CN-121996006-A - Current bias circuit for high-precision current calibration and control method

CN121996006ACN 121996006 ACN121996006 ACN 121996006ACN-121996006-A

Abstract

The invention relates to the technical field of integrated circuit design, in particular to a high-precision current calibration current bias circuit and a control method, wherein the circuit comprises a band gap reference circuit, a current calibration circuit, a current detection circuit and a first bias unit; the band gap reference circuit is used for outputting reference current, the bias unit receives the reference current and outputs bias voltage for the current calibration circuit, the current calibration circuit calibrates input current through the Trim circuit and outputs calibrated current, and the current detection circuit receives the calibrated current and outputs an indication signal. The invention introduces a current calibration circuit, and can realize accurate voltage value and current value output no matter how the process angle changes.

Inventors

YIN HAIYANG
LAI GUANGSHENG
FENG YUAN
LI LEI

Assignees

成都芯卓微电子科技有限公司

Dates

Publication Date: 20260508
Application Date: 20260209

Claims (10)

1. The high-precision current calibration current bias circuit is characterized by comprising a band gap reference circuit, a current calibration circuit, a current detection circuit and a first bias unit; The band gap reference circuit is used for outputting reference current; The first bias unit receives the reference current and outputs a bias voltage for the current calibration circuit; the current calibration circuit calibrates input current through a Trim circuit and outputs calibrated current; The current detection circuit receives the calibrated current and outputs an indication signal.
2. The high precision current calibrated current bias circuit of claim 1, wherein said current calibration circuit comprises an error amplifier, a second bias unit and a resistance unit; The error amplifier forms a symmetrical structure through a plurality of MOS tubes; the resistance unit comprises a second resistance and a third resistance; the second resistor is connected in parallel with one side of the error amplifier and is used for generating a reference voltage after receiving input current; the third resistor is connected in parallel with the other side of the error amplifier, is a variable resistor, and generates clamping voltages at two ends of the third resistor; The second bias unit comprises parallel switch branches consisting of MOS tubes, wherein the first switch branch is used for acquiring input current from the third resistor, the second switch branch is used for generating calibrated current, and the third switch branch is used for generating a preset current value.
3. The current bias circuit for high-precision current calibration according to claim 2, wherein the error amplifier comprises a first MOS transistor PM1, a second MOS transistor PM2, a third MOS transistor PM3, a fourth MOS transistor NM4, a fifth MOS transistor NM1, a sixth MOS transistor NM2, a seventh MOS transistor NM3, In the error amplifier, the source electrodes of the first MOS tube PM1 and the second MOS tube PM2 are connected with a power supply vdd, the grid electrodes of the first MOS tube PM1 and the second MOS tube PM2 are connected with the drain electrode of the fourth MOS tube PM4, the source electrode of the fourth MOS tube NM4NM4 is connected with the drain electrode of the second MOS tube PM2, the grid electrodes of the third MOS tube PM3 and the fourth MOS tube PM4 are connected with a bias voltage V BIAS3 generated by a band gap reference circuit, the drain electrode of the third MOS tube PM3 is connected with the drain electrode of the fifth MOS tube PM5, the drain electrode of the fourth MOS tube PM4 is connected with the drain electrode of the sixth MOS tube PM6, the fourth MOS tube PM4, the grid electrode of the first MOS tube PM1 and the second MOS tube PM2 form a self-bias structure, the grid electrode of the fifth MOS tube PM5 is connected with a current I b generated by the band gap reference circuit and one end of the second resistor R2, the source electrode of the fifth MOS tube PM5 is connected with the source electrode of the sixth MOS tube PM6 and connected with the drain electrode of the seventh MOS tube PM7, and the other end of the seventh MOS tube PM7 is connected with the drain electrode of the seventh MOS tube PM7, and the drain electrode of the seventh MOS tube PM7 is connected with the drain electrode of the fifth MOS tube PM 7.
4. The current bias circuit for high-precision current calibration according to claim 2, wherein the second bias unit comprises an eighth MOS transistor PM5, a ninth MOS transistor PM6, a tenth MOS transistor PM7, an eleventh MOS transistor PM8, a twelfth MOS transistor PM9, and a thirteenth MOS transistor PM10; In the first switch branch, the source electrode of the eighth MOS tube PM5 is connected with a power supply vdd, the drain electrode of the eighth MOS tube PM5 is connected with the source electrode of the ninth MOS tube PM6, the grid electrode of the eighth MOS tube PM5 is connected with one end of the first resistor R1, the grid electrode of the ninth MOS tube PM6 is connected with a bias voltage V BIAS3 generated by a band gap reference circuit, and the drain electrode of the ninth MOS tube PM6 is connected with the third resistor R3; In the second switch branch, the source electrode of the tenth MOS tube PM7 is connected with a power supply vdd, the drain electrode of the tenth MOS tube PM7 is connected with the source electrode of the eleventh MOS tube PM8, the grid electrode of the tenth MOS tube PM7 is connected with one end of the first resistor R1, the grid electrode of the eleventh MOS tube PM8 is connected with a bias voltage V BIAS3 generated by a band gap reference circuit, and the drain electrode of the eleventh MOS tube PM8 outputs calibrated current; In the third switch branch, the source electrode of the twelfth MOS tube PM9 is connected with a power supply vdd, the drain electrode of the twelfth MOS tube PM9 is connected with the source electrode of the thirteenth MOS tube PM10, the grid electrode of the twelfth MOS tube PM9 is connected with one end of the first resistor R1, the grid electrode of the thirteenth MOS tube PM10 is connected with a bias voltage V BIAS3 generated by a band gap reference circuit, and the drain electrode of the thirteenth MOS tube PM10 outputs calibrated current; The other end of the first resistor R1 is connected to the power supply vdd via a capacitor C1.
5. The high-precision current calibration current bias circuit according to claim 1, wherein the current detection circuit comprises a MOS tube PM13, a MOS tube PM11, a fourth resistor R4, a MOS tube PM12, a MOS tube NM4, a fifth resistor R5 and a first comparator com; The source electrode of the MOS tube PM13 is connected with a power supply vdd, the gate electrode of the MOS tube PM13 is connected with a bias voltage V bias1 generated by a band gap reference circuit, the drain electrode of the MOS tube PM13 is connected with the source electrode of the MOS tube PM11, the gate electrode of the MOS tube PM11 is connected with a bias voltage V bias2 generated by the band gap reference circuit, the drain electrode of the MOS tube PM11 is connected with a fourth resistor R4, meanwhile, an uncalibrated output voltage V_ rcal is output, the other end of the fourth resistor R4 is grounded, the source electrode of the MOS tube PM12 is connected with the drain electrode of the MOS tube NM4 and connected with a calibrated current, the gate electrode of the MOS tube NM4 is connected with an enable high level eni _cbc, the drain electrode of the MOS tube NM4 is connected with a fifth resistor R5, meanwhile, the other end of the fifth resistor R5 is grounded, the same-direction input end of the first comparator com is connected with a calibrated voltage V_ extr, the reverse input end of the first comparator com is connected with an uncalibrated voltage V_ rcal, and the calibrated voltage V_ extr and the uncalibrated voltage V_3776 are output signals of the first comparator readout _3798 are used as output signals indicating signals.
6. The high-precision current calibration current bias circuit as claimed in claim 1, wherein the bias unit comprises two MOS transistors, wherein the drain electrode of one MOS transistor is connected with the gate electrode of the other MOS transistor, the drain electrode of the other MOS transistor is connected with the current calibration circuit, and the gates of the two MOS transistors respectively receive bias voltage V bias1 ,V bias2 generated by the band gap reference circuit.
7. The high precision current calibrated current bias circuit of claim 1 wherein said bandgap reference circuit comprises a start-up circuit, a bias circuit and a high order compensation core circuit, said start-up circuit, bias circuit and high order compensation core circuit being connected in parallel between a power supply and ground.
8. A high precision current calibrated current biasing circuit according to claim 7, wherein said high order compensation core circuit comprises three sections; The first part generates PTAT current which is proportional to absolute temperature, and the first part forms a common-source common-gate structure for increasing the power supply rejection ratio of the band-gap reference circuit; The second part generates CTAT current which is inversely proportional to absolute temperature, and the second part forms a common-source common-gate structure; The third part forms a current mirror so as to generate a third current which is the same as the CTAT current of the second part and a fourth current which is the same as the PTAT current of the first part, the third current is divided into a current Ictat2 and a current Ictat3 through a MOS tube, and the fourth current and the current Ictat3 are added through different proportions so as to generate a zero-temperature voltage Vbg.
9. A control method of a high-precision current calibration current bias circuit, which is characterized by constructing the high-precision current calibration current bias circuit according to any one of claims 1-8, and outputting the calibrated current by adjusting the size of a variable resistor in the current calibration circuit to realize temperature compensation.
10. The method of claim 9, wherein the variable resistor is adjusted to stabilize the calibrated current I caf_cbc at a predetermined value, ; Wherein I b is a reference current value output by a band gap reference circuit, R 2 is a resistor for generating a reference voltage based on I b in a current calibration circuit, and R 3 is a variable resistor.

Description

Current bias circuit for high-precision current calibration and control method Technical Field The invention relates to the technical field of integrated circuit design, in particular to a high-precision current calibration current bias circuit and a control method. Background With the rapid development of the digital age, electronic devices have deeply integrated into the aspects of people's life. Among the wireless communication functions of many electronic devices, wiFi technology has become one of the most mainstream wireless connection means at present due to its wide coverage, higher data transmission rate and relatively convenient usage. From smart phones, tablet computers to smart home devices, data interaction from network deployment of offices to industrial Internet of things is performed, wiFi technology is ubiquitous, and application scenes and user demands of the WiFi technology are explosive. Research of the power management circuit in the WiFi field is further conducted, a novel power management circuit with high load capacity, accurate current calibration function and external monitoring state is developed, the stability and reliability of the WiFi chip in a complex application scene are improved for continuous innovation of pushing the WiFi technology, the ever-increasing diversified user demands are met, and the novel power management circuit has extremely important practical significance and urgency. The traditional band gap reference circuit is influenced by VBE high-order effect, and the temperature coefficient of the output voltage can reach 10ppm/°C at the minimum. This effect results in a significant drop in the accuracy of the output voltage when the temperature fluctuations are large, thereby causing a significant change in the output value. The output fluctuation of the traditional band gap reference circuit under different process angles is large, and effective adjustment cannot be performed, so that accurate output voltage and current are difficult to obtain. Disclosure of Invention The invention aims to solve the problems that the output fluctuation of the traditional band gap reference circuit in the prior art is large under different process angles, the effective adjustment cannot be performed, and the accurate output voltage and current are difficult to obtain, and provides a current bias circuit with high-precision current calibration and a control method. In order to achieve the above object, the present invention provides the following technical solutions: a high-precision current calibration current bias circuit comprises a band gap reference circuit, a current calibration circuit, a current detection circuit and a first bias unit; The band gap reference circuit is used for outputting reference current; The first bias unit receives the reference current and outputs a bias voltage for the current calibration circuit; the current calibration circuit calibrates input current through a Trim circuit and outputs calibrated current; The current detection circuit receives the calibrated current and outputs an indication signal. Preferably, the current calibration circuit comprises an error amplifier, a second bias unit and a resistance unit; The error amplifier forms a symmetrical structure through a plurality of MOS tubes; the resistance unit comprises a second resistance and a third resistance; the second resistor is connected in parallel with one side of the error amplifier and is used for generating a reference voltage after receiving input current; the third resistor is connected in parallel with the other side of the error amplifier, is a variable resistor, and generates clamping voltages at two ends of the third resistor; The second bias unit comprises parallel switch branches consisting of MOS tubes, wherein the first switch branch is used for acquiring input current from the third resistor, the second switch branch is used for generating calibrated current, and the third switch branch is used for generating a preset current value. Preferably, the error amplifier comprises a first MOS tube PM1, a second MOS tube PM2, a third MOS tube PM3, a fourth MOS tube NM4, a fifth MOS tube NM1, a sixth MOS tube NM2 and a seventh MOS tube NM3, In the error amplifier, the source electrodes of a first MOS tube PM1 and a second MOS tube PM2 are connected with a power supply vdd, the grid electrodes of the first MOS tube PM1 and the second MOS tube PM2 are connected with the drain electrode of a fourth MOS tube PM4, the source electrode of the fourth MOS tube NM4 is connected with the drain electrode of the second MOS tube PM2, the grid electrodes of a third MOS tube PM3 and the fourth MOS tube NM4 are connected with a bias voltage V BIAS3 generated by a band gap reference circuit, the drain electrode of the third MOS tube PM3 is connected with the drain electrode of a fifth MOS tube PM5, the drain electrode of the fourth MOS tube NM4 is connected with the drain electrode of a sixth MOS