Modeling of Sinking and Sourcing Digital Input Electronic Behavior in Multisim

[Mahmoud_W]

Hello Circuit Designers,

Sinking and Sourcing are terms used to define the control of direct current flow in a load. The concept of sourcing and sinking is independent of the component (transistor, mechanical relay) that implements the operation. While this concept applies to any DC circuitry; the component that implements the circuitry may vary.

A typical application of sinking and sourcing digital inputs is in the connectivity of Automotive Engine Control Units (ECU). The NI-9425 and NI-9426 C-Series modules provide such functionalities.

From a design standpoint. Multisim offers the ability to model this behavior based on electric models of the real components. Accounting for signal delays, power dissipation, and voltage and current levels which are all critical parameters to evaluate before deploying the system.

I created the schematic diagram below to illustrate this idea, the switching itself could be implemented in many different ways. Let me know your feedback on this application.

Mahmoud W

National Instruments