TA201

TA201 High-performance Multiplexing with the DG408 Steve Davies The DG408 and DG409, new multiplexers from Siliconix, represent a new generation of high-performance multiplexers and demultiplexers with many specific improvements over existing products available today. Built with the company’ s high-voltage silicon-gate technology, these new ICs offer significantly reduced on-resistance (<100 W), leakage currents (IS(OFF) < 0.5 nA), power dissipation (2.25 mW), and much faster switching (250 ns) over older industry standards. These improved specifications allow designers to greatly reduce system errors and improve system performance. The DG408 and DG409 will enhance two primary multiplexer and demultiplexer applications: communications and telemetry . Important multiplexer specifications depend on the application and the accuracy required by the system. For example, in communications, switching speed is important; whereas, in telemetry , on-resistance, charge injection, and output capacitance are critical because they determine the accuracy of the system. This article will present examples of these types of applications and discuss the benefits that these new multiplexers bring to their system performance. sampling time of a particular channel and results in lower multiplexer efficiency. The DG408 has switching times (250 ns) guaranteed to be more than four times faster than previously available (1 ms) multiplexers. Its guaranteed break-before-make time (10 ns) prevents cros...