Analog Devices Inc./Maxim Integrated MAX944CPD

Overview

MAX944CPD 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 MAX944CPD datasheet, MAX944CPD pinout, MAX944CPD application, or MAX944CPD 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, output swing within 0.4V of V+ or GND, and compatibility with 14-pin PDIP layout constraints.

Technical Context

The MAX944CPD implements a bipolar process-based comparator core with internal hysteresis (1mV typical input-referred width) to suppress oscillation during slow or noisy input transitions. Its rail-to-rail input stage accepts common-mode voltages from –0.2V to V+ + 0.2V, enabling direct interfacing with sensors or DACs operating near supply rails.

All four comparators share a single V+ and GND, with independent IN+/IN– pairs and open-drain–like outputs capable of sinking 4mA or sourcing 400μA while maintaining VOH ≥ V+ – 0.4V and VOL ≤ 0.4V. No external pull-up is required for TTL/CMOS logic interfacing.

Key Specifications

Pinout & Package

MAX944CPD is housed in a 14-pin plastic DIP (PDIP) package with 0.300-inch width, compatible with standard through-hole prototyping and industrial control PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM339N and TLV3704CDR, MAX944CPD uniquely balances 80ns speed, rail-to-rail input capability including sub-GND operation, and 350μA/comparator current - making it optimal for 3V/5V portable instrumentation requiring precision thresholding at moderate speed.

Availability

MAX944CPD is available at Aetrix Electronics and suitable for battery-powered systems, threshold detectors, and zero-crossing detectors requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for MAX944CPD 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 demanding industrial, medical, and communications applications.

The MAX94x family was engineered specifically for high-speed, low-power, single-supply comparator functions in portable and 3V/5V infrastructure systems - emphasizing rail-to-rail input operation, internal hysteresis, and robust output drive without external components.

FAQ

What is the operating temperature range for MAX944CPD?

The MAX944CPD is specified for 0°C to +70°C operation, as indicated by the 'C' suffix in its ordering code. This commercial-grade temperature range suits indoor instrumentation, consumer electronics, and non-automotive industrial controls where ambient conditions remain within this band. The device's electrical characteristics - including 80ns propagation delay and 350μA supply current - are guaranteed across this full range.

Does MAX944CPD require external pull-up resistors on its outputs?

No, MAX944CPD does not require external pull-up resistors. Its outputs are designed to swing within 0.4V of either supply rail - VOH ≥ V+ – 0.4V and VOL ≤ 0.4V - ensuring direct compatibility with CMOS and TTL logic families without additional components. This rail-swing behavior is verified across load currents up to 4mA sink and 400μA source.

Can MAX944CPD accept input voltages below ground (GND)?

Yes, MAX944CPD supports input common-mode voltages as low as –0.2V relative to GND, per its Electrical Characteristics table. This rail-to-rail input capability allows direct interfacing with AC-coupled signals, sensor outputs referenced below ground, or DACs operating with negative headroom - a feature not found in standard comparators like LM339.

How many independent comparators are integrated in MAX944CPD?

MAX944CPD integrates four fully independent high-speed comparators (labeled A–D) in a single 14-pin PDIP package. Each has dedicated IN+, IN–, and OUT pins with matched propagation delay (<10ns skew between channels), enabling synchronous multi-threshold evaluation in applications such as window comparators or phase-detection circuits.

Is MAX944CPD pin-compatible with other devices in the MAX94x family?

MAX944CPD uses a 14-pin PDIP footprint distinct from the 8-pin packages of MAX941 and MAX942. While pin functions align with the family's standardized labeling (e.g., OUTA, INA+, GND), the 14-pin layout is unique to quad variants and not mechanically or electrically pin-compatible with single or dual versions. Board redesign is required when substituting between package counts.