Analog Devices Inc./Maxim Integrated MAX6722UTSYD3+T

Overview

MAX6722UTSYD3+T from Maxim Integrated is a dual-voltage microprocessor supervisory circuit in SOT23-6 package, monitoring VCC1 (4.625V threshold) and VCC2 (3.075V threshold) with 210ms reset timeout, push-pull active-low RST output, manual reset input, and watchdog timer. It ensures reliable system boot and brownout recovery in low-power embedded systems.

For engineers reviewing the MAX6722UTSYD3+T datasheet, MAX6722UTSYD3+T pinout, MAX6722UTSYD3+T application, or MAX6722UTSYD3+T equivalent, key selection criteria include dual-supply reset assertion timing, guaranteed reset validity down to 0.8V on either supply, low 14µA typical supply current, and integrated watchdog with 35s startup/1.12s normal timeout.

Technical Context

The MAX6722UTSYD3+T implements independent voltage comparators for VCC1 and VCC2, each with factory-trimmed thresholds (4.625V and 3.075V), hysteresis of 0.5%, and temperature coefficient of 20ppm/°C. Reset assertion occurs when either supply falls below its threshold, and reset remains asserted for a minimum 210ms after both supplies recover.

It integrates a dual-mode watchdog timer: 35s minimum initial timeout after power-up/manual reset, transitioning to 1.12s minimum normal timeout after first WDI edge detection. The push-pull RST output is referenced to VCC1 and sinks up to 3.2mA at 4.5V.

Key Specifications

Pinout & Package

MAX6722UTSYD3+T is housed in a 6-pin SOT23-6 package (1.6mm × 2.9mm, 0.95mm height), RoHS-compliant and lead-free (+T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6722UTSYD3+T, MAX6322UR29D3+T reduces functionality to single-rail monitoring with no watchdog or manual reset, while TPS3808G33DBVR offers comparable single-rail performance but omits critical dual-supply and system-hang protection features essential for robust embedded operation.

Availability

MAX6722UTSYD3+T is available at Aetrix Electronics and suitable for industrial PLC controllers, network router power management, medical diagnostic handhelds, and smart energy meter MCU subsystems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6722UTSYD3+T 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 industrial and communications markets.

The MAX6715–MAX6729 family delivers ultra-low-voltage dual/triple supervisory circuits optimized for multirail embedded systems requiring guaranteed reset behavior down to 0.8V and integrated watchdog functionality without external components.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6722UTSYD3+T?

The MAX6722UTSYD3+T has factory-trimmed reset thresholds of 4.625V for VCC1 (±125mV) and 3.075V for VCC2 (±75mV), as indicated by the "SY" suffix per Maxim's Reset Voltage Threshold Suffix Guide. These values are measured under standard conditions and include 0.5% hysteresis referenced to typical threshold.

Does the MAX6722UTSYD3+T support manual reset, and how is it implemented?

Yes, the MAX6722UTSYD3+T includes an active-low manual reset input (MR) on Pin 3 with a 50kΩ internal pullup to VCC1. A logic-low pulse ≥1µs on MR forces the RST output low for the full 210ms timeout period, even if VCC1/VCC2 remain valid. No external components are needed unless noise immunity requires a 0.1µF capacitor to GND.

What watchdog timeout modes does the MAX6722UTSYD3+T provide, and how do they function?

The MAX6722UTSYD3+T implements a dual-mode watchdog: a 35s minimum initial timeout after any reset event (power-up, MR, or watchdog timeout), followed by a 1.12s minimum normal timeout after the first valid WDI edge. This allows safe boot sequencing while maintaining rapid hang detection during runtime-without requiring software to manage multiple timeout states.

Is the MAX6722UTSYD3+T reset output push-pull or open-drain, and what are its drive capabilities?

The MAX6722UTSYD3+T features a push-pull active-low RST output (Pin 1) referenced to VCC1. It can sink up to 3.2mA at 4.5V (VOL ≤ 0.4V) and source up to 800µA (VOH ≥ 0.8×VCC1). This eliminates the need for an external pullup resistor and enables direct interfacing with µP reset pins requiring strong drive strength.

How does the MAX6722UTSYD3+T ensure valid reset operation during deep brownout conditions?

The MAX6722UTSYD3+T guarantees correct RST logic state as long as either VCC1 or VCC2 remains ≥ 0.8V-verified across -40°C to +85°C. This specification ensures deterministic reset assertion and deassertion even during severe undervoltage events, removing reliance on external brownout detectors or LDO enable signals for fail-safe behavior.