An adaptive radiation-resistant dynamic high-precision current compensation circuit

Abstract

The present invention discloses an adaptive radiation-resistant dynamic high-precision current compensation circuit, which belongs to the field of semiconductor integrated circuits, and includes a reference current source, a transmission path, a resistor or capacitor network, a total dose radiation effect leakage induction and compensation module, a comparator, and a bidirectional counter; the total dose radiation effect leakage induction and compensation module is added mainly to adopt a circuit-level reinforcement method to solve the problem that the device leaks under the total dose radiation effect, resulting in a large error in the internal reference current transmission matching. The present invention can sense the total radiation dose level under ordinary processes, perform accurate cycle-by-cycle compensation for different degrees of leakage, restore the reference current in the later stage, improve the output accuracy, achieve the purpose of radiation-resistant reinforcement, and can be applied to radiation-resistant ADCs and oscillators.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor integrated circuits, and in particular to an adaptive radiation-resistant dynamic high-precision current compensation circuit. Background Art

[0002] With the continuous development of science and technology, human exploration of space has increased dramatically. From low-orbit satellite link communications, to Chang'e's lunar exploration, to Zhurong's Mars exploration, semiconductor technology plays an extremely important role. Electronic equipment and systems in the field of aerospace need to have sufficient reliability and operating life in the space radiation environment, and should have sufficient radiation resistance, especially as the core control heart of electronic equipment - chips.

[0003] Traditional semiconductor integrated circuit radiation hardening solutions are mostly carried out at the process level (such as SOI process) and layout level (ring gate, guard ring), with the purpose of reducing device leakage current (Ileak) caused by radiation. They rely heavily on the radiation resistance of the process itself, and the radiation resistance process is expensive. Layout hardening directly leads to an increase in chip area and cost. It cannot provide a good reliability model evaluation at the initial circuit level design. It depends entirely on the process and layout to ensure the reliability of the internal circuit in the future when working in a radiation environment. Figure 1 As shown, during the transmission of the reference current, traditional processes and layout reinforcement can only reduce the leakage (Ileak) after radiation, and it cannot be quantified, and the accuracy of the subsequent output cannot be guaranteed. Summary of the invention

[0004] The object of the present invention is to provide an adaptive radiation-resistant dynamic high-precision current compensation circuit to solve the problems in the background technology.

[0005] To solve the above technical problems, the present invention provides an adaptive radiation-resistant dynamic high-precision current compensation circuit, comprising a reference current source, a transmission path, a resistor or capacitor network, a total dose radiation effect leakage induction and compensation module, a comparator, and a bidirectional counter;

[0006] The reference current source is connected to the transmission path, the transmission path is connected to the resistor or capacitor network, the output of the resistor or capacitor network is connected to the positive input terminal of the comparator, the negative input terminal of the comparator is connected to the set reference voltage Vref, the output terminal of the comparator is connected to the up_dn terminal of the bidirectional counter, the clock terminal of the bidirectional counter is connected to Clk, the output terminal of the bidirectional counter is connected to the total dose radiation effect leakage induction and compensation module, and the output terminal of the total dose radiation effect leakage induction and compensation module is connected to the transmission path.

[0007] In one embodiment, the reference current source Iref flows through a resistor or capacitor network to generate a voltage Vrc. Vrc and the set reference voltage Vref are compared by a comparator to generate a logic signal up_dn;

[0008] When Vrc > Vref, the comparator outputs a high-level signal for up_dn. When Vr < Vref, the comparator outputs a low-level signal for up_db. When up_dn is at a high level, the subsequent bidirectional counter starts forward counting +1. Conversely, when up_dn is at a low level, the subsequent bidirectional counter starts reverse counting -1;

[0009] The output of the bidirectional counter is connected to the total dose radiation effect leakage induction and compensation module, which is used to control the output of the compensation current step by step. After radiation, there is leakage in the devices in the circuit. Assuming the leakage is Ileak and the output compensation current of the total dose radiation effect leakage induction and compensation module is Icomp, then the final current on the resistor is Iout = Iref - Ileak + Icomp. If Icomp = Ileak, then Iout = Iref, restoring the reference current Iref.

[0010] In one embodiment, the total dose radiation effect leakage induction and compensation module includes multiple total dose radiation effect leakage induction units; the total dose radiation effect leakage induction unit includes pmos transistors pm1, pm2, and pm3 <x>, pm4, pm5, nmos tube nm1, nm2, Muller_C buffer;

[0011] The source end of nmos tube nm2 is grounded to VSS, the gate end is connected to its own drain end, and the drain end is connected to the source end of nmos tube nm1; the source end of nmos tube nm1 is connected to the drain end of nmos tube nm2, the gate end is floating, and the drain end is connected to nmos tube pm3 <x>The drain end;

[0012] pmos tube pm3 <x>The drain end is connected to the drain end of nmos tube nm1, the gate end is connected to VSS, and the source end is connected to the drain end of pmos tube pm1; the drain end of pmos tube pm1 is connected to pmos tube pm3 <x>The source end of pmos tube pm2 is connected to the power supply VDD, the gate end is connected to the gate end of pmos tube pm1, and the drain end is connected to the source end of pmos tube pm4;

[0013] The source end of the pmos tube pm4 is connected to the drain end of the pmos tube pm2, the gate end is connected to the output end of the Muller_C buffer, and the drain end is connected to the source end of the pmos tube pm5;

[0014] The source end of the pmos tube pm5 is connected to the drain end of the pmos tube pm4, and the gate end is connected to the output end D of the external counter. <x>The drain end is connected to the external transmission path as the compensation current output end of this unit; the input end of the Muller_C buffer is connected to the drain end of the nmos tube nm1, and the output end is connected to the gate end of the pmos tube pm4.

[0015] The present invention provides an adaptive radiation-resistant dynamic high-precision current compensation circuit.

[0016] The advantages of the present invention compared with the prior art are:

[0017] (1) Through the circuit-level reinforcement method, no radiation resistance process and layout reinforcement are required to achieve the restoration of reference current and improve output accuracy;

[0018] (2) Built-in total dose radiation effect sensing unit outputs different compensation currents for different total dose radiations to achieve adaptive regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the traditional reference current transmission path reinforcement method.

[0020] Figure 2 Schematic diagram of the reference current transmission path reinforcement method provided by the present invention.

[0021] Figure 3 FIG. 4 is a block diagram of a circuit system of the present invention.

[0022] Figure 4 Schematic diagram of the state machine of the present invention.

[0023] Figure 5 It is a schematic diagram of the structure of the total dose radiation effect leakage induction and compensation module in the present invention.

[0024] Figure 6 Schematic diagram of the structure of the induction unit in the total dose radiation effect leakage induction and compensation module.

[0025] Figure 7 Schematic diagram of the timing waveform of the present invention. DETAILED DESCRIPTION

[0026] The following is a further detailed description of an adaptive radiation-resistant dynamic high-precision current compensation circuit proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer according to the following description. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0027] The present invention provides an adaptive radiation-resistant dynamic high-precision current compensation circuit. Aiming at the shortcomings of traditional radiation-resistant reinforcement schemes, the present invention starts with a circuit-level total dose radiation effect induction simulation leakage method, such as Figure 2 As shown, it can achieve adaptive total dose radiation effect detection, perform targeted synchronous parameter hardening, and also has a certain effect on single particle radiation.

[0028] Combined with Figure 3 and Figure 4 , the specific working principle is that the reference current Iref flows through the R or C network to generate the voltage Vrc. Vrc and the set reference voltage Vref are compared by a comparator to generate the logic signal up_dn. When Vrc > Vref, the comparator outputs a high-level signal for up_dn. When Vr < Vref, the comparator outputs a low-level signal for up_db. When up_dn is at a high level, the subsequent bidirectional counter starts positive counting +1. Conversely, when up_dn is at a low level, the subsequent bidirectional counter starts negative counting -1. The output of the bidirectional counter (up_dn counter) is connected to the total dose radiation effect leakage induction and compensation module (TID compensation) to control the output of the compensation current step by step. When the system is irradiated, there is leakage in the devices in the circuit. If the reference current Iref passes through these devices and is transmitted to the subsequent stage, it will be inaccurate and there will be errors. Assuming that the leakage current of these devices is Ileak and the output compensation current of the total dose radiation effect leakage induction and compensation module is Icomp, then the final current on the resistor is Iout = Iref - Ileak + Icomp. If Icomp = Ileak, then Iout = Iref, restoring the reference current Iref. The key point of the present invention is to sense radiation leakage and perform corresponding current compensation for different radiation intensities, aiming to make the compensation current equal to the leakage current, restore the reference current, and improve the output accuracy.

[0029] As Figure 5 shown, the total dose radiation effect leakage induction and compensation module includes multiple radiation leakage induction unit arrays, which can well control the fluctuations of each current branch (the maximum current threshold is set for each unit), ensuring the current stability under full radiation (single particle and total dose) conditions. If the digital switch enable control pm5 is not added and linear compensation is used, it is very easy to bring the single particle radiation current spike into the replica current mirror in the full time domain, resulting in a large output error. Of course, in the normal non-irradiated situation, linear compensation is also very easy to bring the noise influence into the subsequent current mirror, causing error changes.

[0030] The structure of the induction unit array in the total dose radiation effect leakage induction and compensation module is as Figure 6 shown, including PMOS transistors pm1 to pm5 and NMOS transistors nm1 to nm2; nm1 and nm2 form the total dose radiation effect leakage induction module RADmodule (radiation detector module), and the output current Ileak <x>The diode connection of nm2 makes its gate-source voltage not 0 (V gs ≠0), under the TID effect, the leakage current is more easily triggered, and the turn-on voltage of the series-connected nm2 is also increased to prevent the gate of nm2 from being suspended in the air, causing nm2 to be turned on by mistake without radiation. The gate area of ​​nm2 can be expanded in the layout to improve its TID effect. Set pm3 <x>Inverted width-to-length ratio, controls the branch current Ilimit <x>, which plays a role in current limiting. In different units, change PM3 <x>Width-to-length ratio, control branch current limiting Ilimit <x>Increase gradually. PM3 of different units <x>Aspect ratio (W / L) pm3<1> , 2(W / L) pm3<2> , 4(W / L) pm3<3> , …, 2 N-1 (W / L) pm3 <n>< / n> pm1 and pm2 form a current mirror transmission. Muller_C buffer can effectively improve the resistance to single particle radiation. Only when the radiation reaches a certain level of intensity, the leakage current Ileak <x>>Ilim <x>The control tube pmos4 will be turned on to prevent false triggering in invalid conditions (no radiation or insufficient radiation intensity). pm5 feedback adjusts the switch tube and connects to external feedback compensation control. Under a certain radiation intensity, and the unit RAD module induction current Ileak <x>>Ilim <x>When the current mirror is used as the compensation current Icomp <x>Output, and is also enabled by the external feedback module.

[0031] like Figure 7 As shown, the up_dn terminal signal controls the enable terminal of the bidirectional counter. When up_dn is high, the bidirectional counter starts counting forward UP, and the output signal gradually increases by +1. For example, if the output of a certain cycle is binary code 001, the output of the next cycle is 010; when up_dn is low, the bidirectional counter starts counting backward DN, and the output signal gradually decreases by -1. For example, if the output of a certain cycle is binary code 011, the output of the next cycle is 010. The lowest bit of the output signal represents the minimum change in the adjustable current, which is one LSB. The above-mentioned output digital signal controls the on and off of the subsequent compensation current switch array pmos to adjust the compensation current. When the adjustment reaches a certain cycle, the up_dn signal alternates between high and low in two adjacent cycles to achieve a dynamic balance, and Vrc always fluctuates slightly above and below the threshold voltage Vref, indicating that the Iout current is near Iref.

[0032] If the total dose effect leakage inductance and compensation module contains N units, it can adjust at most 2 N -1 cycle, all switches are turned off and the corresponding maximum value is recorded as Icomp_max. Then the minimum step size, i.e. one LSB, is:

[0033]

[0034] Different R or C feedback networks can be set. The internal reference current is Iref, and Vref can be determined by the following formula:

[0035] Vref=Iref×RR network

[0036]

[0037] Where T C is the charging time of the current on the capacitor, T C <T Clk ;

[0038] The R network outputs a stable voltage, which is used in ADC; the C network outputs a timing ramp wave, which is used in an oscillator.

[0039] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.< / x> < / x> < / x> < / x> < / x> < / x> < / x> < / x> < / x> < / x> < / x> < / x> < / x> < / x> < / x> < / x>

Claims

1. An adaptive radiation-resistant dynamic high-precision current compensation circuit, characterized in that: It includes a reference current source, a transmission path, a resistor or capacitor network, a total dose radiation effect leakage induction and compensation module, a comparator, and a bidirectional counter; The reference current source is connected to the transmission path. The transmission path is connected to the resistor or capacitor network. The output of the resistor or capacitor network is connected to the positive input terminal of the comparator. The negative input terminal of the comparator is connected to the set reference voltage Vref. The output terminal of the comparator is connected to the up_dn terminal of the bidirectional counter. The clock terminal of the bidirectional counter is connected to Clk. The output terminal of the bidirectional counter is connected to the total dose radiation effect leakage induction and compensation module. The output terminal of the total dose radiation effect leakage induction and compensation module is connected to the transmission path; The total dose radiation effect leakage induction and compensation module includes a plurality of total dose radiation effect leakage induction units; the total dose radiation effect leakage induction unit includes pmos tubes pm1, pm2, pm3 <x>, pm4, pm5, nmos transistors nm1, nm2, Muller_C buffer;< / x> The source end of nmos tube nm2 is grounded to VSS, the gate end is connected to its own drain end, and the drain end is connected to the source end of nmos tube nm1; the source end of nmos tube nm1 is connected to the drain end of nmos tube nm2, the gate end is floating, and the drain end is connected to nmos tube pm3 <x>The drain terminal of;< / x> pmos tube pm3 <x>The drain end is connected to the drain end of nmos tube nm1, the gate end is connected to VSS, and the source end is connected to the drain end of pmos tube pm1; the drain end of pmos tube pm1 is connected to pmos tube pm3 <x>The source terminal of, the gate terminal is connected to its own drain terminal, and the source terminal is connected to the power supply VDD; The source terminal of pmos transistor pm2 is connected to the power supply VDD, the gate terminal is connected to the gate terminal of pmos transistor pm1, and the drain terminal is connected to the source terminal of pmos transistor pm4;< / x> < / x> The source terminal of pmos transistor pm4 is connected to the drain terminal of pmos transistor pm2, the gate terminal is connected to the output terminal of the Muller_C buffer, and the drain terminal is connected to the source terminal of pmos transistor pm5; The source end of the pmos tube pm5 is connected to the drain end of the pmos tube pm4, and the gate end is connected to the output end D of the external counter. <x>, the drain terminal is connected to the external transmission path and serves as the output terminal of the compensation current of this unit; The input terminal of the Muller_C buffer is connected to the drain terminal of nmos transistor nm1, and the output terminal is connected to the gate terminal of pmos transistor pm4.< / x> 2. The adaptive radiation-resistant dynamic high-precision current compensation circuit according to claim 1, characterized in that: The reference current source Iref flows through the resistor or capacitor network to generate a voltage Vrc. Vrc and the set reference voltage Vref are compared by the comparator to generate a logic signal up_dn; When Vrc > Vref, the comparator outputs a high-level signal for up_dn. When Vr < Vref, the comparator outputs a low-level signal for up_db; When up_dn is at a high level, the subsequent bidirectional counter starts forward counting +1. On the contrary, when up_dn is at a low level, the subsequent bidirectional counter starts reverse counting -1; The output of the bidirectional counter is connected to the total dose radiation effect leakage induction and compensation module to control the output of the compensation current step by step; After radiation, there is leakage in the devices in the circuit. Assuming the leakage is Ileak and the output compensation current added to the total dose radiation effect leakage induction and compensation module is Icomp, then the final current on the resistor is Iout = Iref - Ileak + Icomp. When Icomp = Ileak, then Iout = Iref, restoring the reference current Iref.

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