Patent ID: 7652504
Filing Date: 2010-01-26
Classification: G11C,H03K

Abstract:
1. An apparatus comprising: a circuit supplied by a first supply voltage during use, the circuit having at least a first input signal; and a level shifter supplied by the first supply voltage during use and coupled to provide the first input signal to the circuit, wherein the level shifter is coupled to receive a second input signal sourced from circuitry supplied by a second supply voltage during use, and wherein the level shifter is configured to generate the first input signal by level shifting the second input signal; wherein the level shifter is further coupled to receive a power control signal indicating, when asserted to a first logic state, that the second supply voltage is to be powered down to a ground reference, and wherein the level shifter is configured to assert a predetermined voltage level on the first input signal independent of the second input signal and responsive to an assertion of the power control signal to the first logic state; and wherein the level shifter comprises: at least one additional transistor coupled to the internal node and controlled responsive to the power control signal, and wherein the additional transistor is configured to establish a second voltage on the internal node responsive to the assertion of the power control signal to the first logic state.