A level shifting circuit provides a reference bias voltage to permit signal transfer
between two circuits with different common voltage reference levels. The bias voltage
is less than a common voltage reference level for either of the two connected circuits.
By providing the bias voltage, the range of variation for the common voltage reference
levels between the two circuits is increased when the reference voltages float
with respect to each other. The level shifting circuits permit signals to be transferred
from a low voltage to a high voltage circuit with increased reliability and noise
immunity, and vice versa. The level shifting circuit is particularly useful for
driving a half bridge switch configuration, and transmitting a floating current
sense signal.