The output stage circuit of the integrated circuit

Abstract

The invention discloses an output stage circuit of an integrated circuit. The output stage circuit comprises an upper switch unit and a lower switch unit connected in series, wherein a serially connected node is an output end, the upper switch unit comprises two butted P type transistor elements, and the lower switch unit comprises two N type transistor element connected in series. Autologous diodes of the two N type transistor element connected in series form two reverse diodes connected in series for sharing surge test voltage; the autologous diode of one of the two butted P type transistor elements forms a forward diode, the autologous diode of the other P type transistor element is the reverse diode with one end connected with a high level voltage end, so that the element only needs to bear voltage difference between the surge test voltage and the high level voltage, and thus withstand voltage of each of the P type transistor elements and the N type transistor elements is less than the surge test voltage.

Description

technical field [0001] The present invention relates to an output stage circuit of an integrated circuit, especially an output stage circuit with self-surge test protection. Background technique [0002] The output stage circuit of a general integrated circuit must pass a surge test to confirm that the integrated circuit has the ability to withstand surge. At present, the surge test of the output stage circuit includes three test methods: (1) when the working power is turned off, add the surge test voltage; (2) when the working power is turned on and the logic value of "1" is output, add the surge test and (3) adding a surge test voltage under the logic value of turning on the working power and outputting "0". [0003] Since the output stage circuit of the integrated circuit is mostly composed of PMOS elements and NMOS elements, such as output buffers, inverters, etc.; Image 6 As shown, it is a common circuit structure of the output stage circuit 51 in the integrated circu...

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Problems solved by technology

[0005] However, the use of PMOS or NMOS components with a high withstand voltage of 120V in integrated circuits will inevitably sacrifice the layout area of ​​the components; moreover, more process masks must be used for PMOS or NMOS components with high withstand voltage, and the production cost will be relatively increased. ; Therefore, it is necessary to further improve the output stage circuit of the current integrated circuit

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