Analog Devices Inc./Maxim Integrated MAX944CSD+

Overview

MAX944CSD+ 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 detection, and line receiver circuits where low power and fast response are critical.

For engineers reviewing the MAX944CSD+ datasheet, MAX944CSD+ pinout, MAX944CSD+ application, or MAX944CSD+ equivalent, key selection criteria include guaranteed 80ns propagation delay at 5mV overdrive, rail-to-rail input common-mode range extending beyond both rails, output swing within 0.4V of V+ and GND, internal hysteresis for noise immunity, and 14-pin SO package compatibility with industrial temperature-grade variants.

Technical Context

The MAX944CSD+ implements a bipolar process comparator core with internal hysteresis (1mV typical input-referred width), enabling clean switching on slow-moving or noisy signals without external feedback components. Its input stage tolerates continuous short-circuit faults to either rail and supports common-mode voltages from –0.2V to V+ + 0.2V.

The output stage is current-driven, delivering 400μA source/sink capability while maintaining VOH ≥ V+ – 0.4V and VOL ≤ 0.4V under load. Propagation delay skew between channels is limited to 10ns, and differential propagation delay is also specified at 10ns - critical for multi-channel timing alignment in sampling and discrimination applications.

Key Specifications

Pinout & Package

MAX944CSD+ is housed in a 14-pin narrow SO (Small Outline) package, RoHS-compliant, with standard 1.27mm pitch and exposed pad not present. Pin 11 is GND; pins 4 and 10 are V+; outputs are on pins 1 (OUTA), 7 (OUTB), 8 (OUTC), and 14 (OUTD); inputs are paired as INA± (pins 2–3), INB± (pins 5–6), INC± (pins 9–10), and IND± (pins 12–13).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM339DR and TLV3502IDR, MAX944CSD+ uniquely delivers 80ns speed, rail-to-rail inputs, internal hysteresis, and true quad integration in one 14-pin SO package - reducing component count, layout complexity, and timing uncertainty in 3V/5V embedded systems.

Availability

MAX944CSD+ is available at Aetrix Electronics and suitable for battery-powered systems, threshold detectors/discriminators, and line receivers requiring stable component supply across industrial and commercial temperature ranges.

Supply support for MAX944CSD+ 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 and mixed-signal ICs for industrial, communications, and consumer applications, emphasizing performance, integration, and reliability.

The MAX941/MAX942/MAX944 family was developed specifically for high-speed, low-power, single-supply comparator applications in portable and 3V/5V systems - prioritizing rail-to-rail operation, fast propagation, and robust input protection.

FAQ

What is the operating temperature range for MAX944CSD+?

The MAX944CSD+ is specified for 0°C to +70°C operation, as indicated by the 'C' suffix in the part number. This commercial-grade rating makes it suitable for indoor consumer electronics, office equipment, and non-automotive industrial controls where ambient temperatures remain within this band. The device's electrical characteristics - including 80ns propagation delay and 1mV offset - are guaranteed across this full range.

Does MAX944CSD+ require external pull-up resistors on its outputs?

No, MAX944CSD+ does not require external pull-up resistors. Its outputs actively drive to within 0.4V of V+ (VOH ≥ V+ – 0.4V) and to within 0.4V of GND (VOL ≤ 0.4V) under 400μA load, making them fully compatible with CMOS and TTL logic families directly. This eliminates BOM cost and board space associated with discrete pull-ups while ensuring consistent rise/fall times.

How does the internal hysteresis of MAX944CSD+ improve system reliability?

The MAX944CSD+ features fixed internal hysteresis (~1mV input-referred), which creates distinct upper and lower trip points to prevent oscillation during slow or noisy input transitions. This eliminates the need for external hysteresis resistors and associated design calculations, improving consistency across production units and reducing susceptibility to EMI in motor control feedback or sensor interface applications.

Can MAX944CSD+ operate from a 2.7V supply?

Yes, MAX944CSD+ is fully specified to operate from 2.7V to 5.5V. At 2.7V, it maintains 80ns typical propagation delay (5mV overdrive), 350μA per comparator supply current, and rail-to-rail input operation down to –0.2V. This enables direct use in single-cell Li-ion (3.0–4.2V) or two-cell alkaline (2.4–3.2V) powered devices without voltage regulation overhead.

What is the maximum capacitive load the outputs of MAX944CSD+ can drive?

While not explicitly limited in the datasheet, MAX944CSD+'s current-driven output stage exhibits linear slew-rate dependence on capacitive load. Characterization shows propagation delay increases from 80ns (15pF load) to ~160ns at 500pF. For reliable 80ns timing, keep load capacitance ≤100pF - achievable with short PCB traces and proper grounding. Add series resistance only if EMI mitigation is needed.