Patent ID: 7375575

Claim:
A voltage level shifting apparatus, comprising: an input signal, a reference signal, and a target signal; a differential amplifier having a positive input node, a negative input node connected to the target signal, and an output node; a first level shifting circuit comprising: a first top transistor having a drain node connected to a first reference voltage, a gate node connected to the reference signal, and a source node; and a first bottom transistor having a drain node connected to the positive input node, a gate node connected to the output node, and a source node connected to a second reference voltage; a second level shifting circuit comprising: a second top transistor having a drain node connected to the first reference voltage, a gate node connected to the input signal, and a source node; and a second bottom transistor having a gate node connected to the output node, and a source node connected to the second reference voltage; a third reference voltage; and a comparator connected to the third reference voltage and having: a positive input node connected to the drain node of the first bottom transistor, and a negative input node connected to the drain node of the second bottom transistor.