Analog Devices Inc./Maxim Integrated MAX908EPD

Overview

MAX908EPD from Maxim Integrated is a quad, high-speed, ultra-low-power, single-supply TTL comparator IC designed for precision threshold detection in battery-powered and timing-critical systems. It delivers 40ns propagation delay with only 700µA per comparator (3.5mW), operates from +4.5V to +5.5V, features rail-to-rail input range down to 200mV below GND, and provides TTL-compatible outputs without external pullups. It is used in high-speed A/D converters and zero-crossing detectors.

For engineers reviewing the MAX908EPD datasheet, MAX908EPD pinout, MAX908EPD application, or MAX908EPD equivalent, key selection considerations include its quad-channel configuration, 14-pin PDIP package, -40°C to +85°C industrial temperature rating, internal hysteresis for noise immunity, and compatibility with single +5V supply systems requiring fast, low-power analog decision-making.

Technical Context

The MAX908EPD implements four independent comparators in a single monolithic bipolar process, each with built-in hysteresis to eliminate oscillation during slow or noisy input transitions. Its input stage supports common-mode voltages from -0.2V to V+ − 1.5V, enabling ground-referenced sensing without level-shifting.

All four channels share a common V+ and GND, feature TTL-compatible push-pull outputs (no external pullups required), and are fully short-circuit protected on inputs and outputs. Propagation delay skew between channels is ≤2ns (typ), ensuring tight timing alignment across all four comparators.

Key Specifications

Pinout & Package

MAX908EPD is housed in a 14-pin plastic DIP (dual in-line package) with 0.3-inch body width and through-hole mounting. Pin spacing is 0.1 inch, compatible with standard PCB layouts and socket footprints.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX908EPD, LM339N trades speed and integration for cost, while TLV3704IPW prioritizes power efficiency and supply flexibility over timing performance and output drive - making MAX908EPD uniquely suited for industrial-grade, high-speed, single-supply TTL interface applications.

Availability

MAX908EPD is available at Aetrix Electronics and suitable for battery-powered systems, high-speed A/D converters, and zero-crossing detectors requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX908EPD 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 U.S.-based semiconductor company specializing in high-performance analog and mixed-signal ICs for industrial, communications, and consumer applications.

The MAX907/MAX908/MAX909 family was engineered to replace legacy comparators in space- and power-constrained systems demanding both speed and micropower operation - particularly in portable instrumentation and real-time control.

FAQ

What is the maximum operating supply voltage for MAX908EPD?

The absolute maximum positive supply voltage (V+ to GND) for MAX908EPD is +6V. However, the recommended operating range is +4.5V to +5.5V. Operation beyond +5.5V may increase power dissipation and offset drift without improving performance - the device is optimized for stable TTL-level operation at nominal +5V.

Does MAX908EPD support dual-supply operation like the MAX909?

No, MAX908EPD does not support dual-supply operation. It is strictly a single-supply comparator with V+ and GND pins only. Unlike the MAX909, it lacks a V− pin and cannot accept negative supply rails. Its input common-mode range extends to −0.2V (200mV below GND) but does not support true bipolar supplies.

Can MAX908EPD outputs drive standard TTL logic inputs directly?

Yes, MAX908EPD outputs are fully TTL-compatible: VOH ≥ 2.8V at ISOURCE = 100µA and VOL ≤ 0.55V at ISINK = 3.2mA across −40°C to +85°C. This meets 74LS and 74HC input thresholds without external pullups or buffers - confirmed in the Electrical Characteristics table under VOH/VOL conditions.

Is there internal hysteresis in MAX908EPD, and can it be disabled?

Yes, MAX908EPD includes fixed internal hysteresis (~5mV input-referred) to prevent oscillation on slow or noisy inputs. It cannot be disabled - no external pins or configurations alter this behavior. The hysteresis is inherent to the comparator core design and contributes to guaranteed clean switching without user intervention.

What is the input bias current specification for MAX908EPD at room temperature?

At TA = +25°C, the input bias current (IB) for MAX908EPD is 200nA (typical) and 500nA (maximum), measured with VCM = 0V and VIN = VOS. This value remains stable across the full −40°C to +85°C range, supporting precision applications with high-impedance sources such as photodiode amplifiers or RC-based timing networks.