Internal supply voltage generation circuit

Claim 2

An internal supply voltage generation device, receiving an external supply voltage and having a normal operation mode and a burn-in operation mode, comprising: a reference voltage generator producing a reference voltage; means for level converting said reference voltage; external supply voltage detection means for receiving said reference voltage and for detecting a level of said external supply voltage; burn-in mode setting means for receiving said reference signal and for setting said burn-in operation mode; burn-in signal generation means, responsive to outputs from said external supply voltage detection means and said burn-in mode setting means, for generating a burn-in signal; burn-in voltage control means, responsive to an output of said burn-in signal generation means, for controlling a voltage output level of said means for level converting; and, internal supply voltage output means coupled to outputs of said burn-in voltage control means and said means for level converting for generating an internal supply voltage during said normal operation mode, and said external supply voltage during said burn-in operation mode in accordance with said voltage output level of said means for level converting.

Claim 3

The internal supply voltage generation device of claim 1, wherein said burn-in mode setting means comprises a fuse which can be selectively severed to adjust a level of said burn-in signal.

Claim 4

The internal supply voltage generation device of claim 2, wherein said external supply voltage detection means, comprises: a plurality of diode-connected MOS transistors connected in series between said external supply voltage and ground; an output line connected to one of said plurality of MOS transistors; and, a fuse connected in parallel with at least one of said plurality of MOS transistors.

Claim 5

An internal supply voltage generation device, comprising: a reference voltage generator for generating a reference voltage; a level conversion circuit receiving said reference voltage, said level conversion circuit generating a level conversion output having a voltage level equal to an external supply voltage when said external supply voltage is below a first predetermined threshold, and having a voltage level equal to an internal supply voltage when said external supply voltage reaches said first predetermined threshold; an external supply voltage detector coupled to said reference voltage for generating a detector output having a first logic level when said external supply voltage is below a second predetermined threshold, and a second logic level when said external supply voltage reaches said predetermined second threshold, said external supply voltage detector including a first fuse which can be selectively severed to adjust the level of said second predetermined threshold; a burn-in mode setting circuit coupled to said reference voltage for producing a burn-in mode output which sets a burn-in mode, said burn-in mode setting circuit including a second fuse which can be selectively severed to adjust a level of said burn-in mode output; a burn-in signal generator for generating a burn-in signal in in response to said detector output and said burn-in mode output; a burn-in voltage control circuit for controlling said voltage level of said level conversion output in response to said burn-in signal; and, an internal supply voltage output circuit for selectively outputting said internal supply voltage or said external supply voltage, in accordance with said level conversion output.

Claim 6

An internal supply voltage generation device, comprising: a reference voltage generator for generating a reference voltage; a level conversion circuit receiving said reference voltage, said level conversion circuit generating a level conversion output having a voltage level equal to an external supply voltage when said external supply voltage is below a first predetermined threshold, and having a voltage level equal to an internal supply voltage when said external supply voltage reaches said first predetermined threshold; an external supply voltage detector coupled to said reference voltage for generating a detector output having a first logic level when said external supply voltage is below a second predetermined threshold, and a second logic level when said external supply voltage reaches said predetermined second threshold, said external supply voltage detector including a first fuse which can be selectively severed to adjust the level of said second predetermined threshold; a burn-in mode setting circuit coupled to said reference voltage for producing a burn-in mode output which sets a burn-in mode, said burn-in mode setting circuit including a second fuse which can be selectively severed to adjust a level of said burn-in mode output; a burn-in signal generator for generating a burn-in signal in in response to said detector output and said burn-in mode output; a burn-in voltage control circuit for controlling said voltage level of said level conversion output in response to said burn-in signal; and, an internal supply voltage output circuit for selectively outputting said internal supply voltage or said external supply voltage, in accordance with said level conversion output.

Claim 7

The internal supply voltage generation device of claim 4, wherein said external supply voltage detector, comprises: a plurality of diode-connected MOS transistors connected in series between said external supply voltage and ground; an output line connected to one of said plurality of MOS transistors; and, said first fuse, connected in parallel with at least one of said plurality of MOS transistors.

Claim 8

The internal supply voltage generation device of claims 4, wherein said burn-in signal generator comprises a NOR gate receiving as inputs said burn-in mode output and said detector output.

Claim 9

The internal supply voltage generation device of claim 4, wherein said burn-in voltage control circuit comprises: a MOS transistor connected to said external supply voltage, and responsive to said burn-in signal; a plurality of diode-connected MOS transistors connected in series between said MOS transistor and said level conversion output; and, at least one third fuse connected in parallel with at least one of said plurality of diode-connected MOS transistors.