1. Field of the Invention
The present invention relates to data acquisition systems, and more particularly to a digitally configurable multiplexer/de-multiplexer for routing a number of analog signals to or from selected analog front ends of a digitization block of a data acquisition system.
2. Description of the Related Art
Analog multiplexers/de-multiplexers (MUX/DEMUX) are typically configured as D:1 devices (e.g., 2:1, 4:1, 8:1 or 16:1) with “N” address inputs for selecting from among “D” analog data signals in which D=2N. An analog MUX/DEMUX is typically bidirectional and may be operated as a MUX to select from among multiple inputs to an output or as a DEMUX to route an analog signal to redirect to a selected one of multiple outputs as known to those skilled in the art. The term “multiplexer” or “MUX” as used herein is intended to connote bidirectional operation in which the MUX may be used for MUX or DEMUX operations. Each configuration has traditionally been implemented on a separate integrated circuit (IC) or chip. If an analog signal needed to be dynamically re-routed to another path, additional multiplexers or switches were required and were placed in series with the signal path. Such additional devices added cost and complexity to the overall data acquisition system. In many cases, different configurations are required in the same system, which forced the designer to implement and purchase different ICs that suited each of the configurations. For example, some systems required the same signal to be routed to any number of different analog front ends that performed various functions (e.g., filtering, amplifying, etc.) depending upon the characteristics of the signal.
Conventional analog multiplexers are relatively inflexible and consume a significant amount of printed circuit board (PCB) area of the data acquisition system.