Programmable overvoltage protection device having VDMOS and thyristor

Abstract

The invention relates to a programmable overvoltage protection device with a VDMOS and a thyristor, and belongs to the technical field of power semiconductors. According to the programmable overvoltage protection device, two VDMOSs are used for providing independent control over two NPNP thyristors respectively, and the gate ends of the VDMOSs are connected with negative power supply voltage; or,the two VDMOSs are respectively used for providing independent control over the two PNPN thyristors; the gate end of the VDMOS is connected with positive power supply voltage; when the negative voltage on the telephone line is lower than a threshold voltage of the power supply voltage or the positive voltage is higher than the threshold voltage of the power supply voltage, the device is started and conducts overvoltage generated by surge on the transmission line to the ground, so that a subscriber line interface circuit (SLIC) is protected from surge overvoltage caused by lightning stroke andother factors, one-way programmable protection is realized, and the characteristics of a VDMOS longitudinal structure and a unipolar device are utilized, so that the power consumption is low, the temperature characteristic is good, the programmable input voltage range is wider, and the surge voltage bearing capacity is higher.

Description

technical field [0001] The invention belongs to the technical field of power semiconductors, in particular to a programmable overvoltage protection device with a VDMOS and a thyristor. Background technique [0002] With the rapid development of modern electronic communication technology, the transmission speed and efficiency continue to increase. At the same time, electronic equipment and complete systems have higher and higher requirements for external voltage. Voltage transients and surge currents will cause malfunctions or even damage to communication equipment and the whole system, so surge protection devices are needed to protect them. After Europe and the United States successively promulgated standards for anti-lightning surges of communication equipment, my country promulgated the "People's Republic of China Communication Industry Standards for Telecommunications Terminal Equipment Lightning Protection Technical Requirements and Experimental Methods YD / T9931998" in 1...

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Problems solved by technology

However, this structure also has certain problems. Since the triode is a bipolar device, the switching speed is slow, the frequency is low, the on-resistance is large, so the power consumption is high, and the current amplification factor β is greatly affected by the temperature. For the protection device as a whole It will show undesirable characteristics such as slow response speed, poor temperature characteristics, and large power consumption.

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