Analog Devices Inc./Maxim Integrated MAX6322HPUK29C+T

Overview

MAX6322HPUK29C+T from Maxim Integrated is a 5-pin SOT23 microprocessor supervisory circuit with active-low open-drain reset output, 2.93V factory-trimmed reset threshold, 140ms minimum reset timeout, and 1.6s typical watchdog timeout. It monitors VCC supply integrity and provides manual reset input (MR), enabling reliable power-on, brownout, and software fault recovery in embedded control systems.

For engineers reviewing the MAX6322HPUK29C+T datasheet, MAX6322HPUK29C+T pinout, MAX6322HPUK29C+T application, or MAX6322HPUK29C+T equivalent, key selection criteria include its AEC-Q100 qualification, guaranteed reset validity down to VCC = 1V, immunity to short negative VCC transients (<4µs at 100mV under threshold), and compatibility with multi-supply reset buses via open-drain architecture.

Technical Context

The MAX6322HPUK29C+T implements a precision voltage monitor with laser-trimmed resistor network setting VRST = 2.93V ±2.5% over –40°C to +125°C, combined with a digital reset timer generating ≥140ms active-low assertion after VCC rise. Its watchdog circuit detects µP stall by monitoring WDI edge transitions and triggers reset if no activity occurs within 1.6s (typ).

This device features an open-drain RESET output rated for 3.2mA sink at VCC ≥ 4.5V and ≤0.4V VOL, supporting pullup to any supply up to 6V - enabling interoperability across mixed-voltage systems. MR input includes 52kΩ internal pullup and 100ns glitch rejection, while WDI accepts 50ns minimum pulse width with 0.3×VCC/0.7×VCC thresholds.

Key Specifications

Pinout & Package

MAX6322HPUK29C+T is housed in a RoHS-compliant 5-pin SOT23 package (package code U5+2A, outline 21-0057), measuring 2.9mm × 1.6mm × 1.1mm with gull-wing leads. Thermal resistance θJA = 255.9°C/W on multilayer board enables stable operation at full temperature range without heatsinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6322HPUK29C+T, the MAX6322HPUK29D+T extends reset and watchdog durations for slower systems, while TPS3808G18DBVR trades watchdog functionality and MR support for lower supply current and simpler integration - making each alternative optimal only for specific timing and feature trade-offs.

Availability

MAX6322HPUK29C+T is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLC modules, medical infusion pump controllers, and smart energy meter MCUs requiring stable component supply across extended temperature and lifecycle requirements.

Supply support for MAX6322HPUK29C+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 and mixed-signal ICs for demanding industrial, automotive, and communications applications, emphasizing high reliability and integrated functionality.

The MAX6316–MAX6322 family delivers compact, factory-trimmed supervisory solutions targeting space-constrained embedded systems needing robust power monitoring, manual reset, and watchdog protection without external components.

FAQ

What is the exact reset threshold voltage of MAX6322HPUK29C+T and how does it vary with temperature?

The MAX6322HPUK29C+T has a factory-trimmed nominal reset threshold of 2.93V at +25°C, with tolerance of ±2.5% over the full operating range of –40°C to +125°C. Its temperature coefficient is 40ppm/°C, meaning the threshold drifts less than ±11.7mV across the entire temperature span - ensuring consistent brownout detection in automotive and industrial environments where ambient temperature fluctuates widely.

Does MAX6322HPUK29C+T require an external pullup resistor on the RESET pin, and what value is recommended?

Yes, MAX6322HPUK29C+T requires an external pullup resistor on the RESET pin because it uses an open-drain output structure. A 10kΩ resistor to the target supply rail (up to 6V) is recommended for most applications - it ensures valid logic-high levels while limiting current to <0.5mA during reset assertion and maintaining fast rise time even with 200pF bus capacitance.

Can MAX6322HPUK29C+T be used in systems with multiple voltage domains sharing a common reset line?

Yes, MAX6322HPUK29C+T is specifically designed for multi-supply systems: its open-drain RESET output can be pulled up to any voltage rail ≤6V, allowing direct interfacing with 1.8V, 3.3V, and 5V logic domains on a shared reset bus. This eliminates level-shifters and simplifies design in heterogeneous SoC-based platforms such as smart meters and gateway controllers.

How does the watchdog function behave when the WDI pin is left unconnected on MAX6322HPUK29C+T?

When WDI is left unconnected on MAX6322HPUK29C+T, the internal watchdog timer is automatically serviced at intervals equal to 7/8 of the nominal watchdog period (i.e., ~1.4s for the 1.6s version), preventing unintended reset assertion. This allows safe watchdog disablement without external circuitry - though full functional supervision requires active µP toggling of WDI at least once per timeout period.

Is MAX6322HPUK29C+T compatible with AEC-Q100 automotive qualification requirements?

Yes, MAX6322HPUK29C+T is explicitly AEC-Q100 qualified (Grade 1, –40°C to +125°C), having undergone stress testing for HTOL, TC, UHAST, and ESD per Rev H requirements. This qualification covers the full device family and applies directly to the MAX6322HPUK29C+T variant, making it suitable for automotive powertrain, chassis, and body electronics applications.