Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Why active low signals are used in digital design?

Status
Not open for further replies.

anoop12

Member level 5
Member level 5
Joined
Nov 29, 2006
Messages
89
Helped
6
Reputation
12
Reaction score
3
Trophy points
1,288
Activity points
1,867
Hi,
Most of the time, it is seen that active low signals are used in the digital design.
What must be the reason for this?

regards
anoop
 

Re: active low signals

Most control signals in electronics are active-low signals (usually reset lines, chip select lines and so on). This stems from the fact that most logic families can sink more current than they can source, so fanout and noise immunity increase. (The reason for this is ultimately related to the fact that electrons are negatively charged.) It also allows for wired-OR logic if the logic gates are open-collector/open-drain with a pull-up resistor. Examples of this are the I²C bus and Controller Area Network (CAN).
https://en.wikipedia.org/wiki/Active_low

Regards,
IanP
 
Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top