High voltage open drain electrostatic discharge (ESD) protecting device

Abstract

The invention discloses a high voltage open drain electrostatic discharge (ESD) protecting device which comprises a first high voltage N passage metal-oxide-semiconductor field effect transistor (HV MOSFET) which is connected with a high voltage welding pad and a low voltage end and receives high voltage of the high voltage welding pad so as to operate normally. The high voltage welding pad and the first HV MOSFET are further connected with a high voltage ESD protecting unit which does not influence the normal circuit function at normal operation time, but when ESD events of the high voltage welding pad occur, the high voltage ESD protecting unit can efficiently release ESD currents of the ESD events after receiving the ESD voltage of the high voltage welding pad. The high voltage ESD protecting unit and the low voltage end are connected with a voltage clamping unit. According to the high voltage ESD protecting device, the high voltage ESD protecting unit receives the ESD voltage so as to release the ESD currents.

Description

technical field [0001] The invention relates to a protection device, in particular to a high-voltage open-drain electrostatic discharge (ESD) protection device. Background technique [0002] The open-drain input / output (I / O) cell design is suitable for applications where the external voltage applied to the I / O pad is higher than the internal supply voltage of the I / O cell database. For a high-voltage open-drain buffer, it must not contain a high-voltage P-channel metal-oxide-semiconductor field-effect transistor (HV PMOSFET) connected from the I / O pad to the power line so that the I / O pad remains A voltage higher than the supply voltage. Therefore, it is difficult for an open-drain buffer to have excellent ESD protection capability. [0003] see figure 1 , the traditional multi-channel high-voltage open-drain buffer uses an ESD bus to reduce the size of the open-drain buffer, wherein each open-drain channel shares the same ESD clamping element 10 to discharge the ESD curr...

AI Technical Summary

Problems solved by technology

However, the original open-drain I / O cell does not contain a high-voltage P-channel MOSFET connected to the power line by the I / O pad.

Therefore, the number of mask layers will increase due to the redundant high-voltage P-channel MOSFETs using high-voltage complementary MOSFET inverters, which means that the cost of integrated circuit (IC) manufacturing will also increase. improve

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