Analog Devices Inc./Maxim Integrated MAX6321HPUK30CY

Overview

MAX6321HPUK30CY from Maxim Integrated is a 5-pin SOT23 microprocessor supervisory circuit with active-high push/pull reset output, 3.0V factory-trimmed reset threshold, 140ms minimum reset timeout, and 1.6s typical watchdog timeout. It monitors VCC supply voltage, provides manual reset input (MR), and asserts reset during power-up, brownout, or software hang conditions in embedded control systems.

For engineers reviewing the MAX6321HPUK30CY datasheet, MAX6321HPUK30CY pinout, MAX6321HPUK30CY application, or MAX6321HPUK30CY equivalent, this device supports robust system-level reset management in automotive-qualified designs requiring guaranteed reset validity down to VCC = 1V, immunity to short negative VCC transients, and AEC-Q100 qualification.

Technical Context

The MAX6321HPUK30CY implements a precision voltage monitor with laser-trimmed internal divider setting VRST = 3.0V ±2.5% over -40°C to +125°C, paired with a digital reset timer generating a fixed 140ms (min) active reset pulse after VCC rises above threshold. Its watchdog circuit detects µP inactivity via WDI edge transitions and triggers reset if no activity occurs within 1.6s (typ).

This device features an active-high push/pull RESET output capable of sourcing ≥500µA at VCC ≥2.7V (VOH ≥0.8×VCC) and sinking ≥1.2mA (VOL ≤0.3V), with guaranteed logic-level validity down to VCC = 1V. MR input includes 52kΩ internal pullup and 100ns glitch rejection, while WDI accepts 50ns minimum pulses and draws ≤160µA average current when actively driven.

Key Specifications

Pinout & Package

MAX6321HPUK30CY is housed in a 5-pin SOT23 package (2.9mm × 1.6mm × 1.1mm), optimized for space-constrained PCB layouts in portable and automotive electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6321HPUK30CY, MAX6321HPUK31CY offers a 100mV higher reset threshold for improved noise immunity in noisy 3.3V rails, while TLV803EB30DBVR reduces supply current by 90% but sacrifices watchdog and manual reset capabilities essential for autonomous fault recovery.

Availability

MAX6321HPUK30CY is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial PLC controllers, and medical portable monitors requiring stable component supply with AEC-Q100 qualification and guaranteed long-term availability.

Supply support for MAX6321HPUK30CY 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 computing applications, emphasizing reliability, integration, and performance.

The MAX6316–MAX6322 family delivers highly integrated µP supervisory functions-including reset, watchdog, and manual reset-in miniature SOT23 packages, targeting space- and power-constrained embedded systems needing robust power management.

FAQ

What is the exact reset threshold voltage of MAX6321HPUK30CY and how does it vary with temperature?

The MAX6321HPUK30CY has a factory-trimmed nominal reset threshold of 3.0V, specified as 2.925V (min) to 3.075V (max) at +25°C, and 2.925V (min) to 3.075V (max) over the full -40°C to +125°C operating range. Its reset threshold temperature coefficient is 40ppm/°C, resulting in ≤±0.015V drift across the temperature range-ensuring consistent brownout detection in automotive and industrial environments.

Does MAX6321HPUK30CY require external components to function as a supervisory circuit?

No, MAX6321HPUK30CY operates autonomously without external components: its 3.0V threshold is laser-trimmed on-die, reset timeout is digitally generated, and the active-high push/pull RESET output drives directly into the µP reset pin. Only optional 0.1µF bypass capacitors on VCC and MR are recommended for noise immunity-no pullup resistors, timing capacitors, or voltage dividers are needed.

How does the watchdog feature of MAX6321HPUK30CY interact with the manual reset (MR) input?

In MAX6321HPUK30CY, asserting MR low forces an immediate reset regardless of watchdog state; reset remains active for the full 140ms timeout period after MR returns high. The watchdog timer is independently cleared by WDI edges and resets only if no edge occurs within 1.6s. Both functions share the same RESET output, so either condition produces identical active-high reset assertion-enabling unified fault recovery handling in firmware.

Is MAX6321HPUK30CY qualified for automotive applications and what does that entail?

Yes, MAX6321HPUK30CY is AEC-Q100 Grade 1 qualified (-40°C to +125°C), meaning it has undergone stress testing for temperature cycling, humidity, mechanical shock, and ESD per automotive reliability standards. This qualification validates its use in engine control units, infotainment systems, and ADAS modules where failure could impact safety or regulatory compliance-beyond standard industrial temperature ratings.

What are the absolute maximum ratings for VCC and RESET pins on MAX6321HPUK30CY?

MAX6321HPUK30CY specifies VCC absolute maximum rating as -0.3V to +6V, and RESET pin rating as -0.3V to +6V (since it is open-drain compatible in other variants, but here it's push/pull with rail-to-rail capability). All other pins tolerate -0.3V to (VCC + 0.3V). Exceeding these limits-even briefly-may cause permanent damage; proper decoupling and ESD protection are required in automotive and industrial deployments.