Analog Devices Inc./Maxim Integrated MAX6343MUT+T

Overview

MAX6343MUT+T from Maxim Integrated is a precision microprocessor supervisory circuit with active-low open-drain reset output, factory-trimmed 3.08V 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 MAX6343MUT+T datasheet, MAX6343MUT+T pinout, MAX6343MUT+T application, or MAX6343MUT+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 designs.

Technical Context

The MAX6343MUT+T implements a precision bandgap-based voltage monitor with two independent comparators: one for VCC supervision (3.08V threshold, ±2.5% over temperature), and another for PFI monitoring at +1.25V (±100mV tolerance). Its reset generator asserts an active-low open-drain signal for ≥100ms after VCC rises above threshold or MR deasserts.

Unlike push-pull variants, the MAX6343MUT+T's open-drain RESET requires an external pull-up resistor (e.g., 10kΩ) to any supply ≤+5.5V, enabling level-shifting and wired-OR configurations. The debounced CMOS-compatible MR input supports manual reset triggering with <1µs glitch rejection and 1µs minimum pulse width.

Key Specifications

Pinout & Package

MAX6343MUT+T is housed in a lead-free 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), optimized for high-density PCB layouts in portable and telecom applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6342MUT+T, the MAX6343MUT+T trades push-pull drive for open-drain flexibility and bus sharing; versus TPS3808G30DBVR, it sacrifices quiescent current and threshold accuracy to retain dual-monitoring capability critical for multirail reliability.

Availability

MAX6343MUT+T is available at Aetrix Electronics and suitable for portable/battery-powered equipment, telecom equipment, multivoltage systems, and embedded control systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6343MUT+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 dual-threshold monitoring, manual reset, and power-fail warning-in miniature SOT23-6 packages for space- and power-constrained systems.

FAQ

What is the exact reset threshold voltage for MAX6343MUT+T and how tightly is it specified?

The MAX6343MUT+T has a factory-trimmed VCC reset threshold of 3.08V, specified with ±2.5% tolerance over the full operating temperature range of -40°C to +125°C. This value is laser-trimmed during production and confirmed per Electrical Characteristics table in the datasheet; it applies specifically to the "T" suffix variant and is not adjustable or user-configurable. The MAX6343MUT+T uses this precise threshold to assert reset reliably during 3.3V supply brownout events.

Does MAX6343MUT+T support operation down to 1.0V VCC, and what does that mean for system behavior?

Yes, MAX6343MUT+T guarantees valid RESET output logic levels down to VCC = +1.0V, meaning the open-drain RESET pin remains functional and correctly driven (low when asserted, high-impedance otherwise) even as the supply collapses. This ensures µP reset remains active throughout deep brownout, preventing erratic execution. However, note that PFO and MR inputs require VCC > +1.25V to operate; the MAX6343MUT+T maintains reset assertion until VCC falls below +1.0V, providing maximum safety margin.

How is the PFI input used in MAX6343MUT+T, and what external components are required?

The PFI input of MAX6343MUT+T connects to a resistor divider from a secondary supply (e.g., 5V rail) to monitor for undervoltage. When PFI voltage drops below +1.25V (±100mV), PFO goes low to signal impending failure. No external components are required for basic PFI use - simply tie unused PFI to GND or VCC. For monitoring, a two-resistor divider (e.g., R1 = 200kΩ, R2 = 250kΩ) sets trip point to ~3.25V. The MAX6343MUT+T datasheet provides exact formulas and examples for custom thresholds.

Why does MAX6343MUT+T use an open-drain RESET output instead of push-pull, and what must be added externally?

MAX6343MUT+T uses an open-drain RESET to enable wired-OR reset buses, level shifting across voltage domains (e.g., pull-up to 1.8V while VCC = 3.3V), and compatibility with µPs having bidirectional reset pins. An external pull-up resistor (typically 4.7kΩ–10kΩ) must be connected between RESET and the target logic supply. The MAX6343MUT+T sink capability (3.2mA at VCC = 4.5V) ensures clean low-level assertion; resistor value is chosen to meet VIH/VIL thresholds of downstream devices.

Is MAX6343MUT+T pin-compatible with other members of the MAX6342–MAX6345 family, and which pins differ?

MAX6343MUT+T shares identical 6-pin SOT23-6 pinout with MAX6342/MAX6344/MAX6345, including VCC (1), GND (2), PFI (3), PFO (4), MR (5), and RESET (6). Functionally, only the RESET pin differs: MAX6343MUT+T provides active-low open-drain, while MAX6342/MAX6345 offer active-low push-pull and MAX6344 offers active-high push-pull. MR and PFI/PFO roles are identical across all variants. Thus, MAX6343MUT+T can replace others in same footprint if external pull-up is added and reset logic polarity accommodated.