What is a pull-up resistor used for?

A pull-up resistor connects unused input pins (AND and NAND gates) to the dc supply voltage, (Vcc) to keep the given input HIGH. A pull-down resistor connects unused input pins (OR and NOR gates) to ground, (0V) to keep the given input LOW.

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What is weak pull-up resistor?

A resistor with relatively high resistance is called a "weak" pull-up or pull-down; when the circuit is open, it will pull the output high or low more slowly, but will draw less current. How do you calculate pull-up resistors? In order to calculate pull-up and pull-down resistance, we need to first apply the formula in Ohm's Law: Resistance = Voltage/Current, or R= V/I.

How do pull-down resistors work?

The pull-down resistor holds the logic signal near to zero volts (0V) when no other active device is connected. It pulls the input voltage down to the ground to prevent an undefined state at the input. It should have a larger resistance than the impedance of the logic circuit. Why we use pull-up and pull-down resistor? A pull-up resistor allow controlled current flow from supply voltage source to the digital input pins, where the pull-down resistors could effectively control current flow from digital pins to the ground. At the same time both resistors, pull-down and pull-up resistors hold the digital state either Low or High.

What is pull-up and pull-down device?

Answer: Pull-up and pull-down are methods of processing digital signal lines by connecting them to the power supply side and ground side, respectively. Signals may be connected directly or via a resistor. Why does Port 0 needs pull-up resistors? Features of Port 0

An external pull-up resistor is needed when Port 0 is defined as an output port. Port 0 of the 8051 has two main functions: To be used as a simple input-output port and to access external memory in conjunction with Port 2.

Are pull-ups resistance training?

Pullups are a challenging strength training exercise. Challenging your muscles with difficult moves can improve your overall fitness level, too. If you haven't done pullups before, adding them to your routine may improve how strong you feel and look. What is pull-up resistor in 8051? To ensure the values of an I/P is always in a known state, pull up and pull-down resistors are used.The main function of pull-up and pull-down resistors is that the pull up resistor pulls the signal to high state unless it is driven low; and, a pull-down resistor pulls the signal to low state unless it is driven high.

What is the use of pull-up resistor in i2c?

A pull up resistor is used to provide a default state for a signal line or general purpose input/ouput (GPIO) pin. Typically they are of high resistance thousands or tens of thousands of ohms of resistance.