Analog Devices Inc./Maxim Integrated MAX800LCUE+

Overview

The MAX800LCUE+ from Maxim Integrated is a microprocessor supervisory circuit designed for critical 5V power monitoring and system reset control in embedded controllers and intelligent instruments. It features a 4.65V typical reset threshold, 200ms power-up reset timeout, 30μA operating supply current, guaranteed RESET assertion down to VCC = 1V, and integrated chip-enable gating with ≤10ns propagation delay. It is used to ensure reliable boot sequencing and brownout protection in industrial controllers.

For engineers reviewing the MAX800LCUE+ datasheet, MAX800LCUE+ pinout, MAX800LCUE+ application, or MAX800LCUE+ equivalent, key selection considerations include its ±2% power-fail accuracy, battery-switchover capability with MaxCap®/SuperCap compatibility, open-drain RESET output valid at 1V VCC, and dual watchdog timeout modes (100ms/1.6s) configurable via OSC SEL and OSC IN.

Technical Context

The MAX800LCUE+ implements a dual-output reset architecture with active-low RESET and active-high RESET outputs, both asserted when VCC falls below 4.65V (typ), and held for 200ms after VCC rises above threshold. Its internal oscillator sets timing for reset and watchdog functions, while external capacitor or clock input on OSC IN enables programmable timeout periods.

It integrates a bidirectional VCC/VBATT switchover path with PMOS-based low-resistance switching (≤1.2Ω VCC-to-VOUT, ≤30Ω VBATT-to-VOUT), a dedicated power-fail comparator (PFI/PFO) with 1.25V threshold and ±2% accuracy, and CE signal gating that disables CE IN during reset to prevent RAM corruption - all operating across -40°C to +85°C.

Key Specifications

Pinout & Package

MAX800LCUE+ is housed in a 16-pin TSSOP package (4.4mm × 5.0mm, 0.65mm pitch), lead-free compliant (indicated by '+' suffix), rated for -40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX691AESE and TPS3823MPDBVR, the MAX800LCUE+ uniquely combines precision reset supervision, battery switchover, chip-enable gating, and configurable watchdog timing in a compact TSSOP package - eliminating four discrete functions in industrial controller designs.

Availability

MAX800LCUE+ is available at Aetrix Electronics and suitable for industrial controllers, intelligent instrumentation, and critical μP power monitoring applications requiring stable component supply, long-term lifecycle support, and guaranteed parametric performance across temperature.

Supply support for MAX800LCUE+ 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 computing markets.

The MAX800L family was designed specifically for robust 5V microprocessor supervision in harsh environments, integrating reset, watchdog, power-fail detection, and battery switchover into a single IC to reduce system-level complexity and improve reliability.

FAQ

What is the guaranteed reset threshold voltage for MAX800LCUE+?

The MAX800LCUE+ has a guaranteed reset threshold voltage of 4.50V minimum, 4.65V typical, and 4.75V maximum at TA = +25°C, with hysteresis of 15mV. This specification applies across the full -40°C to +85°C operating range and ensures consistent reset behavior in industrial 5V systems subject to rail tolerance and temperature drift.

Does MAX800LCUE+ support battery backup with supercapacitors?

Yes, the MAX800LCUE+ is explicitly MaxCap® and SuperCap-compatible. Its VBATT input supports low-leakage switchover (VBATT standby current ≤1µA) and handles capacitor values up to 0.47F, as validated in the Typical Operating Circuit. The internal PMOS switch and diode path provide controlled charging/discharging essential for long-life capacitor-based hold-up.

How does the CE gating function work in MAX800LCUE+?

The MAX800LCUE+ gates the CE signal between CE IN and CE OUT using an internal transmission gate. When RESET is asserted (VCC < 4.65V), CE OUT is disabled and driven high-impedance, preventing spurious writes to CMOS RAM. During normal operation, CE IN passes through with ≤10ns propagation delay and 75Ω series resistance, preserving signal integrity for high-speed μPs.

Can MAX800LCUE+ generate different watchdog timeout periods?

Yes, the MAX800LCUE+ supports two configurable watchdog timeout periods: a short period of 70–140ms and a long period of 1.0–2.25s. These are selected via OSC SEL and OSC IN - floating OSC SEL yields 1.6s nominal, grounding OSC SEL and connecting a capacitor to OSC IN allows precise RC-based tuning, and driving OSC IN externally enables clock-synchronized timeouts.

Is MAX800LCUE+ pin-compatible with older Maxim supervisors?

Yes, the MAX800LCUE+ is pin-compatible with the MAX691A and MAX693A families, sharing identical 16-pin TSSOP pinout, terminal functions, and electrical interface. This allows drop-in replacement in existing designs while delivering improved specifications including lower supply current (30μA vs. older 50μA), tighter power-fail accuracy (±2%), and enhanced VCC-down-to-1V RESET validity.