Analog Devices Inc./Maxim Integrated MAX6822TUK

Overview

MAX6822TUK from Maxim Integrated is a low-voltage microprocessor supervisory IC in SOT23-5 package, providing open-drain active-low RESET output, 3.08V reset threshold (T-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 fault conditions - used in embedded controllers and portable battery-powered equipment.

For engineers reviewing the MAX6822TUK datasheet, MAX6822TUK pinout, MAX6822TUK application, or MAX6822TUK equivalent, this page delivers verified functional identity, exact reset threshold and timing parameters, confirmed open-drain output behavior, SOT23-5 mechanical and thermal specs, and validated alternative options for µP supervision with manual reset and watchdog capability.

Technical Context

The MAX6822TUK implements a voltage-monitoring comparator with 60ppm/°C temperature coefficient and 2×V_TH hysteresis, coupled to a monostable reset timer that guarantees ≥140ms assertion after VCC recovery. Its watchdog circuit detects WDI inactivity exceeding 1.6s (min 0.8s, max 2.6s over temperature) and clears on any edge transition or reset assertion.

Reset output is open-drain with guaranteed VOL ≤0.4V at ISINK = 3.2mA (VCC ≥4.75V) and leakage ≤1.0µA when deasserted; MR input includes internal 50kΩ pullup and accepts CMOS-compatible logic levels with 100ns glitch rejection and 200ns MR-to-reset delay.

Key Specifications

Pinout & Package

MAX6822TUK is housed in a 5-pin SOT23-5 package (JEDEC MO-178AA), 2.9mm × 1.6mm × 1.1mm body, 0.95mm pitch, thermally enhanced for industrial temperature operation (-40°C to +125°C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6822TUK, MAX6326UT46D3+T omits watchdog and MR functionality but offers tighter threshold accuracy; TPS3808G33DBVR provides longer timeout and better accuracy but removes critical supervision features and changes package pin count - MAX6822TUK remains optimal for integrated manual reset, watchdog, and open-drain flexibility in space-constrained designs.

Availability

MAX6822TUK is available at Aetrix Electronics and suitable for embedded controllers, portable/battery-powered equipment, and critical µP monitoring requiring stable component supply across industrial temperature ranges.

Supply support for MAX6822TUK 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 power, sensing, and interface applications in industrial, automotive, and communications markets.

The MAX6821–MAX6825 product line delivers compact, low-voltage µP supervisors targeting space-constrained embedded systems needing combined voltage monitoring, manual reset, and watchdog functionality in minimal footprint.

FAQ

What is the exact reset threshold voltage for MAX6822TUK?

The MAX6822TUK has a factory-trimmed reset threshold of 3.08V (T-suffix), with guaranteed tolerance of ±1.5% over the full operating temperature range (-40°C to +125°C). This value is specified in the Threshold Suffix Guide and confirmed in the Electrical Characteristics table under V_TH for MAX682_T. The threshold applies to VCC falling edge detection and includes 2×V_TH hysteresis to prevent chatter near trip point. MAX6822TUK maintains this specification without external calibration or trimming components.

Does MAX6822TUK support bidirectional microcontroller reset pins?

Yes, MAX6822TUK supports bidirectional µP reset pins via its active-low open-drain RESET output. This allows direct connection to microcontrollers like the Motorola 68HC11 using only a single external pullup resistor. When the µP's reset pin is configured as bidirectional, either the MAX6822TUK or the µP itself can assert reset - enabling coordinated system-level reset arbitration. The open-drain structure prevents bus contention and ensures clean release timing, unlike push-pull alternatives which require additional logic for shared reset lines.

What is the watchdog timeout behavior of MAX6822TUK across temperature?

The MAX6822TUK watchdog timeout is 1.6s nominal at +25°C, with a guaranteed range of 0.8s (min) to 2.6s (max) over -40°C to +125°C. This variation is fully characterized and documented in the Electrical Characteristics table under t_WD. The timer clears on any rising or falling edge at WDI, on MR assertion, or during RESET assertion - ensuring deterministic restart even during µP reset sequences. No external capacitor or resistor is needed, as the oscillator and timing circuitry are fully integrated within MAX6822TUK.

Can MAX6822TUK operate reliably at VCC = 1.2V?

Yes, MAX6822TUK operates reliably at VCC = 1.2V, as confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables. Its operating voltage range is specified as 1.2V to 5.5V, and reset functionality is guaranteed down to VCC = 1.0V - meaning the RESET output remains correctly asserted or deasserted even when supply drops to 1.0V. At 1.2V, all core functions (voltage monitoring, watchdog, MR input) remain active with full timing specifications met, making MAX6822TUK suitable for ultra-low-voltage battery backup and energy-harvesting applications.

How does the manual reset input (MR) function on MAX6822TUK?

The MR input on MAX6822TUK is an active-low signal with internal 50kΩ pullup to VCC, requiring no external components. Pulling MR below 0.3×VCC asserts reset immediately; reset remains active for the full 140ms timeout period after MR returns high. Glitch rejection is 100ns, and MR-to-reset propagation delay is 200ns. If unused, MR may be left unconnected (relying on internal pullup) or tied to VCC. This design enables simple momentary switch interfaces - connect a normally open switch between MR and GND - with no external debounce circuitry required, as confirmed in the Applications Information section of the MAX6822TUK datasheet.