4
\$\begingroup\$

First of all I am still in school so perhaps I have not been exposed to material that may answer this question for me.

I have recently become interested in power electronics. I have purchased a book on the subject and I am taking an online course. Like usual they start with basic models where everything is ideal and as the course goes on you begin to model losses. I have breadboard a basic buck and it works great. My question is that I feel a bit disillusioned because almost everything I learn "there's an IC for that" I get the feeling that the fellas that design those IC are REAL engineers and everyone is just pluging and playing parts.

I understand the benefits of using an IC because it will reach an unparalleled level of efficiency versus discretes... but out there in the industry is there anyone making power converters not using a one size fits all IC? if so can anyone give some examples?

I have not taken a formal course on power electronics at school, so that fact contributes to my ignorance on the subject.

\$\endgroup\$
  • 2
    \$\begingroup\$ past about 40W designs start to use external switches, but the controller is usually still an IC \$\endgroup\$ – Jasen Nov 16 '18 at 2:15
  • 3
    \$\begingroup\$ Have a look at PC power supplies. They are extremely cost-optimized and meet strict safety and EMI requirements. In general much difficult analog electronics is done by IC designers and the bulk of engineers just fit building blocks together, but there are always interesting and rewarding exceptions if you don't want to work for an IC house. \$\endgroup\$ – Spehro Pefhany Nov 16 '18 at 2:20
  • 1
    \$\begingroup\$ That’s how engineering works. We stand on the shoulders of giants. We define input/output parameters that allow us to put together the LEGO pieces without having to worry about the details of the pieces themselves. Even though I have designed my own ICs (there are designs that only work in IC form), when it comes to switching power supplies I almost never bother with the pieces. I just use already-made miniaturized power modules that include all the cumbersome passives and pass all the required certifications. \$\endgroup\$ – Edgar Brown Nov 16 '18 at 2:23
  • \$\begingroup\$ Interestingly, there are a lot of areas now where it makes sense to do some power conversion stuff with a microcontroller in charge. Motor control (is very similar to power conversion) and also things like MPPT charge controllers. You may also be able to justify discrete implementation of a hystertic buck controller in some situations (with comparators and maybe op-amps, etc). \$\endgroup\$ – mkeith Nov 16 '18 at 2:47
  • \$\begingroup\$ Also, I think you can actually do everything yourself with op-amps and comparators, etc. It just gets complicated when you add cycle-by-cycle current limiting and slow start, etc., etc. But the BASIC buck or boost can probably be implemented using discreet analog circuitry. \$\endgroup\$ – mkeith Nov 16 '18 at 2:49
2
\$\begingroup\$

It's always good to think about this kind of thing. You can build a circuit like this without using an IC — and in fact if you look at the datasheets of the ICs in question they usually have at least a block diagram (if not a complete circuit diagram) that would give you a good start on replicating what they do — but in practice nobody uses such a design commercially because it would be more expensive than using the IC yet provide no practical benefit. But for educational reasons, doing it yourself is a very good idea. I haven't tried building a switching power supply using this kind of approach, but certainly simpler projects like op amps, logic gates and so on, building it myself from discrete components has often been very educational.

\$\endgroup\$
0
\$\begingroup\$

is there anyone making power converters not using a one size fits all IC?

Yes, because there is no one size fits all. There are many different needs. Input voltage range, output voltage, current range, circuit size, switching speed, ripple, thermal characteristics, efficiency and etc.

Even though the things you are leaning are built into an IC, you need to understand what is inside the IC to make an educated choice when selecting an IC and the external components. What frequency will best meet your needs? What effect will output inductance and capacitance have on cost and performance? Conduction mode. Do you need a boost switcher or charge pump?

No better way to learn these things than by using the basic components.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.