An automated simulation method for single-event effects in bipolar bandgap reference circuits

Abstract

The present invention discloses an automated simulation method for single-particle effects in a bipolar bandgap reference circuit, comprising: S1, analyzing a circuit netlist file to extract transistor names and node information; S2, performing DC characteristic simulation on the circuit to obtain the DC operating point of each transistor and determine the type of each transistor; S3, establishing a transistor model, performing transistor-level single-particle effect simulation, and obtaining transistor-level single-particle effect simulation results; S4, establishing a transient pulse waveform database and a peak value database; S5, screening to obtain sensitive transistors; S6, selecting a sensitive transistor and extracting its corresponding transient pulse data; S7, modifying the circuit netlist file and performing circuit-level single-particle transient characteristic simulation to obtain transient characteristic simulation result data; S8, repeating steps S6 and S7 to obtain transient characteristic simulation result data corresponding to all sensitive transistors. The present invention achieves the location of weak links in the effects of analog devices.

Description

Technical Field

[0001] The invention belongs to the field of aerospace technology, and in particular relates to an automatic simulation method for single-particle effects of a bipolar bandgap reference circuit. Background Art

[0002] In analog integrated circuits, bandgap reference structures are used to provide a temperature-independent bias voltage for the circuits and are a fundamental building block of analog integrated circuits. They are widely used in common electronic products such as low-dropout (LDO) and phase-locked loop (PLL) circuits, analog-to-digital converters (A / Ds), digital-to-analog converters (D / As), and switching power converters. The accuracy and anti-interference capabilities of the reference source undoubtedly impact the performance of these products.

[0003] As integrated circuit feature sizes continue to shrink, single-event effects (SEEs) are increasingly becoming a major factor affecting the operating state of space-based integrated circuits. Single-event transients have become the primary source of soft errors in integrated circuits. As analog integrated circuits become increasingly precise and faster, even small voltage disturbances can significantly impact analog circuits, potentially causing system malfunction. Analog circuits are highly sensitive to the noise and disturbances introduced by SEEs. Of all SEEs in analog integrated circuits, the SET effect is the most critical to analyze and mitigate.

[0004] Common methods for analyzing circuit radiation characteristics include experiments and simulations. However, due to the high cost and extremely limited machine time associated with radiation experiments, they are not widely used. Circuit-level simulation is a better option before final experimental verification. A common approach involves modeling device-level single-event transient pulses, injecting them into circuit nodes for simulation. Based on the simulation results, the impact of single-event effects on circuit characteristics is analyzed, and sensitive nodes in the circuit are identified. Based on this, single-event hardening designs are then implemented for these sensitive nodes to improve the circuit's radiation resistance.

[0005] For large-scale circuits, all circuit nodes must be traversed when searching for sensitive nodes. This is very time-consuming and consumes a lot of computer resources. Even with automated traversal simulation methods, it is difficult to escape the huge workload. Therefore, by using certain methods to preliminarily screen sensitive nodes before traversal, the simulation time and computer resource consumption can be greatly reduced. Summary of the Invention

[0006] The technology of the present invention solves the problem: overcoming the deficiencies of the prior art, providing an automated simulation method for single-particle effects of a bipolar bandgap reference circuit, aiming to locate weak links in the effects of analog devices.

[0007] In order to solve the above technical problems, the present invention discloses an automated simulation method for single event effects of a bipolar bandgap reference circuit, comprising:

[0008] S1, for the determined bandgap reference circuit, analyzing the circuit netlist file and extracting transistor names and node information in the bandgap reference circuit;

[0009] S2, performing a DC characteristic simulation on the bandgap reference circuit based on the extracted transistor names and node information in the bandgap reference circuit, obtaining a DC operating point of each transistor in the bandgap reference circuit, and determining the type of each transistor;

[0010] S3, establishing a transistor model according to the type of transistor used in the determined bandgap reference circuit, and performing a transistor-level single-event effect simulation to obtain a transistor-level single-event effect simulation result;

[0011] S4, based on the transistor-level single-event effect simulation results, establish a transient pulse waveform database and a peak value database;

[0012] S5, based on the peak database, screen and determine the sensitive transistors in the bandgap reference circuit;

[0013] S6, selecting one of the sensitive transistors, and extracting transient pulse data corresponding to the one of the sensitive transistors based on a transient pulse waveform database;

[0014] S7, based on the extracted transient pulse data corresponding to one of the sensitive transistors, modifying the circuit netlist file, and performing circuit-level single-particle transient characteristic simulation to obtain transient characteristic simulation result data corresponding to one of the sensitive transistors;

[0015] S8, repeating the above steps S6 to S7 to obtain transient characteristic simulation result data corresponding to all sensitive transistors.

[0016] In the above-mentioned method for automatic simulation of single event effects of a bipolar bandgap reference circuit, in step S2 , a direct current characteristic simulation of the bandgap reference circuit is performed using SPICE simulation software.

[0017] In the above-mentioned automated SEP simulation method for a bipolar bandgap reference circuit, a transistor model is established based on the type of transistor used in the determined bandgap reference circuit, and a transistor-level SEP simulation is performed to obtain transistor-level SEP simulation results, including:

[0018] According to the type of transistor used in the determined bandgap reference circuit, the transistor model is established using the sde module in the TCAD 3D simulation software and the characteristics are calibrated.

[0019] In the TCAD 3D simulation software, sdevice is used to simulate the single-particle effect at the tube level. The parameters of heavy ions that can penetrate the device are selected to obtain the single-particle effect simulation results at the transistor level, that is, the transient pulse waveform of each transistor under different collector junction reverse bias voltages.

[0020] In the above-mentioned single event effect automated simulation method of the bipolar bandgap reference circuit, the heavy ion parameters include: LET and range; where LET = 37.4 MeV·cm 2 / mg, and the range is 30μm.

[0021] In the above-mentioned automatic simulation method for single-event effects of a bipolar bandgap reference circuit, a transient pulse waveform database and a peak value database are established based on the transistor-level single-event effects simulation results, including:

[0022] Based on the transistor-level single-event effect simulation results, a transient pulse waveform database is established;

[0023] The peak value of the transient pulse waveform is extracted from the established transient pulse waveform database to establish a peak value database.

[0024] In the above-mentioned automated simulation method for single-event effects of a bipolar bandgap reference circuit, sensitive transistors in the bandgap reference circuit are screened and determined based on a peak database, including:

[0025] According to the DC operating point of each transistor in the bandgap reference circuit, the transient current peak value I corresponding to each transistor is obtained from the peak database. max ;

[0026] In the bandgap reference circuit, the collector of each transistor introduces the transient current peak value I corresponding to each transistor. max Based on the circuit structure, the maximum value of the change in the amount of change along its propagation link to the output end is calculated. ref ;

[0027] If the maximum value of the change in the amount of current transistor reaching the output along its propagation link is ΔV ref If the value is greater than the set threshold, the current transistor is determined to be a sensitive transistor.

[0028] In the above-mentioned single event effect automatic simulation method of the bipolar bandgap reference circuit, the threshold is set to 0.1V.

[0029] In the above-mentioned method for automatically simulating single-event effects of a bipolar bandgap reference circuit, selecting one of the sensitive transistors and extracting transient pulse data corresponding to the one of the sensitive transistors based on a transient pulse waveform database include:

[0030] One of the sensitive transistors is selected, and transient pulse data corresponding to the one of the sensitive transistors is extracted from a transient pulse waveform database according to a DC operating point of the one of the sensitive transistors.

[0031] In the above-mentioned method for automating the single-event effect simulation of the bipolar bandgap reference circuit, based on the extracted transient pulse data corresponding to one of the sensitive transistors, the circuit netlist file is modified, and a circuit-level single-event transient characteristic simulation is performed to obtain transient characteristic simulation result data corresponding to the one of the sensitive transistors, including:

[0032] Establishing the extracted transient pulse data corresponding to one of the sensitive transistors as a single particle transient current source module;

[0033] Modify the circuit netlist and inject the established single-particle transient current source module into the collector node corresponding to one of the sensitive transistors; use SPICE simulation software to perform circuit-level single-particle transient characteristic simulation and save the simulation results in a log file;

[0034] Extract the transient characteristic simulation result data corresponding to one of the sensitive transistors from the log file.

[0035] The above-mentioned automatic simulation method for single-event effects of a bipolar bandgap reference circuit further includes: S9, extracting and comparing transient waveform peaks of the obtained transient characteristic simulation result data corresponding to all sensitive transistors, and outputting the most sensitive transistor of the bandgap reference circuit.

[0036] The present invention has the following advantages:

[0037] (1) The present invention discloses an automated simulation method for single-particle effects in a bipolar bandgap reference circuit. By preliminarily screening sensitive transistors, the number of transistors that need to be traversed during the actual simulation process is effectively reduced. Compared with the traditional fault injection method that traverses all transistors in the circuit, the simulation time and storage space are effectively reduced, and the efficiency of the circuit-level single-particle transient effect simulation analysis method is greatly improved.

[0038] (2) The present invention discloses an automated simulation method for single-particle effects of a bipolar bandgap reference circuit, which can be used for the anti-single-particle effect design of different types of analog devices and some mixed digital-analog devices, including DC / DC, LDO, analog switch, analog comparator, operational amplifier, reference source, digital-to-analog converter and other analog devices, overcoming the difficulty of the previous simulation methods not being universal.

[0039] (3) The present invention discloses an automated simulation method for single-particle effects of a bipolar bandgap reference circuit, which can be used to replace the heavy ion single-particle effect test. The heavy ion single-particle effect test cannot accurately locate the weak link of the device to a certain transistor due to its large beam spot area. The present invention can overcome this problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a flow chart of a method for automated simulation of single event effects in a bipolar bandgap reference circuit according to an embodiment of the present invention;

[0041] Figure 2 This is a bandgap reference voltage startup simulation diagram in an embodiment of the present invention;

[0042] Figure 3 Schematic diagram of four transistors selected from a bandgap reference source circuit in an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of output voltage variation caused by a single-particle transient effect of transistor Q1 in an embodiment of the present invention;

[0044] Figure 5 Schematic diagram of output voltage variation caused by a single-particle transient effect of transistor Q2 in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be described in further detail below with reference to the accompanying drawings.

[0046] One of the core ideas of the present invention is to provide an automated simulation method for single-particle effects of a bipolar bandgap reference circuit. For a determined bandgap reference circuit, the circuit netlist file is analyzed to extract the transistor names and node information therein, and the SPICE simulator is controlled to simulate the DC characteristics of the circuit to obtain the DC operating point of each transistor. The transistor to be studied is selected, and the single-particle transient waveform is adjusted according to its bias state. The output voltage change ΔV is calculated using the single-particle transient pulse peak value. ref Through simplified calculation, the maximum offset of the reference voltage is obtained. The screening criteria of the sensitive transistors are determined according to the specific application scenario. Based on this, the screened sensitive transistors are obtained. Then, the Python program is used to control the simulator to perform automatic simulation of single-particle transient effects on the screened transistors. Finally, the waveform is output to obtain the sensitive transistor situation of the entire circuit.

[0047] Reference Figure 1 In this embodiment, the method for automatically simulating single event effects of a bipolar bandgap reference circuit includes:

[0048] S1, for the determined bandgap reference circuit, analyzing the circuit netlist file, and extracting transistor names and node information in the bandgap reference circuit.

[0049] S2, performing a DC characteristic simulation on the bandgap reference circuit according to the extracted transistor names and node information in the bandgap reference circuit, obtaining a DC operating point of each transistor in the bandgap reference circuit, and determining the type of each transistor.

[0050] In this embodiment, SPICE simulation software may be used to simulate the DC characteristics of the bandgap reference circuit.

[0051] S3, establishing a transistor model according to the type of transistor used in the determined bandgap reference circuit, and performing a transistor-level single-particle effect simulation to obtain a transistor-level single-particle effect simulation result.

[0052] In this embodiment, first, based on the type of transistor used in the determined bandgap reference circuit, a transistor model is established using the sde module in TCAD 3D simulation software, and characteristic calibration is performed. Then, a transistor-level single-particle effect simulation is performed using sdevice in TCAD 3D simulation software, and heavy ion parameters that can penetrate the device are selected to obtain transistor-level single-particle effect simulation results, namely, the transient pulse waveforms of each transistor under different collector junction reverse bias voltages. The heavy ion parameters mainly include: LET and range; preferably, LET = 37.4 MeV·cm 2 / mg, and the range is 30μm.

[0053] S4. Based on the transistor-level single-particle effect simulation results, a transient pulse waveform database and a peak value database are established.

[0054] In this embodiment, first, a transient pulse waveform database is established based on transistor-level single-particle effect simulation results; then, the peak values ​​of the transient pulse waveforms are extracted from the established transient pulse waveform database to establish a peak value database.

[0055] S5, based on the peak database, screen and determine the sensitive transistors in the bandgap reference circuit.

[0056] In this embodiment, first, according to the DC operating point of each transistor in the bandgap reference circuit, the transient current peak value I corresponding to each transistor is obtained from the peak database. max Then, the transient current peak value I corresponding to each transistor is introduced into the collector of each transistor in the bandgap reference circuit. max Based on the circuit structure, the maximum value of the change in the amount of change along its propagation link to the output end is calculated. ref ; Further, ΔV refCompared with the set threshold, if the maximum value of the change in the current transistor along its propagation link to the output terminal is ΔV ref If the voltage is greater than a set threshold, the current transistor is determined to be a sensitive transistor. Preferably, the set threshold is 0.1V.

[0057] S6, selecting one of the sensitive transistors, and extracting transient pulse data corresponding to the one of the sensitive transistors based on a transient pulse waveform database.

[0058] In this embodiment, one of the sensitive transistors is selected, and transient pulse data corresponding to the one of the sensitive transistors is extracted from a transient pulse waveform database according to the DC operating point of the one of the sensitive transistors.

[0059] S7, based on the extracted transient pulse data corresponding to one of the sensitive transistors, modify the circuit netlist file, and perform circuit-level single-particle transient characteristic simulation to obtain transient characteristic simulation result data corresponding to one of the sensitive transistors.

[0060] In this embodiment, first, the extracted transient pulse data corresponding to one of the sensitive transistors is established as a single-particle transient current source module; then, the circuit netlist is modified, and the established single-particle transient current source module is injected into the collector node corresponding to one of the sensitive transistors; circuit-level single-particle transient characteristic simulation is performed using SPICE simulation software, and the simulation results are saved in a log file; finally, the transient characteristic simulation result data corresponding to one of the sensitive transistors is extracted from the log file.

[0061] S8, repeating the above steps S6 to S7 to obtain transient characteristic simulation result data corresponding to all sensitive transistors.

[0062] S9, extracting and comparing the transient waveform peaks of the obtained transient characteristic simulation result data corresponding to all sensitive transistors, and outputting the most sensitive transistor of the bandgap reference circuit.

[0063] As can be seen from the above, the automatic simulation method for single event effects of a bipolar bandgap reference circuit according to the embodiment of the present invention mainly includes the following aspects:

[0064] Circuit netlist simulation: mainly realizes the basic principles of circuits.

[0065] Sensitive node screening: It mainly calculates the change in the final node of the circuit caused by the single-particle transient of all transistors, and obtains the transistor whose maximum change is greater than the specified threshold.

[0066] Circuit single-particle transient characteristics simulation: Based on TCAD simulation, the single-particle effect transient response of the transistor is obtained. A transient current transient response model is established using Verilog-A. This transient current response model is added to the sensitive transistor in the circuit and simulation is performed.

[0067] Data analysis and processing: Based on the circuit single-particle transient characteristics simulation results, calculate the impact of different transistors on the final circuit output change.

[0068] Based on the above embodiment, a specific example is provided for explanation.

[0069] Example 1

[0070] Taking a bipolar bandgap reference source circuit as an example, the SPICE simulation software is used to simulate the circuit's conventional characteristics, and the output reference voltage is 1.31V. Figure 2 As shown, the four transistors selected are as follows Figure 3 shown.

[0071] According to the bias states of the four selected transistors and based on the double-exponential current pulse model, the appropriate single-particle transient pulse is selected and its peak value is taken for subsequent calculations.

[0072] For each selected transistor, a transient pulse peak is introduced at its collector, and the maximum output variation ΔV along its propagation link is calculated based on this circuit structure. ref .in:

[0073] The maximum output change ΔV caused by the single-particle transient of transistor Q1 ref(Q1) for:

[0074]

[0075] The maximum output change ΔV caused by the single-particle transient of transistor Q2 ref(Q2) for:

[0076] ΔV ref(Q2) =-I max R4G m4 R2

[0077] The maximum output change ΔV caused by the single-particle transient of transistor Q3 ref(Q3) for:

[0078]

[0079] The maximum output change ΔV caused by the single-particle transient of transistor Q4 ref(Q4) for:

[0080] ΔV ref(Q4) =Imax R2

[0081] Among them, R1~R5 represent the resistance values ​​of resistors R1~R5 respectively, r o,Q2 represents the output resistance of transistor Q2, g m3 represents the transconductance of transistor 3, g m4 represents the transconductance of transistor 4, I max Indicates the maximum current.

[0082] Substitute the numerical value: ΔV ref(Q1) =0.903V, ΔV ref(Q2) =0.24V, ΔV ref(Q3) =0.068V, ΔV ref(Q4) =0.068V.

[0083] Since this circuit is a bandgap reference circuit, ΔV ref Transistors with a voltage >0.1V are sensitive transistors. Therefore, the sensitive transistors screened out by this circuit are transistors Q1 and Q2.

[0084] Based on Python and SPICE simulation software, the single-particle transient effect is automatically simulated. The single-particle transient waveform at the circuit output caused by transistor Q1 and transistor Q2 is as follows Figures 4-5 As shown, it can be seen that the most sensitive transistor of the bandgap reference circuit is transistor Q1.

[0085] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solutions of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the scope of protection of the technical solutions of the present invention.

[0086] The contents not described in detail in the specification of the present invention belong to the common knowledge of professionals in this field.

Claims

1. A method for simulating single event effects in a bipolar bandgap reference circuit, characterized in that: include: S1, for the determined bandgap reference circuit, analyzing the circuit netlist file and extracting transistor names and node information in the bandgap reference circuit; S2, performing a DC characteristic simulation on the bandgap reference circuit based on the extracted transistor names and node information in the bandgap reference circuit, obtaining a DC operating point of each transistor in the bandgap reference circuit, and determining the type of each transistor; S3, establishing a transistor model according to the type of transistor used in the determined bandgap reference circuit, and performing a transistor-level single-event effect simulation to obtain a transistor-level single-event effect simulation result; S4, based on the transistor-level single-event effect simulation results, establish a transient pulse waveform database and a peak value database; S5, based on the peak database, screen and determine the sensitive transistors in the bandgap reference circuit; S6, selecting one of the sensitive transistors, and extracting transient pulse data corresponding to the one of the sensitive transistors based on a transient pulse waveform database; S7, based on the extracted transient pulse data corresponding to one of the sensitive transistors, modifying the circuit netlist file, and performing circuit-level single-particle transient characteristic simulation to obtain transient characteristic simulation result data corresponding to one of the sensitive transistors; S8, repeating the above steps S6 to S7 to obtain transient characteristic simulation result data corresponding to all sensitive transistors.

2. The method for automated simulation of single event effects of a bipolar bandgap reference circuit according to claim 1, wherein: In step S2, a SPICE simulation software is used to simulate the direct current characteristics of the bandgap reference circuit.

3. The method for automated simulation of single event effects of a bipolar bandgap reference circuit according to claim 1, wherein: Based on the type of transistor used in the determined bandgap reference circuit, a transistor model is established and a transistor-level single-particle effect simulation is performed to obtain transistor-level single-particle effect simulation results, including: According to the type of transistor used in the determined bandgap reference circuit, the transistor model is established using the sde module in the TCAD 3D simulation software and the characteristics are calibrated. In the TCAD 3D simulation software, sdevice is used to simulate the single-particle effect at the tube level. The parameters of heavy ions that can penetrate the device are selected to obtain the single-particle effect simulation results at the transistor level, that is, the transient pulse waveform of each transistor under different collector junction reverse bias voltages.

4. The method for automated simulation of single event effects of a bipolar bandgap reference circuit according to claim 3, wherein: Heavy ion parameters, including LET and range; where LET = 37.4 MeV·cm 2 / mg, and the range is 30μm.

5. The method for automated simulation of single event effects of a bipolar bandgap reference circuit according to claim 1, wherein: Based on the transistor-level single-event effect simulation results, a transient pulse waveform database and a peak value database are established, including: Based on the transistor-level single-event effect simulation results, a transient pulse waveform database is established; The peak value of the transient pulse waveform is extracted from the established transient pulse waveform database to establish a peak value database.

6. The method for automated simulation of single event effects of a bipolar bandgap reference circuit according to claim 1, wherein: Based on the peak database, sensitive transistors in the bandgap reference circuit are screened and identified, including: According to the DC operating point of each transistor in the bandgap reference circuit, the transient current peak value I corresponding to each transistor is obtained from the peak database. max ; In the bandgap reference circuit, the collector of each transistor introduces the transient current peak value I corresponding to each transistor. max Based on the circuit structure, the maximum value of the change in the amount of change along its propagation link to the output end is calculated. ref ; If the maximum value of the change in the amount of current transistor reaching the output along its propagation link is ΔV ref If the value is greater than the set threshold, the current transistor is determined to be a sensitive transistor.

7. The method for automated simulation of single event effects of a bipolar bandgap reference circuit according to claim 6, wherein: Set the threshold to 0.1V.

8. The method for automated simulation of single event effects of a bipolar bandgap reference circuit according to claim 1, wherein: Selecting one of the sensitive transistors and extracting transient pulse data corresponding to the one of the sensitive transistors based on a transient pulse waveform database, including: One of the sensitive transistors is selected, and transient pulse data corresponding to the one of the sensitive transistors is extracted from a transient pulse waveform database according to a DC operating point of the one of the sensitive transistors.

9. The method for automated simulation of single event effects of a bipolar bandgap reference circuit according to claim 1, wherein: Based on the extracted transient pulse data corresponding to one of the sensitive transistors, the circuit netlist file is modified, and a circuit-level single-particle transient characteristic simulation is performed to obtain transient characteristic simulation result data corresponding to one of the sensitive transistors, including: Establishing the extracted transient pulse data corresponding to one of the sensitive transistors as a single particle transient current source module; Modify the circuit netlist and inject the established single-particle transient current source module into the collector node corresponding to one of the sensitive transistors; use SPICE simulation software to perform circuit-level single-particle transient characteristic simulation and save the simulation results in a log file; Extract the transient characteristic simulation result data corresponding to one of the sensitive transistors from the log file.

10. The method for automated simulation of single event effects of a bipolar bandgap reference circuit according to claim 1, wherein: Also includes: S9, extracting and comparing the transient waveform peaks of the obtained transient characteristic simulation result data corresponding to all sensitive transistors, and outputting the most sensitive transistor of the bandgap reference circuit.

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