The max Pd of that chip is mw. Please check for damaged diode or IC. Hi Kumar, could you send me the gerber file? It accepts an input voltage between 2. You have it correct. Front Page What’s New?

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So all this means that with an lm26623 of maybe 4. Connect Vdd to a separate voltage source, such as three batteries in series, or better yet: Flashlights and Parts WTS: Hi i need to charge my samsung s8 with this kind of circuit via aa batteries.

Thanks 2 years ago.

What are the exact dimensions of the pcb drawn in this page. New chip from National LM Wow, very interesting. If you want you can go ahead and calculate max power heating in the mosfet assuming 0.

The inductor current waveform is non linear due to the Coilcraft swinging inductance. Yes this chip does look interesting, and maybe a good candidate for the 5w LS. Voltage supply connected to pin 7 BOOT that varies from 3v to 7v at least.

For BOOT voltage settings of 3v, 4v, and 7 volts and 2. Ldd there any suggestion for me? Having looked at the circuit again though shows that perhaps this is normal for such high lwd currents and voltages or the inductor has too much current for it’s size.


However, now that we have established that the Vdd pin is bootstrapped, that ALMOST eliminates the problems associated with Vin possibly causing the heating problems. New chip from National LM MrAl, I reference it in formula since it really depends on how many watts lm623 are trying to drive to the load. So the LM I would expect to behave very lsd.

Let us know how you make out with the new chip if you can. I wont get into the details, but will propose some tests that will reveal the problem.

This could very well be the case too, and would mean the circuit wouldnt be functional below a certain input voltage threshold. I haven’t been analyzing my results or data. Bookmarks Bookmarks Digg del. No National LM samples.

New chip from National LM

Current waveform and voltage waveform on the scope. LM design info Thanks, I’ll take another look. Are you asking the basic question that according to the data sheet the RDS le typical is.


The dominating factor is the FET switch current. If it’s too hard to get all those waveforms, then a minimum recording of three points on each waveform might be sufficient to find out what is going on plus the duty cycle. Looks very similar to the LM New chip from National LM Hi again wayne, When you experience the highest power heating of the ic chip, what is the input voltage to the ic chip?

This is almost twice what the data sheet shows.

2.4V to 5V Step Up DC-DC Converter

A single 1W LS at mA would then hit the magic point somewhere around 3. Can you recommend an alternative inductor that is not surface mounted because i need it ,ed my project and we need to put it on breadboard.

The max Pd of that chip is mw. I will say this.

The magic point threshold is around 1.

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