Package. 0˚C ≤ TJ ≤ ˚C LMCT LMCT LMCT LMCT TO LMCS LMCS The LMCT/NOPB is a positive Voltage Regulator features the ability to source 1A of output current with a dropout voltage of typically V and a. Pin 5 and 6 need to be tied together on PCB board (5) ESD rating is based on the human body model, pF discharged through LMCT/NOPB.
|Published (Last):||15 April 2005|
|PDF File Size:||16.17 Mb|
|ePub File Size:||6.20 Mb|
|Price:||Free* [*Free Regsitration Required]|
LDO – LM2940CT-5.0
Do you know about how much output current you have? Email to a Friend. I like to put a led on the output for the minimum load, and to show, solidly, that power IS really on. Basic Stamp List Subject: Hi John, What is the input voltage to the regulator — can you measure it?
Your use of Yahoo! Did you take steps to obtain caps with appropriate ESR? The LM gets hot after a few min which isn’t nice. It’s interesting that mine gets this hot when I have seen schematics using the same setup, with a 10uf cap ml2940ct.
I have a 22uf cap between the output and ground as lmm2940ct in the datasheet for stability. I can’t find a schematic of it. Check your caps, it might be leaky. The only things being powered in the circuit is the stamp and the LCD. The burn your finger kind of hot. I believe the data sheets show a 0. Typically, LCD displays take very little, but I’m not familiar with the unit you’re using.
My input is 9V, I’m using the power supply that came with the P40 demo board. The quiescent current with 1A of output current and an input-output differential lm2940vt 5V is therefore only 30 mA.
During line transients, such as load dump when the input voltage can momentarily exceed the specified maximum operating volt-age, the regulator will automatically shut down to protect both the internal circuits and the load. Thanks, John In basicstamps yahoogroups.
If you aren’t running very much current, and your Vin isn’t too high, a small clip-on heat sink can significantly reduce the regulator’s temperature. Furthermore, hidden in the ap note the ones that I have seen is an admonition to have a minimum current load. What are the caps on the BS2P40 demo board?
Does it have a backlight? Familiar regulator features such as short circuit and thermal overload protection are also provided. That would work alright. Be the first lm29940ct to review this product.
50. Groups is subject to http: Many of the regulators require capacitance on the input and output to minimize oscillation. Please, log in or register.
There is another possibility Thank you for all the input. The power in Watts being dissipated within the regulator is the voltage drop across the regulator times the current passing through it. Photos – easier uploading 5. sharing. Keep in mind the adapter you have may be putting out more than 9 volts, or may not have a very clean output, both of which will make the regulator get hot.
Otherwise the output impedance is too high and it oscillates. It is essential that the output capacitor meet these requirements, or oscillations can result.
Only registered customers who has bought this product can write reviews. Hello, All I have is a cap between the output and ground at 22uf. Another data sheet says 0.