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LM3915 Dot/Bar Display Driver1FEATURES
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.
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