Abstract: A level shifter circuit including first and second circuits and a protection layer. The first circuit receives an input signal and switches first and second nodes to opposite states within a first voltage range between first and second supply voltages. The second circuit switches the third and fourth nodes to opposite states within a second voltage range between third and fourth supply voltages in response to switching of the first and second nodes. The protection layer couples the first and second nodes to third and fourth nodes via respective first and second isolation paths. The isolation paths operate to keep the first and second nodes within the first voltage range and to keep the third and fourth nodes within the second voltage range. Isolation enables the use of thin gate-oxide devices for speed while extending the voltage range beyond the maximum voltage allowable for a single thin gate-oxide device.

Abstract: A high speed output buffer including an input circuit providing first and second signals within a first voltage range having a first common mode voltage, an AC interface receiving the first and second signals and providing first and second preliminary drive signals, a detection and correction circuit that corrects a state of the first preliminary drive signal AC coupled to the first signal, first and second drive circuits receiving the preliminary drive signals and providing first and second drive signals, where the first drive circuit operates within a second voltage range having a greater common mode voltage and where the second drive circuit operates within a third voltage range, and an output that switches an output node within a voltage range that is greater than a maximum voltage range. The first, second and third voltage ranges are each within the maximum voltage range suitable for thin-gate devices.

Abstract: A programmable PLL including a receiver, a phase frequency detector, a charge pump, and a VCO. The receiver includes a programmable capacitor voltage divider that shifts voltage of an input clock to provide a level-shifted clock. The AC interface includes a state detection and correction circuit that ensures proper state of the level-shifted clock. The PLL includes a pulse delay modulator for generating delayed clock control signals. The VCO includes a programmable phase control circuit that dynamically adjusts phase using the delayed clock control signals. The VCO circuit includes a ring oscillator circuit with one or more phase control nodes. The programmable phase control circuit selectively couples devices to the phase control node using the clock control signals to adjust phase. The devices may be capacitors or transistors, each switched using switches controlled by the delayed clock control signals. The capacitors may be metal capacitors or semiconductor transistor capacitors.