CN113708747B - Controlled switch switching circuit and switching device - Google Patents
Controlled switch switching circuit and switching device Download PDFInfo
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- CN113708747B CN113708747B CN202111260804.1A CN202111260804A CN113708747B CN 113708747 B CN113708747 B CN 113708747B CN 202111260804 A CN202111260804 A CN 202111260804A CN 113708747 B CN113708747 B CN 113708747B
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/04—Modifications for accelerating switching
- H03K17/041—Modifications for accelerating switching without feedback from the output circuit to the control circuit
- H03K17/04106—Modifications for accelerating switching without feedback from the output circuit to the control circuit in field-effect transistor switches
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
- H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
- H03K17/687—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being field-effect transistors
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Abstract
The invention provides a controlled switch switching circuit and a switching device; the circuit comprises: the first enabling signal receiving end is used for receiving a first enabling signal of the negative pressure module; the control output end is used for being connected with a controlled end of a controlled switch in the negative pressure module; the second control assembly is configured to: outputting a first voltage when the first enable signal is enabled and outputting a second voltage when the first enable signal is disabled, the first voltage being a ground voltage, the second voltage being to be gradually increased from a negative voltage value to the ground voltage; the difference value between the negative pressure value and the output voltage of the negative pressure module is smaller than a preset threshold value; the first control assembly is configured to: when the first enable signal is enabled, a first control signal is output to control the controlled switch to be switched off, and when the first enable signal is disabled, a second control signal is output to control the controlled switch to be switched on.
Description
Technical Field
The invention relates to the technical field of electronics, in particular to a controlled switch switching circuit and a switch device.
Background
Negative voltage is often used in integrated circuit systems, for example, a switch in an rf front end needs to be turned on or off by the negative voltage. The negative voltage module structure in the related art can be as shown in fig. 1, and the operation principle is that before the enable signal (EN) is asserted, the switches S1a and S2 are closed, the switch S1b is opened, and at this time, the capacitor C is precharged by the power supply NVDD, wherein the switches S1a, S1b and S2 are controlled by the enable signal EN, and after the enable signal EN is asserted, the switches S1a and S2 are opened, and the switch S1b is closed. When the switch S1B is closed, the capacitor VNEG _ B which is originally positively charged is pulled to the ground level, and the charge stored in the capacitor C cannot suddenly change, so that the VNEG end is changed from the original ground level to the negative level, and meanwhile, the enable signal EN enables the negative voltage generation module NVG core to start working, continuously provides charge for the VNEG end, and keeps the VNEG end outputting the negative level.
A schematic diagram of a conventional controlled switch S2 in the negative pressure module is shown in fig. 2. Under the condition that the load driven by the VNEG end is heavy when the negative pressure module works, when the enable signal fails, the power can flow back to the NVDD through the switch S1a in FIG. 1 because S2 cannot be closed in time. When the enable signal EN fails, a waveform schematic diagram of each node of a conventional controlled switch switching circuit in the negative voltage module is shown in fig. 3, and the phenomenon becomes more obvious as a load driven by VNEG is heavier, the NVDD level is raised by the backward-flowing current, the NVDD generation circuit is affected, the overvoltage risk exists, and meanwhile, the circuit module using the NVDD in the whole system is likely to be affected by the raised NVDD.
Disclosure of Invention
The embodiment of the invention provides a controlled switch switching circuit and a switch device. The technical scheme of the embodiment of the invention is realized as follows:
the embodiment of the invention provides a controlled switch switching circuit, which is applied to a negative pressure module and comprises the following components:
a first enable signal receiving end, configured to receive a first enable signal of the negative pressure module, where the first enable signal indicates the negative pressure module to output a negative pressure signal;
the control output end is used for being connected with a controlled end of a controlled switch in the negative pressure module; the controlled switch is connected between the output end of the negative pressure module and the grounding point;
enabling a control assembly comprising: the first controlled end of the first control assembly is connected with the first enabling signal receiving end, and the second controlled end of the first control assembly is connected with the second control assembly; the output end of the first control component is connected with the control output end;
the second control assembly is configured to: outputting a first voltage when the first enable signal is enabled and outputting a second voltage when the first enable signal is disabled, wherein the first voltage is higher than the voltage at the output end of the negative module, and the second voltage is lower than or equal to the voltage at the output end of the negative module;
the first control assembly is configured to: when the first enable signal is enabled and the output voltage of the second control component is higher than the output voltage of the negative pressure module, outputting a first control signal, and when the first enable signal fails and the output voltage of the second control component is lower than or equal to the output voltage of the negative pressure module, outputting a second control signal; the first control signal can control the controlled switch to be switched off, and the second control signal can control the controlled switch to be switched on.
The embodiment of the present invention further provides a switch device, which is applied to a negative pressure module, and includes:
the controlled switch is used for controlling the negative pressure signal output of the negative pressure module; the first end of the controlled switch is connected with the output end of the negative pressure module, and the second end of the controlled switch is grounded;
the controlled switch switching circuit provided in any one of the embodiments above, connected to the controlled terminal of the controlled switch, and configured to control the controlled switch to be turned off when the first enable signal is enabled, and to be turned on when the first enable signal is disabled; wherein the first enable signal is used for instructing the negative pressure module to output a negative pressure signal.
Controlled switch in traditional negative pressure module under the condition that the negative pressure output end is driving the heavy load, the switch switches untimely, and electric capacity among the negative pressure module overcharges, will lead to the switch to appear after the switching that the electric current flows backward and makes the power level be raised in the power to cause the influence and have the excessive pressure risk to power generation circuit. According to the embodiment of the invention, when the enable signal of the negative pressure module fails, the second control assembly outputs the second voltage to the first control assembly, so that the first control assembly can timely output the second control signal for conducting the controlled switch, and the state switching of the controlled switch is timely realized, thereby avoiding the phenomenon of current backflow, protecting the circuit module from being influenced by the raised power supply, protecting the circuit under the power supply domain, avoiding the risk of overvoltage, improving the stability and safety of the circuit, and improving the working performance of the negative pressure module.
Drawings
Fig. 1 is a schematic structural diagram of a negative pressure module provided in an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a conventional controlled switch S2 in the negative pressure module according to an embodiment of the present invention;
fig. 3 is a schematic waveform diagram of nodes of a switching circuit of a conventional controlled switch in a negative voltage module according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of a controlled switch switching circuit according to an embodiment of the present invention;
FIG. 5 is a schematic structural diagram of a switching device provided in an embodiment of the present invention;
fig. 6 is a schematic circuit diagram of a controlled switching device according to an embodiment of the present invention;
fig. 7 is a schematic waveform diagram of each node of a controlled switch switching circuit in a negative voltage module when an enable signal EN fails according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail with reference to the accompanying drawings, the described embodiments should not be construed as limiting the present invention, and all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
In the following description, reference is made to "some embodiments" which describe a subset of all possible embodiments, but it is understood that "some embodiments" may be the same subset or different subsets of all possible embodiments, and may be combined with each other without conflict.
In the following description, references to the terms "first \ second \ third" are only to distinguish similar objects and do not denote a particular order, but rather the terms "first \ second \ third" are used to interchange specific orders or sequences, where appropriate, to enable embodiments of the invention described herein to be practiced in other than the order shown or described herein.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing embodiments of the invention only and is not intended to be limiting of the invention.
The following describes a controlled switch switching circuit provided by an embodiment of the present invention. Referring to fig. 4, fig. 4 is a schematic structural diagram of a controlled switch switching circuit according to an embodiment of the present invention.
In some embodiments, the controlled switch switching circuit can be applied to a negative module having a structure as shown in fig. 1. The negative pressure module is a device capable of outputting negative pressure. After the first enabling signal of the negative pressure module is enabled, the negative pressure module outputs negative pressure, and after the first enabling signal of the negative pressure module is disabled, the negative pressure module stops outputting negative pressure.
The controlled switch switching circuit 400 provided by the embodiment of the present invention includes:
a first enable signal receiving end 410, configured to receive a first enable signal of the negative pressure module, where the first enable signal indicates that the negative pressure module outputs a negative pressure signal;
a control output terminal 440, configured to be connected to a controlled terminal of a controlled switch in the negative pressure module; the controlled switch is connected between the output end of the negative pressure module and the grounding point;
a first control component 420 and a second control component 430, wherein a first controlled end 4201 of the first control component is connected to the first enable signal receiving end 410, and a second controlled end 4202 of the first control component 420 is connected to the second control component 430; the output 4203 of the first control component 420 is connected to the control output 440;
the second control assembly 430 is configured to: outputting a first voltage when the first enable signal is enabled and outputting a second voltage when the first enable signal is disabled, wherein the first voltage is a ground voltage and the second voltage is gradually increased from a negative voltage value to the ground voltage; the difference value between the negative pressure value and the output voltage of the negative pressure module is smaller than a preset threshold value; in one embodiment, the negative voltage value is similar to the negative module output voltage value, and the preset threshold value does not exceed 0.3V.
The first control component 420 is configured to: outputting a first control signal when the first enable signal is enabled and the output voltage of the second control element 430 is a first voltage, and outputting a second control signal when the first enable signal is disabled and the output voltage of the second control element 430 is a second voltage; the first control signal can control the controlled switch to be switched off, and the second control signal can control the controlled switch to be switched on.
In an embodiment, the controlled switch controlled by the controlled switch switching circuit of this embodiment is a controlled switching device, including but not limited to a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) and an Insulated Gate Bipolar Transistor (IGBT).
In one embodiment, the voltage of the first enable signal is a ground voltage, and the first enable signal is disabled; the voltage of the first enable signal is a first power supply voltage, and the first enable signal is enabled. The ground voltage is lower than the first power supply voltage.
When the first enable signal is enabled, the voltage value of the first enable signal is changed from the ground voltage to the first power voltage, the second control component outputs the first voltage, and the first control component is controlled by the first voltage and the first enable signal to output a first control signal capable of controlling the controlled switch to be turned off.
When the first enable signal fails, the voltage value of the first enable signal is changed from the first power supply voltage to the ground voltage, the second control component outputs the second voltage, and the first control component is controlled by the second voltage and the first enable signal to output a second control signal capable of controlling the controlled switch to be conducted.
In this embodiment, when the first enable signal changes, the second control component outputs different voltage values, so that when the first enable signal fails, the voltage value of the signal output by the first control component is not interfered by the negative voltage at the output end of the negative voltage module, and the controlled switch can be controlled to be closed timely.
In the embodiment of the invention, when the enable signal of the negative pressure module fails, the second control component outputs the second voltage to the first control component, the second voltage is gradually recovered to the ground voltage from the voltage value close to the output voltage of the negative pressure module, so that the first control component can timely output the second control signal for switching off the controlled switch, the state switching of the controlled switch is timely realized, the phenomenon that the capacitor in the negative pressure module is overcharged due to untimely switch switching under the condition that the negative pressure output end of the controlled switch in the traditional negative pressure module drives a large load, the current is back-poured into the power supply after the switch switching and the power supply level is raised is avoided, the circuit module is protected from being influenced by the raised power supply, meanwhile, the circuit in the power supply domain is protected from generating overvoltage risk, and the stability and the safety of the circuit are improved, the working performance of the negative pressure module is improved.
In some embodiments, the first control assembly comprises: a first output path and a second output path; the controlled end of the first output path is the first controlled end, and the controlled end of the second output path is the second controlled end;
the input end of the first output path is connected with a first power supply, and the output end of the first output path is connected with the control output end; the input end of the second output path is connected with the output end of the negative pressure module, and the output end of the second output path is connected with the control output end;
when the first enable signal is enabled, the voltage value of the first enable signal is the first power voltage, the second control component outputs a first voltage, the first output path is cut off, and the second output path is conducted and outputs the first control signal;
when the first enable signal fails, the voltage value of the first enable signal is the ground voltage, the second control component outputs a second voltage, the second output path is cut off, and the first output path is conducted and outputs the second control signal.
In one embodiment, the first control component is controlled by the first enable signal and the output signal of the second control component. When the first enable signal is enabled, the second control assembly outputs a first voltage, the first output path of the first control assembly is cut off, the second output path is conducted, the second path outputs a first control signal, and the voltage value of the first control signal is the voltage value of the output end of the negative pressure module. When the first enable fails, the voltage value of the output end of the negative pressure module maintains negative voltage within a first time period due to the existence of a capacitor in the negative pressure module structure, the negative voltage gradually rises to 0V as time goes on, the second control assembly outputs a second voltage, the second output path of the first control assembly is cut off, the first output path is conducted to output a second control signal, and the voltage value of the second control signal is the first power supply voltage value.
In some embodiments, the second control component is connected to the controlled end of the second output path, and is configured to control the conducting state of the second output path based on a second enable signal; the second enable signal is controlled by the first enable signal, when the voltage value of the first enable signal is the ground voltage, the voltage value of the second enable signal is the second power voltage, and when the voltage value of the first enable signal is the first power voltage, the voltage value of the second enable signal is the ground voltage.
When the voltage value of the second enable signal is a second power supply voltage, the output voltage value of the second control assembly is increased from a negative voltage value to a voltage value of 0V, and the second output path is in a cut-off state; and the difference value between the negative pressure value and the voltage at the output end of the negative pressure module is smaller than a preset threshold value, and the negative pressure value is close to the voltage value at the output end of the negative pressure module. In one embodiment, the predetermined threshold is determined by a circuit element in the second output path controlled by the output signal of the second control component.
The voltage value of the second enable signal is ground voltage, the voltage value of the output end of the second control assembly is 0V, and the second output path is in a conducting state.
In some embodiments, the first output path comprises: the PMOS transistor comprises a first NMOS transistor, a first PMOS transistor, a second PMOS transistor and a third PMOS transistor; the first NMOS transistor and the first PMOS transistor are controlled by the first enabling signal; the source electrode of the first NMOS tube is grounded, the drain electrode of the first NMOS tube is connected with the source electrode of the third PMOS tube, the source electrode of the first PMOS tube is connected with a first power supply, the drain electrode of the first PMOS tube is connected with the source electrode of the second PMOS tube, the grid electrode of the second PMOS tube is grounded, the drain electrode of the second PMOS tube is connected with the source electrode of the third PMOS tube, the grid electrode of the third PMOS tube is grounded, and the drain electrode of the third PMOS tube is connected with the controlled end of the controlled switch;
when the voltage value of the first enable signal is the ground voltage, the first NMOS tube is cut off, and the first PMOS tube, the second PMOS tube and the third PMOS tube are conducted;
the voltage value of the first enable signal is the first power voltage, the first NMOS transistor is turned on, and the first PMOS transistor, the second PMOS transistor and the third PMOS transistor are turned off.
In some embodiments, the second output path comprises at least: a second NMOS transistor and a third NMOS transistor; the source electrode of the second NMOS tube is connected with the output end of the negative pressure module, the grid electrode of the second NMOS tube is grounded, the drain electrode of the second NMOS tube is connected with the source electrode of the third NMOS tube, the grid electrode of the third NMOS tube is connected with the output end of the second control component, and the drain electrode of the third NMOS tube is connected with the controlled end of the controlled switch;
when the voltage value of the first enable signal is the ground voltage, the second NMOS tube and the third NMOS tube are cut off;
the voltage value of the first enable signal is the first power voltage, and the second NMOS tube and the third NMOS tube are conducted.
In some embodiments, the second control assembly comprises: the device comprises an energy storage assembly, a charging assembly and a discharging assembly;
the charging assembly and the discharging assembly are controlled by a second enabling signal; the energy storage assembly is respectively connected with the charging assembly and the discharging assembly; the charging assembly is used for charging the energy storage assembly, and the discharging assembly is used for discharging the energy storage assembly; the negative electrode of the energy storage assembly is connected with the output end of the second control assembly; the voltage value of the second enable signal is different from the voltage value of the first enable signal;
when the second enable signal is the ground voltage, the charging assembly works, the discharging assembly stops working, the energy storage assembly is in a charging state, and the second control assembly outputs a first voltage;
when the second enable signal is the second power voltage, the discharging component works, the charging component stops working, the energy storage component is in a discharging state, and the second control component outputs a second voltage.
In one embodiment, the energy storage component may be an energy storage element, including but not limited to a capacitor and an inductor.
In an embodiment, the first enable signal is enabled, the voltage of the second enable signal is a ground voltage, the output voltage of the negative voltage module is a negative voltage, the charging module operates and the discharging module stops operating, the energy storage module is in a charging state, and the voltage value of the output end of the second control module is 0V.
If the first enabling signal fails, the voltage value of the second enabling signal is a second power supply voltage, the output voltage of the negative voltage module maintains a negative voltage state within a first time period and is increased to a voltage value of 0V along with the lapse of time, the discharging assembly works and the charging assembly stops working, the energy storage assembly is in a discharging state, the output voltage value of the second control assembly is increased to a voltage value of 0V from the negative voltage value, the negative voltage value is determined by the charging and discharging power of the energy storage assembly and is close to the voltage value of the output end of the negative voltage module.
In the embodiment, the second voltage close to the voltage of the output end of the negative pressure module can be output through the voltage change in the discharging and charging processes of the energy storage assembly, so that the influence of the negative pressure of the output end of the negative pressure module on the voltage of the output signal of the first control assembly when the first enabling signal fails is reduced, the first control assembly can timely output the second control signal for controlling the conduction of the controlled switch, and the condition of overvoltage caused by untimely conduction of the controlled switch is reduced.
In some embodiments, the charging assembly comprises: the fourth PMOS tube, the fifth PMOS tube, the fourth NMOS tube and the fifth NMOS tube, wherein the fourth PMOS tube is controlled by the second enable signal; the source electrode of the fourth PMOS tube is connected with a second power supply, the drain electrode of the fourth PMOS tube is connected with the source electrode of the fifth PMOS tube, and the source electrode of the fifth PMOS tube is connected with the anode of the energy storage component; the grid electrode of the fifth PMOS tube is grounded, and the drain electrode of the fifth PMOS tube is connected with the grid electrode of the fourth NMOS tube; the drain electrode of the fourth NMOS tube is connected with the cathode of the energy storage assembly, and the source electrode of the fourth NMOS tube is grounded; the source electrode of the fifth NMOS tube is connected with the cathode of the energy storage assembly, the drain electrode of the fifth NMOS tube is connected with the grid electrode of the fourth NMOS tube, and the grid electrode of the fifth NMOS tube is grounded;
when the voltage value of the second enable signal is the ground voltage, the fourth PMOS tube, the fifth PMOS tube and the fourth NMOS tube are conducted, the fifth NMOS tube is cut off, the discharging assembly stops working, and the energy storage assembly is in a charging state;
when the voltage value of the second enable signal is a second power supply voltage, the fourth PMOS tube, the fifth PMOS tube and the fourth NMOS tube are cut off, the fifth NMOS tube is conducted, the discharging assembly works, and the energy storage assembly is in a discharging state.
In some embodiments, the discharge assembly comprises: a sixth NMOS tube and a discharge resistor; the sixth NMOS tube is controlled by the second enable signal, the source electrode of the sixth NMOS tube is grounded, the drain electrode of the sixth NMOS tube is connected with the anode of the energy storage assembly, one end of the two ends of the discharge resistor is connected with the cathode of the energy storage assembly, and the other end of the two ends of the discharge resistor is grounded;
the voltage value of the second enable signal is ground voltage, the sixth NMOS tube is cut off, the charging assembly works, and the energy storage assembly is in a charging state;
the voltage value of the second enable signal is a second power voltage, the sixth NMOS tube is conducted, the charging assembly stops working, the energy storage assembly is in a discharging state, and discharging is conducted through the discharging resistor.
In some embodiments, the circuit further comprises: and one end of the two ends of the protection assembly is connected with the output end of the negative pressure module, the other end of the protection assembly is connected with the output end of the second control assembly, and the output voltage of the second control assembly is increased when being lower than a preset protection value.
In some embodiments, the protection component comprises at least: a seventh NMOS transistor; the source electrode of the seventh NMOS tube is connected with the grid electrode, the source electrode of the seventh NMOS tube is connected with the output end of the negative pressure module, and the drain electrode of the seventh NMOS tube is connected with the output end of the second control component.
The seventh NMOS tube is in a cut-off state, the anode of a parasitic diode in the seventh NMOS tube is connected with the output end of the negative voltage module, and the cathode of the parasitic diode in the seventh NMOS tube is connected with the output end of the second control assembly, so that the condition that the voltage of the output end of the second control assembly is too low can be reduced.
A switching apparatus provided in an embodiment of the present invention is described below, the switching apparatus being applied to a negative pressure module, and as shown in fig. 5, the switching apparatus 5000 includes:
the controlled switch 300 is used for controlling the negative pressure signal output of the negative pressure module; the first end of the controlled switch is connected with the output end of the negative pressure module, and the second end of the controlled switch is grounded;
the controlled switch switching circuit 400 provided in any of the embodiments of the present invention is connected to the controlled end of the controlled switch, and is configured to control the controlled switch to be turned off when the first enable signal is enabled, and to control the controlled switch to be turned on when the first enable signal is disabled; wherein the first enable signal is used for instructing the negative pressure module to output a negative pressure signal.
The controlled switch in this embodiment is a controllable switching device, including but not limited to: MOSFETs and IGBTs.
In connection with the above embodiments, a specific example is provided:
by studying the conventional negative pressure module (as shown in fig. 1), when the enable signal of the negative pressure module fails, current flows back to the power supply (NVDD), so that the NVDD is over-pressurized, and the reason for the overvoltage is analyzed, which is caused by that the controlled switch S2 in the conventional negative pressure module cannot be closed in time after the enable signal fails.
The structural schematic diagram of the conventional controlled switch S2 in the negative-pressure module is shown in fig. 2, and the operating principle thereof is as follows:
before the enable signal EN takes effect, EN is at a low level, the NMOS transistor MN1 is turned off, the PMOS transistor MP1 is turned on, so that the source of MP2 is at a high level NVDD, since the gate of MP2 is at a ground level GND, MP2 is turned on, the point a is at a high level, similarly, the MP3 transistor is turned on, since the VNEG terminal is at a ground level in an initial state, the MN2 transistor is turned off, and the point B is also at a high level, so that MN3 is turned on, that is, the switch S2 in fig. 1 is closed, and the VNEG terminal is pulled to the ground level GND; after the enable signal EN is asserted, EN is switched to a high level, the MP1 and MP2 transistors are turned off, the MN1 transistor is turned on, and the point a is pulled to the ground level GND, so the MP3 transistor is turned off, and due to the conservation of charge in the capacitor, as the VNEG _ B terminal level is changed from NVDD to GND, the VNEG terminal level is changed from GND to a negative level, so that the MN2 transistor is turned on, and as the VNEG terminal level is changed to a negative level, the MN3 transistor is turned off, that is, the switch S2 in fig. 1 is turned off.
When the enable signal EN fails, EN is switched to a low level again, and the state of the switch is expected to be restored to the state before the enable signal EN becomes effective, but different from the state before the enable signal EN becomes effective, the level of the VNEG end is no longer the initial ground level but is a negative level at this time, and particularly, when the load driven by the VNEG end is heavy when the negative voltage module operates, because the VNEG end still accumulates more negative charges, the MN2 tube is not immediately turned off while the MP3 tube is turned on, so that the potential at the B point is not immediately pulled high, and the MN3 tube is not immediately turned on, that is, the switch S2 in fig. 1 is not immediately closed, so that the VNEG end is not pulled to the ground level GND but still maintains a certain negative level. After the enable signal EN fails, the switch S1a in fig. 1 is closed, and the power supply NVDD continues to charge the capacitor C, at this time, since the VNEG end still maintains a certain negative level, the voltage difference between the two ends of the capacitor C will be greater than NVDD. After the enable signal EN fails, the module NVG core no longer provides charges to the VNEG end, the charges at the VNEG end are consumed all the time, the negative level at the VNEG end is raised continuously until the gate-source voltage of the MN2 transistor is smaller than the threshold voltage thereof to turn off the MN2 transistor, the level at the B point is pulled up rapidly, the MN3 transistor is turned on, that is, the switch S2 in fig. 1 is closed, so that the VNEG end is pulled to the ground level rapidly. According to the principle of conservation of charge, when VNEG is pulled up to ground rapidly, because the voltage difference of capacitor C is greater than NVDD, VNEG _ B in fig. 1 is also lifted, causing current to flow back to power supply NVDD through switch S1a in fig. 1, which is more obvious as VNEG drives a heavier load, and the level of NVDD is raised by the flowing back current, which affects the NVDD generating circuit, and there is a risk of overvoltage, and at the same time, circuit modules using NVDD in the whole system may be affected by the lifted NVDD.
Based on this, the present example provides a controlled switching device, which is applied to the negative voltage module shown in fig. 1, and the controlled switching device provided by the present example is adopted to replace the controlled switch S2 in the negative voltage module.
Fig. 6 is a schematic circuit diagram illustrating a controlled switching device according to an example. The present example provides a controlled switching device, comprising: a first control component, a second control component, a protection component MN8 and a controlled switch MN 3. The first control assembly includes: controlled switch MN1, controlled switch MN2, controlled switch MN4, controlled switch MP1, controlled switch MP2, and controlled switch MP 3.
MP1 is controlled by an enable signal EN, the source of MP1 is connected to the power supply DVDD, the drain of MP1 is connected to the source of MP2, the drain of MP2 is connected to the source of MP3, the drain of MP3 is connected to the gate of MN3, the gates of MP2 and MP3 are grounded, MN1 is controlled by an enable signal EN, the source of MN1 is grounded, the drain of MN1 is connected to the source of MP3, the gate of MN4 is connected to the output terminal of the second control module, the drain of MN4 is connected to the gate of MN3, the source of MN4 is connected to the drain of MN2, the gate of MN2 is grounded, and the source of MN2 is connected to the VNEG terminal (negative voltage module output terminal) of the negative voltage module.
The second control assembly includes: controlled switch MN5, controlled switch MN6, controlled switch MN7, controlled switch MP4, controlled switch MP5, capacitor C1 and resistor R.
MN5 and MP4 are controlled by a signal EN _ N of opposite level to the enable signal EN, the source of MP4 is connected to the power supply NVDD, the drain of MP4 is connected to the source of MP5, the drain of MP5 is connected to the drain of MN6, the gates of MN5 and MN6 are grounded, the source of MN6 is connected to the output terminal of the second control component, the drain of MN6 is connected to the gate of MN7, the source of MN7 is grounded, the drain of MN7 is connected to the cathode of C1, the anode of C1 is connected to the drain of MN5, one end of R is connected to the cathode of C1, and the other end of R is grounded.
The working principle of the controlled switching device provided by the example is as follows:
before the enable signal EN takes effect, the signal EN is at low level, the MP1, MP2 and MP3 tubes are turned on, the MN1 tube is turned off, the signal EN _ N is at high level, the MP4 tube is turned off, the MN5 tube is turned on, the D point is at ground level GND, the MP5, MN6 and MN7 tubes are all turned off, the E point is also at ground level GND, and since the VNEG is at ground level in the initial state, the MN4 and the MN2 tubes are turned off, the B point is pulled up to high level, the MN3 is turned on, namely the switch S2 in FIG. 1 is closed, and the VNEG end is pulled to ground level GND; after the enable signal EN is asserted, EN is switched to high level, MP1 and MP2 transistors are turned off, MN1 transistor is on, point a is pulled to ground GND, so MP3 transistor is turned off, because of the conservation of charge in the capacitor, as the VNEG _ B level is changed from NVDD to GND, VNEG level is changed from GND to negative level, MN2 transistor is turned on, the drain H point level of MN2 is changed to negative level along with VNEG level, signal EN _ N is switched to low level along with the assertion of enable signal EN, MP4 transistor is turned on, MN5 transistor is turned off, point D is changed to high level, MP5 transistor is turned on, MN6 transistor is turned off, point F is also changed to high level, MN7 transistor is turned on, point E is pulled to ground level, at this time, capacitor C1 is charged by power supply NVDD, if the H point level is changed to negative level along with VNEG level, MN3 transistor is turned on, point B level is changed to VNEG 7375 level, thus the negative switch 84 in the graph is turned off.
When the enable signal EN is disabled, EN _ N switches to high level again, the MP4 tube is turned off, the MN5 tube is turned on, the point D is pulled to ground level, due to the conservation of charge of the capacitor C1, point E becomes a negative level, and the voltage at point E is then restored to ground level through the resistor R, unlike conventional controlled switch switching circuits, even if the VNEG terminal is still at a negative level at this time, the MN2 transistor is not immediately turned off, point H is at a negative level, but because point E is also negative, the gate-source voltage of MN4 is still less than its threshold voltage, therefore, the MN4 transistor is turned off, the node B can be pulled to a high level, so that the MN3 transistor is turned on, that is, the switch S2 in fig. 1 is closed, so that the VNEG terminal is quickly pulled to a ground level, thereby avoiding the situation that the voltage difference between the two terminals of the capacitor C is greater than NVDD due to the charging of the capacitor C in fig. 1 after the enabling failure, therefore, the current is prevented from flowing back to the NVDD to cause the NVDD to be raised to cause adverse effects on the circuit.
After the negative-voltage controlled switch switching circuit is used, waveforms of nodes of the controlled switch switching circuit in the negative-voltage module when the enable signal EN fails are shown in FIG. 7. In the example, an additional control logic is added to control the gate of an MOS transistor in a conventional negative-pressure controlled switching circuit (as shown in fig. 2) in a conventional negative-pressure module by using the charge conservation principle of a capacitor, so that the switching speed of the controlled switch is increased, the controlled switch can be quickly turned on or off at the moment of enabling switching, and meanwhile, the phenomena of current backflow and voltage rising after switching due to untimely over-charging of the capacitor in the negative-pressure module caused by switching of the controlled switch under the condition that a negative-pressure output end drives a large load are avoided, so that a preceding-stage circuit is protected from generating overvoltage, and other circuit modules in the system can normally work.
It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application. The above-mentioned serial numbers of the embodiments of the present application are merely for description and do not represent the merits of the embodiments.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
The above description is only for the embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (11)
1. A controlled switch switching circuit is applied to a negative voltage module and is characterized by comprising:
a first enable signal receiving end, configured to receive a first enable signal of the negative pressure module, where the first enable signal indicates the negative pressure module to output a negative pressure signal;
the control output end is used for being connected with a controlled end of a controlled switch in the negative pressure module; the controlled switch is connected between the output end of the negative pressure module and the grounding point; the controlled switch is conducted, the output end of the negative pressure module is grounded, and the negative pressure module stops outputting negative voltage; the controlled switch is cut off, and the output end of the negative pressure module outputs negative pressure;
enabling a control assembly comprising: the first controlled end of the first control assembly is connected with the first enabling signal receiving end, and the second controlled end of the first control assembly is connected with the second control assembly; the output end of the first control component is connected with the control output end; the first control assembly is connected with a first power supply, and the second control assembly is connected with a second power supply;
the second control assembly is configured to: outputting a first voltage when the first enable signal is enabled and outputting a second voltage when the first enable signal is disabled, wherein the first voltage is a ground voltage and the second voltage is gradually increased from a negative voltage value to the ground voltage; the difference value between the negative pressure value and the output voltage of the negative pressure module is smaller than a preset threshold value;
the first control assembly is configured to: outputting a first control signal when the first enable signal is enabled and the second control component outputs a first voltage, and outputting a second control signal when the first enable signal is disabled and the second control component outputs a second voltage; the first control signal can control the controlled switch to be switched off, and the second control signal can control the controlled switch to be switched on.
2. The circuit of claim 1, wherein the first control component comprises: a first output path and a second output path; the controlled end of the first output path is the first controlled end, and the controlled end of the second output path is the second controlled end;
the input end of the first output path is connected with a first power supply, and the output end of the first output path is connected with the control output end; the input end of the second output path is connected with the output end of the negative pressure module, and the output end of the second output path is connected with the control output end;
when the first enable signal is enabled, the voltage value of the first enable signal is a first power supply voltage, the second control component outputs a first voltage, the first output path is cut off, and the second output path is conducted and outputs the first control signal;
when the first enable signal fails, the voltage value of the first enable signal is the ground voltage, the second control component outputs a second voltage, the second output path is cut off, and the first output path is conducted and outputs the second control signal.
3. The circuit of claim 2, wherein the second control component is connected to the controlled terminal of the second output path for controlling the conducting state of the second output path based on a second enable signal; the second enable signal is controlled by the first enable signal, when the voltage value of the first enable signal is the ground voltage, the voltage value of the second enable signal is the second power voltage, and when the voltage value of the first enable signal is the first power voltage, the voltage value of the second enable signal is the ground voltage.
4. The circuit of claim 2, wherein the first output path comprises: the PMOS transistor comprises a first NMOS transistor, a first PMOS transistor, a second PMOS transistor and a third PMOS transistor; the first NMOS transistor and the first PMOS transistor are controlled by the first enabling signal; the source electrode of the first NMOS tube is grounded, the drain electrode of the first NMOS tube is connected with the source electrode of the third PMOS tube, the source electrode of the first PMOS tube is connected with a first power supply, the drain electrode of the first PMOS tube is connected with the source electrode of the second PMOS tube, the grid electrode of the second PMOS tube is grounded, the drain electrode of the second PMOS tube is connected with the source electrode of the third PMOS tube, the grid electrode of the third PMOS tube is grounded, and the drain electrode of the third PMOS tube is connected with the controlled end of the controlled switch;
when the voltage value of the first enable signal is the ground voltage, the first NMOS tube is cut off, and the first PMOS tube, the second PMOS tube and the third PMOS tube are conducted;
when the voltage value of the first enable signal is a first power voltage, the first NMOS tube is switched on, and the first PMOS tube, the second PMOS tube and the third PMOS tube are switched off.
5. The circuit of claim 2, wherein the second output path comprises at least: a second NMOS transistor and a third NMOS transistor; the source electrode of the second NMOS tube is connected with the output end of the negative pressure module, the grid electrode of the second NMOS tube is grounded, the drain electrode of the second NMOS tube is connected with the source electrode of the third NMOS tube, the grid electrode of the third NMOS tube is connected with the output end of the second control component, and the drain electrode of the third NMOS tube is connected with the controlled end of the controlled switch;
when the voltage value of the first enable signal is the ground voltage, the second NMOS tube and the third NMOS tube are cut off;
the voltage value of the first enable signal is a first power voltage, and the second NMOS tube and the third NMOS tube are conducted.
6. The circuit of claim 1, wherein the second control component comprises: the device comprises an energy storage assembly, a charging assembly and a discharging assembly;
the charging assembly and the discharging assembly are controlled by a second enabling signal; the energy storage assembly is respectively connected with the charging assembly and the discharging assembly; the charging assembly is used for charging the energy storage assembly, and the discharging assembly is used for discharging the energy storage assembly; the negative electrode of the energy storage assembly is connected with the output end of the second control assembly;
when the second enable signal is the ground voltage, the charging assembly works, the discharging assembly stops working, the energy storage assembly is in a charging state, and the second control assembly outputs a first voltage;
when the second enable signal is a second power supply voltage, the discharging assembly works, the charging assembly stops working, the energy storage assembly is in a discharging state, and the second control assembly outputs a second voltage.
7. The circuit of claim 6, wherein the charging component comprises: the fourth PMOS tube, the fifth PMOS tube, the fourth NMOS tube and the fifth NMOS tube, wherein the fourth PMOS tube is controlled by the second enable signal; the source electrode of the fourth PMOS tube is connected with a second power supply, the drain electrode of the fourth PMOS tube is connected with the source electrode of the fifth PMOS tube, and the source electrode of the fifth PMOS tube is connected with the anode of the energy storage component; the grid electrode of the fifth PMOS tube is grounded, and the drain electrode of the fifth PMOS tube is connected with the grid electrode of the fourth NMOS tube; the drain electrode of the fourth NMOS tube is connected with the cathode of the energy storage assembly, and the source electrode of the fourth NMOS tube is grounded; the source electrode of the fifth NMOS tube is connected with the cathode of the energy storage assembly, the drain electrode of the fifth NMOS tube is connected with the grid electrode of the fourth NMOS tube, and the grid electrode of the fifth NMOS tube is grounded;
when the voltage value of the second enable signal is the ground voltage, the fourth PMOS tube, the fifth PMOS tube and the fourth NMOS tube are conducted, the fifth NMOS tube is cut off, the discharging assembly stops working, and the energy storage assembly is in a charging state;
when the voltage value of the second enable signal is a second power supply voltage, the fourth PMOS tube, the fifth PMOS tube and the fourth NMOS tube are cut off, the fifth NMOS tube is conducted, the discharging assembly works, and the energy storage assembly is in a discharging state.
8. The circuit of claim 6, wherein the discharge assembly comprises: a sixth NMOS tube and a discharge resistor; the sixth NMOS tube is controlled by the second enable signal, the source electrode of the sixth NMOS tube is grounded, the drain electrode of the sixth NMOS tube is connected with the anode of the energy storage assembly, one end of the two ends of the discharge resistor is connected with the cathode of the energy storage assembly, and the other end of the two ends of the discharge resistor is grounded;
the voltage value of the second enable signal is ground voltage, the sixth NMOS tube is cut off, the charging assembly works, and the energy storage assembly is in a charging state;
the voltage value of the second enable signal is a second power voltage, the sixth NMOS tube is conducted, the charging assembly stops working, the energy storage assembly is in a discharging state, and discharging is conducted through the discharging resistor.
9. The circuit of claim 1, further comprising: and one end of the two ends of the protection assembly is connected with the output end of the negative pressure module, the other end of the protection assembly is connected with the output end of the second control assembly, and the output voltage of the second control assembly is increased when being lower than a preset protection value.
10. The circuit of claim 9, wherein the protection component comprises at least: a seventh NMOS transistor; the source electrode of the seventh NMOS tube is connected with the grid electrode, the source electrode of the seventh NMOS tube is connected with the output end of the negative pressure module, and the drain electrode of the seventh NMOS tube is connected with the output end of the second control component.
11. A switching device, applied to a negative pressure module, comprising:
the controlled switch is used for controlling the negative pressure signal output of the negative pressure module; the first end of the controlled switch is connected with the output end of the negative pressure module, and the second end of the controlled switch is grounded;
the controlled switch switching circuit as claimed in any one of claims 1 to 10, connected to the controlled terminal of the controlled switch, for controlling the controlled switch to be turned off when the first enable signal is enabled, and to be turned on when the first enable signal is disabled; the first enabling signal is used for indicating the negative pressure module to output a negative pressure signal.
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| US8044707B2 (en) * | 2009-10-09 | 2011-10-25 | Dialog Semiconductor Gmbh | VDD/5 or VDD/6 charge-pump |
| US9111601B2 (en) * | 2012-06-08 | 2015-08-18 | Qualcomm Incorporated | Negative voltage generators |
| JP5911614B1 (en) * | 2015-01-19 | 2016-04-27 | 力晶科技股▲ふん▼有限公司 | Negative reference voltage generator |
| CN205992796U (en) * | 2016-06-30 | 2017-03-01 | 程劲 | A kind of handover source of integrated charge formula vacuum cavitations |
| CN112202440B (en) * | 2020-09-15 | 2022-08-09 | 广州慧智微电子股份有限公司 | Negative voltage level conversion control circuit and method |
| CN112600410B (en) * | 2020-12-24 | 2022-01-04 | 芯天下技术股份有限公司 | Discharge circuit of negative voltage charge pump and nonvolatile storage |
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