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Electrical & Electronics Engineering vocabulary · Digital Electronics and Microcontrollers

Pull-up resistor

Meaning in electrical & electronics engineering, with examples

nounCommon term

In electrical & electronics engineering, pull-up resistor means: A resistor that connects a signal line to the supply voltage so that the line stays at a defined high level when nothing is driving it, instead of floating.

In Turkish: pull-up direnci, yukarı çekme direnci

How it is used

Used on buttons, reset lines, open-drain outputs and buses such as I2C. Typical values are 4.7 kΩ to 10 kΩ. Many microcontrollers have internal pull-ups that firmware can enable. The opposite is a pull-down resistor, which holds a line low.

Example sentences

  1. The button input is floating because there's no pull-up resistor on it.

  2. Add 4.7 k pull-up resistors on SDA and SCL.

Common collocations

  • internal pull-up
  • pull-up resistor value
  • pull-down resistor
  • enable the pull-up
  • GPIOShort for general-purpose input/output: a microcontroller pin that firmware can set as an input to read a logic level or as an output to drive something.
  • I2CA two-wire serial bus, with a data line (SDA) and a clock line (SCL), that lets a microcontroller talk to many chips, each with its own address. It is common for sensors, EEPROMs and small displays.
  • resistorA component that limits current or divides voltage by providing a fixed amount of resistance. Its value is given in ohms and its power rating in watts.
  • microcontrollerA small computer on a single chip, with a processor, memory and input/output peripherals. It runs firmware to control devices such as appliances, sensors and motors.

More terms: Digital Electronics and Microcontrollers

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