STMicroelectronics LM339DT

Overview

LM339DT from STMicroelectronics is a low-power quad voltage comparator in SO14 package, designed for single-supply operation from +2 V to +36 V (or ±1 V to ±18 V dual supply), with 1.1 mA typical supply current, ±1 mV typical input offset voltage, and rail-to-rail input common-mode range including ground. It drives TTL/CMOS loads and is used in voltage monitoring, window detection, and analog-to-digital interface circuits.

For engineers reviewing the LM339DT datasheet, LM339DT pinout, LM339DT application, or LM339DT equivalent, key selection criteria include input offset voltage stability over temperature, output sink capability (6–16 mA), common-mode input range down to ground on single supply, and compatibility with legacy 14-pin DIP/SO footprints in industrial control and power management systems.

Technical Context

The LM339DT implements four independent open-collector comparators with PNP input stages, enabling input voltages down to −0.3 V relative to ground while operating from a single +5 V to +30 V supply. Its input bias current (25 nA typ) and offset current (±5 nA typ) minimize reference loading in precision threshold detection.

Each comparator delivers 250 mV typical low-level output saturation voltage at 4 mA sink current, supporting direct interfacing to TTL, CMOS, and MOS logic without pull-up resistors. Differential input voltage range equals full supply voltage, allowing inputs to swing beyond rails without damage-critical for transducer signal conditioning and zero-crossing detection.

Key Specifications

Pinout & Package

LM339DT is supplied in SO14 (Small Outline, 14-pin) plastic micropackage per JEDEC MS-012, with 1.27 mm pitch, 8.75 mm body length, and 4.0 mm width. Thermal resistance junction-to-ambient is 105 °C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad voltage comparator applications.

Compared with LM339DR, LM339DT offers identical functionality and pinout but differs in traceability and qualification for extended temperature industrial use; TLV339 trades high-voltage robustness for ultra-low power, making it unsuitable for mains-connected or automotive battery monitoring.

Availability

LM339DT is available at Aetrix Electronics and suitable for voltage monitoring, window detection, zero-crossing sensing, and transducer interface applications requiring stable component supply across automotive, industrial control, and power conversion programs.

Supply support for LM339DT 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The LM339 series belongs to ST's precision analog comparators product line, engineered for robust, low-cost threshold detection in harsh environments where rail-to-rail input operation and supply voltage flexibility are critical.

FAQ

Can LM339DT operate from a single 3.3 V supply?

Yes-LM339DT functions across +2 V to +36 V single supply. At 3.3 V, its input common-mode range is 0 V to 1.8 V, and output saturation voltage remains ≤400 mV at 4 mA sink. However, TTL compatibility is reduced; CMOS or dedicated pull-up to 3.3 V is recommended for logic interfacing.

Does LM339DT require external hysteresis resistors?

Yes-LM339DT has no internal hysteresis. For noise immunity in slow-moving or noisy signals (e.g., temperature sensors), external positive feedback resistors must be added between output and non-inverting input. Typical values range from 100 kΩ to 1 MΩ depending on required hysteresis width and source impedance.

What is the maximum sink current per output of LM339DT?

The absolute maximum sink current per output is 20 mA, but the datasheet specifies 6–16 mA over temperature at V_OL ≤ 400 mV. Sustained operation above 16 mA increases junction temperature and may exceed thermal limits in SO14 package; derating is advised above 10 mA continuous load.

Is LM339DT pin-compatible with LM324 operational amplifier?

No-LM339DT (14-pin SO) and LM324 (14-pin SO) share the same package outline but have entirely different pin functions. LM324 outputs are push-pull and voltage-driven; LM339DT outputs are open-collector and current-sinking. Direct substitution will cause functional failure and potential damage due to incorrect biasing.