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 high-speed signal conditioning systems. It delivers 40ns propagation delay with 5mV input overdrive, consumes only 3.5mW per comparator (700µA total supply current), and operates from a single +5V supply (4.5V to 5.5V). Its inputs accept common-mode voltages from –0.2V to V+–1.5V, and outputs are TTL-compatible without external pullups.

For engineers reviewing the MAX908EPD+ datasheet, MAX908EPD+ pinout, MAX908EPD+ application, or MAX908EPD+ equivalent, key selection considerations include its quad-channel configuration in 14-pin PDIP, guaranteed 40ns timing at 5mV overdrive, internal hysteresis for noise immunity, rail-to-rail input capability down to –0.2V, and compatibility with +5V-only systems requiring low quiescent power and clean switching.

Technical Context

The MAX908EPD+ implements four independent bipolar comparator cells with fixed internal hysteresis (≈1mV input-referred), eliminating need for external feedback resistors. Each channel features TTL-compatible push-pull outputs capable of sinking 3.2mA or sourcing 100µA while maintaining VOH ≥2.8V and VOL ≤0.55V across –40°C to +85°C.

Its input stage supports common-mode operation from –0.2V (below GND) to V+–1.5V, enabling direct interfacing with signals near ground or slightly negative-critical for zero-crossing and line-receiver applications. Propagation delay skew between channels is limited to 2ns (typ), ensuring tight timing alignment in multi-channel sampling circuits.

Key Specifications

Pinout & Package

MAX908EPD+ is housed in a 14-pin plastic dual in-line package (PDIP) with 0.3-inch body width and standard 0.1-inch pin pitch. Pin 1 is marked by a notch or dot; pins are numbered counter-clockwise from top-left when viewed from the component side.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM339DR and TLV3704IPW, MAX908EPD+ uniquely balances nanosecond-speed response, TTL-native drive, internal hysteresis, and sub-mA power-making it irreplaceable in battery-operated high-speed thresholding where timing, simplicity, and noise immunity are jointly constrained.

Availability

MAX908EPD+ is available at Aetrix Electronics and suitable for battery-powered instrumentation, industrial line receivers, high-speed sampling circuits, and zero-crossing detectors requiring stable component supply across extended temperature ranges.

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 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 engineered to replace legacy comparators in +5V systems demanding speed, precision, and micropower operation-specifically targeting portable test equipment, data acquisition front-ends, and real-time signal monitoring.

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 device is specified for reliable operation only within 4.5V to 5.5V. Operating at 6V risks parametric degradation and is not guaranteed by the datasheet. MAX908EPD+ does not support negative supply rails-unlike the MAX909 variant-and must be used with a single +5V nominal supply.

Does MAX908EPD+ include internal hysteresis, and how wide is it?

Yes, MAX908EPD+ incorporates fixed internal hysteresis of approximately 1mV input-referred. This is derived from the difference between the positive trip point (VTRIP+ = +2mV typ) and negative trip point (VTRIP− = −2mV typ), yielding a hysteresis width (VHYST) of ~4mV centered at the offset voltage. This eliminates need for external hysteresis resistors and ensures clean output transitions even with slowly varying inputs.

Can MAX908EPD+ inputs be driven below ground, and what is the safe limit?

Yes, MAX908EPD+ inputs tolerate voltages down to –0.2V relative to GND (i.e., 200mV below ground) under normal operation. The absolute maximum rating allows –0.3V, but sustained operation below –0.2V may increase input bias current or offset drift. Unlike the MAX909, MAX908EPD+ has no dedicated negative supply pin and cannot accept true negative input voltages beyond this limit.

Is MAX908EPD+ pin-compatible with other devices in the MAX907/MAX908/MAX909 family?

MAX908EPD+ is pin-compatible with other MAX908 variants (e.g., MAX908CSD, MAX908CPD) in the same 14-pin DIP or SO package. However, it is not pin-compatible with the dual MAX907 (8-pin) or single MAX909 (8-pin with latch and complementary outputs). Pin functions match exactly across MAX908 versions, including V+, GND×2, four IN+/IN− pairs, and four TTL outputs.

What is the output drive capability of MAX908EPD+ at –40°C?

At –40°C, MAX908EPD+ guarantees VOL ≤0.55V when sinking 3.2mA per output (per datasheet Conditions table, TMIN = –40°C). VOH remains ≥2.8V when sourcing 100µA. These specifications ensure reliable TTL logic-level compatibility across the full industrial temperature range without derating or external buffering.