Pulldown

Have do I calculate the size of the resistor when I make pulldown?

Posted by Robert (robertbonde@hotmail.com) on 11/05/2005, at 14:11 GMT

Pulldown Resistors

When calculating the resistor value you probably need to know the current flowing and(or) the voltage present at the point in the circuit.
When dealing with the different logic families, I would say that the 4000 CMOS is probably the easiest (apart from handling precautions) to deal with. Its valid logic operating voltages are usually about 30 percent (logic 0) and 70 percent (logic 1) of the supply voltage.
The 74 TTL series logic operating voltages are about 0.8v (logic 0) and at least 2.3-2.8v (logic 1) as a valid logic voltage starting point.

Posted by Anonymous on 15/05/2010, at 14:45 GMT