How does LM3914 IC work?
How does LM3914 IC work?
The LM3914 is a monolithic integrated circuit that senses analog voltage levels and drives 10 LEDs, providing a linear analog display. A single pin changes the display from a moving dot to a bar graph. Current drive to the LEDs is regulated and programmable, eliminating the need for resistors.
What is the maximum output current of LM3914 IC?
Typical standby supply current (all LEDs OFF) is 1.6mA (2.5mA max).
What are two modes of LEDs the lm3914 can control and how?
The IC can operate in two different modes, one is the dot mode and the other is bar mode. In dot mode the mode pin (pin 9) has to be left floating, in this mode only one LED will be turned on based on the input voltage.
How do you read IC components?
Read the serial number from the top side of the IC. The top side of the IC is facing up when the chip is standing on its pins. You may require a magnifying glass while reading the IC serial information.
How does a LED driver circuit work?
An LED driver is an electrical device that regulates power to an LED or a string of LEDs. Forward Voltage is the amount of volts the light emitting diode requires to conduct electricity and light up. As temperature increases, the forward voltage of the LED decreases, causing the LED to draw more current.
What is LM3914 IC?
LM3914 is an analog controlled LED driver IC, launched by the national semiconductor in 1980. It can control 10 LED lights based on an analog input voltage. It is best to alternate microcontroller ic where 10 LEDs have to control so it reduces the hardware.
How to control an LED bar graph with The LM3914 driver?
The LM3914 bar/dot display driver that we will build to control an LED bar graph is shown below. To connect power to the LM3914, we connect +5V to pin 3 and we connect pin 2 to ground. We can use this same voltage for V LED to power on the LEDs.
How many LEDs can a single LM3914 drive?
A single LM3914 can drive up to 10 LEDs, LCDs, or vacuum fluorescent displays on its outputs. The output threshold linear scaling will make the apparatus functional like a voltmeter. In the basic pattern, it gives a 10 step scale which is flexible to over hundred sections with additional LM series integrated circuits in series.
How to connect a transistor to an IC?
The connection of this transistor can be done among the LED positive terminal as well as the negative terminal, and the base terminal of the transistor is connected to the pin-10 of the IC to make the LED10 drive. An alarm unit is connected to the collector terminal of the transistor in series.
