As central processing units (CPUs), chipsets, field-programmable gate array (FPGA) devices, application-specific integrated circuits (ASICs) and other input/output (I/O) devices migrate to use of lower voltage levels to reduce device power consumption, the need for voltage level shifting of voltage signals to and from input/output (I/O) pins becomes a necessity. In addition, for I/O devices, bidirectional signaling, whereby transmitted and received signals are carried using the same circuit, is advantageous because it reduces pin count and reduces front I/O plate circuit board space used for I/O. Bidirectional signaling also permits user flexibility for using the I/O circuit to transfer transmitted or received signals.

Some discrete bidirectional voltage level shifters lack the ability to provide the high amounts of current necessary to drive long capacitive cables while maintaining fast signal rise times. Some time-synchronization devices do not have circuit protection from bus contention when connected incorrectly as an input and output by the user whereby signals are driven in and out (receive and transmit) simultaneously and can cause permanent damage to the device.

Some level shifters exhibit longer propagation delays, which is detrimental to precision phase alignment needed in certain applications, such as IEEE 1588 synchronization for 5G networks or other systems that require single-digit nanosecond time synchronization precision. Some level shifters support specific voltages rather than a range of voltages.