Apparatus and method for preventing current leakage when a low voltage domain is powered down

An apparatus, comprising:

• a voltage transition circuit connected between a low voltage domain and a high voltage domain, the voltage transition circuit including a circuit component for preventing a current leakage or direct current when the low voltage domain is powered down;
• wherein the voltage transition circuit includes an input-rising-transition circuit, the input-rising-transition circuit comprising:
• a first n-type transistor having a gate connected to a single-rail input, the first n-type transistor having a source connected to a ground voltage, and a drain connected to an output contact point, the output contact point being connected to a gate of a first p-type transistor of an input-falling-transition circuit;
• and
• a second p-type transistor having a drain connected to the output contact point and a gate connected to a contact point of the input-falling-transition circuit;
• wherein the input-rising-transition circuit has a third p-type transistor connected in series with the second p-type transistor, the third p-type transistor having a drain connected to a source of the second p-type transistor and a gate connected to the single-rail input.

A method, comprising:

• receiving at a voltage transition circuit a power supply voltage from a low voltage domain;
• converting the power supply voltage from the low voltage domain to a high voltage domain;
• and
• preventing a current leakage or direct current when the low voltage domain is powered down;
• wherein the voltage transition circuit includes an input-falling-transition circuit, the input-falling-transition circuit comprising:
• a p-type transistor;
• and
• an n-type transistor having a drain connected to a drain of the p-type transistor at a contact point, a source connected to a single-rail input, the p-type transistor having a source connected to a VDDH voltage of the high voltage domains;
• wherein the n-type transistor has a gate connected to a power down input.

A system, comprising:

• means for receiving at a voltage transition circuit a power supply voltage from a low voltage domain;
• means for converting the power supply voltage from the low voltage domain to a high voltage domain;
• and
• means for preventing a current leakage or direct current when the low voltage domain is powered down;
• wherein the voltage transition circuit includes an input-falling-transition circuit, the input-falling-transition circuit comprising:
• a p-type transistor;
• and
• an n-type transistor having a drain connected to a drain of the p-type transistor at a contact point, a source connected to a single-rail input, the p-type transistor having a source connected to a VDDH voltage of the high voltage domain;
• wherein the n-type transistor has a gate connected to a power down input.