Many modern systems include multiple circuits that interact with each other.  Some circuits operate at a low voltage level in order to reduce power consumption.  However, many systems also have circuits that operate at a higher voltage level.  Level shifting circuits are generally interposed between circuits operating at different voltage levels in order to facilitate communication.  For example, a leveling shifting circuit can be employed for transferring a signal generated by a circuit having a low voltage level to a circuit having a higher voltage level and vice versa. 
Conventional level shifting circuits tend to leak current between reference voltages.  This leakage current increases power consumption of the circuit, which is undesirable. 
It is therefore desirable, among other things, to provide a level shifting circuit that reduces leakage current between references voltages and thus consumes less power than conventional level shifting circuits.