Patent ID: 7005908
Filing Date: 2006-02-28
Classification: H03K

Abstract:
1. A voltage level shift circuit comprising: a power detector circuit which generates a control signal in response to a first power supply voltage and a second power supply voltage; an input circuit, connected between the first power supply voltage and a ground voltage, which receives an input signal and outputs a first signal; and, an output circuit, connected between the second power supply voltage and the ground voltage, which generates an output signal in response to the control signal and the first signal output from the input circuit; wherein the power detector comprises: a first voltage divider, connected between the first power supply voltage and the ground voltage, which outputs a signal in accordance with the first power supply voltage; a second voltage divider, connected between the second power supply voltage and the ground voltage, which divides the second power supply voltage in response to the signal output from the first voltage divider; a comparator which compares the signal output from the first voltage divider with an output of the second voltage divider; and an inverter which receives an output of the comparator and which outputs the control signal.