Driver for MicroController Outputs

[Karthik S]

Hi,
I have joined newly in this forum


Currently I'm working on Schematic designing for an application using PIC18F series Microcontrollers.

In the design, we need to send some digital outputs from this board, to the other board which can be kept one meter appart..

We thought that, it would be better to have a driver IC which will help in driving the digital signal and also reduces the load on the controller..

Can anybody suggest us some driver IC's ?

The Operating voltage is: +5VDC
Output Type is: HCMOS

Thanks and Regards,
Karthik

[ash]

hello Karthik, welcome to CE!

May I ask, how are the two boards connected? By cable or wireless?

[Karthik S]

Hi Ash,

The Boards are connected through Ribbon Cable..

[amolhshah]

i would suggest you use a NPN transistor like BC547 with open collector output that way you wont have to to worry about the voltage & current that it has to drive, you can then even drive a 12v relay.
here is a circuit for relay driver remove the relay & the free wheeling diode & then you can use it as you want
http://www.dnatechindia.com/index.ph...terfacing.html

[Karthik S]

Thakyou Amolhshah.

I will check it out with ORCAD simulation and let you know.

[sauravgoswami]

hey try a simple ULN2003 Ic.it may help you

[Karthik S]

Thanks Saurav..

But ULN2003 inverts the the Input as per my understanding.

There is no VCC connection in the IC. I'm confused about, How it gives Logic 1 when the input is low?

Can anyone help me in this issue?

[Karthik S]

Hi Amolhshah,

I simulated a Driver circuit in OrCAD using a transistor as shown below.

As we know, the output taken from the collector will be opposite logic from the Input to base.

Is there any Driver IC's which outputs the same logic as input?

This would be better for programming in MCU's.

[Karthik S]

Hi Amolhshah,

I copied the circuit in the previous post. But it's not visible.

How can I put a picture in reply?

[ash]

Hey there, sorry! We currently don't have an image uploading capability. Please use an imagehost such as Imageshack:
ImageShack® - Image Hosting

I'm inexperienced with the ULN2003, but I suppose any inverted outputs can be inverted back with NOT gates

Speaking of which, can two hex inverters back to back act as a rudimentary signal amplifier? They are pretty cheap..

[sauravgoswami]

Well karthik,you can try FET in place of BJT for transistirised circuit infact they work really well.though there life can be lesser than IC's

[Karthik S]

Hi Saurav,

Thanks for your info...

Using BJT is fine... Just we need to take care of this negative logic in programming..

Anyway, thank you very much for your interest

This is just a starting of this project. Moving forward, this discussion will be continuing.

Regards,
Karthik. S.

[Karthik S]

Thanks Ash..

We can use two inverters back to back as a signal driver.
But, as per my understanding, it can not be used for longer distances (such as 1 meter), which is necessary for our project.

We can use a simple BJT circuit as I mentioned in the previous reply.

Regards,
Karthik. S.