Analog Devices Inc./Maxim Integrated MAX908CPD

Overview

MAX908CPD 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 timing systems. It delivers 40ns propagation delay with 5mV input overdrive, consumes only 700µA per comparator (3.5mW), and operates from a single +5V supply (4.5V–5.5V). Its inputs accept common-mode voltages from –0.2V to V+–1.5V, and outputs are TTL-compatible without external pullups - used in A/D converters, zero-crossing detectors, and line receivers.

For engineers reviewing the MAX908CPD datasheet, MAX908CPD pinout, MAX908CPD application, or MAX908CPD equivalent, this page provides verified technical context, exact pin functions, real-world application mappings, and two validated alternative comparators suitable for dual/quad, single-supply, sub-50ns TTL-comparator designs requiring micropower operation and built-in hysteresis.

Technical Context

The MAX908CPD implements four independent high-gain bipolar comparators with internal hysteresis (5mV typical input-referred hysteresis width), eliminating need for external feedback resistors. Each channel features rail-to-rail input capability down to –0.2V and up to V+–1.5V, and TTL-compatible push-pull outputs that sink 3.2mA or source 100µA while maintaining VOH ≥2.8V and VOL ≤0.55V across temperature.

It uses a dedicated ground (Pin 11) and positive supply (Pin 1) shared across all four comparators, with fully independent input pairs (INA±, INB±, INC±, IND±) and output terminals (OUTA–OUTD). No latch, complementary outputs, or negative supply support - distinguishing it from the MAX909; unlike the MAX907, it integrates four channels in a 14-pin DIP package with defined channel ordering and pin isolation.

Key Specifications

Pinout & Package

MAX908CPD is housed in a 14-pin plastic DIP (dual in-line package) with 0.3-inch body width, through-hole mounting, and industry-standard lead pitch (0.1 inch). Pin 1 is V+, Pin 11 is GND, and all pins follow the official Maxim top-view layout for the MAX908 family.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad, single-supply, TTL-output comparator applications.

Compared with LM339N and TLV3704CDR, MAX908CPD uniquely combines TTL output drive, 40ns speed, internal hysteresis, and 700µA/channel consumption - making it irreplaceable in compact, battery-operated, high-speed threshold-detection systems where layout area and BOM count are constrained.

Availability

MAX908CPD is available at Aetrix Electronics and suitable for battery-powered systems, high-speed A/D converters, and industrial line receivers requiring stable component supply and long-term obsolescence management.

Supply support for MAX908CPD 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 product line was engineered specifically for single-supply, high-speed, ultra-low-power comparator applications demanding TTL compatibility, integrated hysteresis, and robust input/output protection - targeting portable instrumentation and real-time signal conditioning.

FAQ

What is the operating temperature range for MAX908CPD?

The MAX908CPD is specified for commercial temperature operation from 0°C to +70°C. This range is confirmed in the Ordering Information table of the official Maxim datasheet, where "MAX908CPD" is explicitly listed with "0°C to +70°C" under TEMP RANGE. It uses the plastic DIP package variant rated for this range, not the extended –40°C to +85°C (EPD) or military-grade versions.

Does MAX908CPD support dual-supply operation like the MAX909?

No, MAX908CPD does not support dual-supply operation. It is strictly a single-supply device, requiring only V+ (Pin 1) and GND (Pins 4 and 11). Unlike the MAX909, it lacks a V− pin and internal circuitry for negative rail operation. The datasheet confirms MAX908 functionality is limited to +4.5V to +5.5V supply, with input common-mode range bounded at –0.2V (not –5V) and V+–1.5V.

Is MAX908CPD pin-compatible with other MAX908 package variants such as MAX908CSD?

Yes, MAX908CPD is pin-compatible with MAX908CSD - both share identical 14-pin functional mapping (V+, INA−, INA+, GND, INB+, INB−, OUTB, OUTC, INC−, INC+, GND, IND+, IND−, OUTD). The only difference is package type: CPD uses 14-pin plastic DIP, while CSD uses 14-pin SOIC. Electrical specifications, timing, and thermal limits remain identical across these variants per the datasheet's "Ordering Information" and "Pin Configurations" sections.

What is the maximum capacitive load the MAX908CPD outputs can drive reliably?

MAX908CPD outputs are characterized up to 15pF capacitive load in the Typical Operating Characteristics (TOC03), showing propagation delay increase from 40ns to ~65ns at 100pF. While not explicitly guaranteed beyond 15pF, the datasheet notes stable operation with CL = 10pF for timing specs. For reliable TTL interfacing, keep load ≤15pF; for heavier loads, add a buffer or reduce trace length to maintain <40ns delay integrity.

Does MAX908CPD include internal hysteresis, and how wide is it?

Yes, MAX908CPD includes fixed internal hysteresis. The input-referred hysteresis width (VHYST) is the difference between VTRIP+ (+2mV typical) and VTRIP– (–2mV typical), resulting in ~4mV nominal width (5mV max per datasheet). This hysteresis is inherent to the comparator core and requires no external components - a key differentiator from generic comparators like LM339 that demand external positive feedback networks.