With the intelligent and digital development of electronic products, the integration of their internal ICs is getting higher and higher, making their worth more and more expensive. For this reason, it is necessary to strengthen circuit safety protection. Everyone in the industry knows that the more sophisticated electronic products, the higher the demand for protection levels, and higher requirements for the circuit protection components to be used. In the circuit protection scheme design process, it is natural not to choose a single protection device, but a combination of multiple protection components. For a veritable electronic engineer, the various protection components in the circuit must be clear. Circuit protection components can be divided into overvoltage and overcurrent according to protection requirements. Overvoltage protection includes surge and electrostatic discharge protection. The current mainstream overcurrent protection components are self-recovery fuses.

Overvoltage protection components can be divided into clamp type and switch type according to the mode of action. The clamp type is the well-known TVS transient suppression diode, ESD electrostatic protection diode, and varistor; the switch type includes: ceramic gas discharge tube , Semiconductor discharge tube. Next, Dongwo Electronics, a professional high-quality protection device manufacturer, focuses on the overvoltage surge suppression protection components commonly used in circuit protection.

TVS transient suppression diode

TVS (Transient Voltage Suppressors) diode is a new type of high-efficiency circuit protection component invented on the basis of Zener diode technology. It has PS-level response speed, large transient power, low leakage current and capacitance, and easy control of clamping voltage. With the advantages of small voltage deviation, high reliability, small size, and convenient installation, it is widely used in the overvoltage protection of sensitive electronic parts. When the two ends of the TVS diode undergo an instantaneous high-energy impact, it changes the impedance between the two ends from high impedance to low impedance at a speed of PS seconds, so as to absorb an instantaneous large current and clamp the voltage between its two ends. A predetermined value, so as to protect the precision components behind from the impact of transient high-voltage spikes. Dongwo Electronics develops, produces, and sells TVS diodes with a wide range of types, complete models, spot inventory, lightning delivery, and free samples. It is a circuit protection device supplier with both strength and technology. The product quality and reliability can be compared with imported brands (such as VISHAY). , ONSEMI, LITTLEFUSE, etc.) are comparable.

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 electrostatic protection diode

ESD (Electrostatic Discharge Protection Devices), a transient voltage suppression diode array (TVS Array), is a single-channel or multiple-channel ESD protection device with specific functions designed by multiple TVS dies or diodes with different layouts. ESD electrostatic protection diode has fast response speed (less than 0.5ns), low capacitance, low on-voltage, high integration, small size, easy installation, and can protect multiple data lines at the same time. It is the most ideal high-frequency data protection device in the industry .

At present, the ESD electrostatic protection diodes independently supplied by Dongwo Electronics are mainly used for electrostatic protection of various communication interfaces, such as USB, HDMI, RS485, RS232, VGA, RJ11, RJ45, BNC, SIM, SD, etc. At the same time, Dongwo Electronics has diversified packaging of ESD electrostatic protection components, from single-channel SOD-323 to multi-channel SOT-23, SOT23-6L, QFN-10, etc., circuit design engineers can choose according to circuit board layout and interface type ESD electrostatic protection diodes in different packages.

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.

Varistor

At present, the varistors used in the surge protection of low-voltage electrical appliances on the market are mostly varistors with zinc oxide as the main material. The varistors are mainly made of zinc oxide, doped with various metal oxides, and are made of typical electronic ceramic processes. Crystal semiconductor ceramic components.

The varistor has a symmetrical volt-ampere characteristic curve, and the current flowing through the MOV increases exponentially with the increase of the voltage across the MOV. In application, MOV is generally connected in parallel in the circuit. When the circuit works normally, it is in a high-impedance state and does not affect the normal operation of the circuit. When an abnormal transient overvoltage occurs in the circuit and reaches its turn-on voltage, the MOV quickly changes from a high-resistance state to a low-resistance state, discharging the transient overcurrent caused by the abnormal transient overvoltage, and simultaneously clamping the abnormal transient overvoltage to one Within the safety level, so as to protect the subsequent circuit from abnormal transient overvoltage damage. MOV has high instantaneous pulse absorption capacity and large capacitance, and is generally used for lightning protection of AC input terminals. Since the surge absorption capacity of a 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

The ceramic gas discharge tube is a closed device composed of one or more discharge gaps filled with inert gas. The electrical performance of GDT depends on factors such as gas type, gas pressure, internal electrode structure, and manufacturing process. When the voltage applied to the two electrode ends causes the gas in the GDT to break down, the discharge begins, changing from high impedance to low impedance, causing the surge voltage to quickly short-circuit to near zero voltage, and releasing the overcurrent to the ground. The subsequent circuit plays a protective role.

GDT can withstand surge currents of up to tens or even hundreds of thousands of amperes, and has extremely low junction capacitance. It is used to protect electronic equipment and humans from transient high voltage hazards. It is the most widely used lightning protection device. Switching components. Dongwo Electronics GDT surge current can reach 20KA, 40KA, 50KA, 60KA, 100KA, 150KA, or even higher; insulation resistance can reach 10G; inter-electrode capacitance as low as 1PF; widely used in communication lines and communication distribution frames Lightning protection in the security unit and high-frequency circuit.

Specification series: ceramic gas discharge diode, ceramic gas discharge triode, chip ceramic discharge tube, low pulse ceramic gas discharge tube, large current discharge tube, switch ceramic gas discharge tube, large current interruption current tube.