I am hoping someone can help me work this problem out please!
I am using a MP1584EN DC-DC Converter Module in my project - specifically the one made by D-Sun as shown in the image below:
The reason I specifically use D-SUN is because they have the necessary components on board required to break out the EN pin so I can control it using a pin on my Atmega to shut the converter down when not being used. Other manufacturers omit these components and / or slightly re-design the board to save money but you can't tell unless you look closely.
The problem is, I had expected to see around 20uA being drawn while the MP1584EN converter is shutdown / sleeping - but instead it's taking around 94uA. Waaay more than I want.
I got the expected figure of 20uA from the datasheet here:
This is a screen grab of the section I was looking at where it says Shutdown Supply Current Ven MAX 20uA
So am I looking at the wrong figure or am I doing something wrong?
As far as I am aware, all I should need to do is ground the EN pin to get it to fully shut down - and it does. There's no voltage coming from the output but the current draw is higher than expected for some reason.
To rule out anything else upsetting my measurements, I set up just the MP1584EN module on its own with no load. I measured around 210uA at idle and I measured 94uA when the EN pin was grounded to put the IC to sleep.
Have I read something wrong / done something wrong or is there something with the design of these modules that causes this problem and if so is there anything I can do to modify / adapt them?
If not then it's back to the drawing board because that's a massive amount of wasted energy where my project is concerned.
Any help really appreciated!