What is a trigger diode? The basic structure, characteristics, working principle, application, detection, and measurement methods, installation steps, and development history of trigger diodes

Trigger diode, also known as bipolar trigger or bipolar rheostat, is a special type of diode. Compared with ordinary diodes, trigger diodes have more control methods and higher sensitivity. It can use changes in external voltage or current to regulate the conduction or cutoff state of the device, thereby achieving control over the circuit. The following will provide a detailed introduction to the basic knowledge of triggering diodes.

1、 Basic structure:

A trigger diode is composed of three layers of semiconductor material, with the P-type semiconductor layer sandwiched in the middle called the trigger layer, and the N-type semiconductor layers on both sides called the main region. The structure of the trigger diode is similar to that of a regular diode, but the doping concentration of the trigger layer is lower, resulting in higher resistance in this region.

2、 Characteristics:

1. Amplification capability: The trigger diode can amplify the input signal and achieve signal amplification.

2. Controllability: By controlling the current in the base area, the current in the collector area can be controlled to achieve signal control.

3. High frequency characteristics: Trigger diodes have high frequency response capability and are suitable for high-frequency circuits.

4. High reliability: Trigger diodes have high reliability and stability.

3、 Working principle:

The working principle of the trigger diode is based on the conductivity characteristics of the PN junction. When the control junction is in a forward bias state, the trigger diode is in a conducting state, and current can flow through the device. When the control junction is in a reverse bias state, the trigger diode is in an off state, and current cannot pass through the device.

The trigger diode can change the bias state of the control junction through external voltage or current, thereby achieving control of the device. When the input signal is applied to the control junction, if its polarity causes the control junction to be in a forward bias state, it triggers the diode to conduct; If the input signal causes the control junction to be in a reverse bias state, it triggers the diode to turn off. In this way, by changing the polarity and amplitude of the input signal, control of the trigger diode can be achieved.

4、 Application:

Trigger diodes are widely used in various electronic circuits due to their high sensitivity and fast speed, including:

1. Pulse circuit: Trigger diodes can be used to construct various pulse circuits, such as multi harmonic oscillators, counters, pulse generators, etc.

2. Voltage control circuit: Trigger diodes can be used to construct voltage control circuits, such as voltage regulators, voltage comparators, etc.

3. Logic circuit: Trigger diodes can be used to construct logic gate circuits, such as AND gates, OR gates, NOT gates, etc.

4. Amplification circuit: Trigger diodes can be used to construct amplification circuits, such as amplifiers, switch circuits, etc.

5、 Testing:

In order to ensure the normal operation of diodes, there are several commonly used detection methods, including the following:

1. Voltage test: Use a multimeter or oscilloscope to measure the forward voltage and reverse resistance of a diode.

2. Current testing: Use an ammeter to measure the forward and reverse currents of a diode.

3. Peak Reverse Voltage (PRV) Test: Test the maximum reverse voltage that a diode can withstand.

4. Reverse current test: Test the leakage current of a diode under reverse voltage.

6、 Method for measuring the transition voltage of a trigger diode:

The transition voltage (also known as the turn-on voltage or trigger voltage) that triggers a diode refers to the voltage at which the diode transitions from the off state to the on state under forward bias. There are several methods for measuring the transition voltage of a trigger diode, including the following:

1. Multimeter method: Use a multimeter to forward bias the trigger diode and gradually increase the voltage until the diode transitions from the off state to the on state, at which point the voltage is the transition voltage.

2. Oscilloscope method: Use an oscilloscope and a signal generator to form a testing circuit. Connect the output signal of the signal generator to the forward bias terminal of the trigger diode, and observe the conduction state of the diode through the oscilloscope. When the output voltage of the signal generator gradually increases and the trigger diode transitions from the off state to the on state, a jumping signal waveform will appear on the oscilloscope, and the voltage at this time is the transition voltage.

3. Semiconductor parameter tester method: Using a dedicated semiconductor parameter tester, the trigger diode is forward biased and the turning voltage of the diode is measured through the tester.

7、 Installation steps:

The installation steps for triggering diodes are generally as follows:

1. Preparation work: Clean the workbench, ensure it is dust-free, and prepare the necessary tools and materials.

2. Determine installation location: According to the circuit design requirements, determine the installation location of the trigger diode and mark it on the circuit board.

3. Prepare trigger diode: Remove the trigger diode from the packaging, check for damage, and confirm the pin markings and specifications.

4. Welding: Use solder to solder the pins of the trigger diode to the corresponding positions on the circuit board. Pay attention to maintaining good contact between the pins and the circuit board, and ensure that the soldering points are firm and reliable.

5. Check: After welding is completed, use a multimeter or other testing equipment to check for short circuits or open circuits between the pins of the trigger diode.

6. Insulation treatment: Insulate the trigger diode as needed to prevent interference or damage to the surrounding circuit.

7. Cleaning and organization: Clean up the welding slag and debris generated during the welding process, and organize other components and circuits on the circuit board.

8、 Development history:

The trigger diode was first invented by American physicist Walter H. Schottky in 1938, who introduced a potential barrier between metal and semiconductor to achieve the triggering function of the diode. With the development of semiconductor technology, the performance of trigger diodes continues to improve, and their application scope is becoming more and more extensive.

In the early days, trigger diodes were mainly used in the field of wireless communication for detecting, modulating, and demodulating wireless signals. With the rise of digital electronic technology, trigger diodes have been widely used in digital circuits, counters, timers, and other fields. The high-speed switching and high-frequency characteristics of trigger diodes make them one of the important components in digital circuits.

In recent years, with the continuous development of electronic technology, the performance of trigger diodes has been further improved. Some new materials and structures of trigger diodes have emerged, such as Schottky barrier diodes, PIN diodes, etc. These new trigger diodes have higher switching speeds, lower power consumption, and better linearity, making them suitable for a wider range of application fields