Input/output circuit with high voltage tolerance and associated apparatus
AssigneeMStar Semiconductor, Inc.
InventorsYao-Zhong Zhang, Ju-Ming Chou, Chih-Tien Chang
Life of this patent
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Abstract
An input/output (IO) circuit with high voltage tolerance is provided. In an integrated circuit, the IO circuit includes a charge pump for generating a bias voltage higher than an internal operating voltage of the charge pump itself, and a switch between an external circuit and an internal circuit of the integrated circuit. When the switch conducts between the external circuit and the internal circuit, the switch provides a clamping voltage according to the bias voltage and a cross voltage of the switch, so that a voltage of the internal circuit is bounded by the clamping voltage to prevent the internal circuit from over-voltage.
Claims19
An input/output (IO) circuit with high voltage tolerance, comprising:
- a charge pump, for generating a bias voltage;
- and
- a switch circuit, having a first end, a second end and a third end, the first end receiving an external signal, the second end being coupled to the charge pump;
- wherein, the switch circuit provides a predetermined cross voltage between the second end and the third end when the switch circuit conducts between the first end and the third end, so that the IO circuit determines a clamping voltage range according to the bias voltage and the predetermined cross voltage to clamp a voltage at the third end within the clamping voltage range.
An IO circuit with high voltage tolerance, comprising:
- a charge pump, for generating a bias voltage Vg;
- and
- a switch circuit, having a first end, a second end and a third end;
- the first end being coupled to an external signal, and the second end being coupled to the charge pump;
- wherein, the switch circuit provides a predetermined cross voltage Vth between the second end and the third end when the switch circuit conducts the first end to the third end, so as to clamp a voltage at the third end below a voltage (Vg−Vth).
An integrated circuit with high voltage tolerance, comprising:
- a charge pump, for generating a bias voltage Vg;
- and
- a plurality of pad circuits, each comprising:
- a switch circuit, having a first end, a second end, and a third end;
- the first end for receiving an external signal, and the second end being coupled to the bias voltage Vg;
- wherein, the switch circuit provides a predetermined cross voltage Vth between the second end and the third end when the switch circuit conducts the first end to the third end, and provides a clamping voltage according to the bias voltage Vg and the predetermined cross voltage Vth to clamp a voltage at the third end.
Dependencies are inferred from the claim text.