This establishes power to the chip. Submitted by webmaster on 27 September It will remain in our system until you withdraw your consent. How to use a LM? According to the datasheet, if you are not using LEDs with leads that are 6″ or longer, you can connect this pin directly to ground.

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TL — Programmable Reference Voltage. At 4V, 8 LEDs turn on. In this circuit, we will be using the same for both. At 5V, all 10 LEDs turn on.

LM Dot/Bar Display Driver IC | NightFire Electronics LLC

Pin 4 is the R LO. Since the reference voltage is 5V and there are 10 LEDs, each 0. These are the pins where the LED bar graph connects to. This varies displa voltage that is fed into the LM Always note that the voltage used to power the IC here 9V should be at least 1. If you are using LEDs with pins 6″ or longer, then you would place a capacitor in parallel to this pin.


As you might have noticed we have connected all the 10 LEDs directly to the IC without any current limiting resistor this is because the IC has an internal current limiter and the value of current can be set by using the pin VRO pin 7.

How we go about computing this is this: Here we have used 9V to power the IC to monitor an analogy voltage of V. The simplified block diagram illustrates this extremely simple external circuitry.

You can replace the potentiometer so with any type of sensor do/tbar to measure anything. LED bar graphs are used often in VU meter circuits, in which the LED bar graph can be lit up in proportion to the amount of voltage a device is outputting. Pins 6, 7, 8 all work together. So you can use whatever you have.

Displah not a big deal. Sign in Register Email. The advantage of using LM is that it requires minimum hardware and can be easily set up.

In the above example we have used a ohm resistor as Rl and hence the current through each LED will be around 25mA, you can modify the value as required.


At 1V, 2 LEDs turn on. Next, we connect the potentiometer.

Pin 9 is the mode pin. Or for every 0. Dispplay 10mA, resistor R1 calculates out to be 1. This is more or less.

LM3914 Dot/Bar Display Driver IC

This includes the pinout and all the details of how to connect the LED Bar graph. With varying voltage, we get varying LEDs lit. We GRobotronics also save your IP address as a security precaution, but in can only be viewed by our staff. An LED bar graph is a device that can be a visual indicator of voltage output.

It will remain in our system until you withdraw your consent. Password Forgot your password? And then we can calculate resistor R1.