Analog Devices Inc./Maxim Integrated MAX944CSD-T

Overview

MAX944CSD-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 circuits, and line receivers where low power and fast response are critical.

For engineers reviewing the MAX944CSD-T datasheet, MAX944CSD-T pinout, MAX944CSD-T application, or MAX944CSD-T equivalent, key selection criteria include guaranteed 80ns propagation delay across temperature, internal hysteresis for noise immunity, rail-to-rail input range extending beyond supply rails, and compatibility with 3V/5V logic interfaces without external pullups.

Technical Context

The MAX944CSD-T implements a bipolar process-based comparator core with fixed internal hysteresis (1mV typical input-referred width), enabling clean switching on slow-moving signals without external components. Its rail-to-rail input stage supports common-mode voltages from –0.2V to V+ + 0.2V, and its current-driven output stage delivers VOH = V+ – 0.2V (at 400μA) and VOL = 0.2V (at 400μA).

All four comparators share a single ground and positive supply, with independent IN+/IN– pairs and open-drain–like outputs capable of sinking 4mA or sourcing 400μA while maintaining rail-aligned logic levels. Input bias current remains below 300nA over temperature, and differential propagation delay skew is limited to 10ns between channels.

Key Specifications

Pinout & Package

MAX944CSD-T is housed in a 14-pin narrow SO (Small Outline) package, 150 mil width, RoHS-compliant, with exposed pad not electrically connected. Pin pitch is 1.27mm; body dimensions are 8.65mm × 3.91mm × 1.75mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM339DR and TLV3201IDR, the MAX944CSD-T uniquely balances speed (80ns), low power (350μA), rail-to-rail inputs, and true quad integration in one SO package-making it optimal for space-constrained, battery-aware, and timing-sensitive embedded systems requiring four parallel comparisons.

Availability

MAX944CSD-T is available at Aetrix Electronics and suitable for battery-powered systems, threshold detectors, and zero-crossing detectors requiring stable component supply across industrial and medical product lifecycles.

Supply support for MAX944CSD-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) designs precision analog and mixed-signal ICs for industrial, medical, communications, and consumer applications, emphasizing performance, integration, and reliability.

The MAX944CSD-T belongs to Maxim's high-speed comparator family engineered for low-voltage, low-power, rail-to-rail operation in portable and embedded systems where timing accuracy and supply efficiency are critical.

FAQ

What is the operating temperature range for MAX944CSD-T?

The MAX944CSD-T 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 and industrial equipment where ambient temperatures remain within this range. The device maintains full performance-including 80ns propagation delay and 1mV offset voltage-across this entire span, with derating applied only for power dissipation above +70°C per the datasheet's absolute maximum ratings.

Does MAX944CSD-T require external pullup resistors on its outputs?

No, MAX944CSD-T does not require external pullup resistors. Its outputs are designed to swing to within 0.2V of GND (VOL) and within 0.2V of V+ (VOH) while sourcing or sinking up to 400μA, ensuring direct compatibility with CMOS and TTL logic families. This rail-swinging capability eliminates the need for external components, reducing bill-of-materials cost and PCB footprint compared to open-collector comparators.

Can MAX944CSD-T operate from a 2.7V supply?

Yes, MAX944CSD-T 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 low-voltage capability supports direct integration into modern 3.3V and energy-harvesting systems without intermediate regulation, preserving power efficiency and design simplicity.

How does the internal hysteresis of MAX944CSD-T improve noise immunity?

The MAX944CSD-T incorporates fixed internal hysteresis (~1mV input-referred), creating distinct upper and lower trip points that prevent output oscillation during slow or noisy input transitions near the threshold. Unlike external hysteresis networks-which add component count, layout sensitivity, and calculation error-the integrated solution ensures consistent noise margin across all four channels without design overhead or calibration.

Is MAX944CSD-T pin-compatible with other devices in the MAX94x family?

No, MAX944CSD-T is not pin-compatible with MAX941 or MAX942 variants due to its quad-channel architecture and 14-pin SO package. While MAX941 (8-pin) and MAX942 (8-pin) share pinouts within their respective packages, the MAX944 uses a unique 14-pin layout with dedicated pins for all four comparator inputs and outputs plus shared V+ and GND. Board redesign is required when migrating from dual or single comparators to the quad MAX944CSD-T.