The CD40109, unlike other low-to-high level-shifting circuits, does not require the presence of the high-voltage supply (VDD) before the application of either the low-voltage supply (VCC) or the input signals. There are no restrictions on the sequence of application of VDD, VCC, or the input signals. In addition, with one exception there are no restrictions on the relative magnitudes of the supply voltages or input signals within the device maximum ratings, provided that the input signal swings between VSS and at least 0.7 VCC; VCC may exceed VDD, and input signals may exceed VCC and VDD. When operated in the mode VCC > VDD, the CD40109 will operate as a high-to-low level-shifter.