The LM3915N-1/NOPB is a monolithic IC that senses analogue voltage levels and drives ten LEDs, LCDs or vacuum fluorescent displays, providing a logarithmic 3dB/step analogue 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 1db.
3dB/Step, 30dB Range
Drives LEDs, LCDs or Vacuum Fluorescents
Bar or Dot Display Mode Externally Selectable by User
Expandable to Displays of 90dB
Internal Voltage Reference from 1.2 to 12V
Inputs Operate Down to Ground
Output Current Programmable from 1 to 30mA
Input Withstands ±35V without Damage or False Outputs
Outputs are Current Regulated, Open Collectors
Directly Drives TTL or CMOS
Internal 10-step Divider is Floating and can be Referenced to a Wide Range of Voltages
(EN)
