Analog Devices Inc./Maxim Integrated MAX944ESD-T

Overview

The MAX944ESD-T from Maxim Integrated is a quad high-speed comparator optimized for 3V/5V single-supply systems, featuring rail-to-rail inputs, 80ns propagation delay (5mV overdrive), 350μA per comparator supply current, and CMOS/TTL-compatible outputs. It operates from 2.7V to 5.5V and is used in threshold detection, zero-crossing sensing, and line receiver circuits where low power and fast response are critical.

For engineers reviewing the MAX944ESD-T datasheet, MAX944ESD-T pinout, MAX944ESD-T application, or MAX944ESD-T equivalent, key selection considerations include guaranteed 80ns propagation delay at 5mV overdrive, rail-to-rail input common-mode range extending beyond both supply rails, output swing within 0.4V of V+ and GND without pullups, internal hysteresis for noise immunity, and 14-pin SO package compatibility with industrial temperature range (-40°C to +85°C).

Technical Context

The MAX944ESD-T implements a bipolar process-based comparator core with internal hysteresis (typical 1–3mV input-referred width), enabling clean switching on slow-moving or noisy signals without external components. Its rail-to-rail input stage accepts voltages from -0.2V to (V+ + 0.2V), and its current-driven output stage delivers VOH ≥ V+ − 0.4V and VOL ≤ 0.4V at 400μA load.

As a quad comparator, it provides matched propagation delay skew ≤10ns between channels and differential propagation delay ≤10ns, ensuring precise timing alignment across all four comparators. Supply current remains stable across 2.7V–5.5V operation, with typical ICC = 400μA per comparator at 5V and 350μA at 3V.

Key Specifications

Pinout & Package

MAX944ESD-T is housed in a 14-pin narrow SO (Small Outline) package, 150mil body width, with standard SOIC footprint (outline S14-1, land pattern 90-0112). Pin 11 is GND; pins 1, 8, 14 are outputs (OUTA, OUTB, OUTC, OUTD); pins 2–7 and 9–10 are input pairs (INA±, INB±, INC±, IND±); pin 4 is V+.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM339DR and TLV3704IDR, the MAX944ESD-T uniquely balances 80ns speed, 350μA/channel efficiency, rail-to-rail input operation, internal hysteresis, and full industrial temperature qualification - making it optimal for time-critical embedded sensing where robustness and precision coexist.

Availability

MAX944ESD-T is available at Aetrix Electronics and suitable for industrial automation, battery-powered instrumentation, and communications infrastructure requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX944ESD-T 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The MAX941/MAX942/MAX944 family was designed specifically for low-voltage, high-speed comparator applications in portable and industrial systems where rail-to-rail input capability, low quiescent current, and fast propagation delay are essential.

FAQ

What is the maximum supply voltage rating for the MAX944ESD-T?

The MAX944ESD-T has an absolute maximum supply voltage (V+ to GND) of +6.5V. Operation is specified from 2.7V to 5.5V. Exceeding 6.5V risks permanent damage, even momentarily. The device is commonly used at 3.3V or 5V, and its rail-to-rail input stage tolerates common-mode voltages up to V+ + 0.2V, making it robust in systems with transient overvoltage conditions. Always observe derating curves for continuous power dissipation above +70°C ambient.

Does the MAX944ESD-T include internal hysteresis, and how does it affect design?

Yes, the MAX944ESD-T includes fixed internal hysteresis with a typical input-referred width of 1–3mV. This eliminates the need for external positive feedback resistors typically required to prevent oscillation on slow or noisy input signals. The hysteresis creates distinct upper and lower trip points, ensuring clean, chatter-free output transitions - especially valuable in threshold detectors and zero-crossing applications. Designers benefit from reduced component count, smaller PCB area, and guaranteed performance across temperature without tuning.

Can the MAX944ESD-T drive TTL and CMOS logic directly without external pull-up resistors?

Yes, the MAX944ESD-T outputs are fully compatible with both TTL and CMOS logic families without external pull-up resistors. At 400μA sink/source load, VOH is guaranteed ≥ V+ − 0.4V and VOL ≤ 0.4V, meeting standard 3.3V and 5V logic high/low thresholds. This rail-swing capability simplifies interface design, reduces component count, and improves signal integrity by avoiding resistor-induced delays or loading effects - a key advantage over older comparators like the LM339.

What is the operating temperature range of the MAX944ESD-T, and how is it verified?

The MAX944ESD-T is rated for operation from −40°C to +85°C, qualified per industrial standards. This range is confirmed through production testing and characterization across temperature extremes, with electrical parameters (e.g., propagation delay, offset voltage, supply current) guaranteed over the full range. The "E" grade designation in MAX944ESD-T explicitly denotes this industrial temperature qualification, distinguishing it from commercial-grade variants (e.g., MAX944CPD, 0°C to +70°C). Thermal derating guidelines are provided in the datasheet for reliable long-term operation.

How does the pinout of the MAX944ESD-T differ from the MAX941 or MAX942?

The MAX944ESD-T uses a 14-pin SO package with dedicated pins for all four comparator inputs and outputs: pins 1/7/8/14 are OUTA/OUTB/OUTC/OUTD; pins 2–3, 5–6, 9–10, and 12–13 are the four input pairs. In contrast, the MAX941 (single) and MAX942 (dual) use 8-pin packages with fewer I/Os. No shared pinout exists - the MAX944ESD-T is not pin-compatible with MAX941 or MAX942. Migration requires PCB layout revision, though functional equivalency (speed, supply, hysteresis) allows reuse of circuit topology and bill-of-material logic.