Interpreting data sheet specifications

[gary36]

I was referring datasheet of DC-DC converter, link: https://www.xppower.com/portals/0/pdfs/SF_HRL30.pdf

I wanted to know the right interpretation of safe operating area mentioned in the datasheet. For example ,a 6kV device has maxpower of 30W and the output voltage is controllable ie.. 0 to6kV. Is it right to interpret that power will be constant ,no matter what voltage we program. For instance, setting a 1V ,gives 600V output from this converter. Can i interpret that current is increased 10 fold to maintain that power? In other words, can I use this DC-DC converter as variable voltage and current source?

 

[D.A.(Tony)Stewart]

The limiting factor is output current = 5.0 mA. Max.
The max power only occurs at max voltage = 600 V

 

[gary36]

Can I draw 50mA@600V DC?( for 6kV DC-DC converter)

 

[D.A.(Tony)Stewart]

No that would exceed spec. 5.0 mA max. See models & ratings p. 2 of 6.

 

[BradtheRad]

This reply assumes an inductor is in the crucial role...
At the moment of shut-off it has some amount of Amperes going through it. Instantly the inductor tries to continue carrying that same level of current. It generates whatever level of voltage accomplishes this through any path along any wiring available.

It generates a sufficiently high voltage, capable of adding some charge to the reservoir capacitor, or conducts through the load (or splits portions among those). To apply a simple approximate mathematical formula, this voltage can be calculated as:

V = Amperes x resistance,
and...
Add the charge that's presently on the capacitor.

Throughout every switching cycle, the inductor's Henry value contributes its own characteristics, as well as current drained by the load. The result is for the output voltage to settle at some equilibrium level. Theory can take us only so far when we try to calculate the behavior of a boost converter.

If a load is absent, then (with every switching cycle) the capacitor eventually charges up to an unpredictably enormous voltage.

 

[KlausST]

For instance, setting a 1V ,gives 600V output from this converter.

how do you come to this conclusion?

I see the control voltage is 0...5V .. representing 0..100% of output voltage range.
Thus 1V control voltage should equal to 1200V output voltage on a 6kV device.

Klaus

 

[gary36]

Yes, I thought 0-10V as control voltage. But I assumed that power would be constant. Would that not be right. At any voltage, I can draw the current that matches with the max power rating

 

[KlausST]

Would that not be right. At any voltage, I can draw the current that matches with the max power rating

I very sure this is not the case.

Let´s say you want to do a current limit of 10mA ... and this on an unknown voltage.
What setup would you chose for Voltage and what for Current? (each 0..5V representing 0..100% according datasheet)

Klaus

 

[D.A.(Tony)Stewart]

It is very misleading to assume to interpret the 1st two lines of this spec exist in any one product.
They are the maximum of all products from 200 V to 6000 V.

This miniature regulator offers both current limit and voltage output features but has no specifications for safe operating area, SOA.

It does state that it has a rectangular VI plot for short circuit , and is not degraded by case temperature.
The datasheet is very brief and lacks many specifications from standard power supplies such as SOA, step load plots, change voltage settling times and many others because of it sacrifices these features for the size and topology.

I learnt how to specify power supply performance back in the 80's then test and validate to these design specs including power start/stop and accelerated MTBF tests.

The specs would often consume more than 20 pages. If you have more expectations than this table or concerns, you must define and verify them yourself and/or ask the supplier.