How can i get a model for the following ICs

[beryour]

I need to design a circuit with some ICs but cant find them on multism 

How can i get a model for the following ICs;

LM35 Linear temperature sensor IC,

LM331 Voltage-frequency converter IC

78L06 Voltage regulatorIC.

78L12 Voltage regulator IC 

I hope i dont have to re-design my circuit.

Thanks 

[yyao]

Hi Beryour,

The 78L* regulators are available in our master database. They are listed as MC78L* (i.e. MC78L06* and MC78L12*).

As for the other two ICs, we don't have them in our database, but, you might find them in other places on the internet.

Hope that helps.

[beryour]

Hi Yi,

Thank you so much for your assistance. Is there any possibility of creating a model for LM35 and LM331 to be used on multism, can you also give me an idea of some other places where i can get it online.

thanks

[_user32]

beryour,

For the LM35, you can use a simple Voltage Source to model the output voltage at a specific temperature, for a temp sweep simulation see the following:

http://forums.ni.com/ni/board/message?board.id=370&message.id=6228

For the LM331, you could try to replicate the behavior of the VtoF conversion with our Voltage Controlled Square Wave (Master DB -> Sources -> CONTROLLED_VOLTAGE_SOURCES -> VOLTAGE_CONTROLLED_SQUARE_WAVE).

Regards,

Patrick Noonan
Business Development Manager
National Instruments - Electronics Workbench Group
50 Market St 1-A
South Portland, ME 04106
Phone: 207 892-9130
Email: patrick.noonan@ni.com 

[rankot]

Voltage to frequency is quite straightforward as you descibed, but LM331 also provide frequency to voltage conversion, and I can't find any Multisim component that can do the same. So I tried to model LM331 using it's LTSpice model, and in LTS it looks like this:

So I have tried to model it in Multisim, and there is a file in attachment, but it doesn't work as expected. I have tried datasheet example of basic F2V convertor and it doesn't work. Any ideas?

[akaiser]

Hi everybody! I'm also on the hunt for a functioning LTSpice Model of the LM331, specifically for its application as an F-to-V converter. The model that OP is showing seems to be flawed in such a way that it is unusable for this application. A pnp current mirror (called current reflector in the datasheet) seems to be missing, and so does the current switch (c.f. section 8.2 in the datasheet). The current mirror should be connect to a current source (to set the reference current via pin 2), and its output to a spdt switch that is controlled by the Q output of the RS flip-flop. One output of the switch goes to pin 1 (current output), the other one goes straight to ground. In this way, the pulsed current output can be used to pump up a capacitor as shown in the example circuit in the datasheet. I hope this helps! -- Haven't had time to test it, though.

[azp7]

Hi, if the current model on the program doesn't work for you, you can create your own custom component.

See this link: http://www.ni.com/tutorial/3173/en/

[gilberto256]

Hi did you continue your schematic project about the Lm331? If yes, does it work now? I tried with your multisim project but it didn't work. Let me know!