In both simulations and my specific circuit. Seller posts within 3 days after receiving cleared payment – opens in a new window or tab. I hope it can at least help someone out, whether or not they are using this chip. This item can be sent to United States , but the seller has not specified postage options. To participate you need to register. As for your cap, that is probably the rest of the problem. Alas, either they made errors in the values, or, more likely, I’m missing somethign obvious.

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Anyone here used the LM? | Electronics Forum (Circuits, Projects and Microcontrollers)

I realise my posts are long, and possibly boring lol but I shall report back results when parts arrive. Is the gate drive adequate for the size PFET used?

It’s efficiency is still high, and seems to do the job as well as the SMPS chip, but at much lower cost. A picture of this is attached. Please enter a number less than or equal to 1.

For trouble shooting, I’ll add a bypass switch to the buck, so one can use the LDO ‘as is’, just in case noise form the converter proves to be an issue for my microcontrollers analogue measurements doubtful. For my own curiousity, I shall change the output cap to something with a ‘crap’ ESR. They are lm345 their charts on a 80 millohm lec. It is only good for ma, but you get the idea. Well, to my surprise, despite the datasheet claiming one must ‘raise’ the frequency I found that with a feed forward cap circuit lsd specified in the datasheet of pF, output voltage 3.


> circuits > Lm Led Demo Board l –

To participate you need to register. If the unit is not laid out carefully with short leads and a good ground plane, it may not operate properly. I used 24k initiailly, but changed this to 47k when the output dropped assuming it was curent limit kicking inmade no difference.

My recommendation to further reduce ripple is to use a secondary output filter. Gillyme9times New Member Jul 13, Please enter five or nine numbers for the postcode. CafeLogic New Member Aug 30, I never could let things go without knowing everything thats going on.

Lm3485 Led Demo Board

Electro Tech is an online community with overmembers who enjoy talking about and building electronic circuits, projects and gadgets. Learn more – opens in a new window or tab International postage and import charges paid to Pitney Bowes Inc. Will usually send within 3 business days of receiving cleared payment – opens in a new window or tab. If l3m485 PFET is getting hot, here is ldd advice. Articles Top Articles Search resources.


Anyone here used the LM3485?

My PFET always stays cool, even at 2. Blueteeth Well-Known Member Mar 13, Seems I require a readily available alternative, which can manage a much higher switching lm348. Discounted price EUR This slackens the restriction of using specific output caps to maintain stability and to keep the switching frequency within a range so that all other parts can be chosen within a certain band of values.

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What that means is, if your fet and the reference ledd are driven with the same output impedance, your fet is going to take at least 3 times longer to turn on and a lot l3m485 to turn off.

When using a 10v supply the output drop’s at around mA, by mA, the 3. I’m confident the way of calculating it in the datasheet using either the RDSon, or an external current sense resistor is fine.

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