Analog Devices Inc./Maxim Integrated MAX708CUA+T

Overview

MAX708CUA+T from Maxim Integrated is a microprocessor supervisory circuit providing active-high reset output, 4.40V supply-voltage monitoring, 1.25V power-fail comparator input, and manual-reset input - all in an 8-pin µMAX package. It ensures reliable power-up/power-down sequencing and brownout protection for +5V systems in industrial controllers and embedded instrumentation.

For engineers reviewing the MAX708CUA+T datasheet, MAX708CUA+T pinout, MAX708CUA+T application, or MAX708CUA+T equivalent, this page delivers verified electrical parameters, confirmed µMAX-8 package mapping, validated reset timing (200ms pulse width), and two field-tested alternative parts with documented functional differences.

Technical Context

The MAX708CUA+T integrates a precision voltage monitor with 4.40V threshold (±15mV typical hysteresis), a debounced TTL/CMOS-compatible manual-reset input (150ns minimum pulse width), and a 1.25V reference-based power-fail comparator. Its active-high RESET output remains valid down to VCC = 1V, enabling robust reset assertion during deep brownout conditions.

Unlike the MAX705/MAX706 series, the MAX708 substitutes watchdog timer functionality with a second reset output (RESET), delivering complementary active-low and active-high reset signals. This dual-output architecture eliminates external inverters in systems requiring both logic polarities - such as Intel 80C51-based designs and mixed-signal controllers with bidirectional reset pins.

Key Specifications

Pinout & Package

MAX708CUA+T is housed in an 8-pin µMAX package (package code U8+1, outline 21-0036), measuring 3.0mm × 3.0mm × 0.8mm with exposed pad for thermal enhancement. The package is RoHS-compliant and lead(Pb)-free.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with MAX707CUA+T and MAX813LCUA+T, the MAX708CUA+T uniquely delivers 4.40V reset threshold plus dual active reset outputs in µMAX-8 - making it optimal for cost-sensitive industrial controllers requiring precise brownout response and hardware-level reset polarity flexibility.

Availability

MAX708CUA+T is available at Aetrix Electronics and suitable for industrial controllers, embedded data loggers, medical diagnostic instruments, and communications gateways requiring stable component supply across multi-year production cycles.

Supply support for MAX708CUA+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) designs high-performance analog and mixed-signal ICs for power, sensing, connectivity, and security applications.

The MAX705–MAX708/MAX813L family delivers integrated µP supervisory functions - specifically engineered to replace discrete reset generators and voltage monitors in space-constrained, reliability-critical embedded systems.

FAQ

What is the reset threshold voltage for MAX708CUA+T?

The MAX708CUA+T has a nominal reset threshold of 4.40V with ±0.15V tolerance over temperature. This value is factory-trimmed and guaranteed across the 0°C to +70°C operating range. The threshold triggers reset assertion whenever VCC falls below this level, ensuring compatibility with standard +5V systems requiring tighter brownout protection than the 4.65V variants like MAX707CUA+T. The MAX708CUA+T maintains this specification in its 8-pin µMAX package.

Does MAX708CUA+T include a watchdog timer function?

No, the MAX708CUA+T does not include a watchdog timer. Unlike the MAX705/MAX706/MAX813L, the MAX708 replaces the watchdog input (WDI) and watchdog output (WDO) with a second reset output (RESET). Pin 6 is designated as N.C. (no connect) in the MAX708CUA+T datasheet. This design choice prioritizes dual-polarity reset capability over watchdog supervision - a key differentiator confirmed in the Pin Description table and block diagrams.

What is the function of the PFI and PFO pins on MAX708CUA+T?

The PFI (Power-Fail Input) pin accepts an external voltage for comparison against an internal 1.25V reference. When the applied voltage drops below 1.25V, the PFO (Power-Fail Output) pin goes low to signal impending supply failure. This pair enables early-warning detection of secondary rails (e.g., +12V) or negative supplies using simple resistor dividers. The MAX708CUA+T specifies PFI input current as ±25nA and PFO sink capability of 3.2mA - enabling direct connection to µP interrupt lines without buffering.

Can MAX708CUA+T operate with supply voltages below 5V?

Yes, the MAX708CUA+T operates from 1.0V to 5.5V and guarantees valid RESET/RESET output down to VCC = 1.0V. At 1V, the active-low RESET output remains ≤0.3V (at 50μA sink), and the active-high RESET output is ≥0.8V (at 4μA source). This ultra-low-voltage operation supports safe shutdown sequencing in battery-backed systems and enables reset assertion during deep brownout conditions where other supervisors fail - a feature explicitly tested and specified in the Electrical Characteristics table.

What package type is used for MAX708CUA+T?

The MAX708CUA+T uses the 8-pin µMAX package (outline 21-0036), identified by package code U8+1. It measures 3.0mm × 3.0mm × 0.8mm with an exposed thermal pad. The "+T" suffix denotes tape-and-reel packaging, and the "+" in "U8+1" confirms RoHS-compliant, lead(Pb)-free construction. This package is pin-compatible with SO-8 and PDIP-8 variants of the same family but offers superior board-area efficiency - critical for compact industrial and medical PCBs.