Now that I've covered how an ideal or perfect diode works and some of the protection you can add to it to make it work better, I'll look into the specifications & features I'd like to have for myself which hobbyists and hackers could find useful.
- Wide Voltage Range
- External Power
- Low Current Draw Option
- High Load Current
- Off/On Support
- Low Cost
- Easy to Assemble
Since hobbyists & hackers may need to use the circuit in a wide range of uses, the wider the voltage range while keeping the costs down, the better. Some IC chips are designed for mobile devices or very specific usage don't allow a wide operating voltage range. I'd prefer if it can handle at least 48VDC, and hopefully more. The low voltage drop of an ideal diode matches very well with many uses when combined with 24VDC or higher, such as solar or off-grid power for example. Cases like this is where low loss can be beneficial enough to spend the extra money.
External Power Option
Most IC chips with a wide voltage range have minimum operating voltages because of how they need to be designed. These voltages can easily be 5V or higher, that means either the ideal diode doesn't turn on until you reach that input voltage or you need to be able to supply external power for it to work. A circuit using an external power source can then begin to work at very low voltages improving the efficiency while reducing the turn on time.
Low Current Draw Option
Since many uses hobbyists would have are cases where high efficiency is important, the IC & final circuit should have very low current draw. Otherwise, you start loosing benefits of using such a circuit.
High Load Current
Since there are many low cost diodes with very low voltage drops at low current, hobbyists & hackers will be more interested in high current then low current. While there are many good uses for low current ideal diode circuits, those often are also in very space constrained designs which often means they need to be integrated with other circuits instead of a general purpose solution I'm interested in at this time.
Off/On Support
While a normal diode doesn't have Off/On support and a basic MOSFET does, if the ideal diode circuit can support on external Off/On input, that greatly enhances a lot of different places it can be used, such as power control circuits that are both a relay & a diode between a battery and a load or a solar panel and it's batteries.
Low Cost
If the price goes up too much, fewer people will be interested in experimenting or using the circuit. This means that the cost of the IC as well as the supporting circuitry needs to be kept down. While more expensive designs can be very useful, have a low cost circuit can be a good entry point to many people who then may go on to other designs .
Easy to Assemble
We're looking at mostly hobbyists and hackers, so the IC used needs to be easily soldered or that part would need to be already mounted (but that makes it hard to repair). That means the IC chip chosen can't have the pads on the bottom side of the chip or a lot of leads close together. This also means that the rest of the design should try to use through hole parts both for assembly & easy of modification by most hobbyists.
TI LM5050MK-1
Keeping all of those things in mind, I like the looks of the Texas Instruments LM5050MK-1 . It operates from 5V-75V with an optional external power, on Off/On control which defaults on to, and can do load balancing when multiple units are in parallel. While the SOIC chip is rather smaller to solder, it only has 6 pins so magnifying glass, tweezers, and a steady hand with a soldering iron still works, The chip uses external Logic Level MOSFET's, so some very high current capabilities are possible. It's also very simple to use with very few external components in most cases, while also keeping the cost low.
Note on the power for the LM5050MK-1, it has a built in diode from Vin, so connecting the power pin can be optional, though common practice is to connect it either to Vin, Vout or an external power source. It only draws about 300 uA during normal operation with peaks up to 700uA during turn on/off, so it's always below 1mA, which is perfect for many uses.
