Radio-frequency LDMOS transistor with overheat protection function

Abstract

The invention provides a radio-frequency LDMOS transistor with an overheat protection function. The radio-frequency LDMOS transistor comprises an SONOS device, an NPN BJT heat sensor and a radio-frequency LDMOS device integrated on a same chip, wherein positive charges are stored at a gate of the SONOS device; the gate of the SONOS device is connected to a base of the NPN BJT heat sensor through a metal and provides an emitter junction of the NPN BJT heat sensor with bias; and a collector of the NPN BJT heat sensor is connected to the gate of the LDMOS device and provides the gate of the LDMOS device with a current discharge channel. An overheat protection circuit of the radio-frequency LDMOS device is integrated on the radio-frequency LDMOS chip and an independent power supply pin is not needed, so that the complexity of a radio-frequency system is greatly reduced and the manufacturing cost and the maintenance cost of the radio-frequency system employing the radio-frequency LDMOS device as a core are reduced.

Description

Technical field [0001] This application relates to a semiconductor device, specifically a radio frequency LDMOS transistor with overheating protection function. Background technique [0002] Radio frequency LDMOS (Laterally Double-Diffused Metal Oxide Semiconductors, lateral double diffused transistors) field effect transistor is a wide range of radio frequency devices, with good linearity, high power gain, high withstand voltage, good matching performance, high efficiency and output High power and other advantages. It is widely used in wireless communications, mobile base stations, satellite communications, radar and navigation. [0003] The conventional RF LDMOS structure is as figure 1 Shown. In the application of high-power RF LDMOS devices, the heating of RF LDMOS devices cannot be ignored. If the heat dissipation of the radio frequency system fails or the device works under other poor heat dissipation conditions, the radio frequency LDMOS device is easily burned out due to...

AI Technical Summary

Problems solved by technology

Traditional overheating protection has two forms, 1) consists of an external circuit with a thermal sensor as the core, which increases the complexity of the RF system and increases the cost; 2) integrates the thermal sensor and protection circuit inside the chip, so that Reduced cost, but internal sensors and circuits require independent power supply, which requires additional external power supply pins, which is not compatible with existing packages, and additional power supply in the RF system will also increase the cost

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