Furthermore, a quiescent current reduction circuit has been included which reduces the ground current when the differential between the input voltage and the output voltage exceeds approximately 3V. The quiescent current with 1A of output current and an inputoutput differential of 5V is therefore only 30 mA. During line transients, such as load dump when the input voltage can momentarily exceed the specified maximum operating voltage, the regulator will automatically shut down to protect both the internal circuits and the load. Familiar regulator features such as short circuit and thermal overload protection are also provided. Features n n n n n n n Dropout voltage typically 0. May be increased without bound to maintain regulation during transients.

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Perhaps I have misunderstood this specification? Please see updated question with attached schematic. The vishay datasheet shows change of ESR with frequency.

For reference, this is the LM datasheet. If you look at page 18 in its datasheet the ESR for the uF, 6. Read 1 time previous topic — next topic. Do you also have the input capacitor 0. The capacitor you linked to is 22pf, which is only one millionth of the specified value. Hi Russel, thanks for the feedback. This capacitor must be rated over the same operating temperature range as the regulator and.

They need to be rated above my voltages also. Your oscillations are at 18 Mhz where the ESR is hopefully very low. Sign up using Facebook. You quote the ESR at kHz. Or offer an alternative regulator that is more linear at high frequency As suggested in this answer? Anything with that l, or higher is fine. I believe that I have conformed to the guidelines in the datasheet. I live in Lincoln. I read the data sheet for the LM and understand I need two capacitors one on the input and one on the output.

NB — in the pdf you cite they say: Sign up using Email and Password. What is the input voltage? Tom Wilson 68 7. Related Posts


LM2940-N Datasheet PDF - Texas Instruments

Nominally 12 Volt Lead acid batteries typically operate in the range of When under charge, the voltage can easily get over 14V — sufficient to cause damage to sensitive 12V equipment. Voltage Regulators A voltage regulator is a device which takes an input voltage and outputs a stable fixed voltage. Variable voltage regulators are available such as the very useful LMT which the user can set to output any required voltage 1. For the more commonly required voltages of 3. Unfortunately the regulators mentioned above have quite a high voltage drop — typically up to 3 Volts.


LM2940 direct replacement for LM7805?

You quote the ESR at kHz. Schematic of the regulation circuit. I believe that I have conformed to the ddatasheet in the datasheet. Tom Wilson 68 7. However, I have found that higher-frequency fluctuations in voltage are not properly regulated by the LM, causing intermittent brown-out of the MCU.


LM2940 direct replacement for LM7805?

I was using datashet above to supply 5v to my Atmegap-pu project in my automotive environment for controlling the signal that datqsheet on some lights via Mosfet. Email Required, but never shown. This capacitor must be rated over the same operating temperature range as the regulator and 2 the ESR is critical — see curve. Sign up using Email and Password.

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