Analog Devices Inc./Maxim Integrated MAX6342RUT

Overview

MAX6342RUT from Maxim Integrated is a precision 6-pin SOT23 microprocessor supervisory circuit with factory-trimmed 2.63V VCC reset threshold, active-low push-pull RESET output, and manual-reset (MR) input. It monitors supply voltage in digital systems, asserts valid reset down to VCC = +1V, guarantees ≥100ms reset pulse width, and includes a dedicated +1.25V power-fail comparator (PFI/PFO) for low-battery or auxiliary supply monitoring - used in portable telecom and multivoltage embedded control.

For engineers reviewing the MAX6342RUT datasheet, MAX6342RUT pinout, MAX6342RUT application, or MAX6342RUT equivalent, key selection criteria include its 2.63V reset threshold tolerance (±25mV over –40°C to +125°C), MR debounce capability, guaranteed RESET validity at VCC = 1V, and compatibility with battery-backed systems requiring early power-fail warning via PFO.

Technical Context

The MAX6342RUT implements a precision bandgap-based reset comparator with factory-laser-trimmed VTH = 2.63V (±25mV max deviation over full temperature range), enabling reliable brownout detection in low-voltage microcontroller systems. Its internal +1.25V reference drives a separate PFI comparator, allowing independent monitoring of secondary supplies without affecting reset timing.

It features a debounced CMOS-compatible MR input with 1µs minimum glitch rejection and 0.1µs minimum pulse width, and an active-low push-pull RESET output capable of sinking 1.2mA at VCC > 2.7V while maintaining VOL ≤ 0.4V - ensuring robust interface with µP reset inputs across wide VCC (1.0V–5.5V) and temperature (–40°C to +125°C) ranges.

Key Specifications

Pinout & Package

MAX6342RUT is housed in a RoHS-compliant 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), optimized for space-constrained portable and embedded designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6343RUT-T, MAX6342RUT offers push-pull drive eliminating external components, while TLV803RDBZR sacrifices PFI monitoring and MR flexibility for reduced cost and size - making MAX6342RUT optimal where integrated power-fail warning and field-serviceable reset are required.

Availability

MAX6342RUT is available at Aetrix Electronics and suitable for portable computers, telecom equipment, and battery-powered embedded systems requiring stable component supply across extended temperature and long product lifecycles.

Supply support for MAX6342RUT 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, and connectivity applications in industrial, automotive, and communications markets.

The MAX6342–MAX6345 family was engineered specifically for reliable power supervision in space- and power-constrained digital systems - delivering precision reset, power-fail warning, and manual reset in a miniature 6-pin SOT23 package.

FAQ

What is the exact reset threshold voltage of MAX6342RUT and how tightly is it specified?

The MAX6342RUT has a factory-trimmed nominal reset threshold of 2.63V, with a maximum deviation of ±25mV over the full operating temperature range of –40°C to +125°C. This specification is guaranteed per device and documented in the Electrical Characteristics table of the official datasheet. The "R" suffix in MAX6342RUT explicitly denotes this 2.63V variant, and the tolerance ensures consistent brownout behavior across extreme environmental conditions without external calibration.

Does MAX6342RUT support operation down to 1.0V VCC, and what does that mean for system reliability?

Yes, MAX6342RUT guarantees valid RESET assertion down to VCC = +1.0V - meaning its internal comparators and output driver remain functional and produce correct logic levels even during deep brownout events. This ensures the connected microprocessor receives a clean, unambiguous reset signal before supply collapse, preventing erratic execution, memory corruption, or latch-up. For systems powered by fading batteries or unstable energy harvesters, this feature is essential to maintain deterministic fail-safe behavior.

How is the PFI/PFO function used in MAX6342RUT, and what external components are needed?

In MAX6342RUT, the PFI pin connects to a resistor divider from a monitored supply (e.g., battery or auxiliary rail), and the internal +1.25V comparator triggers PFO low when the divided voltage falls below that reference. No external components are required for basic operation - only two resistors for the divider. PFO is an open-drain output, so a pull-up resistor (typically 10kΩ to VCC or another supply) is needed to generate a logic-high idle state. This enables early-warning shutdown, low-battery alerts, or secondary-rail fault detection independent of the main reset function.

What is the reset timeout period of MAX6342RUT, and is it adjustable?

The MAX6342RUT provides a fixed minimum reset timeout period of 100ms (tRP), guaranteed over –40°C to +125°C. This duration is factory-programmed and not user-adjustable. It is designed to exceed the power-up stabilization time of most microcontrollers and FPGAs, ensuring the host device completes internal initialization before release. The actual timeout may extend up to 280ms at temperature extremes, but the 100ms minimum is the design-critical value used for system timing margining.

Can MAX6342RUT be used with a microprocessor that has a bidirectional reset pin?

Yes, MAX6342RUT is compatible with µPs featuring bidirectional reset I/O. Its active-low push-pull RESET output can directly drive such pins when configured as an output. To avoid contention during µP-controlled reset assertion, a series buffer (e.g., 4.7kΩ resistor) is recommended between MAX6342RUT's RESET and the µP pin - as shown in Figure 9 of the datasheet. This preserves signal integrity while allowing the µP to override reset when necessary, without loading the supervisory circuit's output driver.