I have a couple of those cheap modules based on the XL6009 or that's what they claim to be anyway and they work but the quiescent draw is around 40-50mA, not a lot but when something is powered 24/7 it adds up. Can I do better?
That draw does not come from the chip:
Quiescent Supply Current: 2.5mA
Shutdown Supply Current: 70uA
As I learned the hard way, the datasheet Iq unfortunately does NOT mean what you probably think it means (the current draw with the power supply running, but with no load). It actually means the current in the chip when it is enabled, but not switching the MOSFET. But even with no load, in reality your MOSFET will be switching, in order to maintain the output voltage. Note that in the datasheet, the test condition for Iq is Ven=2V (i.e. enabled, running) and Vfb=Vin (and above the table, it says Vin=12V). Meanwhile, the nominal Vfb voltage is 1.25V. So basically, they’re applying a really high feedback voltage, ensuring the thing doesn’t switch, because from its point of view, the output voltage is already much too high, so it doesn’t need any pulses.
Most other data sheets I have looked at simply say that the condition is “non-switching” for Iq.
Remember in my comment above about my boost converter with a quiescent current of about 40μA? That is roughly what I expected from simulations. But the datasheet Iq is 1μA (0.07μA in shutdown).