Specifications

Switching and Linear Power Products
Question: Which power supplies are switchers, and which are linears?
Answer: 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, Agilent
pioneered switching supplies such as the 6670 series which offered the performance of linears with the advantages of
switchers. Today, all Agilent 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 Agilent 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, Agilent 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. Agilent 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. The list on the following page indicates the type of each model of power supply
that Agilent has offered recently.
** 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.