Analog Devices Inc./Maxim Integrated LMX339AUD+

Overview

LMX339AUD+ from Maxim Integrated is a quad, open-drain, low-voltage comparator with internal 2mV hysteresis, designed for noise-immune threshold detection in automotive and portable systems. It operates from 1.8V to 5.5V, delivers 140–200µA total supply current at 5V, supports –40°C to +125°C operation, and features rail-to-rail input common-mode range down to ground - used in battery-monitoring circuits where slow-moving signals require stable switching.

For engineers reviewing the LMX339AUD+ datasheet, LMX339AUD+ pinout, LMX339AUD+ application, or LMX339AUD+ equivalent, key selection criteria include guaranteed hysteresis, open-drain output drive capability (73mA sink at 5V), low input bias current (±400nA over full temperature range), and TSSOP-14 packaging compatible with high-density PCB layouts.

Technical Context

The LMX339AUD+ implements four independent comparators on a single submicron CMOS die, each with internally trimmed 2mV hysteresis to eliminate oscillation during slow input transitions. Its input stage accepts common-mode voltages from –0.1V to VDD – 0.7V, enabling direct ground-referenced sensing without level-shifting.

Each comparator features an open-drain NMOS output stage capable of sinking up to 73mA at 5V, with saturation voltage as low as 50mV at 1mA load. Propagation delay is 90ns (tPHL) / 200ns (tPLH) at 100mV overdrive and 5V supply, optimized for response to fast transients while maintaining stability under noisy conditions.

Key Specifications

Pinout & Package

LMX339AUD+ is housed in a 14-pin TSSOP package (4.4mm × 5.0mm × 1.2mm), RoHS-compliant, with exposed pad for thermal enhancement. Pin numbering follows JEDEC MO-153 standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM339DR and TLV339IPWR, the LMX339AUD+ uniquely combines automotive-grade temperature range, integrated 2mV hysteresis, and open-drain drive strength in a compact TSSOP-14 - making it optimal for cost-sensitive, noise-prone, low-voltage embedded systems where reliability trumps raw power efficiency.

Availability

LMX339AUD+ is available at Aetrix Electronics and suitable for battery management systems, automotive HVAC controllers, industrial sensor interfaces, and portable medical devices requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LMX339AUD+ 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

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for demanding industrial, automotive, and communications applications.

The LMX339AUD+ belongs to Maxim's LMX339 family of low-voltage, hysteresis-equipped comparators - engineered specifically for robust threshold detection in resource-constrained, noise-sensitive embedded systems.

FAQ

What is the maximum sink current capability of each output in LMX339AUD+?

Each open-drain output of the LMX339AUD+ can sink up to 73mA when VO ≤ 1.5V and VDD = 5.0V, as specified in the DC Electrical Characteristics table. This allows direct driving of LEDs, small relays, or MOSFET gates without external buffers. At 1.8V supply, the sink current drops to 15mA, reflecting the reduced drive strength at lower voltages. The LMX339AUD+ maintains this performance across its full –40°C to +125°C operating range.

Does LMX339AUD+ include internal hysteresis, and how does it affect design?

Yes, the LMX339AUD+ includes 2mV of internal hysteresis - a key differentiator from standard quad comparators like LM339. This hysteresis creates distinct upper and lower trip points, preventing output oscillation when input signals move slowly or contain noise. Designers benefit by eliminating external hysteresis resistors, reducing component count and PCB area. The hysteresis value remains stable across temperature (±0.2mV variation from –40°C to +125°C) and supply voltage (1.8V–5.5V), ensuring consistent behavior in automotive and industrial applications.

Can LMX339AUD+ operate with a 1.8V supply, and what performance trade-offs exist?

Yes, the LMX339AUD+ is fully specified and guaranteed to operate from 1.8V to 5.5V. At 1.8V, supply current drops to 120–200µA (for all four comparators), input offset voltage remains ≤5mV, and output saturation voltage is as low as 35mV at 1mA load. Propagation delay increases slightly (500ns typical at 10mV overdrive), but the device retains full functionality including internal hysteresis and rail-to-rail input range. This makes the LMX339AUD+ ideal for single-cell LiFePO₄ or energy-harvesting systems where ultra-low voltage operation is mandatory.

What is the input common-mode voltage range of LMX339AUD+?

The LMX339AUD+ supports an input common-mode voltage range from –0.1V to VDD – 0.7V, which includes ground (0V) across all supply voltages. This rail-to-rail input capability enables direct interfacing with ground-referenced sensors such as current-sense shunts, thermistors, or potentiometers without level-shifting circuitry. At 1.8V supply, the upper limit is 1.1V; at 5.5V, it extends to 4.8V. The specification is guaranteed over the full –40°C to +125°C temperature range, ensuring reliable operation in automotive under-hood environments.

Is LMX339AUD+ pin-compatible with standard quad comparators like LM339?

No, the LMX339AUD+ is not pin-compatible with LM339. While both are quad comparators in 14-pin packages, the LMX339AUD+ uses a TSSOP-14 footprint with different pin assignments - for example, VSS is on Pin 2 (not Pin 4), and outputs are distributed across Pins 4, 8, 13, and 14 rather than grouped. Additionally, the LMX339AUD+ integrates internal hysteresis and operates down to 1.8V, whereas LM339 requires external hysteresis and minimum 2V supply. Migration requires PCB layout revision and schematic updates to match the LMX339AUD+ pinout and electrical characteristics.