Analog Devices Inc./Maxim Integrated MAX941CPA+

Overview

The MAX941CPA+ from Maxim Integrated is a single high-speed comparator optimized for 3V/5V single-supply systems, featuring rail-to-rail inputs, 80ns propagation delay (5mV overdrive), 350μA supply current per comparator, and integrated latch/shutdown functions. It operates from 2.7V to 5.5V and is used in battery-powered threshold detection and zero-crossing circuits where low power and fast response are critical.

For engineers reviewing the MAX941CPA+ datasheet, MAX941CPA+ pinout, MAX941CPA+ application, or MAX941CPA+ equivalent, key selection considerations include its 8-pin PDIP package, latch-enable and shutdown control pins, rail-to-rail input range extending beyond supply rails, and CMOS/TTL-compatible push-pull output without external pullups.

Technical Context

The MAX941CPA+ implements a bipolar process comparator core with internal hysteresis (1mV typical input-referred hysteresis width) to ensure clean switching on slow-moving signals. Its input stage includes back-to-back diodes and 4.1kΩ series resistors, enabling common-mode voltage operation from –0.2V to V+ + 0.2V and tolerance of continuous short-circuit faults to either rail.

The output stage is current-driven, delivering VOH = V+ – 0.2V (at 400μA source) and VOL = 0.2V (at 400μA sink), supporting direct interface to CMOS and TTL logic. Latch and shutdown functions are controlled via dedicated high-impedance digital inputs (LATCH and SHDN), with defined setup/hold timing (tS = 20ns, tH = 30ns) and sub-10ns shutdown disable time.

Key Specifications

Pinout & Package

MAX941CPA+ is housed in an 8-pin plastic DIP (PDIP) package with 0.3-inch body width and through-hole mounting. Pin 1 is marked with a notch or dot; pin numbering follows standard DIP convention (counterclockwise from top-left).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM311N and TLV3501CD, the MAX941CPA+ uniquely combines latch, shutdown, rail-to-rail inputs, and 1mV offset in an 8-pin PDIP - making it optimal for space-constrained, battery-operated systems requiring deterministic timing and low quiescent power.

Availability

MAX941CPA+ is available at Aetrix Electronics and suitable for battery-powered systems, 3V/5V threshold detectors, and zero-crossing detector applications requiring stable component supply across industrial temperature ranges and long-lifecycle production.

Supply support for MAX941CPA+ 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 power, sensing, and interface applications, with emphasis on high performance and integration.

The MAX941CPA+ belongs to Maxim's high-speed comparator product line, engineered specifically for low-voltage, low-power, rail-to-rail operation in portable and energy-sensitive systems.

FAQ

What is the operating temperature range of the MAX941CPA+?

The MAX941CPA+ is rated for 0°C to +70°C ambient operation, matching the "C" grade designation in Maxim's ordering nomenclature. This commercial-grade temperature range is validated across all electrical specifications including propagation delay, offset voltage, and supply current. The device uses a bipolar process and is packaged in an 8-pin PDIP, which supports reliable thermal dissipation within this range. For extended temperature applications, consider the MAX941EPA (–40°C to +85°C) or MAX941AUA (–40°C to +125°C) variants.

Does the MAX941CPA+ require external pullup resistors on its output?

No, the MAX941CPA+ does not require external pullup resistors. Its output stage is a push-pull configuration that actively drives high (to V+ – 0.2V at 400μA) and low (to 0.2V at 400μA), ensuring full CMOS/TTL logic compatibility without external components. This design eliminates bus contention risks and reduces board area and BOM count. The output remains functional across the full 2.7V–5.5V supply range and maintains specified voltage swing even at temperature extremes within the 0°C to +70°C rating.

How does the internal hysteresis of the MAX941CPA+ improve noise immunity?

The MAX941CPA+ integrates fixed internal hysteresis (~1mV input-referred) that creates distinct upper and lower trip points, preventing output oscillation when input signals hover near the threshold. This eliminates the need for external hysteresis resistors and associated calculations. In practice, it ensures clean, bounce-free transitions for slow-moving or noisy inputs such as thermistor outputs or AC line monitoring - directly improving reliability in threshold detection and zero-crossing applications without adding design complexity.

Can the MAX941CPA+ operate from a 2.7V supply?

Yes, the MAX941CPA+ is fully specified to operate from 2.7V to 5.5V, making it compatible with single-cell Li-ion (3.0–4.2V), two-cell alkaline (2.4–3.2V), and regulated 3.3V systems. At 2.7V, typical supply current is 380μA, propagation delay remains ≤150ns (with 5mV overdrive), and output swing is VOH ≥ 2.5V and VOL ≤ 0.4V - maintaining robust logic interfacing. All key parameters including offset voltage and input common-mode range are guaranteed across this full voltage range per the datasheet's Electrical Characteristics table.

What happens to the output of the MAX941CPA+ during shutdown mode?

When the SHDN pin of the MAX941CPA+ is driven low, the device enters shutdown mode: supply current drops below 60μA, and the output transitions to a high-impedance (three-state) condition - neither sourcing nor sinking current. This prevents loading of downstream logic and enables safe sharing of output buses. To exit shutdown, SHDN must be driven high while LATCH is held high; otherwise, the output state is indeterminate. The shutdown disable time is 10ns, ensuring rapid reactivation for burst-mode operation.