LM3915 LM3915N LM3915N-1 IC DRIVER DOT BAR DISPLAY 18-DIP

1FEATURES DESCRIPTION
The LM3915 is a monolithic integrated circuit that
2• 3 dB/step, 30 dB Range
senses analog voltage levels and drives ten LEDs,
• Drives LEDs, LCDs, or Vacuum Fluorescents LCDs or vacuum fluorescent displays, providing a
• Bar or Dot Display Mode Externally Selectable logarithmic 3 dB/step analog display. One pin
by User changes the display from a bar graph to a moving dot
display. LED current drive is regulated and • Expandable to Displays of 90 dB
programmable, eliminating the need for current
• Internal Voltage Reference from 1.2V to 12V limiting resistors. The whole display system can
• Operates with Single Supply of 3V to 25V operate from a single supply as low as 3V or as high
as 25V. • Inputs Operate Down to Ground
• Output Current Programmable from 1 mA to 30 The IC contains an adjustable voltage reference and
mA an accurate ten-step voltage divider. The highimpedance input buffer accepts signals down to • Input Withstands ±35V without Damage or ground and up to within 1.5V of the positive supply. False Outputs Further, it needs no protection against inputs of ±35V.
• Outputs are Current Regulated, Open The input buffer drives 10 individual comparators
Collectors referenced to the precision divider. Accuracy is
typically better than 1 dB. • Directly Drives TTL or CMOS
• The Internal 10-step Divider is Floating and The LM3915's 3 dB/step display is suited for signals
can be Referenced to a Wide Range of with wide dynamic range, such as audio level, power,
Voltages light intensity or vibration. Audio applications include
average or peak level indicators, power meters and The LM3915 is Rated for Operation from 0°C to RF signal strength meters. Replacing conventional +70°C. The LM3915N-1 is Available in an 18- meters with an LED bar graph results in a faster lead PDIP Package. responding, more rugged display with high visibility
that retains the ease of interpretation of an analog
display.
The LM3915 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.
The LM3915 is very versatile. The outputs can drive
LCDs, vacuum fluorescents and incandescent bulbs
as well as LEDs of any color. Multiple devices can be
cascaded for a dot or bar mode display with a range
of 60 or 90 dB. LM3915s can also be cascaded with
LM3914s for a linear/log display or with LM3916s for
an extended-range VU meter.

Data Sheet