Texas Instruments LM3914V

Overview

LM3914V from Texas Instruments is a monolithic dot/bar display driver IC that senses analog voltage levels and drives 10 LEDs with linear, current-regulated outputs. It features externally selectable dot or bar mode, programmable LED current (2–30 mA), internal 1.2V–12V adjustable reference, and operation from single supply <3V. It is used in precision analog metering, visual alarms, and expanded-scale instrumentation.

For engineers reviewing the LM3914V datasheet, LM3914V pinout, LM3914V application, or LM3914V equivalent, key selection considerations include its 10-step linear voltage divider accuracy (±0.5%), input tolerance to ±35V, open-collector LED driver architecture, and zero-center meter chaining capability.

Technical Context

The LM3914V integrates a high-impedance input buffer, precision 10-step resistor ladder (8–17 kΩ total), and 10 individually regulated current-source outputs. Its reference amplifier delivers 1.2–1.34 V with ±1% temperature drift and supports external programming via REF ADJ (pin 8).

Each comparator drives an open-collector NPN output with saturation voltage ≤0.4 V at 2 mA and dropout voltage ≤1.5 V. Mode selection (dot vs. bar) is controlled by pin 9 voltage relative to V+, enabling cascading up to 100+ segments without multiplexing or interaction between outputs.

Key Specifications

Pinout & Package

LM3914V is housed in an 18-pin plastic dual in-line package (PDIP, package code NFK), 0.300″ body width, with standard through-hole mounting and JEDEC MS-001AC footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar analog display driver applications.

Compared with LM3914V, LM3915N-1 offers logarithmic response ideal for compressing wide-spectrum signals, while LM3916N-1 adds audio-specific calibration and reference-neither provides linear 10-step scaling or zero-center flexibility inherent to LM3914V.

Availability

LM3914V is available at Aetrix Electronics and suitable for industrial process monitoring, battery management systems, and audio instrumentation requiring stable component supply and long-term obsolescence support.

Supply support for LM3914V includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies with over 90 years of innovation in precision analog ICs.

The LM3914V belongs to TI's legacy analog display driver product line, engineered for direct analog-to-visual conversion in test equipment, industrial controls, and instrumentation where microcontroller-free simplicity and deterministic real-time response are critical.

FAQ

What is the operating temperature range for the LM3914V?

The LM3914V is rated for operation from 0°C to +70°C ambient temperature. Its internal voltage reference exhibits ±1% variation across this range, and LED current regulation remains within ±3% over the same interval. Thermal derating is required above 70°C due to junction temperature limits (100°C max), with PDIP package thermal resistance of 55°C/W.

Can the LM3914V drive LEDs directly from a 3.3 V supply?

Yes, the LM3914V operates with single supplies as low as <3 V and can drive LEDs directly from a 3.3 V rail. Its LED driver saturation voltage is ≤0.4 V at 2 mA, ensuring sufficient headroom for red, green, or yellow LEDs with forward voltages ≤2.9 V. For higher-current operation, verify VLED ≥ (V+ − 1.5 V) per datasheet conditions.

How does the LM3914V achieve zero-center meter functionality?

The LM3914V achieves zero-center meter operation by exposing both ends of its internal 10-step voltage divider (pins 4 and 6). Connecting VRLO (pin 4) to a negative reference and VRHI (pin 6) to a positive reference creates a bipolar scaling range. The input signal (pin 5) is then referenced to the midpoint, enabling symmetrical LED activation above and below zero.

What is the maximum number of LM3914V ICs that can be cascaded?

Multiple LM3914V ICs can be cascaded to form displays of 20 to over 100 segments. In bar mode, chaining is straightforward via VRHI/VRLO interconnection. In dot mode, pin 9 of each device connects to pin 1 of the next, with specific resistor networks (e.g., 20 kΩ across pin 11) ensuring proper carry logic. No practical upper limit is specified, but thermal and layout constraints govern large-scale implementations.

Does the LM3914V require external current-limiting resistors for LEDs?

No, the LM3914V does not require external current-limiting resistors for LEDs. Its 10 outputs are individually regulated current sources, with LED current set by the load on the REF OUT (pin 7) terminal. A single resistor from pin 7 to ground programs all outputs simultaneously-typically ~10× the reference current-enabling precise, temperature-stable brightness control without per-LED components.