High voltage stabilizer and high voltage intrinsic NMOS tube

Abstract

The invention discloses a high voltage stabilizer which comprises a current limiting resistor, a clamping circuit and a high voltage intrinsic NMOS tube, wherein the current limiting resistor and the clamping circuit are connected in series between an external power source and the ground, and the source electrode of the high voltage intrinsic NMOS tube is connected with an internal circuit, the drain electrode is connected with an external electric end, and a gate electrode is connected with the current limiting resistor and the clamping circuit. The invention also discloses a high voltage intrinsic NMOS tube. A part of a gate oxide layer close to a source electrode N+ is a thin gate oxide layer; a part of the gate oxide layer close to a drain electrode N+ is a thick gate oxide layer; high voltage N wells are generated below the drain electrode N+ and the thick gate oxide layer; the high voltage N wells completely envelope the thick gate oxide layer and the drain electrode N+; the doping concentration of the high voltage N-well region is smaller than that of a P substrate region; and a polysilicon part of the gate electrode covers the thick gate oxide layer. The high voltage stabilizer of the invention has simple structure, large driving capacity and low power consumption.

Description

technical field [0001] The invention relates to semiconductor technology, in particular to a high-voltage voltage stabilizer and a high-voltage intrinsic NMOS tube. Background technique [0002] There are usually two solutions for the high-voltage regulator circuit currently used. One is the voltage regulation circuit made of high-voltage PMOS and high-voltage NMOS. Due to the complicated manufacturing process and high cost of high-voltage PMOS and high-voltage NMOS, high-voltage PMOS and high-voltage NMOS are used. The voltage adjustment circuit will obviously increase the production cost; the other is to use a general voltage clamping circuit, such as figure 1 As shown, the external power supply VDD is connected to a clamping circuit through a current limiting resistor, and the output voltage VOUT of the voltage clamping circuit is equal to the external power supply voltage VDD minus the product of the internal circuit load current and the current limiting resistor R, so a...

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Problems solved by technology

[0002] There are usually two solutions for the high-voltage regulator circuit currently used. One is the voltage regulation circuit made of high-voltage PMOS and high-voltage NMOS. Due to the complicated manufacturing process and high cost of high-voltage PMOS and high-voltage NMOS, high-voltage PMOS and high-voltage NMOS are used. The voltage adjustment circuit will obviously increase the production cost; the other is to use a general voltage clamping circuit, such as figure 1 As shown, the external power supply VDD is connected to a clamping circuit through a current limiting resistor, and the output voltage VOUT of the voltage clamping circuit is equal to the external power supply voltage VDD minus the product of the internal circuit load current and the current limiting resistor R, so as the load current increases increase, the output voltage VOUT will decrease correspondingly, in order to meet the demand of larger load current, the current limiting resistor R can only take a smaller resistance; on the other hand, for the input of higher external power supply voltage VDD, A current-limiting resistor R with a smaller resistance value will inevitably bring greater power consumption. Therefore, common voltage clamping circuits cannot have a larger current drive capability and a smaller power consumption at the same time. The drive capability is limited and the drive capability increases. while the power consumption will increase rapidly

[0003] Existing intrinsic NMOS such as figure 2 As shown, the channel under the gate oxide layer is P-substrate silicon without ion implantation. The cost of intrinsic NMOS is low, but the gate, source and drain cannot withstand high voltage, and the threshold voltage is -0.3 Between V and 0.3V, generally only used in low-voltage circuits

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