66xxA, 68xxA and E36xxA: Switching vs. Linear Power Supplies

The downloadable at the right indicates the type of each model of power supply that Keysight has offered recently.

Some people avoid switching power supplies because they have a poor reputation for performance, specifically high p-p noise on the output, in addition to higher radiated and conducted EMI. However, Keysight pioneered switching supplies such as the 6670 series which offered the performance of linears with the advantages of switchers. Today, all Keysight power supplies offer very low p-p ripple and noise specifications, and very low radiated and conducted EMI. The reputation for superior performance of products such as the Keysight 6670 and 6680 series is well established. The 5kW 6680 series offers peak-peak noise as low as 10 mV and output programming response times as low as 9 ms. In fact, Keysight switchers can be quieter than some linears! Poorly designed linears can have commutating spikes when their bridge rectifier diodes turn off. These spikes occur at two times the power line frequency, but the sharp edges radiate noise in the megahertz range and above. Keysight design engineers have gone to a lot of effort to make both our linear and switching power supplies as noise-free as possible!

However, many switching supplies are still available from other manufacturers that do not offer this level of performance. So as not to unfairly prejudice customers on the performance of these supplies, we have avoided blatantly labeling them as switchers.

** Note: The "Hybrid" technology utilizes either primary or secondary 60 Hz SCR phase control switching followed by a Linear regulator on the DC secondary side.