Analog Devices Inc./Maxim Integrated MAX6822VUK

Overview

MAX6822VUK from Maxim Integrated is a low-voltage microprocessor supervisory IC in SOT23-5 package, providing open-drain active-low RESET output, 1.58V reset threshold (V suffix), 140ms minimum reset timeout, and 1.6s watchdog timeout. It monitors VCC for brownout detection, accepts manual reset via MR pin, and asserts reset during power-up, power-down, or software hang - used in portable battery-powered equipment requiring reliable µP reset under low-VCC conditions.

For engineers reviewing the MAX6822VUK datasheet, MAX6822VUK pinout, MAX6822VUK application, or MAX6822VUK equivalent, this page delivers verified functional identity, exact reset threshold and timing values, SOT23-5 terminal mapping, real-world use cases in embedded controllers and automotive systems, and two validated alternative parts with documented technical differences.

Technical Context

The MAX6822VUK integrates voltage monitoring, watchdog timer, and manual reset logic in a single BiCMOS IC. Its reset generator triggers on VCC falling below 1.58V (±20mV over temperature), holds RESET asserted for ≥140ms after VCC recovers, and guarantees valid reset state down to VCC = +1.0V. The watchdog circuit clears on any WDI edge and times out after 1.6s if no transition occurs.

It features an internal 50kΩ MR pullup, 50ns WDI pulse-width detection capability, and immunity to negative VCC transients ≤20µs at 100mV overdrive. The open-drain RESET output supports bidirectional µP reset pins (e.g., Motorola 68HC11) with external pullup, enabling shared reset bus architectures.

Key Specifications

Pinout & Package

SOT23-5 package (5-pin, 1.6mm × 2.9mm footprint, 0.95mm height), JEDEC MO-178AC compliant, lead-free compatible (UK+T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6822VUK, MAX6823VUK offers identical supervision functionality but replaces open-drain RESET with push-pull for direct drive, while TPS3808G15DBVR removes watchdog entirely - making MAX6822VUK uniquely suitable for systems requiring both precise low-threshold monitoring and autonomous firmware hang detection.

Availability

MAX6822VUK is available at Aetrix Electronics and suitable for portable/battery-powered equipment, automotive systems, embedded controllers, and critical µP monitoring applications requiring stable component supply across extended temperature ranges (-40°C to +125°C).

Supply support for MAX6822VUK 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 industrial, automotive, communications, and computing markets.

The MAX6821–MAX6825 product line delivers ultra-low-voltage microprocessor supervisors with integrated watchdog and manual reset, targeting space-constrained, battery-sensitive applications where reliability under brownout and firmware fault conditions is essential.

FAQ

What is the exact reset threshold voltage for MAX6822VUK?

The MAX6822VUK has a factory-programmed reset threshold of 1.58V, with tolerance of ±20mV over the full temperature range (-40°C to +125°C). This value is confirmed in the Threshold Suffix Guide (V = 1.58V) and Electrical Characteristics table under VTH parameter for MAX682_V variant. The MAX6822VUK maintains this threshold stability with a temperature coefficient of 60ppm/°C.

Does MAX6822VUK include a watchdog timer, and what is its timeout period?

Yes, the MAX6822VUK includes a watchdog timer with a nominal timeout period of 1.6 seconds. This is specified in the Features section and Electrical Characteristics table under tWD parameter for MAX6821–MAX6824 variants. The timeout varies from 0.80s to 2.60s over temperature (-40°C to +125°C), and the timer clears on any rising or falling edge at the WDI pin.

What type of RESET output does MAX6822VUK provide, and how is it used?

The MAX6822VUK provides an active-low open-drain RESET output (Pin 1). It requires an external pullup resistor to VCC or another supply rail and is designed to interface with bidirectional µP reset pins (e.g., Motorola 68HC11). When asserted, RESET sinks ≥50µA at VCC ≥1.0V; when deasserted, it presents high-impedance state, allowing multiple devices to share a common reset bus.

Can MAX6822VUK operate reliably at very low supply voltages?

Yes, the MAX6822VUK guarantees valid reset assertion and release functionality down to VCC = +1.0V, as explicitly stated in the General Description and Electrical Characteristics. Its internal circuitry remains fully operational and its reset output remains in correct logic state even when VCC drops to 1.0V - critical for battery-powered systems during end-of-discharge conditions.

How does the manual reset input (MR) function on MAX6822VUK?

The MR pin (Pin 3) on MAX6822VUK is an active-low input with an internal 50kΩ pullup resistor to VCC. Pulling MR low forces a reset that remains active for the full 140ms timeout period after MR returns high. MR accepts CMOS logic levels and can be driven by open-drain outputs or momentary switches to GND; no external debounce components are required due to internal filtering.