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
an   accurate   ten-step   voltage   divider.   The   high-
mA
impedance  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
with wide dynamic range, such as audio level, power,
can be Referenced to a Wide Range of
light intensity or vibration. Audio applications include
Voltages
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.