Electronic detonator chip and module

Abstract

This invention provides an electronic detonator chip and module. The chip includes a digital control logic circuit, a ignition control signal drive circuit, an internal bias resistor, a voltage detection and comparison circuit, and a bypass discharge switch. By setting the internal bias resistor to be greater than the corresponding external resistor, when the GND or VCHG pins are loosely connected, the voltage difference is mainly distributed across the internal resistor, ensuring that the gate voltage of the ignition switch is lower than its conduction threshold, preventing false triggering. The voltage detection and comparison circuit monitors the ignition control pin potential in real time during non-ignition states. Once an abnormal voltage caused by external interference is detected, it immediately controls the bypass discharge switch to conduct, safely discharging the energy from the energy storage capacitor and preventing false ignition. This invention provides corresponding embodiments for both NMOS and PMOS ignition switches, effectively solving the problem of premature detonation caused by loose pin connections and external interference, significantly improving the safety of electronic detonators.

Description

Technical Field

[0001] This invention relates to the field of electronic detonator technology, and more specifically, to electronic detonator chips and modules. Background Technology

[0002] Premature detonation occurs when an electronic detonator detonates before receiving a detonation command after charging, or before the scheduled detonation time has elapsed after receiving a detonation command. If the charging process at the blasting site is not properly monitored, this type of malfunction can lead to serious personal injury accidents. Even if no personal injury occurs, this failure to detonate according to the correct delay time will inevitably severely affect the blasting results.

[0003] Based on our experience using hundreds of millions of electronic detonators, we have identified the following situations that may cause premature detonation:

[0004] 1. External abnormal interference—such as static electricity generated by the detonation of other detonators during the delay process—causes an abnormal high level to be generated on the gate of the ignition switch, turning on the ignition switch and ultimately causing premature detonation;

[0005] 2. A loose connection at the chip's GND pin. Due to the presence of the rectifier bridge in the electronic detonator module, the internal GND voltage is higher than the external GND voltage. If a large current flows through the rectifier bridge for a short period during chip operation, this voltage difference can reach up to 2V. If the resistance between the internal FIRE_EN ignition enable pin and GND is low, this voltage difference will affect the FIRE_EN signal, thus turning on the NMOS ignition switch and ultimately causing premature detonation.

[0006] 3. A loose connection at the VCHG pin on the chip. Because the electronic detonator module is powered by the energy storage capacitor during delay, the contact resistance will cause the on-chip VCHG voltage to be lower than the off-chip VCHG voltage. This voltage difference can reach up to 2V. If the resistance between the on-chip FIRE_ENB pin and VCHG is small, this voltage difference will affect the FIRE_ENB signal, thereby turning on the PMOS ignition switch and ultimately causing premature detonation.

[0007] Chinese patent document CN111076629B discloses a discharge control circuit and an electronic detonator. The anti-premature detonation protection function is actually a detailed description of the ignition switch control circuit in this invention. It has no effect on preventing premature detonation caused by external interference leading to malfunction of the ignition switch or by malfunction of the ignition switch itself.

[0008] Chinese patent document CN220083833U discloses a circuit for preventing premature detonation of electronic detonators. The principle of preventing premature detonation is to optimize the design of the detonator to prevent premature detonation of the electronic detonator caused by voltage change of the detonator. However, it has no effect on preventing premature detonation caused by interference at the electronic detonator module end.

[0009] Chinese patent document CN114812304A discloses an ignition control system and method, which uses five switching signals and an anti-interference logic unit to control ignition. This structure can indeed prevent premature detonation caused by internal interference signals of the chip. However, it uses a Schmitt trigger as the final output stage. When the control signal is invalid, the Schmitt trigger actively outputs a low level. The resistance between the internal ignition enable pin FIRE_EN and GND is relatively small. If the chip's GND pin is loosely connected, it can lead to premature detonation. Summary of the Invention

[0010] In view of the deficiencies in the prior art, the purpose of this invention is to provide an electronic detonator chip and module.

[0011] An electronic detonator chip provided by the present invention comprises:

[0012] Digital control logic circuits are used to generate internal raw ignition control signals according to bus instructions;

[0013] The ignition control signal drive circuit is connected to the digital control logic circuit and is used to drive the chip ignition enable pin to turn on the external ignition switch in response to the valid internal raw ignition control signal.

[0014] An internal resistor network is connected between the ignition enable pin and the chip's internal reference voltage network.

[0015] The comparator has its first input connected to the ignition enable pin and its second input connected to a reference voltage source. The enable pin is controlled by the internal original ignition control signal.

[0016] A bypass discharge switch is connected between the charging pin and the system ground pin, and its control terminal is connected to the output terminal of the comparator.

[0017] Specifically, when the internal original ignition control signal is invalid, the comparator is enabled to monitor the potential of the ignition enable pin and, upon detecting an anomaly, controls the bypass discharge switch to conduct to discharge the energy of the energy storage capacitor; when the internal original ignition control signal is valid, the comparator is disabled.

[0018] Preferably, the ignition enable pin is the FIRE_EN pin used to control the NMOS ignition switch;

[0019] The internal resistor network consists of internal pull-down resistors connected between the FIRE_EN pin and the chip's internal system ground.

[0020] The ignition control signal driving circuit includes a PMOS transistor, whose source is connected to the low-voltage power supply pin of the chip, its drain is connected to the FIRE_EN pin, and its gate receives the internal raw ignition control signal.

[0021] The first input of the comparator is directly connected to the FIRE_EN pin.

[0022] Preferably, the internal pull-down resistor is configured to have a resistance value greater than that of the external pull-down resistor connected between the FIRE_EN pin and the external system ground.

[0023] Preferably, the ignition enable pin is the FIRE_ENB ignition enable pin used to control the PMOS ignition switch;

[0024] The internal resistor network is an internal pull-up resistor connected between the FIRE_ENB pin and the chip's internal charging voltage network;

[0025] The ignition control signal driving circuit includes an NMOS transistor, whose source is connected to the internal system ground of the chip, whose drain is connected to the FIRE_ENB pin, and whose gate receives the internal raw ignition control signal.

[0026] It also includes an operational amplifier, whose non-inverting input is connected to the charging pin, its inverting input is connected to the FIRE_ENB pin, and its output is connected to the first input of the comparator.

[0027] Preferably, the internal pull-up resistor is configured to have a resistance value greater than that of the external pull-up resistor connected between the FIRE_ENB pin and the external charging voltage.

[0028] Preferably, the voltage value of the reference voltage source is less than the conduction threshold voltage of the external ignition switch.

[0029] Preferably, the internal raw ignition control signal includes a first control signal active at low level and a second control signal active at high level;

[0030] The chip also includes:

[0031] The first ignition enable pin and the first internal resistor network, the first comparator, and the first ignition control signal drive circuit connected thereto constitute an NMOS ignition switch protection circuit.

[0032] The second ignition enable pin and the second internal resistor network, second comparator, second ignition control signal drive circuit and operational amplifier connected thereto constitute a PMOS ignition switch protection circuit.

[0033] The outputs of the first comparator and the second comparator are used to jointly control the bypass discharge switch or control their respective bypass discharge switches via a logic OR gate.

[0034] An electronic detonator module according to the present invention includes an energy storage capacitor, an ignition element, an ignition switch, and the electronic detonator chip.

[0035] Preferably, when the ignition switch is an NMOS transistor, its gate is connected to the FIRE_EN pin of the chip, its source is connected to system ground, and its drain is connected to the negative terminal of the ignition element; the positive terminal of the ignition element is connected to the charging voltage; and the FIRE_EN pin is connected to system ground through an external pull-down resistor.

[0036] Preferably, when the ignition switch is a PMOS transistor, its gate is connected to the FIRE_ENB pin of the chip, its source is connected to the charging voltage, and its drain is connected to the positive terminal of the ignition element; the negative terminal of the ignition element is connected to system ground; and the FIRE_ENB pin is connected to the charging voltage through an external pull-up resistor.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. This invention configures the internal resistor (e.g., R2) of the chip to have a resistance value significantly greater than that of the corresponding external resistor (e.g., R1). When a loose connection occurs at the GND or VCHG pin and a large voltage difference is generated, the majority of this voltage difference is borne by the internal resistor with the larger resistance value, thereby significantly reducing the voltage drop across the ignition switch control electrode (gate). This voltage is designed to be below the ignition switch's turn-on threshold, thus fundamentally avoiding false turn-on caused by loose pin connections, providing targeted and reliable protection.

[0039] 2. This invention innovatively integrates a real-time monitoring and energy discharge channel consisting of comparators (CMP1 / CMP2) and a bypass discharge switch (Q3). In the non-ignition state, this monitoring circuit operates continuously. Once an abnormal potential of the ignition control pin is detected due to external interference (such as an abnormal rise in FIRE_EN or an abnormal drop in FIRE_ENB), the comparator will quickly output a signal to trigger the bypass discharge switch to open, allowing the energy on the energy storage capacitor to be discharged through this safe path instead of flowing through the ignition element, thereby actively eliminating the possibility of false ignition caused by interference.

[0040] 3. This invention achieves comprehensive protection at the detonator chip level, and provides effective hardware circuit solutions for the three identified core premature detonation causes: "external abnormal interference", "GND pin connection", and "VCHG pin connection", thereby improving the overall safety and reliability of the electronic detonator system. Attached Figure Description

[0041] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0042] Figure 1 This is a block diagram of the electronic detonator chip and related peripheral circuits used for NMOS ignition switch protection in an embodiment of the present invention;

[0043] Figure 2 This is a block diagram of the electronic detonator chip and related peripheral circuits used for PMOS ignition switch protection in an embodiment of the present invention. Detailed Implementation

[0044] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0045] This invention provides an electronic detonator chip that can prevent premature detonation caused by erroneous ignition control signals. Through a unique circuit design, this chip effectively avoids misfires of the ignition switch due to loose connections at chip pins or external abnormal interference, thereby fundamentally reducing the risk of premature detonation accidents in electronic detonators.

[0046] Example 1

[0047] Please see Figure 1 The electronic detonator module in this embodiment of the invention includes: an electronic detonator chip for NMOS ignition switch protection and its related peripheral circuits.

[0048] The electronic detonator chip has a low-voltage power supply pin (VLDO), a charging pin (VCHG), a system ground pin (GND), and a firing enable pin (FIRE_EN), which connect to the external circuitry. The external circuitry mainly includes: a storage capacitor (C1), a firing element (YT, such as a bridge wire), an NMOS firing switch (Q1), and a pull-down resistor (R1).

[0049] The circuit connections are as follows: the positive terminal of the energy storage capacitor C1 is connected to the charging pin VCHG, and the negative terminal is connected to the system ground pin GND. The positive terminal of the ignition element YT is connected to the charging pin VCHG, and the negative terminal is connected to the drain of the ignition switch Q1. The source of the ignition switch Q1 is connected to the system ground pin GND, and the gate is connected to the ignition enable pin FIRE_EN. A pull-down resistor R1 is connected between the ignition enable pin FIRE_EN and the system ground pin GND to ensure that Q1 is reliably turned off when there is no drive signal.

[0050] The electronic detonator chip includes a digital control logic circuit, a firing control signal drive circuit, an internal pull-down resistor R2, a comparator CMP1, a reference voltage source Vref1, and a bypass discharge switch Q3.

[0051] The digital control logic circuit generates an internal raw ignition control signal (FE_N) based on the received bus instructions. This signal is active low.

[0052] The ignition control signal drive circuit mainly consists of a PMOS transistor Q2. The source of Q2 is connected to the low-voltage power supply pin VLDO, the drain is connected to the ignition enable pin FIRE_EN, and the gate receives the internal raw ignition control signal (FE_N). When FE_N is high (invalid), Q2 is off; when FE_N is low (valid), Q2 is on, outputting the high level introduced from the low-voltage power supply pin VLDO to the ignition enable pin FIRE_EN.

[0053] The internal pull-down resistor R2 is connected between the FIRE_EN ignition enable pin and the GND system ground pin. To ensure voltage division protection in the event of a loose GND connection, the resistance of R2 (e.g., 100kΩ) should be significantly greater than that of the external pull-down resistor R1 (e.g., 50kΩ). The equivalent resistance of R1 and R2 in parallel is preferably between 10kΩ and 100kΩ to balance drive capability and pull-down effect.

[0054] The non-inverting input (+) of comparator CMP1 is connected to the FIRE_EN ignition enable pin, the inverting input (-) is connected to the reference voltage source Vref1 (e.g., 0.8V), the enable pin EN is connected to the FE_N signal, and the output is connected to the gate of the bypass discharge switch Q3. Comparator CMP1 operates when EN is high and forces the output low when EN is low.

[0055] The bypass discharge switch Q3 is preferably an NMOS transistor, with its drain connected to the VCHG pin and its source connected to the system ground pin GND pin. When Q3 is turned on, the energy stored in the energy storage capacitor C1 will be directly discharged to ground through Q3, without flowing through the ignition element YT, thus preventing accidental ignition.

[0056] Working principle of Example 1:

[0057] When the electronic detonator chip is powered on, the digital control logic circuit actively disables the internal original ignition control signal. When the internal original ignition control signal is disabled, the gate of the ignition control signal-driven switch is high, causing the switch to turn off. The gate of the ignition switch is connected to GND through two pull-down resistors, thus turning off the ignition switch. Simultaneously, the enable signal of the on-chip comparator CMP1 is also high, and the on-chip comparator CMP1 operates in real time.

[0058] In this state, if the chip's GND pin is loosely connected, the voltage on the internal GND may be greater than the voltage on the external GND. This voltage difference comes from the forward voltage drop of the diodes in the rectifier bridge of the electronic detonator module, and can reach a maximum of 2V when the current is large. At this time, the voltage difference between the internal and external GND is divided by the internal and external pull-down resistors. Because the internal pull-down resistor is larger than the external pull-down resistor, the voltage after division is no greater than 1V. The high-voltage NMOS devices commonly used in ignition switches typically have a turn-on threshold of over 1V. The voltage after the above division is insufficient to turn on the ignition switch, thus preventing premature detonation.

[0059] In this state, if an abnormal external interference voltage causes the FIRE_EN voltage to rise, when its voltage is greater than the voltage of the on-chip reference voltage source Vref1, the output of the on-chip comparator CMP1 becomes high, controlling the bypass discharge switch to turn on, so that the charge on the energy storage capacitor is discharged to GND without passing through the ignition element, thus preventing premature explosion.

[0060] When the electronic detonator chip is controlled by instructions sent by the host computer (such as the detonator or electronic detonator module / finished product testing equipment, etc.) through the bus, it completes the necessary detonation process such as clock calibration, password verification, and energy storage capacitor charging. After receiving the detonation command and completing the internal delay, the digital control logic circuit will actively control the internal original ignition control signal to become valid.

[0061] When the internal ignition control signal is valid, the gate of the ignition control signal-driven switch is at a low level, the ignition control signal drives the switch to conduct, the gate of the ignition switch connects to the chip's low-voltage power supply, and the ignition switch conducts, thus achieving ignition. At the same time, the enable signal of the on-chip comparator CMP1 is also at a low level, and its output is fixed at a low level, which will not interfere with the ignition process.

[0062] Example 2

[0063] Please see Figure 2 The diagram shows the principle block diagram of the electronic detonator chip and its related peripheral circuits for PMOS ignition switch protection according to the present invention.

[0064] The external circuit structure changes as follows: the positive terminal of the ignition element YT is connected to the drain of the PMOS ignition switch Q1, and the negative terminal is grounded; the source of the PMOS ignition switch Q1 is connected to VCHG, and the gate of the PMOS ignition switch Q1 is connected to the ignition enable pin FIRE_ENB of the chip; the pull-up resistor R1 is connected between the FIRE_ENB pin and VCHG to ensure that Q1 is turned off when there is no drive.

[0065] The internal circuitry of the chip was adjusted accordingly:

[0066] The digital control logic circuit generates a high-level active internal raw ignition control signal FE_P.

[0067] The ignition control signal drive circuit is composed of NMOS transistor Q2. The source of Q2 is connected to GND_INT, the drain is connected to the FIRE_ENB pin, and the gate is controlled by FE_P. When FE_P is low, Q2 is off, and when it is high, Q2 is on.

[0068] The internal pull-up resistor R2 is connected between the FIRE_ENB pin and the internal VCHG network of the chip. Its resistance (e.g., 1MΩ) should be significantly larger than the external pull-up resistor R1 (e.g., 500kΩ), and the parallel equivalent resistance is preferably between 10kΩ and 500kΩ.

[0069] An operational amplifier (OPA) was added, with its non-inverting input connected to the VCHG pin and its inverting input connected to the FIRE_ENB pin, to detect the voltage difference between the two.

[0070] The non-inverting input of comparator CMP2 is connected to the output of OPA, and the inverting input is connected to the reference voltage source Vref2 (e.g., 0.8V). The enable input ENB is connected to the FE_P signal (the logic is the opposite of CMP1; CMP2 is disabled when FE_P is high). The output of CMP2 controls the gate of the bypass discharge switch Q3.

[0071] The working principle of this embodiment 2 is as follows:

[0072] When the electronic detonator chip is powered on, the digital control logic circuit actively disables the internal raw ignition control signal. When the raw ignition control signal is disabled, the gate of the ignition control signal-driven switch is low, turning the switch off. The gate of the ignition switch is connected to VCHG through two pull-up resistors, thus turning off the ignition switch. Simultaneously, the enable signal of the on-chip comparator is also low, enabling the on-chip comparator to operate in real-time.

[0073] In this state, if the VCHG pin of the chip is loosely connected, the voltage of the on-chip VCHG may be lower than the external GND voltage. This voltage difference comes from the contact resistance when the pin is loosely connected, and it can reach a maximum of 2V when the current is large. At this time, the voltage difference between the on-chip and external VCHG is divided by the on-chip pull-up resistor and the external pull-up resistor. Because the on-chip pull-up resistor is larger than the external pull-up resistor, the voltage after voltage division is no greater than 1V. However, the turn-on threshold of the high-voltage PMOS devices commonly used in ignition switches is usually above 1V. The voltage after the above voltage division is insufficient to turn on the ignition switch, so it will not cause premature detonation.

[0074] In this state, if an abnormal external interference voltage causes the FIRE_ENB voltage to drop, when the voltage difference between VCHG and FIRE_ENB is greater than the voltage of the on-chip reference voltage source, the on-chip comparator output becomes high, controlling the bypass discharge switch to turn on, so that the charge on the energy storage capacitor is discharged to GND without passing through the ignition element, thus preventing premature explosion.

[0075] When the electronic detonator chip is controlled by instructions sent by the host computer (such as the detonator or electronic detonator module / finished product testing equipment, etc.) through the bus, it completes the necessary detonation process such as clock calibration, password verification, and energy storage capacitor charging. After receiving the detonation command and completing the internal delay, the digital control logic circuit will actively control the internal original ignition control signal to become valid.

[0076] When the internal ignition control signal is valid, the gate of the ignition control signal drives the switch to a high level, turning the switch on. The gate of the ignition switch is connected to the chip's GND, thus igniting the switch and achieving ignition. At the same time, the enable signal of the on-chip comparator is also high, and its output is fixed at a low level, so it will not interfere with the ignition process.

[0077] Example 3

[0078] In another preferred embodiment of the invention, the two protection circuits described above can be integrated into the same electronic detonator chip. This chip will simultaneously possess two ignition control pins, FIRE_EN and FIRE_ENB, and internally contain two corresponding drive circuits, resistor networks, and comparator (or OPA+comparator) logic. The outputs of the two comparators can jointly control the same or a group of bypass discharge switches through an OR logic (e.g., an OR gate). This design allows the same chip to flexibly adapt to different detonator module designs employing NMOS or PMOS ignition switches, providing comprehensive premature detonation protection.

[0079] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. An electronic detonator chip, characterized in that, include: Digital control logic circuits are used to generate internal raw ignition control signals according to bus instructions; The ignition control signal drive circuit is connected to the digital control logic circuit and is used to drive the chip ignition enable pin to turn on the external ignition switch in response to the valid internal raw ignition control signal. An internal resistor network is connected between the ignition enable pin and the system ground pin; The comparator has its first input connected to the ignition enable pin and its second input connected to a reference voltage source. The enable pin is controlled by the internal original ignition control signal. A bypass discharge switch is connected between the charging pin and the system ground pin, and its control terminal is connected to the output terminal of the comparator. When the internal original ignition control signal is invalid, the comparator is enabled to monitor the potential of the ignition enable pin and, upon detecting an anomaly, controls the bypass discharge switch to conduct to discharge the energy of the energy storage capacitor; when the internal original ignition control signal is valid, the comparator is disabled. The ignition enable pin is the FIRE_EN pin used to control the NMOS ignition switch; The internal resistor network consists of internal pull-down resistors connected between the FIRE_EN ignition enable pin and the system ground pin. The ignition control signal driving circuit includes a PMOS transistor, whose source is connected to the low-voltage power supply pin of the chip, its drain is connected to the ignition enable pin FIRE_EN, and its gate receives the internal raw ignition control signal. The first input of the comparator is directly connected to the FIRE_EN ignition enable pin. The internal pull-down resistor is configured to have a resistance value greater than that of the external pull-down resistor connected between the FIRE_EN ignition enable pin and the system ground pin.

2. The electronic detonator chip according to claim 1, characterized in that, The voltage value of the reference voltage source is less than the conduction threshold voltage of the external ignition switch.

3. An electronic detonator chip, characterized in that, include: Digital control logic circuits are used to generate internal raw ignition control signals according to bus instructions; The ignition control signal drive circuit is connected to the digital control logic circuit and is used to drive the chip ignition enable pin to turn on the external ignition switch in response to the valid internal raw ignition control signal. An internal resistor network is connected between the ignition enable pin and the charging pin; The comparator has its first input connected to the output of the operational amplifier and its second input connected to a reference voltage source. Its enable terminal is controlled by the internal original ignition control signal. A bypass discharge switch is connected between the charging pin and the system ground pin, and its control terminal is connected to the output terminal of the comparator. When the internal original ignition control signal is invalid, the comparator is enabled to monitor the potential of the ignition enable pin and, upon detecting an anomaly, controls the bypass discharge switch to conduct to discharge the energy of the energy storage capacitor; when the internal original ignition control signal is valid, the comparator is disabled. The ignition enable pin is the FIRE_ENB pin used to control the PMOS ignition switch; The internal resistor network is an internal pull-up resistor connected between the FIRE_ENB ignition enable pin and the charging pin. The ignition control signal driving circuit includes an NMOS transistor, whose source is connected to the system ground pin, its drain is connected to the ignition enable pin FIRE_ENB, and its gate receives the internal raw ignition control signal. An operational amplifier, whose non-inverting input is connected to the charging pin and whose inverting input is connected to the FIRE_ENB firing enable pin; The internal pull-up resistor is configured to have a resistance value greater than that of the external pull-up resistor connected between the ignition enable pin FIRE_ENB and the charging pin.

4. The electronic detonator chip according to claim 3, characterized in that, The voltage value of the reference voltage source is less than the conduction threshold voltage of the external ignition switch.

5. An electronic detonator module, characterized in that, Includes an energy storage capacitor, an ignition element, an ignition switch, and the electronic detonator chip as described in claim 1; The ignition switch is an NMOS transistor, whose gate is connected to the ignition enable pin FIRE_EN of the chip, its source is connected to the system ground pin, and its drain is connected to the negative terminal of the ignition element; the positive terminal of the ignition element is connected to the charging pin; the ignition enable pin FIRE_EN is connected to the system ground pin through an external pull-down resistor.

6. An electronic detonator module, characterized in that, Includes an energy storage capacitor, an ignition element, an ignition switch, and the electronic detonator chip as described in claim 3; The ignition switch is a PMOS transistor, whose gate is connected to the ignition enable pin FIRE_ENB of the chip, its source is connected to the charging pin, and its drain is connected to the positive terminal of the ignition element; the negative terminal of the ignition element is connected to the system ground pin; the ignition enable pin FIRE_ENB is connected to the charging pin through an external pull-up resistor.

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