The LM3915N is a monolithic integrated circuit that senses analog voltage levels and drives 10 LEDs, providing a logarithmic analog display. Manufactured by National Semiconductor (now Texas Instruments), it is commonly used as a volume unit (VU) meter or bar graph display.

Applications

• Audio level meters (VU meters)
• Bar graph displays
• Signal strength indicators
• LED bargraph voltmeter
• Alarm indicators

Features

• Drives 10 LEDs in bar or dot display mode
• Logarithmic display scale (3dB/step)
• Operates from a single supply
• Wide supply voltage range
• Adjustable reference voltage
• Can be cascaded for displays of 20 LEDs or more

Benefits

• Provides a visual representation of analog signals
• Easy to use and requires minimal external components
• Offers a logarithmic display, ideal for audio level indication
• Versatile and can be used in various display applications
• Cost-effective solution for analog level monitoring

Technical Specifications

The LM3915N operates from a single supply voltage, typically between 3V and 25V. It has an adjustable reference voltage, allowing for customization of the display range. The logarithmic display provides a 3dB step between each LED, making it suitable for audio level indication. The device can drive up to 10 LEDs in either bar or dot display mode, selectable via a mode pin. It can be cascaded with other LM3915 or LM3914/LM3916 devices to create larger displays. The operating temperature range typically spans from 0°C to +70°C. It is available in a 18-pin DIP package.

The LM3915N is a versatile and cost-effective solution for displaying analog voltage levels in a visually intuitive manner.