High speed voltage level shifter

A voltage level shifter, comprising:

• an input terminal, for receiving a non-inverted input signal having a first voltage level and a second voltage level, wherein the first voltage level is a reference voltage level and the second voltage level is higher than the first voltage level;
• a boost circuit, for producing a boosted signal, which includes:
• a capacitor, for producing an intermediate signal at a third voltage level when an inverted input signal is at the second voltage level, wherein the third voltage level is higher than the second voltage level;
• a first P-type transistor, responsive to the inverted input signal, for charging the capacitor when the inverted input signal is at the first voltage;
• a first N-type transistor, responsive to the non-inverted input signal, for pulling down the boosted signal to the first voltage level when the non-inverted input signal is at the second voltage level;
• and
• a second P-type transistor, for passing the intermediate signal to the boosted signal when the non-inverted input signal is at the first voltage level;
• wherein the capacitor is charged, by way of the first P-type transistor, from a first power source having the second voltage level, such that the intermediate signal substantially remains at the second voltage level when the inverted input signal is at the first voltage level;
• a voltage shifting stage coupled to the boost circuit, for producing an output signal in response to the inverted input signal and the boosted signal, the output signal at a fourth voltage level when the inverted input signal and the boosted signal are both at the first voltage level, and at the first voltage level when the inverted input signal is at the second voltage level and the boosted signal is at the third voltage level;
• and
• an output terminal, for providing the output signal which has an output voltage swing between the first voltage level and the fourth voltage level.