Analog Devices Inc./Maxim Integrated MAX6722UTVDD3+

Overview

MAX6722UTVDD3+ 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 = 3.075 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 MAX6722UTVDD3+ datasheet, MAX6722UTVDD3+ pinout, MAX6722UTVDD3+ application, or MAX6722UTVDD3+ equivalent, key selection criteria include dual-supply threshold accuracy (±1.5% over temperature), guaranteed reset validity at 0.8 V supply, 14 µA typical supply current, and integrated 35 s / 1.12 s dual-mode watchdog timing.

Technical Context

The MAX6722UTVDD3+ implements two independent voltage comparators with internal 1.5% accurate reference for VCC1 and VCC2 monitoring, plus a dedicated manual reset input with 50 kΩ internal pullup and 1 µs minimum pulse width requirement. Its watchdog timer features a long startup period (35 s min) followed by normal timeout (1.12 s min), triggered by WDI edge transitions.

This device uses BiCMOS process technology (1072 transistors), guarantees correct reset logic state when either VCC1 or VCC2 ≥ 0.8 V, and provides push-pull RST output referenced to VCC1 with VOL ≤ 0.4 V at 3.2 mA sink and VOH ≥ 0.8 × VCC1 at 800 µA source - enabling direct interface to 1.8–5.0 V µP reset inputs without external level-shifting.

Key Specifications

Pinout & Package

MAX6722UTVDD3+ is housed in a 6-pin SOT23-6 package (2.9 mm × 1.6 mm × 1.1 mm), surface-mount, lead-free (+ suffix), RoHS-compliant, with thermal pad not connected internally.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6722UTVDD3+, MAX6720UTVD3+ requires external pullup for RST but offers identical supervision logic, while TPS3808G33DBVR reduces current consumption by 90% but sacrifices dual-rail monitoring, MR, and WDI functionality - making it unsuitable for complex multi-supply systems requiring coordinated reset and watchdog coverage.

Availability

MAX6722UTVDD3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial control, and medical diagnostic equipment requiring stable component supply, long-term lifecycle support, and guaranteed reset behavior under brownout conditions.

Supply support for MAX6722UTVDD3+ 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) is a semiconductor company specializing in precision analog, mixed-signal, and power management ICs for demanding industrial, automotive, and communications applications.

The MAX6715–MAX6729 family was designed specifically for ultra-low-voltage microprocessor supervision in multivoltage systems, emphasizing guaranteed reset validity at sub-1 V supplies, minimal quiescent current, and integrated watchdog functionality without external components.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6722UTVDD3+?

The MAX6722UTVDD3+ has factory-trimmed reset thresholds of 3.075 V for both VCC1 and VCC2, with ±1.5% tolerance over the full -40°C to +85°C operating temperature range. This value is encoded in the "VD" suffix per Maxim's Reset Voltage Threshold Suffix Guide and verified in the Electrical Characteristics table (VTH1/VTH2 = 3.075 V typical, 3.000 V min, 3.150 V max). The MAX6722UTVDD3+ does not support adjustable thresholds - all monitoring is fixed at these values.

Does the MAX6722UTVDD3+ support manual reset, and how is it implemented?

Yes, the MAX6722UTVDD3+ includes an active-low manual reset input (MR) on Pin 3. It features a 50 kΩ internal pullup resistor to VCC1, so MR can be left floating or tied to VCC1 when unused. To assert reset, MR must be pulled low for ≥1 µs; reset remains active for the full 210 ms timeout period after MR returns high. This function enables field-service recovery, test-mode entry, or emergency shutdown without modifying firmware.

What watchdog timeout periods does the MAX6722UTVDD3+ provide, and how do they operate?

The MAX6722UTVDD3+ implements a dual-mode watchdog: a 35 s minimum startup period after any reset event (power-up, MR, or watchdog timeout), followed by a 1.12 s minimum normal timeout. The first valid WDI edge (rising or falling) terminates the startup mode and initiates the 1.12 s window. If no subsequent edge occurs within that time, RST asserts for 210 ms. This architecture accommodates lengthy boot sequences while ensuring rapid detection of runtime hangs.

Can the MAX6722UTVDD3+ monitor a third supply voltage like VCC3?

No, the MAX6722UTVDD3+ is a dual-supply supervisor and does not include RSTIN or PFI inputs. It monitors only VCC1 and VCC2. For triple-voltage monitoring, Maxim offers variants such as MAX6724UTVD3+ (same thresholds/timing, but adds RSTIN) or MAX6729KAUD3+ (adds both RSTIN and PFO). The MAX6722UTVDD3+ pinout and internal functional diagram confirm absence of RSTIN, PFI, or PFO terminals.

What is the output type of the RST pin on the MAX6722UTVDD3+, and what are its drive capabilities?

The RST pin on the MAX6722UTVDD3+ is a push-pull active-low output referenced to VCC1. It sources ≥0.8 × VCC1 at 800 µA and sinks ≤0.4 V at 3.2 mA (for VCC1 ≥ 4.5 V). This eliminates the need for external pullup resistors and enables direct interfacing with µP reset pins across 1.8–5.0 V logic families. The push-pull structure ensures fast, deterministic rise/fall times critical for meeting µP reset setup/hold requirements.