Analog Devices Inc./Maxim Integrated MAX6722AUTSDD3+

Overview

MAX6722AUTSDD3+ from Maxim Integrated is a dual-voltage microprocessor supervisory IC that monitors VCC1 (primary supply) and VCC2 (secondary supply) to assert an active-low reset when either falls below factory-trimmed thresholds-specifically 3.075V (VTH1, suffix 'T') and 3.075V (VTH2, suffix 'T')-with a 140ms minimum reset timeout period (suffix 'D3'). It operates from -40°C to +125°C in a 6-pin SOT23 package and guarantees valid reset output down to VCC1 or VCC2 = 0.8V. It is used in telecom power management systems requiring reliable dual-rail monitoring and brownout protection.

For engineers reviewing the MAX6722AUTSDD3+ datasheet, MAX6722AUTSDD3+ pinout, MAX6722AUTSDD3+ application, or MAX6722AUTSDD3+ equivalent, key selection considerations include its dual-supply threshold matching (both at 3.075V), push-pull RST output referenced to VCC1, manual-reset input with internal 50kΩ pullup, watchdog disable capability via open WDI, and guaranteed operation at ultra-low supply voltage (0.8V).

Technical Context

The MAX6722AUTSDD3+ integrates two independent voltage comparators for VCC1 and VCC2, each with 0.5% hysteresis and 20ppm/°C tempco, feeding into a digital reset timeout timer. Its reset logic asserts RST low when either supply drops below its threshold and holds it for ≥140ms after both supplies recover.

This device includes a manual-reset input (MR) with 1µs minimum pulse width and 100ns glitch rejection, and supports watchdog functionality (disabled by default via unconnected WDI). It features push-pull RST output with VOH ≥ 0.8×VCC1 and VOL ≤ 0.3V at ISINK = 500µA, ensuring robust interface with modern µPs.

Key Specifications

Pinout & Package

MAX6722AUTSDD3+ is housed in a 6-pin SOT23 package (2.9mm × 1.6mm × 1.1mm), RoHS-compliant and lead-free.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supply supervisory applications.

Compared with MAX6722AUTSDD3+, MAX6723AUTSDD3+ adds RSTIN for flexible third-rail monitoring without altering dual-threshold behavior, while TPS3808G33DBVR sacrifices VCC2 supervision entirely-making it unsuitable for true dual-rail fault coverage despite shared package and timeout.

Availability

MAX6722AUTSDD3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, and automotive infotainment systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6722AUTSDD3+ 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.

The MAX6715A–MAX6729A family delivers ultra-low-voltage, multi-rail supervisory circuits optimized for systems requiring guaranteed reset validity down to 0.8V and tight threshold matching across dual supplies.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6722AUTSDD3+?

The MAX6722AUTSDD3+ has factory-trimmed reset thresholds of 3.075V (minimum 3.000V, maximum 3.150V) for both VCC1 and VCC2, as indicated by the 'T' suffix in its part number. This matched dual-threshold configuration ensures symmetrical supervision of two 3.3V rails, critical for avoiding timing skew in multi-domain power systems. The 0.5% hysteresis prevents chatter near threshold crossing.

Does the MAX6722AUTSDD3+ support watchdog functionality, and how is it enabled?

The MAX6722AUTSDD3+ includes watchdog capability but ships with it disabled by default. To enable it, connect the WDI pin to a microprocessor I/O line that toggles within 1.12s (normal mode) after the initial 35s startup window. Leaving WDI unconnected activates the internal 200nA detector, which disables the watchdog-ensuring zero-risk operation in systems where watchdog monitoring is unnecessary.

What is the reset timeout period of the MAX6722AUTSDD3+, and how is it implemented?

The MAX6722AUTSDD3+ provides a minimum reset timeout period of 140ms ('D3' suffix), guaranteed over -40°C to +125°C. This timeout is generated by an internal digital timer that starts upon reset assertion and holds RST low until completion-even if VCC1/VCC2 recover earlier. The timer restarts if either supply dips below threshold before timeout expires, ensuring robust fault containment.

Can the MAX6722AUTSDD3+ operate reliably when VCC1 or VCC2 drops below 1.0V?

Yes-the MAX6722AUTSDD3+ guarantees valid reset output logic state down to VCC1 or VCC2 = 0.8V, per its Absolute Maximum Ratings and Electrical Characteristics. This enables deterministic brownout response in systems with slow-failing supplies or battery depletion scenarios. Below 0.8V, reset behavior is not specified; for sub-0.8V operation, external pulldown/pullup resistors may be required depending on output type.

Is the MAX6722AUTSDD3+ pin-compatible with other devices in the MAX6715A–MAX6729A family?

The MAX6722AUTSDD3+ uses a standard 6-pin SOT23 footprint shared across MAX6715A–MAX6722A and MAX6723A–MAX6724A variants. However, pin functions differ: MAX6722AUTSDD3+ assigns Pin 6 to WDI, whereas MAX6723AUTSDD3+ uses Pin 6 for RSTIN. Direct substitution requires verification of signal mapping-especially for WDI/RSTIN and RST output type (push-pull vs. open-drain)-to avoid functional mismatch.