Patent ID: 9257973
Filing Date: 2016-02-09
CPC Classification: H03K

Claim Text:
1. Level-shifting circuitry comprising: (a) an enable circuit receiving an input enable signal that is referenced to a first supply voltage and also generating a corresponding level-shifted output enable signal that is referenced to a second supply voltage, the enable circuit including bias control circuitry which both prevents shoot-through currents from occurring in the enable circuit during ramping of the first supply voltage and also prevents indeterminate voltage and logic levels of the level-shifted output enable signal during the ramping of the first supply voltage; and (b) an enabled level-shifting circuit receiving an input logic signal that is referenced to the first supply voltage and also generating a corresponding level-shifted output logic signal that is referenced to the second supply voltage, the enabled level-shifting circuit including enable circuitry which operates in response to the level-shifted output enable signal to enable normal level-shifting operation while the first and second supply voltages are at normal operating levels and to prevent the shoot-through currents from occurring in the enabled level-shifting circuit during the ramping of the first supply voltage and also to force the level-shifted output logic signal to a predetermined level during the ramping of the first supply voltage.