1 = I a1 + I b1 , I c0 = I a0 + I b0 Formula (1)

[0094] I a1 = VBG*g mm1 , I b1 = 15*V1*g mm2 ​, I a0 = VM * g mm0 , I b0 =

[0095] (15 - m) * V2 * g mm3 + m * V1 * g mm2 Equation (2)

[0096] Wherein, VM is the feedback voltage of the resistor R, g mm1 is the transconductance value of the twelfth switch tube, g mm2 is the transconductance value of the switch tube in the second switch group M2, g mm0 is the transconductance value of the eleventh switch tube, g mm3 is the transconductance value of the switch tube in the third switch unit M3, and formula (3) can be obtained from formula (1) and formula (2):

[0097] VBG * g mm1 - VM * g mm0 = (15 - m) * V2 * g mm3 - (15 - m) * V1 * g mm2

[0098] = ΔI Equation (3)

[0099] When m = 0, that is, the gate voltage of the switch tube in the second switch group M2 is the first voltage V1, and the gate voltage of the switch tube in the third switch unit M3 is the second voltage V2, since V1, V2 are voltages with positive temperature coefficient voltage difference, then the value of ΔI is maximum and is a positive temperature coefficient current, but since VBG is zero temperature voltage, the feedback voltage VM is negative temperature voltage, formula (3) is established, at this time the output current of the current trimming unit 302 is positive temperature current. It can be understood that when the feedback voltage of the resistor R is negative temperature voltage, the current trimming unit 302 controls the combination of the gate voltage of the MOS tube in the second switch group M2 and the third switch unit M3 through the trimming proportional control unit 305, so that the output current of the current trimming unit 302 is positive temperature current, which compensates the negative temperature voltage generated by the resistor R, so that the current output by the reference source generation unit 304 is zero temperature current.

[0100] When m = 15, that is, the gate voltage of the switch tube in the second switch group M2 and the gate voltage of the switch tube in the third switch unit M3 are both the first voltage V1, so ΔI is equal to 0, then the voltage temperature characteristic of the feedback voltage VM is consistent with the zero temperature voltage VBG, at this time the output current of the current trimming unit 302 is zero temperature current. When it is detected that the feedback voltage of the resistor R is zero temperature voltage, at this time the resistor has no temperature coefficient, and the current output by the current trimming unit 302 is also zero temperature current, without the need for temperature trimming.

[0101] Similarly, when the gate voltage of the MOS transistor in the second switch group M2 is the second voltage, and the gate voltage of the switch transistor in the third switch unit M3 is the first voltage V1, the current trimming unit 302 can obtain an output current as a negative temperature current.

[0102] When the resistance R has a temperature characteristic (positive temperature voltage, negative temperature voltage, or zero temperature voltage), the current trimming unit 302 adjusts the proportion of the first voltage V1 and the second voltage V2 in the second switch group M2 and the third switch unit M3 to compensate for the resistance temperature characteristic, adjusts the temperature characteristic, and realizes zero temperature current output.

[0103] In an optional embodiment, the second switch group M2 includes 2 n MOS transistors, the third switch unit M3 includes n groups of switch transistors, the i-th group of switch transistors includes 2 i-1 MOS transistors, 1≤i≤n, n is a positive integer; the number of bits of the trimming register is also n, the larger the value of n, the greater the number of bits of the trimming register required, the more the proportion of the first voltage and the second voltage in the second switch group M2 and the third switch unit M3, and the higher the accuracy in adjusting the temperature characteristic.

[0104] In an optional embodiment, the trimming proportion control unit 305 is configured to control the trimming accuracy by adjusting the voltage difference ΔV of the first voltage V1 and the second voltage V2. The smaller the voltage difference ΔV, the higher the accuracy of the current trimming unit 302. The smaller the voltage difference, the smaller the difference in changes caused by different voltage proportions in the trimming process, and the easier it is to select the optimal output current for a current with high accuracy.

[0105] In an optional embodiment, the ratio of the width-length ratio of the first switch transistor M1 to the width-length ratio of the tenth switch transistor M10 is a first ratio, and the first ratio is used to adjust the source current of the second switch group M2 and the third switch unit M3 to control the trimming accuracy.

[0106] The first switch transistor M1 and the tenth switch transistor M10 are mirror images of each other, and the ratio of the width-length ratio of the first switch transistor M1 to the width-length ratio of the tenth switch transistor M10 is adjusted to adjust the proportion of the source current in the second switch group M2 and the third switch unit M3, so that the proportion of the source current in the second switch group M2 and the third switch unit M3 is reduced. The current flowing through the first switch transistor M1 divided by the current flowing through the tenth switch transistor M10 will obtain a percentage A, if the register controlling the second switch group M2 and the third switch unit M3 is 5 bits, 32 trimming bits will be generated, and the trimming accuracy is equal to A / 32, that is, the smaller the current proportion of the first switch transistor M1 to the tenth switch transistor M10, the higher the trimming accuracy. Therefore, reducing the source current of the second switch group M2 and the third switch unit M3 also reduces the drain current of the second switch group M2 and the third switch unit M3, thereby realizing more accurate current output.

[0107] After the temperature characteristic trimming is completed, the current absolute value trimming is performed, and the output current formula can be approximated as I=(VBG+K*△V) / R, wherein K is a trimming ratio of the temperature coefficient, and△V is a difference between the first voltage V1 and the second voltage V2. When the current temperature characteristic trimming is completed, K and△V are fixed, and the output current absolute value is changed by trimming R.

[0108] The temperature characteristic trimming is performed first in the present application, the proportion of the first voltage and the second voltage in the second switch group M2 and the third switch unit M3 in the current trimming unit is adjusted to compensate for the resistance temperature characteristic, and then the current absolute value trimming is performed, so that the temperature characteristic trimming and the current absolute value trimming do not affect each other.

[0109] The present application provides an integrated circuit chip comprising the trimming circuit as any of the above. The integrated circuit chip can be a microprocessor chip or the like, and the trimming circuit is connected to a functional circuit module such as an ADC, a reference voltage source, or the like which is sensitive to temperature.

[0110] The present application also provides a trimming method, as shown in the following Figure 6 The trimming method is applied to the trimming current as described above, and the trimming method comprises the following steps:

[0111] Step S702, performing current temperature characteristic trimming according to the feedback voltage of the reference source generation unit 304;

[0112] Step S704, after the current temperature characteristic trimming is completed, performing current absolute value trimming.

[0113] In an optional embodiment, the step S702 specifically comprises:

[0114] If the feedback voltage is a positive temperature voltage, the control current trimming unit 302 outputs a negative temperature current, so that the reference current output by the reference source generation unit 304 is a zero temperature current; or

[0115] If the feedback voltage is a zero temperature voltage, the control current trimming unit 302 outputs a zero temperature current, so that the reference current output by the reference source generation unit 304 is a zero temperature current; or

[0116] If the feedback voltage is a positive temperature voltage, the control current trimming unit 302 outputs a negative temperature current, so that the reference current output by the reference source generation unit 304 is a zero temperature current.

[0117] The temperature characteristic trimming is performed first in the present application, the proportion of the first voltage and the second voltage in the second switch group M2 and the third switch unit M3 in the current trimming unit is adjusted to compensate for the resistance temperature characteristic, and then the current absolute value trimming is performed, so that the temperature characteristic trimming and the current absolute value trimming do not affect each other.

[0118] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the application being indicated by the following claims.

[0119] It is to be understood that the application is not limited to the precise construction herein disclosed and shown in the drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application is limited only by the claims that follow.

Claims

1. A tuning circuit, characterized in that, It includes a reference source generation unit, a current mirror unit, a current adjustment unit, and a voltage clamping unit; The first input terminal of the voltage clamping unit is used to input a positive power supply voltage, the second input terminal of the voltage clamping unit is used to input a zero-temperature voltage, the third input terminal of the voltage clamping unit is used to input a feedback voltage, the first output terminal and the second output terminal of the voltage clamping unit are connected to the current mirror unit, the first output terminal of the voltage clamping unit is used to output a first current, and the second output terminal of the voltage clamping unit is used to output a second current. The first input terminal of the current adjustment unit is connected to the first power supply, the second input terminal of the current adjustment unit is used to input the positive power supply voltage, the first output terminal and the second output terminal of the current adjustment unit are connected to the current mirror unit, the first output terminal of the current adjustment unit is used to output the third current, and the second output terminal of the current adjustment unit is used to output the fourth current. The first input terminal of the current mirror unit is used to input a positive power supply voltage, the second input terminal of the current mirror unit is used to input a negative power supply voltage, the third input terminal of the current mirror unit is used to input a fifth current, the fourth input terminal of the current mirror unit is used to input a sixth current, and the output terminal of the current mirror unit is connected to the reference source generation unit. The fifth current is the sum of the first current and the third current, and the sixth current is the sum of the second current and the fourth current. The reference source generation unit is used to generate a stable reference current, the voltage clamping unit is used to clamp the feedback voltage of the reference source generation unit, the current adjustment unit is used to compensate for temperature characteristics, and the current mirror unit is used to control the matching of the fifth current and the sixth current.

2. The adjustment circuit according to claim 1, characterized in that, The adjustment circuit also includes an adjustment ratio control unit. The second terminal of the current adjustment unit is connected to the adjustment ratio control unit. The adjustment ratio control unit is used to input a first voltage or a second voltage to the current adjustment unit. There is a pressure difference with a positive or negative temperature coefficient between the first voltage and the second voltage.

3. The adjustment circuit according to claim 2, characterized in that, The current adjustment unit includes a first switching transistor, a second switching group, and a third switching unit; The first terminal of the first switching transistor is connected to the first power supply, the control terminal of the first switching transistor is used to input a positive power supply voltage, and the second terminal of the first switching transistor is connected to the first terminal of the second switching group and the third switching unit. The second terminal of the second switch group is connected to the fourth input terminal of the current mirror unit, and the control terminal of the second switch group is connected to the adjustment ratio control unit. The second end of the third switching unit is connected to the third input end of the current mirror unit, and the control end of the third switching unit is connected to the adjustment ratio control unit.

4. The adjustment circuit according to claim 3, characterized in that, The second switch group includes The third switching unit includes n groups of switching transistors, with the i-th group of switching transistors including... There are n MOSFETs, where 1 ≤ i ≤ n, and n is a positive integer; The drains of all MOSFETs in the second switching group are connected to the fourth input terminal of the current mirror unit, and the control terminals of all MOSFETs in the second switching group are connected to one end and to the adjustment ratio control unit. The drains of all the switching transistors in the third switching unit are connected to the third input terminal of the current mirror unit, and the control terminals of all the switching transistors in the third switching unit are connected to the adjustment ratio control unit.

5. The adjustment circuit according to claim 3, characterized in that, The adjustment ratio control unit includes an adjustment register; The adjustment register stores adjustment instructions, which are used to control the output current of the current adjustment unit to be one of negative temperature current, zero temperature current, and positive temperature current.

6. The adjustment circuit according to claim 5, characterized in that, The adjustment command is used to control the voltage combination of the MOS transistor control terminals in the second switch group and the third switch unit.

7. The adjustment circuit according to claim 1, characterized in that, The current mirror unit includes a fourth switch, a fifth switch, a sixth switch, a seventh switch, an eighth switch, and a ninth switch. The drain of the fourth switch is connected to the second output terminal of the voltage clamping unit and the second output terminal of the current trimming unit, the source of the fourth switch is grounded, and the control terminal of the fourth switch is connected to the control terminal of the fifth switch. The drain of the fifth switching transistor is connected to the first output terminal of the voltage clamping unit and the first output terminal of the current trimming unit, and the source of the fifth switching transistor is grounded. The source of the sixth switch is connected to the first power supply, the control terminal of the sixth switch is used to input a positive power supply voltage, and the drain of the sixth switch is connected to the drain of the eighth switch. The source of the seventh switch is connected to the first power supply, the control terminal of the seventh switch is used to input a positive power supply voltage, and the drain of the seventh switch is connected to the drain of the ninth switch. The control terminal of the eighth switch is used to input a negative power supply voltage, and the source of the eighth switch is connected to the drain of the fourth switch. The control terminal of the ninth switch is used to input a negative power supply voltage. The source of the ninth switch is connected to the drain of the fifth switch, and the drain of the ninth switch is connected to the reference source generation unit. The drain of the eighth switch is connected to the control terminal of the fourth switch.

8. The adjustment circuit according to claim 7, characterized in that, The voltage clamping unit includes a tenth switch, an eleventh switch, and a twelfth switch; The source of the tenth switch is connected to the first power supply, the control terminal of the tenth switch is used to input a positive power supply voltage, and the drain of the tenth switch is connected to the source of the first switch and the source of the sixth switch. The control terminal of the twelfth switch is used to input a zero-temperature voltage, and the drain of the twelfth switch is connected to the drain of the fourth switch. The control terminal of the eleventh switch is connected to the reference source generation unit and is used to input the feedback voltage of the reference source generation unit. The drain of the eleventh switch is connected to the drain of the fifth switch.

9. The adjustment circuit according to claim 8, characterized in that, The reference source generation unit includes a thirteenth switch, a fourteenth switch, a fifteenth switch, and a first resistor; The source of the thirteenth switch is connected to the first power supply, the control terminal of the thirteenth switch is connected to the control terminal of the fourteenth switch, the control terminal of the thirteenth switch is connected to the drain of the thirteenth switch, and the drain of the thirteenth switch is connected to the drain of the fifteenth switch. The source of the fifteenth switch is connected to the first end of the first resistor, and the control terminal of the fifteenth switch is connected to the drain of the ninth switch. The first end of the first resistor is connected to the voltage clamping unit to provide feedback voltage to the voltage clamping unit, and the second end of the first resistor is grounded. The source of the fourteenth switch is connected to the first power supply, and the drain of the fourteenth switch is used to output zero-temperature current.

10. The adjustment circuit according to claim 9, characterized in that, The first resistor is an adjustable resistor.

11. The adjustment circuit according to claim 3 or claim 8, characterized in that, The ratio of the width-to-length ratio of the first switching transistor to the width-to-length ratio of the tenth switching transistor is the first ratio value. The first ratio value is used to adjust the source current of the second switching group and the third switching unit to control the adjustment accuracy.

12. The adjustment circuit according to claim 7, characterized in that, The width-to-length ratio of the fourth, fifth, sixth, seventh, eighth, and ninth switching transistors is the same.

13. The adjustment circuit according to claim 4, characterized in that, The adjustment ratio control unit is used to control the adjustment accuracy by adjusting the voltage difference between the first voltage and the second voltage.

14. An integrated circuit chip, characterized in that, Includes the adjustment circuit as described in any one of claims 1-13.

15. A method for adjusting settings, characterized in that, Based on the adjustment circuit according to any one of claims 1-13, the adjustment method includes: The current-temperature characteristics are adjusted based on the feedback voltage of the reference source generation unit. After the current-temperature characteristic adjustment is completed, the absolute value of the current is adjusted.

16. The adjustment method according to claim 15, characterized in that, The current-temperature characteristics are adjusted based on the feedback voltage of the reference source generation unit, specifically including: If the feedback voltage is a negative temperature voltage, the current adjustment unit is controlled to output a positive temperature current, so that the reference current output by the reference source generation unit is a zero temperature current; or If the feedback voltage is a zero-temperature voltage, control the current adjustment unit to output a zero-temperature current, so that the reference current output by the reference source generation unit is a zero-temperature current; or If the feedback voltage is a positive temperature voltage, the current adjustment unit is controlled to output a negative temperature current, so that the reference current output by the reference source generation unit is a zero temperature current.

Images