I'm looking for a quick and easy way to compare DCDC boost Converter IC, to all or most manufacturers. Does anyone know tools, sheets or charts?
Looking for a smart way to compare DCDC Converter IC
converterintegrated-circuit
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Energy stored in a capacitor is \$ \frac{1}{2}CV^2 \$.
Energy stored in a inductor is \$ \frac{1}{2}LI^2 \$.
So the conservation of energy equation would be: $$ \frac{1}{2}LI_i^2 - \frac{1}{2}LI_f^2 = \frac{1}{2}CV_f^2 - \frac{1}{2}CV_i^2 $$ (subscript i means initial, f means final)
Using an assumption that \$V_{out}\$ is near constant over one cycle, that is \$ V_{out} \gg V_f-V_i \$, then \$ 2 V_{out} \approx V_{f} + V_{i} \$. $$ \frac{1}{2}CV_f^2 - \frac{1}{2}CV_i^2 = \frac{1}{2}C(V_f^2-V_i^2) = \frac{1}{2}C(V_f+V_i)(V_f-V_i) = C V_{out} \Delta V$$ This is the answer given by jp314.
LTSpice has a model for the controller built in, so you can model the system fairly easily. This doesn't take into account effects from your actual PCB layout. While you could try and model those effects, it's best to just build the circuit go from there.
I generally start with the default values and go from there, unless there's some known stuff I can simulate which will let me adjust them.
I like to simulate converters with various kinds of loads. Simple switched loads like what's in the screenshot can give you some basic indications as to what will happen under certain conditions. You can also use arbitrary sources to force certain loads and see how the converter handles those, but they can cause odd situations to happen if you're not careful.
If you wind up with crazy voltage spikes, try lowering your timestep size.
This also lets you try a whole range of different configurations at once. This screenshot shows the output voltage for 10k steps in compensation resistor from 1k to 300k.
The datasheet actually shows how the system works at the bottom of page 5 in the block diagram. The compensation network sits at the output of the error amplifier.
The error amplifier outputs how far away the output voltage is from a target at any given time, which in this instance is 1.24V. At the target voltage your feedback divider would give 1.24V at the output. It uses this as a part of a calculation to adjust the duty cycle of the MOSFET to achieve the desired output.
Adding the RC filtering to this error signal helps keep the loop stable. If there was no compensation the loop would react so fast it would start to oscillate uncontrollably, as the output shot up and down the feedback system would keep overreacting to correct the output. This would be an underdamped condition.
If the compensation network slows down the error response too much on the other hand the regulator will be slow to react to changes at the output. For instance if something suddenly placed a heavy load on the regulator the output could sag very low before the regulator catches up. This would be an overdamped condition.
The goal of this network is to make sure the regulator can respond fast enough to react to the loads you will be placing on it, but not so fast enough it starts jerking itself around.
Linear and TI both have excellent app notes on current mode boost converter compensation which are a good place to start.
Here's one from linear: http://cds.linear.com/docs/en/application-note/AN149fa.pdf
From my personal experience many people use the given application circuit as a starting point, and then build out from there.
This document by TI is a great resource for understanding current mode control theory at a deeper level. Page 10 has an example of the control loop and transfer function. You can use that as a base and start add more circuit elements in.
Best Answer
Learn to use the parametric searches of most of the main suppliers, such as Digikey, Farnell, Mouser, Newark, and the many others. Selecting components and researching options for your designs is an extremely important and often overlooked part of designing something.
You may start the process first by thinking about what kind of device you want, so in your case a "DCDC boost Converter" which you can find categories in most supplier websites for at least the DC-DC converter part, and then you should be able to search for the "boost" or sometimes "buck-boost" if they have multiple/selectable modes of operation.
Then think about if you want internal switches and low current handling capability (usually ~3A max for integrated ones) or if you want an external switch controller to handle 10's of Amps.
Be sure to find ICs with proper voltage ratings for what you are doing, and be aware that some may have annoying little options/hidden issues so always check the datasheets after finding something that you THINK at first look seems to fit the need you have.
Some ICs may have huge amounts of external circuitry required too, especially if they have lots of really cool options like built in current limiting, microncontroller feedback interfaces etc. whereas some are very simple and need only ~6-8 or less external components.
Many many hours can be taken up by looking for the right IC, and should be a very important part of your project. Do not think you can just whack any old IC whose part number you see thrown around on random forums.