Analog Devices Inc./Maxim Integrated MAX6722UTWGD3+

Overview

MAX6722UTWGD3+ from Maxim Integrated is a dual-voltage microprocessor supervisory IC monitoring VCC1 (primary) and VCC2 (secondary) supplies, with manual reset input (MR), watchdog timer (WDI), and push-pull active-low RST output. It asserts reset if either supply drops below factory-trimmed thresholds (VTH1 = 4.625 V, VTH2 = 3.075 V), maintains reset for 210 ms (min), and operates down to VCC = 0.8 V. Used in telecom power management and industrial embedded controllers requiring reliable brownout detection.

For engineers reviewing the MAX6722UTWGD3+ datasheet, MAX6722UTWGD3+ pinout, MAX6722UTWGD3+ application, or MAX6722UTWGD3+ equivalent, key selection factors include its dual-supply monitoring capability, guaranteed reset validity at low VCC, integrated watchdog with 35 s startup/1.12 s normal timeout, manual reset input with 50 kΩ internal pullup, and SOT23-6 push-pull output configuration.

Technical Context

The MAX6722UTWGD3+ implements independent voltage comparators for VCC1 and VCC2, each with ±0.5% hysteresis and 20 ppm/°C tempco, ensuring stable threshold behavior across -40°C to +85°C. Its reset logic combines ORed fault conditions (VCC1/VCC2 undervoltage, MR low, WDI timeout) with a monolithic timeout counter that restarts on any valid recovery event.

It features a dual-mode watchdog: 35 s minimum initial timeout after power-up or reset, followed by 1.12 s minimum normal timeout triggered by first WDI edge; WDI accepts CMOS/TTL levels with 100 ns glitch rejection and 200 ns MR-to-reset delay. The push-pull RST output drives high to 0.8 × VCC1 at 800 µA and sinks to 0.4 V at 3.2 mA.

Key Specifications

Pinout & Package

MAX6722UTWGD3+ is housed in a 6-pin SOT23-6 package (2.9 mm × 1.6 mm × 1.1 mm), RoHS-compliant and lead-free (+ suffix). Pin 1 is marked with a dot; device orientation follows JEDEC MO-178AB standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6722UTWGD3+, MAX6720UTWGD3+ offers identical supervision logic but requires board-level pullup for RST, while TPS3808G33DBVR reduces BOM count in single-rail designs but sacrifices dual-monitoring, watchdog, and manual reset functionality essential for complex embedded systems.

Availability

MAX6722UTWGD3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial control, and battery-operated edge computing applications requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for MAX6722UTWGD3+ 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 connectivity applications, with emphasis on reliability and integration for harsh environments.

The MAX6715–MAX6729 family delivers ultra-low-voltage supervisory circuits targeting multivoltage embedded systems where space, power, and fault coverage are critical - especially in telecom, industrial, and portable equipment.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6722UTWGD3+?

The MAX6722UTWGD3+ has a factory-trimmed VCC1 reset threshold of 4.625 V (typical), with a guaranteed range of 4.500 V to 4.750 V over temperature. This value is encoded in the "WG" suffix per Maxim's Reset Voltage Threshold Suffix Guide and is validated across the full -40°C to +85°C operating range. The MAX6722UTWGD3+ uses this precise threshold to ensure reset assertion occurs before downstream 5 V logic becomes unreliable.

Does the MAX6722UTWGD3+ support monitoring a third voltage rail?

No, the MAX6722UTWGD3+ is a dual-voltage supervisor and does not include the RSTIN input required for triple-voltage monitoring. That function is reserved for variants like MAX6723–MAX6727. The MAX6722UTWGD3+ monitors only VCC1 and VCC2, with fixed thresholds of 4.625 V and 3.075 V respectively. Adding a third rail would require external circuitry or selecting a different part number within the MAX6715–MAX6729 family.

What is the watchdog timeout behavior of the MAX6722UTWGD3+ after power-up?

The MAX6722UTWGD3+ implements a dual-mode watchdog: after power-up or any reset event, it enters a 35 s (minimum) startup timeout period. Once the first valid WDI edge occurs - rising or falling - it transitions to the 1.12 s (minimum) normal timeout mode. This architecture prevents false timeouts during boot while enabling rapid hang detection during runtime. The MAX6722UTWGD3+ guarantees both timing values across temperature and supply variations.

Can the MAX6722UTWGD3+ operate with VCC1 below 1.8 V?

No - the MAX6722UTWGD3+ specifies a minimum VCC1 operating voltage of 1.8 V per its Absolute Maximum Ratings and Electrical Characteristics tables. While reset output validity is guaranteed down to VCC = 0.8 V, the device requires VCC1 ≥ 1.8 V to power internal circuitry and maintain functional operation. Operating VCC1 below 1.8 V may result in undefined behavior, including failure to assert reset or incorrect watchdog timing. The MAX6722UTWGD3+ is not rated for sub-1.8 V primary supply use.

Is the MR input on the MAX6722UTWGD3+ compatible with 1.8 V logic levels?

Yes - the MR input on the MAX6722UTWGD3+ accepts standard CMOS/TTL logic levels referenced to VCC1: VIH ≥ 0.7 × VCC1 and VIL ≤ 0.3 × VCC1. With VCC1 = 1.8 V, this translates to VIH ≥ 1.26 V and VIL ≤ 0.54 V, fully compatible with 1.8 V logic families. The internal 50 kΩ pullup ensures MR defaults high when floating, and the 1 µs minimum pulse width requirement accommodates standard GPIO toggle speeds. This makes the MAX6722UTWGD3+ suitable for direct interfacing with low-voltage microcontrollers.