Overvoltage surge suppression protection components ensure the safety of the circuit.
With the intelligent and digital development of electronic products, the integration degree of their internal ICs has been increasing, making their prices rise accordingly. Therefore, it is necessary to strengthen circuit safety protection. Everyone in the industry knows that the more sophisticated the electronic products are, the higher the demand for protection levels becomes, and higher requirements are placed on the circuit protection components to be used. In the design of circuit protection schemes, it is not just a single protection component that is selected, but rather a combination of multiple protection components. For a genuine electronic engineer, all the various protection components in the circuit must be well understood. Circuit protection components can be classified into two major categories based on protection needs: overvoltage protection and overcurrent protection. Among them, overvoltage protection includes surge and electrostatic discharge protection. Currently, the mainstream overcurrent protection components are self-recovery fuses.
Overvoltage protection components can be classified into clamp-type and switch-type based on their working modes. The clamp-type includes the well-known TVS transient suppressor diodes, ESD static protection diodes, and varistors; the switch-type includes: ceramic gas discharge tubes and semiconductor discharge tubes. Next, Dongwo Electronics, a professional and high-quality protection component manufacturer, will focus on introducing the commonly used overvoltage surge suppression protection components in circuit protection.
TVS transient voltage suppression diode
TVS (Transient Voltage Suppressor) diodes are a new type of highly efficient circuit protection component invented based on the technology of zener diodes. They possess advantages such as PS-level response speed, large transient power capacity, low leakage current and capacitance, easy control of clamping voltage, small breakdown voltage deviation, high reliability, small size, and convenient installation. They are widely used in overvoltage protection of sensitive electronic components. When the two ends of a TVS diode are subjected to a sudden high-energy impact, it changes the impedance value between the two ends from high impedance to low impedance at a PS-second speed to absorb a sudden large current, clamping the voltage between the two ends to a predetermined value, thereby protecting the subsequent precision components from the impact of transient high-voltage spike pulses. Dongwo Electronics, a manufacturer specializing in research, production and sales of TVS diodes, offers a wide variety of types and models, with full stock inventory, lightning-fast delivery, free samples. It is a circuit protection component supplier with both strength and technology, and its product quality and reliability can be comparable to imported brands (such as VISHAY, ONSEMI, LITTLEFUSE, etc.).
Specification series: SM5S, SM6S, SM8S, SMAJ, P4SMA, TPSMAJ, SMA6J, TPSMA, SACA, SMBJ, P6SMB, TPSMBJ, SMB10J, SACB, 1.0SMB, TPSMB, 1.5SMC, SMCJ, TPSMCJ, SMDJ, TPSMDJ, 5.0SMDJ, TP5.0SMDJ, TPSMC, SMF, TPSMF, SMF4L, SMF3.3A, P4KE, SA, P6KE, SAC, 1.5KE, LCE, 3KP, 5KP, LDP, 15KP, 30KP, Blue Baby Surge Suppressor NA, etc.
ESD static electricity protection diode
ESD (Electrostatic Discharge Protection Devices), transient voltage suppression diode array (TVS Array), is a single-channel or multi-channel ESD protection device with specific functions, which is composed of multiple TVS diodes or diodes with different layout designs. ESD static protection diodes have fast response speed (less than 0.5ns), low capacitance, low on-state voltage, high integration, small size, easy installation, and can simultaneously protect multiple data lines. It is the most ideal high-frequency data protection device in the industry.
Currently, the ESD static protection diodes independently supplied by Dongwo Electronics are mainly used for static protection in various communication interfaces, such as USB, HDMI, RS485, RS232, VGA, RJ11, RJ45, BNC, SIM, SD, etc. At the same time, the packaging of Dongwo Electronics' ESD static protection components is diverse, ranging from single-channel SOD-323 to multi-channel SOT-23, SOT23-6L, QFN-10, etc. Circuit design engineers can select different packaged ESD static protection diodes based on the layout of the circuit board and the type of interface.
Specification series: Single-channel ESD and EOS protection devices, low-capacitance TVS arrays, standard capacitance TVS arrays, low-voltage TVS arrays, high-power TVS arrays, SM712, PSM712, etc.
Pressure-sensitive resistor
At present, the varistors used in low-voltage electrical equipment for surge protection are mostly varistors with zinc oxide as the main material. They are made by doping various metal oxides into zinc oxide and then using the typical electronic ceramic process to fabricate polycrystalline semiconductor ceramic components.
The varistor has a symmetrical volt-ampere characteristic curve. The current flowing through the MOV increases exponentially with the increase of the voltage between the two terminals of the MOV. When used, the MOV is generally connected in parallel in the circuit. When the circuit is working normally, it is in a high-resistance state and does not affect the normal operation of the circuit. When an abnormal transient overvoltage occurs in the circuit and reaches its conduction voltage, the MOV rapidly changes from a high-resistance state to a low-resistance state, discharging the transient overcurrent caused by the abnormal transient overvoltage and clamping the abnormal transient overvoltage within a safe level, thereby protecting the subsequent circuit from damage caused by the abnormal transient overvoltage. The varistor has a high instantaneous pulse absorption capacity and a large capacitance. It is generally applied in AC input end lightning protection. Since the surge absorption capacity of the varistor depends on its physical size, different transient surge current values can be obtained by custom manufacturing MOVs of different sizes.
Specification series: 05D series, 07D series, 10D series, 14D series, 20D series, 25D series.
Ceramic gas discharge tube
A ceramic gas discharge tube is a sealed device composed of one or more discharge gaps filled with an inert gas inside. The electrical performance of GDT depends on factors such as the type of gas, gas pressure, internal electrode structure, and manufacturing process. When the voltage applied to the two electrodes reaches the point where the gas inside the GDT breaks down, discharge begins. The high impedance changes to low impedance, causing the surge voltage to quickly short-circuit to nearly zero voltage and releasing the overcurrent into the ground, thereby providing protection for the subsequent circuit.
The GDT can withstand surge currents of up to tens or even hundreds of thousands of amperes, with extremely low junction capacitance. It is used to protect electronic equipment and personnel from transient high voltages, and is the most widely used switching component in lightning protection devices. Dongwo Electronics' GDT surge currents can reach 20KA, 40KA, 50KA, 60KA, 100KA, 150KA, and even higher; the insulation resistance can reach 10G; the inter-electrode capacitance is as low as 1PF; and it is widely used in communication lines, communication distribution frames' security units, and high-frequency circuits for lightning protection.
Specification series: Ceramic gas discharge diodes, Ceramic gas discharge triodes, Surface mount ceramic discharge tubes, Low pulse ceramic gas discharge tubes, High current discharge tubes, Switching ceramic gas discharge tubes, High current intermittent discharge tubes.
