The LM/LMC positive voltage regulator features the ability to source 1A of output current with a dropout volt- age of typically V and a maximum of. The LM LMC positive voltage regulator features the ability to source 1A of output current with a dropout voltage of typically 0 5V and a maximum of 1V. The LM positive-voltage regulator features the Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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Anything with that rating or higher is fine. Have you taken their compulsory advice re the output capacitor? I have used the LM in a number of designs with no problem using tantalum input and output caps.
What is the input voltage? Could that datashete to the oscillation? Would something like this work? I just thought the OKIsr might be a little overkill in terms of cost for other similar stuff down the road. Sign up using Email and Password. Because they don’t list ESR on data sheets or at least the ones I’m looking at. Alas the data on minimum ESR is rather sketchy nothing for “C” case for exampleso you have to guesstimate from just these two graphs or get an ESR meter and measure it, or even just with your scope and a function gen that can hit those MHz frequencies fatasheet you see oscillation.
Hi Russel, thanks for the feedback. As, if anything, your ESR may be too high it seems I’d try another cap in parallel. In second case the OKI is highly suggested.
You quote datashfet ESR at kHz.
The average voltage at the input is around 6. Also why do you have 18MHz 1.
This capacitor must be rated over the same operating temperature range lm9240 the regulator and. NB – in the pdf you cite they say: Is the scope trace datashfet when under load? Perhaps I have misunderstood this specification? As a general rule, the higher the voltage rating the larger the size so a 0. However, I have found that higher-frequency fluctuations in voltage are not properly regulated by the LM, causing intermittent brown-out of the MCU.
Do you also have the input capacitor 0. Whether this is really what they intend is unknown.
And also separately a resistor in series for belts and braces coverage: Tying down what manufacturers really mean can be a challenge. Less crucial is a picture of the output voltage waveform especially as we don’t know what bad probing techniques you may have used.
Tom Wilson 68 7. Sign up or log in Sign up using Google. I believe that I have conformed to the guidelines in the datasheet.
For reference, this is the LM datasheet.
LM datasheet & applicatoin notes – Datasheet Archive
This capacitor must be rated over the same operating temperature range as the regulator and 2 the ESR is critical – see curve. Locate as close as possible to the regulator. Now my confusion starts with ESR and capacitor type Is your automotive environment 12V or 24V? This chip predates big cheap ceramic caps, I think.
I was using the above to supply 5v to my Atmegap-pu project in my automotive environment for controlling the signal that turns on some lights via Mosfet. Or offer an alternative regulator that is more linear at high frequency As suggested in this answer?
ln2940 Schematic of the regulation circuit. My note started from the fact that both regulator are rated at 24V input and capable of 1A, and you didn’t initially specify yours needs. Home Questions Tags Users Unanswered. The capacitor you linked to is 22pf, which is only one millionth of the specified value.
They need to be rated above my voltages also. Whether the or Hz ESR is relevant is tbd BUT datasheer you have a 2 x mains input ripple that the regulator is dealing with this may be the instability trigger.