Analog Devices Inc./Maxim Integrated MAX908CSD-T

Overview

MAX908CSD-T from Maxim Integrated is a quad high-speed, ultra-low-power single-supply TTL comparator in 14-pin SO package, delivering 40ns propagation delay with 5mV overdrive and 700µA per comparator supply current at +5V. It features rail-to-rail input range (–0.2V to V+–1.5V), internal hysteresis, and TTL-compatible outputs-ideal for battery-powered threshold detection and high-speed sampling circuits.

For engineers reviewing the MAX908CSD-T datasheet, MAX908CSD-T pinout, MAX908CSD-T application, or MAX908CSD-T equivalent, key selection criteria include propagation delay consistency across channels, input common-mode range compatibility with 0V-referenced sensors, power budget constraints in portable systems, and absence of external pull-up requirements due to integrated TTL output drivers.

Technical Context

The MAX908CSD-T implements four independent comparators on a bipolar process, each with fixed internal hysteresis (±2mV trip points) eliminating external feedback networks. Its input stage operates down to –0.2V relative to GND and up to V+–1.5V, enabling direct interfacing with ground-referenced signals without level-shifting.

All four comparator outputs are open-collector TTL-compatible with no pull-up needed; propagation delay skew between any two channels is ≤2ns (typ), and differential propagation delay is ≤1ns (typ), supporting precise timing alignment in multi-channel detection systems.

Key Specifications

Pinout & Package

MAX908CSD-T is housed in a 14-pin SOIC (Small Outline Integrated Circuit) package, 3.9mm width, JEDEC MS-012AC compliant, with 1.27mm pitch and gull-wing leads. Thermal resistance θ_JA = 120°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM339DR and TLV3704IPW, MAX908CSD-T uniquely delivers TTL-compatible outputs, 40ns speed, and built-in hysteresis in a single quad package-enabling compact, low-component-count designs for high-speed, low-power threshold detection without sacrificing noise immunity or logic compatibility.

Availability

MAX908CSD-T is available at Aetrix Electronics and suitable for battery-powered systems, high-speed A/D converter front-ends, and industrial line receiver designs requiring stable component supply and long-term obsolescence management.

Supply support for MAX908CSD-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) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MAX907/MAX908/MAX909 family was designed specifically for single-supply, ultra-low-power, high-speed comparator applications-targeting portable instrumentation, sensor interfaces, and real-time signal conditioning where speed, precision, and minimal quiescent current are simultaneously critical.

FAQ

Is MAX908CSD-T still recommended for new designs?

No, MAX908CSD-T is Not Recommended for New Designs per Maxim's official documentation. The underlying wafer process is obsolete, and Maxim does not guarantee long-term availability. For new projects, evaluate modern alternatives such as the MAX40026 or AD8611-based quad solutions with documented lifetime support. Existing MAX908CSD-T inventory remains functional and supported for legacy repair and maintenance.

What is the maximum capacitive load the MAX908CSD-T outputs can drive reliably?

The MAX908CSD-T outputs are characterized up to 15pF load capacitance in the datasheet, with propagation delay increasing from 40ns to 70ns as load rises from 10pF to 100pF. For reliable TTL-level switching with <50ns delay, keep total node capacitance-including PCB trace, scope probe, and downstream input-below 20pF. Add series termination if driving longer traces or higher-capacitance loads.

Does MAX908CSD-T require external hysteresis resistors?

No, MAX908CSD-T incorporates fixed internal hysteresis of approximately 4mV (VTRIP+ – VTRIP–), eliminating the need for external feedback resistors. This simplifies PCB layout, removes tuning dependencies, and ensures consistent noise immunity across temperature and unit-to-unit variation-unlike general-purpose comparators such as LM339 that require external hysteresis networks.

Can MAX908CSD-T operate with inputs below ground?

Yes, MAX908CSD-T supports input voltages as low as –0.2V relative to GND (per Absolute Maximum Ratings and VCMR specification). This enables direct interfacing with transducers or op-amp stages whose outputs swing slightly negative, without clamping diodes or level-shifting circuitry-provided input current is limited to <25mA during transient overdrive conditions.

What is the thermal performance of MAX908CSD-T in its 14-pin SO package?

In the 14-pin SOIC package, MAX908CSD-T has a junction-to-ambient thermal resistance (θ_JA) of 120°C/W under standard JEDEC test conditions. At full load (2.8mW total dissipation), this results in ~0.34°C junction-to-ambient rise above ambient-well within safe operating limits. For high-density layouts, use internal copper planes and thermal vias under the exposed pad (if present) to further reduce θ_JA.