Analog Devices Inc./Maxim Integrated MAX6343ZUT+T

Overview

MAX6343ZUT+T from Maxim Integrated is a precision microprocessor supervisory circuit with active-low open-drain reset output, factory-trimmed 2.33V VCC reset threshold, +1.25V power-fail comparator input, and guaranteed RESET validity down to VCC = +1V. It operates across -40°C to +125°C in portable/battery-powered systems requiring reliable brownout detection and orderly shutdown.

For engineers reviewing the MAX6343ZUT+T datasheet, MAX6343ZUT+T pinout, MAX6343ZUT+T application, or MAX6343ZUT+T equivalent, key selection criteria include its open-drain reset configuration, 100ms minimum reset timeout, PFI/PFO monitoring capability for secondary supply tracking, and SOT23-6 package compatibility with space-constrained embedded control designs.

Technical Context

The MAX6343ZUT+T implements a precision bandgap-based reset generator with hysteresis, paired with an independent +1.25V reference comparator for PFI monitoring. Its reset assertion logic responds to VCC falling below 2.33V (±1.5% over temperature) or MR pull-down, with built-in glitch rejection (1µs minimum MR pulse width).

Unlike push-pull variants, the open-drain RESET output requires an external pull-up resistor (e.g., 10kΩ to +3.3V or +5V), enabling level-shifting and wired-OR configurations. The PFO output asserts low when PFI falls below 1.25V, supporting early power-fail warning and multi-rail supervision without additional ICs.

Key Specifications

Pinout & Package

MAX6343ZUT+T is housed in a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), optimized for high-density PCB layouts in portable and embedded systems.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G125DBVR and ADM6315-23ARTZ-RL, the MAX6343ZUT+T uniquely integrates both precision 2.33V reset supervision and a dedicated +1.25V PFI comparator in one SOT23-6 device-enabling compact, dual-function supervision without external components or timing compromises.

Availability

MAX6343ZUT+T is available at Aetrix Electronics and suitable for portable computers, telecom equipment, multivoltage systems, and embedded control systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6343ZUT+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 precision analog, mixed-signal, and power management ICs for demanding industrial, automotive, and communications applications.

The MAX6342–MAX6345 family delivers highly integrated µP supervisory functions-including reset generation, manual reset, and power-fail monitoring-in miniature packages for space- and power-constrained embedded systems.

FAQ

What is the exact reset threshold voltage of the MAX6343ZUT+T and how tightly is it specified?

The MAX6343ZUT+T has a factory-trimmed VCC reset threshold of 2.33V, with a tolerance of ±1.5% over the full operating temperature range of -40°C to +125°C. This specification is guaranteed in production test and documented in the Electrical Characteristics table of the official datasheet. The 'Z' suffix explicitly denotes the 2.33V variant within the MAX6342–MAX6345 family, and the value is not adjustable or user-configurable.

Does the MAX6343ZUT+T provide both reset and power-fail monitoring functions simultaneously?

Yes, the MAX6343ZUT+T provides concurrent reset supervision and power-fail monitoring. Its VCC input triggers the primary reset function at 2.33V, while the independent PFI pin accepts an external voltage and compares it to an internal +1.25V reference-asserting the PFO output when PFI falls below that threshold. These two functions operate autonomously, allowing the same device to supervise the main supply and monitor a secondary rail or battery voltage without interference.

What type of reset output does the MAX6343ZUT+T feature, and what external components are required?

The MAX6343ZUT+T features an active-low open-drain RESET output (Pin 6). Because it cannot source current, an external pull-up resistor is mandatory-typically 10kΩ connected to a positive supply (≤+5.5V). This configuration enables level translation, wired-OR reset buses, and compatibility with µPs requiring specific reset voltage levels. No pull-up is needed for the PFO output, which also uses open-drain architecture.

Can the MAX6343ZUT+T operate reliably during severe supply voltage droops?

Yes, the MAX6343ZUT+T is guaranteed to assert valid RESET logic levels down to VCC = +1V, making it exceptionally robust during deep brownout conditions. Unlike many supervisors that cease functioning below ~2.0V, this device maintains proper reset timing and comparator accuracy even as VCC collapses-critical for preventing undefined µP states in battery-powered or automotive applications experiencing cranking events.

How is the manual reset (MR) input debounced, and what is the minimum pulse width it requires?

The MR input of the MAX6343ZUT+T is internally debounced with a 1µs minimum pulse width requirement. This eliminates the need for external RC filters or firmware debouncing routines. When MR is pulled low (to GND), RESET asserts immediately and remains active for the full reset timeout period (≥100ms) after MR returns high. The input is CMOS-compatible, with VIH = 0.7×VCC and VIL = 0.3×VCC, ensuring reliable switching across the entire supply range.