LM3915 – Backlight LED Driver – National

Part number : LM3915, LM3915N

Function : Dot / Bar Display Driver

Package information : DIP 18 Pin type

Manufacturer : National Semiconductor, TI


LM3915 display driver

Product Information

The LM3915 is a monolithic integrated circuit that senses analog voltage levels and drives ten LEDs, LCDs or vacuum fluorescent displays, providing a logarithmic 3 dB/step analog display. One pin changes the display from a bar graph to a moving dot display. 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 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 divider. Accuracy is typically better than 1 dB.


LM3915 pinout datasheet



1. 3 dB/step, 30 dB range
2. Drives LEDs, LCDs, or vacuum fluorescents
3. Bar or dot display mode externally selectable by user
4. Expandable to displays of 90 dB
5. Internal voltage reference from 1.2V to 12V
6. Operates with single supply of 3V to 25V
7. Inputs operate down to ground
8. Output current programmable from 1 mA to 30 mA


Typical Applications

LM3915 circuit


Reference site : https://en.wikipedia.org/wiki/LM3914


LM3915 Datasheet PDF