Low-power RC oscillator circuit and working method thereof
By designing a chopper circuit and a path delay cancellation loop, the effects of comparator offset and path delay in the RC oscillator are eliminated, achieving low power consumption and improved frequency accuracy, and ensuring stability under temperature and power supply variations.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-04
- Publication Date
- 2026-05-15
AI Technical Summary
Traditional RC oscillators have shortcomings in terms of frequency stability, power consumption, and power supply temperature variation, and existing optimization techniques have failed to effectively solve the problems of path delay and comparator offset.
A chopper circuit and a path delay cancellation loop were designed. The chopper structure eliminates comparator offset, and the path delay cancellation loop extracts the delay and feeds it back to cancel the path delay. Combined with the power supply structure, low power consumption and frequency accuracy are achieved.
A more stable clock signal was achieved under varying temperature and power conditions, with improved frequency accuracy, reduced power consumption, and enhanced temperature and power stability.
Smart Images
Figure CN122052694A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of circuit design technology, and more specifically, to a low-power RC oscillator circuit and its operating method. Background Technology
[0002] An RC oscillator is an oscillator circuit based on passive components consisting of capacitors and capacitors. It feeds a portion of the output signal back to the input through a feedback loop, forming a positive feedback loop that generates continuous oscillation. It is commonly used as an oscillator to produce stable frequency output signals. By adjusting the values of the capacitors and resistors, oscillators of different frequencies can be achieved. Oscillators are widely used in clock generators, audio oscillators, and local oscillators in wireless communications. Traditional neural network accelerators consume significant resources at each architectural stage, such as the power consumption and latency of multipliers and adders, and their performance is limited by the bandwidth between memory and the processor. In-memory computing alleviates the performance limitations imposed by bandwidth to some extent, but classic analog-based in-memory computing requires complex peripheral circuits, such as… Sensitive amplifiers, etc.; In-memory computing architectures based on digital circuits may cause significant interference to memory circuits and frequent charging / discharging of word / bit lines, leading to increased power consumption and the possibility of frequent unexpected errors. Compared to LC oscillators and ring oscillators, Oscillators have a smaller area and lower power consumption in the kilohertz-megahertz frequency range. However, they exhibit process-voltage-temperature characteristics. The frequency stability during the change process is poor, and the performance deteriorates as the power budget decreases. Some existing techniques have optimized the oscillator to a certain extent through various means, but problems still exist, such as ignoring the effect of path delay, occupying additional area, comparator offset, and high sensitivity to power supply and temperature changes.
[0003] In view of this, the present invention provides a low-power RC oscillator circuit and its operating method, which designs a chopper circuit and a path delay cancellation loop; the comparator offset is canceled by the chopper structure, and the path delay is canceled by setting a secondary comparator path in the path delay cancellation loop; the frequency accuracy of the circuit is improved, low voltage and low power consumption performance is achieved, and a more stable clock signal is achieved under temperature and power supply changes. Summary of the Invention
[0004] The present invention aims to provide a low-power RC oscillator circuit, comprising a chopper circuit, a path delay cancellation loop, a power supply structure, and an RC circuit; the chopper circuit is connected to the path delay cancellation loop and the RC circuit to eliminate the influence of comparator offset; the path delay cancellation loop is also connected to the RC circuit to extract delay to cancel path delay; the power supply structure is used to supply power to the chopper circuit, the path delay cancellation loop, and the RC circuit; the RC circuit is used to generate an oscillation signal.
[0005] Furthermore, the chopper circuit includes a MOSFET; the MOSFET gate connection signal The source is connected to the RC circuit and the MOS transistor. The source is connected, and the drain is connected to the power supply structure; the MOS transistor gate connection signal The drain is connected to the power supply structure; the MOS transistor is connected to the power supply structure. and the MOS transistor The node connecting the RC circuit is denoted as node REF, and the voltage at node REF is denoted as... .
[0006] Furthermore, the path delay cancellation loop includes a main comparison path, a secondary comparison path, and a main-secondary connection path; the main comparison path and the secondary comparison path have the same structure, both including a comparator and a Schmitt trigger; for the main comparison path: comparator The positive input terminal and voltage Connection, negative input terminal and voltage Connect the output terminal to the Schmitt trigger. The input terminals are connected; the Schmitt trigger The output terminal of the inverter The input terminal and the AND gate of the main and slave connection paths The input terminal of the inverter is connected; The output terminal of the AND gate is connected to the main and secondary connection paths. The input terminals are connected; for the secondary comparison path: comparator The positive input terminals are respectively connected to the voltage via switches. and The negative input terminal is connected to the voltage via a switch. and Connect the output terminal to the Schmitt trigger. The input terminals are connected; the Schmitt trigger The output terminal of the inverter The input terminal and the AND gate of the main and slave connection paths The other input terminal is connected; the inverter The output terminal of the AND gate is connected to the main and secondary connection paths. The other input terminal is connected; the main and secondary connection paths include AND gates and NOR gates; the AND gate The output of the AND-OR-NOT gate The input terminals are connected; the AND gate The output terminal of the OR gate The other input terminal is connected; the NOR gate Output voltage at the output terminal .
[0007] Furthermore, the comparator includes a MOSFET and a current source PTAT; the MOSFET The gate of the MOS transistor drain, MOSFET Gate and MOSFET The drain is connected, and the source is connected to the power supply; the MOS transistor The source is connected to the power supply, and the drain is connected to the MOSFET. drain, MOSFET Gate and MOSFET The gate connection of the MOS transistor; gate voltage The source is connected to the current source PTAT and the MOS transistor. The source of the current source PTAT; the other end of the current source PTAT is grounded; the MOS transistor gate voltage The MOS transistor The source is connected to the power supply, and the drain is connected to the Schmitt trigger and the MOS transistor. The drain of the MOS transistor; The source electrode is grounded.
[0008] Furthermore, the Schmitt trigger includes a MOS transistor; the MOS transistor The gate of the comparator and the MOS transistor Gate and MOSFET The gate is connected, the source is connected to the power supply, and the drain is connected to the MOS transistor. drain and MOSFET The gate is connected and outputs a signal. The MOS transistor The source of the MOS transistor The source and the MOS transistor The drain connection; the MOS transistor The drain of the MOSFET is connected to the power supply; The source electrode is grounded.
[0009] Furthermore, the power supply structure includes a charging circuit and a power supply circuit; the charging circuit includes a resistor, a capacitor, and a MOSFET. The gate is connected to the power supply circuit, the source is connected to the power supply, and the drain is connected to the ground capacitor. and resistance Connect; connect the MOS transistor With capacitor and the resistor The connected node is denoted as r, and the voltage at node r is denoted as... The resistor The other end is connected to the MOSFET The drain connection; the MOS transistor gate and voltage Connection, source grounded; the power supply circuit includes a capacitor, a MOSFET, and a current source PTAT: MOSFET The gate of the MOS transistor drain, MOSFET The gate, the current source PTAT, the MOS transistor Gate, MOSFET Gate, MOSFET The gate of the MOSFET is connected to the charging circuit, and the source is connected to the power supply. The source is connected to the power supply, and the drain is connected to the MOSFET. The drain, the chopper circuit, and the MOSFET The source of the MOS transistor is connected, and the MOS transistor is connected to the source of the MOS transistor. The node connected to the chopper circuit is denoted as node p, and the voltage at node p is denoted as... The MOS transistor The source is connected to the power supply, and the drain is connected to the MOSFET. The drain connection; the MOS transistor The source is connected to the power supply, and the drain is connected to the chopper circuit and the MOSFET. The source and MOSFET The drain of the MOS transistor is connected; and the MOS transistor is connected to the drain of the MOS transistor. The node connected to the chopper circuit is denoted as node n, and the voltage at node n is denoted as... The MOS transistor The source is connected to the power supply, and the drain is connected to the MOS transistor. The drain of the MOSFET is connected; the other end of the current source PTAT is grounded; the MOSFET... gate voltage The MOS transistor gate voltage The MOS transistor Gate connection signal Source capacitor connected to ground and MOSFET The drain of the MOS transistor; The gate is connected to the signal The source is grounded; the MOS transistor gate connection signal Source capacitor connected to ground and MOSFET The drain of the MOS transistor; gate connection signal The source electrode is grounded.
[0010] Furthermore, the current source PTAT includes a MOSFET and a resistor; the MOSFET The gate of the MOS transistor drain, MOSFET drain and MOSFET The gate connection of the MOS transistor; The source is connected to the power supply, and the drain is connected to the MOS transistor. Gate, MOSFET Gate and drain and MOSFET The gate connection of the MOS transistor; Source grounding resistance The MOS transistor The source of the MOS transistor is grounded; The source is grounded, and the drain is connected to a 20nA power supply.
[0011] Furthermore, the voltage The polarity is ;in, This represents the offset voltage of the comparator.
[0012] Furthermore, the RC circuit includes a resistor and an inductor; the resistor One end of the resistor is connected to the chopper circuit and the path delay cancellation loop, and the other end is grounded; and the resistor is connected to... The node connected to the chopper circuit and the path delay cancellation loop is denoted as node REF, and the voltage of node REF is denoted as... ;capacitance One end is connected to the resistor The chopper circuit and the path delay cancellation loop are connected, and the other end is grounded.
[0013] The purpose of this invention is to provide a method for operating a low-power RC oscillator circuit as described in any of the above claims, comprising: using a chopper circuit to eliminate the influence of comparator offset; and changing the voltage by periodically switching the voltages at the connection nodes p and v between the power supply structure and the chopper circuit. The polarity is changed; the two periods before and after the polarity change are added together to cancel out the offset; the oscillation period becomes ;in, Add a secondary comparison path with the same delay as the primary comparison path, and then extract the delay. The signal is fed back to the main comparison path to charge the capacitor for compensation; the output signal is then sent. When the change occurs, the secondary comparison path operates; the AND gate logic extracts the delay between the output of the secondary comparison path and the output of the primary comparison path. Add a charging circuit to generate the replication voltage. The input voltage of the secondary comparison path is made the same as the input voltage of the primary comparison path to achieve precise matching, ensuring that the delay of the secondary comparison path is equal to the delay. The resistance value of the RC circuit is configured to be equal to the resistance value of the charging circuit, and the capacitance value of the charging circuit is equal to the capacitance value of the power supply circuit.
[0014] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:
[0015] This invention eliminates the influence of comparator offset and path delay on the circuit by rationally constructing the chopper circuit and path delay cancellation loop, improves the frequency accuracy of the circuit, achieves low voltage and low power consumption performance, and realizes a more stable clock signal under temperature and power supply changes.
[0016] This invention utilizes a chopper circuit and a path delay cancellation loop to implement a method based on The time-constant relaxor oscillator eliminates the effects of comparator offset and path delay, respectively. to Within the temperature range, the frequency accuracy is... Power consumption is The power supply is Energy is Temperature stability is With the help of the proposed path delay elimination, temperature and power supply stability are improved respectively. Double times. Attached Figure Description
[0017] Figure 1 An exemplary circuit diagram of a low-power RC oscillator circuit provided by the present invention;
[0018] Figure 2 An exemplary circuit diagram of the current source PTAT provided by the present invention;
[0019] Figure 3An exemplary circuit diagram of the comparator and Schmitt trigger provided for this invention. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0021] Figure 1 An exemplary circuit diagram of a low-power RC oscillator circuit provided by the present invention is shown below. Figure 1 As shown, the low-power RC oscillator circuit includes a chopper circuit, a path delay cancellation loop, a power supply structure, and an RC circuit.
[0022] The chopper circuit is connected to the path delay cancellation loop and the RC circuit to eliminate the comparator offset effect.
[0023] The chopper circuit includes a MOSFET; the MOSFET gate connection signal The source is connected to the RC circuit and the MOS transistor. The source is connected, and the drain is connected to the power supply structure; the MOS transistor gate connection signal The drain is connected to the power supply structure; the MOS transistor is connected to the power supply structure. and the MOS transistor The node connecting the RC circuit is denoted as node REF, and the voltage at node REF is denoted as... .
[0024] The path delay cancellation loop is also connected to the RC circuit to extract the delay and cancel the path delay.
[0025] The path delay cancellation loop includes a main comparison path, a secondary comparison path, and a main-secondary connection path; the main comparison path and the secondary comparison path have the same structure, both including a comparator and a Schmitt trigger.
[0026] For the main comparison path: comparator The positive input terminal and voltage Connection, negative input terminal and voltage Connect the output terminal to the Schmitt trigger. The input terminals are connected; the Schmitt trigger The output terminal of the inverter The input terminal and the AND gate of the main and slave connection paths The input terminal of the inverter is connected; The output terminal of the AND gate is connected to the main and secondary connection paths. The input terminal is connected.
[0027] For the sub-comparison path: comparator The positive input terminals are respectively connected to the voltage via switches. and The negative input terminal is connected to the voltage via a switch. and Connect the output terminal to the Schmitt trigger. The input terminals are connected; the Schmitt trigger The output terminal of the inverter The input terminal and the AND gate of the main and slave connection paths The other input terminal is connected; the inverter The output terminal of the AND gate is connected to the main and secondary connection paths. The other input is connected. For more information on comparators and Schmitt triggers, see [link to relevant documentation]. Figure 3 And its related descriptions.
[0028] The primary and secondary connection paths include AND gates and NOR gates; the AND gates The output of the AND-OR-NOT gate The input terminal is connected; the AND gate The output terminal of the OR gate The other input terminal is connected; the NOR gate Output voltage at the output terminal Wherein, the voltage The polarity is ;in, This represents the offset voltage of the comparator.
[0029] The power supply structure is used to supply power to the chopper circuit, the path delay cancellation loop, and the RC circuit.
[0030] The power supply structure includes a charging circuit and a power supply circuit.
[0031] The charging circuit includes resistors, capacitors, and MOSFETs: MOSFETs The gate is connected to the power supply circuit, the source is connected to the power supply, and the drain is connected to the ground capacitor. and resistance Connect; connect the MOS transistor With capacitor and the resistor The connected node is denoted as r, and the voltage at node r is denoted as... The resistor The other end is connected to the MOSFET The drain connection; the MOS transistor gate and voltage Connect, source grounded.
[0032] The power supply circuit includes capacitors, MOSFETs, and a current source PTAT: MOSFET. The gate of the MOS transistor drain, MOSFET The gate, the current source PTAT, the MOS transistor Gate, MOSFET Gate, MOSFET The gate of the MOSFET is connected to the charging circuit, and the source is connected to the power supply. The source is connected to the power supply, and the drain is connected to the MOSFET. The drain, the chopper circuit, and the MOSFET The source terminal is connected, and the MOS transistor is connected. The node connected to the chopper circuit is denoted as node p, and the voltage at node p is denoted as... The MOS transistor The source is connected to the power supply, and the drain is connected to the MOSFET. The drain connection; the MOS transistor The source is connected to the power supply, and the drain is connected to the chopper circuit and the MOSFET. The source and MOSFET The drain of the MOS transistor is connected; and the MOS transistor is connected. The node connected to the chopper circuit is denoted as node n, and the voltage at node n is denoted as... The MOS transistor The source is connected to the power supply, and the drain is connected to the MOS transistor. The drain of the MOSFET is connected; the other end of the current source PTAT is grounded; the MOSFET... gate voltage The MOS transistor gate voltage The MOS transistor gate connection signal Source capacitor connected to ground and MOSFET The drain of the MOS transistor; The gate is connected to the signal The source is grounded; the MOS transistor gate connection signal Source capacitor connected to ground and MOSFET The drain of the MOS transistor; gate connection signal The source is grounded. For more information on current source PTAT, see [link to relevant documentation]. Figure 2 And its related descriptions.
[0033] The RC circuit is used to generate an oscillation signal.
[0034] The RC circuit includes a resistor and an inductor; the resistor One end of the resistor is connected to the chopper circuit and the path delay cancellation loop, and the other end is grounded; and the resistor is connected to... The node connected to the chopper circuit and the path delay cancellation loop is denoted as node REF, and the voltage of node REF is denoted as... ;capacitance One end is connected to the resistor The chopper circuit and the path delay cancellation loop are connected, and the other end is grounded.
[0035] Figure 2 An exemplary circuit diagram of the current source PTAT provided by the present invention.
[0036] like Figure 2 As shown, the current source PTAT includes a MOSFET and a resistor; the MOSFET The gate of the MOS transistor drain, MOSFET drain and MOSFET The gate connection of the MOS transistor; The source is connected to the power supply, and the drain is connected to the MOS transistor. Gate, MOSFET Gate and drain and MOSFET The gate connection of the MOS transistor; Source grounding resistance The MOS transistor The source of the MOS transistor is grounded; The source is grounded, and the drain is connected to a 20nA power supply.
[0037] Figure 3 An exemplary circuit diagram of the comparator and Schmitt trigger provided for this invention.
[0038] like Figure 3 As shown, the comparator includes a MOSFET and a current source PTAT; the MOSFET The gate of the MOS transistor drain, MOSFET Gate and MOSFET The drain is connected, and the source is connected to the power supply; the MOS transistor The source is connected to the power supply, and the drain is connected to the MOSFET. drain, MOSFET Gate and MOSFET The gate connection of the MOS transistor; gate voltage The source is connected to the current source PTAT and the MOS transistor. The source of the current source PTAT; the other end of the current source PTAT is grounded; the MOS transistor gate voltage The MOS transistor The source is connected to the power supply, and the drain is connected to the Schmitt trigger and the MOS transistor. The drain of the MOS transistor; The source electrode is grounded.
[0039] like Figure 3 As shown, the Schmitt trigger includes a MOS transistor; the MOS transistor The gate of the comparator and the MOS transistor Gate and MOSFET The gate is connected, the source is connected to the power supply, and the drain is connected to the MOS transistor. drain and MOSFET The gate is connected and outputs a signal. The MOS transistor The source of the MOS transistor The source and the MOS transistor The drain connection; the MOS transistor The drain of the MOSFET is connected to the power supply; The source electrode is grounded.
[0040] The operating method of the low-power RC oscillator circuit provided by this invention includes the following:
[0041] A chopper circuit is used to eliminate the effect of comparator offset; the voltages at nodes p and v, which are connected to the chopper circuit, are periodically switched. and Change voltage polarity .
[0042] Adding the two periods before and after the polarity change cancels out the offset; the oscillation period becomes... ;in, .
[0043] Add a secondary comparison path (RCP) with the same delay as the primary comparison path, and then extract the delay. It is then fed back to the main comparison path to charge the capacitor and thus perform compensation.
[0044] Output signal When the change occurs, the secondary comparison path operates; the AND gate logic extracts the delay between the output of the secondary comparison path and the output of the primary comparison path. .
[0045] Add a charging circuit to generate the replication voltage The input voltage of the secondary comparison path is made the same as the input voltage of the primary comparison path to achieve precise matching, ensuring that the delay of the secondary comparison path is equal to the delay. .
[0046] The resistance value of the RC circuit is configured to be equal to the resistance value of the charging circuit (i.e., The value of the capacitor in the charging circuit is equal to the value of the capacitor in the power supply circuit (i.e., ).
[0047] Specifically, when When changing, Lower, Start with The charging slope is adjusted to match the main charging path. Therefore... and The pulse width is equal to the path delay. The switch is in Inner The current charges the circuit, effectively compensating for path delay. Finally, the offset and delay cancel each other out, and the period stabilizes. .
[0048] It also includes the construction of other modules; these other modules include current source PTAT, comparators, and Schmitt triggers, etc. The power supply serves as a reference for other modules. Components with larger lengths and widths are selected to improve the comparator's matching performance. An improved Schmitt trigger is employed to reduce power consumption. For example, using... The power supply serves as a reference for other modules. Configure the resistor. for This makes the static current be The output current is Meanwhile, due to offset and delay cancellation, the comparator bias only needs to be adjusted. The low current draw saves power. Since the comparator operates in the subthreshold region, devices with larger lengths and widths are chosen to improve the comparator's matching performance. This invention employs an improved Schmitt trigger, which effectively reduces power consumption as delay is increased.
[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A low-power RC oscillator circuit, characterized in that, This includes chopper circuits, path delay cancellation loops, power supply structures, and RC circuits; The chopper circuit is connected to the path delay cancellation loop and the RC circuit to eliminate the comparator offset effect; The path delay cancellation loop is also connected to the RC circuit to extract the delay in order to cancel the path delay. The power supply structure is used to supply power to the chopper circuit, the path delay cancellation loop, and the RC circuit; The RC circuit is used to generate an oscillation signal.
2. The low-power RC oscillator circuit according to claim 1, characterized in that, The chopper circuit includes a MOSFET; MOSFET Gate connection signal The source is connected to the RC circuit and the MOS transistor. The source is connected, and the drain is connected to the power supply structure. The MOS transistor Gate connection signal The drain is connected to the power supply structure; the MOS transistor is connected to the power supply structure. and the MOS transistor The node connecting the RC circuit is denoted as node REF, and the voltage at node REF is denoted as... .
3. The low-power RC oscillator circuit according to claim 2, characterized in that, The path delay cancellation loop includes a main comparison path, a secondary comparison path, and a main-secondary connection path; the main comparison path and the secondary comparison path have the same structure, both including a comparator and a Schmitt trigger; For the primary comparison path: comparator The positive input terminal and voltage Connection, negative input terminal and voltage Connect the output terminal to the Schmitt trigger. The input terminal is connected; The Schmitt trigger The output terminal of the inverter The input terminal and the AND gate of the main and slave connection paths The input terminal is connected; The inverter The output terminal of the AND gate is connected to the main and secondary connection paths. The input terminal is connected; For the secondary comparison path: comparator The positive input terminals are respectively connected to the voltage via switches. and The negative input terminal is connected to the voltage via a switch. and Connect the output terminal to the Schmitt trigger. The input terminal is connected; The Schmitt trigger The output terminal of the inverter The input terminal and the AND gate of the main and slave connection paths The other input terminal is connected; The inverter The output terminal of the AND gate is connected to the main and secondary connection paths. The other input terminal is connected; The primary and secondary connection paths include AND gates and OR NOT gates; The AND gate The output of the AND-OR-NOT gate The input terminal is connected; The AND gate The output terminal of the OR gate The other input terminal is connected; The OR NOT gate Output voltage at the output terminal .
4. The low-power RC oscillator circuit according to claim 3, characterized in that, The comparator includes a MOSFET and a current source PTAT; MOSFET The gate of the MOS transistor drain, MOSFET Gate and MOSFET The drain is connected, and the source is connected to the power supply; The MOS transistor The source is connected to the power supply, and the drain is connected to the MOSFET. drain, MOSFET Gate and MOSFET Gate connection; The MOS transistor gate voltage The source is connected to the current source PTAT and the MOS transistor. The source pole; The other end of the current source PTAT is grounded; The MOS transistor gate voltage ; The MOS transistor The source is connected to the power supply, and the drain is connected to the Schmitt trigger and the MOS transistor. The drain electrode; The MOS transistor The source electrode is grounded.
5. The low-power RC oscillator circuit according to claim 3, characterized in that, The Schmitt trigger includes a MOS transistor; MOSFET The gate of the comparator and the MOS transistor Gate and MOSFET The gate is connected, the source is connected to the power supply, and the drain is connected to the MOS transistor. drain and MOSFET The gate is connected and outputs a signal. ; The MOS transistor The source of the MOS transistor The source and the MOS transistor Drain connection; The MOS transistor The drain is connected to the power supply; The MOS transistor The source electrode is grounded.
6. The low-power RC oscillator circuit according to claim 1, characterized in that, The power supply structure includes a charging circuit and a power supply circuit; The charging circuit includes resistors, capacitors, and MOSFETs: MOSFET The gate is connected to the power supply circuit, the source is connected to the power supply, and the drain is connected to the ground capacitor. and resistance Connect; connect the MOS transistor With capacitor and the resistor The connected node is denoted as r, and the voltage at node r is denoted as... ; The resistor The other end is connected to the MOSFET Drain connection; The MOS transistor gate and voltage Connection, source grounded; The power supply circuit includes capacitors, MOSFETs, and a current source PTAT. MOSFET The gate of the MOS transistor drain, MOSFET The gate, the current source PTAT, the MOS transistor Gate, MOSFET Gate, MOSFET The gate is connected to the charging circuit, and the source is connected to the power supply; The MOS transistor The source is connected to the power supply, and the drain is connected to the MOSFET. The drain, the chopper circuit, and the MOSFET The source of the MOS transistor is connected, and the MOS transistor is connected to the source of the MOS transistor. The node connected to the chopper circuit is denoted as node p, and the voltage at node p is denoted as... ; The MOS transistor The source is connected to the power supply, and the drain is connected to the MOSFET. Drain connection; The MOS transistor The source is connected to the power supply, and the drain is connected to the chopper circuit and the MOSFET. The source and MOSFET The drain of the MOS transistor is connected; and the MOS transistor is connected. The node connected to the chopper circuit is denoted as node n, and the voltage at node n is denoted as... ; The MOS transistor The source is connected to the power supply, and the drain is connected to the MOS transistor. Drain connection; The other end of the current source PTAT is grounded; The MOS transistor gate voltage ; The MOS transistor gate voltage ; The MOS transistor Gate connection signal Source capacitor connected to ground and MOSFET The drain electrode; The MOS transistor The gate is connected to the signal The source is grounded; The MOS transistor Gate connection signal Source capacitor connected to ground and MOSFET The drain electrode; The MOS transistor Gate connection signal The source electrode is grounded.
7. The low-power RC oscillator circuit according to any one of claims 4 or 6, characterized in that, The current source PTAT consists of a MOSFET and a resistor; MOSFET The gate of the MOS transistor drain, MOSFET drain and MOSFET Gate connection; The MOS transistor The source is connected to the power supply, and the drain is connected to the MOS transistor. Gate, MOSFET Gate and drain and MOSFET Gate connection; The MOS transistor Source grounding resistance ; The MOS transistor The source is grounded; The MOS transistor The source is grounded, and the drain is connected to a 20nA power supply.
8. The low-power RC oscillator circuit according to any one of claims 3 or 6, characterized in that, The voltage The polarity is ; in, This represents the offset voltage of the comparator.
9. The low-power RC oscillator circuit according to claim 1, characterized in that, The RC circuit includes a resistor and an inductor; resistance One end of the resistor is connected to the chopper circuit and the path delay cancellation loop, and the other end is grounded; and the resistor is connected to... The node connected to the chopper circuit and the path delay cancellation loop is denoted as node REF, and the voltage of node REF is denoted as... ; capacitance One end is connected to the resistor The chopper circuit and the path delay cancellation loop are connected, and the other end is grounded.
10. A method of operating a low-power RC oscillator circuit as described in any one of claims 1-9, characterized in that, include: A chopper circuit is used to eliminate the influence of comparator offset; the voltage is changed by periodically switching the voltage at the connection nodes p and v between the power supply structure and the chopper circuit. polarity; Adding the two periods before and after the polarity change cancels out the offset; the oscillation period becomes... ;in, ; Add a secondary comparison path with the same delay as the primary comparison path, and then extract the delay. And feed it back to the main comparison path to charge the capacitor, thereby performing compensation; Output signal When the change occurs, the secondary comparison path operates; the AND gate logic extracts the delay between the output of the secondary comparison path and the output of the primary comparison path. ; Add a charging circuit to generate the replication voltage The input voltage of the secondary comparison path is made the same as the input voltage of the primary comparison path to achieve precise matching, ensuring that the delay of the secondary comparison path is equal to the delay. ; The resistance value of the RC circuit is configured to be equal to the resistance value of the charging circuit, and the capacitance value of the charging circuit is equal to the capacitance value of the power supply circuit.