The LM LM series are monolithic frequency to voltage converters with a high gain op amp comparator de- signed to operate a relay lamp or other load. uses a charge pump technique and offers frequency doubling for low ripple, full input protection in two versions (LM,. LM) and its. The LM, LM series are monolithic frequency to voltage converters with a high gain op Details, datasheet, quote on part number: LM
|Published (Last):||9 August 2017|
|PDF File Size:||17.23 Mb|
|ePub File Size:||4.50 Mb|
|Price:||Free* [*Free Regsitration Required]|
Yeah – I figured that i needed a decent ‘frequency’ I’m guessing the AC input is required to be centered on 0V, incidentally, but a DC blocking cap outside the chip would easily achieve that. Then put a dstasheet resistor to the cathode of D3 and the other end of it to ground.
I think you problem lies with the input circuitry of the LM But how does this charge pump do this? Its datasheet is very old and it doesn’t explain function of the IC well.
Andy aka k 10 I created a custom library for this IC and set up my own circuit as datashet in the schematics above.
Its driving me nuts Sign up using Email and Password.
Page 1 of the data sheet says it all. The first op-amp is a camparator as your question states. If I pulse 14V onto the “Signal In” port with that powersupply also connected to ground The sig-in line goes from 5.
Can anyone offer some guidance? An example circuit from the datasheet. I guessed the roles of the capacitors completely wrong initially.
National Semiconductor – datasheet pdf
Home Questions Tags Users Unanswered. Then you stand a chance of getting the input to switch. Sign up or log datasbeet Sign up using Google. I’ve built this on a breadboard using a modified version of http: I’ve substantially edited this text to make it more true, see the edit history to see my incorrect babbling if you really want to.
Sign up using Facebook. I’m not game to hook it to my ‘duino nor can I be buggered going out to the bike yet The charge pump is datashee a capacitor which one? I’m hoping someone can take a moment to help me and possible restor my sanity! How are you pulsing the 14V? I would take pin 1 and bias it with two 20K or so resistors going to supply and ground.
I’ve played around with a few variations.
I think the problem is my Internal Zener references.