The LM3916 is a monolithic integrated circuit that senses analog voltage levels and drives ten LEDs, LCDs, or vacuum fluorescent displays, providing an electronic version of the popular VU meter. One pin changes the display from a bar graph to a moving dot display. The LED current drive is regulated and programmable, eliminating the need for current-limiting resistors. The whole display system can operate from a single supply as low as 3V or as high as 25V.
The IC contains an adjustable voltage reference and an accurate ten-step voltage divider. The high-impedance input buffer accepts signals down to the ground and up to within 1.5V of the positive supply. Further, it needs no protection against inputs of ±35V. The input buffer drives 10 individual comparators referenced to the precision. Accuracy is typically better than 0.2 dB.
