LM3915 IC

The LM3915 IC is a dot/bar display driver that senses an analog voltage and lights up to 10 LEDs on a logarithmic scale, with 3 dB per step. This makes it the classic chip for audio VU meters and signal-strength indicators, where a log scale matches how we hear sound levels. It has a built-in adjustable reference and regulated LED outputs, so the LEDs need no current-limiting resistors.

LM3915 IC Specifications

• Function: logarithmic dot/bar display driver
• Outputs: 10 LED outputs, constant current
• Scale: 3 dB per step, 30 dB total range
• Display mode: dot or bar, selected with one pin
• Supply voltage: 3 V to 25 V
• Reference: internal, adjustable from 1.2 V to 12 V
• LED current: programmable from about 2 mA to 30 mA

LM3915 IC Applications

• Audio VU meters and peak level indicators
• Signal-strength meters for radio receivers
• Sound-reactive LED bar displays
• Analog voltage level displays and power meters

What's in the Box

• 1 × LM3915 IC

Tip: The LED current is about 10 times the current drawn from the reference output (pin 7), roughly 12.5 V / R1, so R1 = 1.2 kΩ gives about 10 mA. For audio, feed the input through a rectifier or peak detector so the display follows the signal level.

Orders placed before 14:00 are ready for pickup the same day. Delivery across Lebanon usually takes 1–3 working days.