Analog Devices Inc./Maxim Integrated MAX6720UTWGD3+T

Overview

MAX6720UTWGD3+T from Maxim Integrated is a triple-voltage microprocessor supervisory circuit in SOT23-6 package, monitoring VCC1 (primary), VCC2 (secondary), and RSTIN (adjustable third supply) with factory-trimmed thresholds of 4.625V and 3.075V, 210ms reset timeout, and push-pull active-low RST output. It ensures reliable system reset during power-up, brownout, or software fault in battery-powered and multivoltage embedded systems.

For engineers reviewing the MAX6720UTWGD3+T datasheet, MAX6720UTWGD3+T pinout, MAX6720UTWGD3+T application, or MAX6720UTWGD3+T equivalent, key selection criteria include dual-supply threshold accuracy (±1.5% over temperature), guaranteed reset validity down to VCC1/VCC2 = 0.8V, low 14µA typical supply current at 3.6V, and integrated watchdog timer with 35s startup/1.12s normal timeout modes.

Technical Context

The MAX6720UTWGD3+T implements a dual-threshold voltage monitor with independent comparators for VCC1 and VCC2, plus an external RSTIN input referenced to a 626.5mV internal bandgap reference. Its reset logic asserts RST low when any monitored voltage falls below its threshold and holds for a fixed 210ms minimum timeout after recovery.

It integrates a dual-mode watchdog timer: a 35s minimum initial timeout after reset enables full system boot, followed by a 1.12s minimum normal timeout requiring periodic WDI transitions. The push-pull RST output is referenced to VCC1 and drives high to 0.8×VCC1 under load, eliminating need for external pullup.

Key Specifications

Pinout & Package

MAX6720UTWGD3+T is housed in a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), surface-mount, lead-free (+T suffix), with gull-wing leads and standard JEDEC MO-178 footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6720UTWD3+T, the MAX6720UTWGD3+T eliminates external pullup needs and improves reset timing predictability; versus TPS3808G33DBVR, it adds critical dual-threshold and RSTIN flexibility at the cost of higher quiescent current - essential for multivoltage automotive or industrial control designs.

Availability

MAX6720UTWGD3+T is available at Aetrix Electronics and suitable for industrial PLCs, portable medical devices, telecom edge equipment, and automotive infotainment systems requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6720UTWGD3+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) is a semiconductor company specializing in precision analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The MAX6715–MAX6729 family was designed specifically for space-constrained, multivoltage embedded systems requiring highly accurate, low-power, and feature-rich power supervision - targeting applications where discrete solutions increase risk and board area.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6720UTWGD3+T?

The MAX6720UTWGD3+T has factory-trimmed reset thresholds of 4.625V for VCC1 and 3.075V for VCC2, with ±1.5% tolerance over the full -40°C to +85°C operating range. These values are encoded in the "WG" suffix per Maxim's Reset Voltage Threshold Suffix Guide and are verified in the Electrical Characteristics table of the official datasheet.

Does the MAX6720UTWGD3+T support monitoring a third supply voltage, and how is it implemented?

Yes, the MAX6720UTWGD3+T supports third-supply monitoring via the RSTIN pin, which references an internal 626.5mV bandgap. A resistor divider from the target supply to GND and RSTIN sets the trip point using V_{EXT_TH} = 626.5mV × (R1 + R2)/R2. This enables monitoring of supplies as low as 0.62V without external comparators.

What is the function of the WDI (watchdog input) pin on the MAX6720UTWGD3+T, and what are its timing requirements?

The WDI pin on the MAX6720UTWGD3+T enables dual-mode watchdog supervision: after reset, it provides a 35s minimum startup timeout to allow full system boot, then switches to a 1.12s minimum normal timeout requiring a rising or falling edge before expiration. Pulse width must exceed 50ns, and VIH/VIL thresholds are 0.7×VCC1 and 0.3×VCC1 respectively.

Is the MAX6720UTWGD3+T pin-compatible with other devices in the MAX6715–MAX6729 family?

The MAX6720UTWGD3+T uses the 6-pin SOT23-6 package and shares identical pinout with MAX6716, MAX6719, MAX6722, and MAX6724. However, functional differences exist: MAX6720UTWGD3+T features push-pull RST, RSTIN input, and no PFI/PFO - substitution requires verification of required features and output type against the Selector Guide.

How does the MAX6720UTWGD3+T ensure reliable reset assertion during deep brownout conditions?

The MAX6720UTWGD3+T guarantees valid reset output logic state as long as either VCC1 or VCC2 remains above 0.8V - confirmed in Absolute Maximum Ratings and Detailed Description sections. Its internal biasing and comparator design maintain threshold accuracy and output drive strength down to this level, preventing premature release during slow power decay.