Dot/Bar Display Driver - LM3916 (VU Taper)
This is the LM3916 Dot/Bar display analog-controlled LED driver that uses a more logarithmic/VU scale, which makes it well-suited to audio applications like VU meters. With this driver all it takes is a single, analog signal to drive a string of 10+ LEDs, which can be configured into either bar mode (where all LEDs below a certain point turn on) or dot mode (with only a single LED on at a time). Hook them up properly, and you can create all sorts of nifty multi-LED displays.
Audio applications include average or peak level indicators, and power meters. Replacing conventional meters with an LED bar graph results in a faster responding, more rugged display with high visibility that retains the ease of interpretation of an analog display.
The LM3916 is extremely easy to apply. A 1.2V fullscale meter requires only one resistor in addition to the ten LEDs. One more resistor programs the fullscale anywhere from 1.2V to 12V independent of supply voltage. LED brightness is easily controlled with a single pot.