DC/DC Converter – Minimum Load Requirements

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I'm using the NTE0506MC DC/DC converter which boosts 5V to 6V. The output voltage I'm measuring with no load is 9V not 6V. In page 3 of the datasheet they mention that it needs a minimum load of 10% of the rated load, which in my case is 16.7mA (0.1*167mA).

So I decided to put a dummy resistance of 232 Ohms (after trying several larger values) in parallel with the output decoupling capacitor. The measured output voltage in this case is 6.33V which is much better but still not 6V (my acceptable tolerance is +-300mV). The 232 Ohms should maintain an output current of ~27mA (6.33V/232) which is more than the required minimum current (16.7mA). Why is the output still not close to 6V? How can i solve this issue?

My circuit is exactly the same as the one in page 4 of the datasheet for the part NTE0506MC and my load needs a max of 20mA.

Update: 25/5/2013

I added two 200 Ohm 0.25W in parallel to the output of the regulator and the ouput voltage is now 6.18V which is within my specs.

Best Answer

The converter is operating within its specifications. See the "Tolerance Envelopes" at the top of page 3 of the datasheet. The output is allowed to be as much as 10% high at 10% load, which could be as high as 6.6 V in your case.

Try other loads, up to 100%, and see if it generally follows the load line that they show.