Most electronic systems contain at least one voltage regulator, with many systems requiring several regulators, each providing a different voltage. The performance of these regulators is critical to the performance of the downstream circuits that they power. Many important characteristics of these voltage regulators are either not specified by the manufacturer or worse, the data is incomplete or misleading. The latter is often due to the limited bandwidth of the test equipment used by the device manufacturers in their testing.
In this article, we will look at the role that fidelity (i.e. signal accuracy and quality) plays in the regulator characterization process and also compare the correct performance with that specified in the datasheet for a sample device. These are low cost, high-fidelity instruments, meaning that the ability to make these measurements is within almost all of our budgets. The equipment used is an OMICRON Lab Bode 100 Vector Network Analyzer in conjunction with the Picotest J2100A series of signal injectors and a Picotest G5100A function/arbitrary wave generator.