Analog Devices Inc./Maxim Integrated MAX6720AUTVHD3+T

Overview

MAX6720AUTVHD3+T from Maxim Integrated is a triple-voltage microprocessor supervisory circuit in SOT23-6 package, monitoring VCC1 (4.625V threshold), VCC2 (3.075V threshold), and an externally adjustable RSTIN input (626.5mV reference). It asserts active-low push-pull reset for ≥210ms after any supply drop, supports manual reset and watchdog timer, and operates from -40°C to +85°C in multivoltage embedded systems.

For engineers reviewing the MAX6720AUTVHD3+T datasheet, MAX6720AUTVHD3+T pinout, MAX6720AUTVHD3+T application, or MAX6720AUTVHD3+T equivalent, key selection factors include dual-supply threshold accuracy (±1.5% over temp), 14µA typical supply current at 3.6V, guaranteed reset validity down to VCC1/VCC2 = 0.8V, and integrated 35s startup / 1.12s normal watchdog timeout.

Technical Context

The MAX6720AUTVHD3+T implements independent voltage comparators for primary (VCC1), secondary (VCC2), and auxiliary (RSTIN) supplies, each with factory-trimmed thresholds and 20ppm/°C tempco. Its push-pull RST output is referenced to VCC1 and guarantees VOL ≤ 0.4V at ISINK = 3.2mA.

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. Reset assertion is latched for a fixed 210ms (typ) timeout period, restartable if any monitored voltage falls below threshold before timeout completion.

Key Specifications

Pinout & Package

MAX6720AUTVHD3+T is housed in a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), RoHS-compliant and lead-free (+T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6720AUTVHD5+T and TPS3808G33DBVR, the MAX6720AUTVHD3+T uniquely delivers triple-voltage monitoring (VCC1/VCC2/RSTIN), integrated dual-mode watchdog, and precise 210ms reset timeout in a 6-pin SOT23 - making it optimal for compact, multirail embedded systems requiring both power integrity and firmware reliability assurance.

Availability

MAX6720AUTVHD3+T is available at Aetrix Electronics and suitable for industrial PLC controllers, network routers, medical patient monitors, and automotive infotainment head units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6720AUTVHD3+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, mixed-signal, and power management ICs for demanding industrial, communications, and computing applications.

The MAX6715–MAX6729 family was engineered specifically for multivoltage embedded systems needing simultaneous monitoring of primary, secondary, and auxiliary rails with integrated watchdog and manual reset - targeting space-constrained, low-power, high-reliability applications.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6720AUTVHD3+T?

The MAX6720AUTVHD3+T has a factory-trimmed VCC1 reset threshold of 4.625V, with guaranteed tolerance of ±1.5% over the full -40°C to +85°C operating temperature range. This value is encoded in the "TV" suffix per Maxim's Reset Voltage Threshold Suffix Guide and confirmed in the Electrical Characteristics table of the official datasheet.

Does the MAX6720AUTVHD3+T support monitoring a third voltage, and how is it configured?

Yes, the MAX6720AUTVHD3+T supports third-voltage monitoring via its RSTIN pin, which uses an internal 626.5mV reference. To monitor an external supply (e.g., 12V), connect a resistor divider between that supply and GND, with the midpoint fed to RSTIN. The threshold is set by V_{EXT_TH} = 626.5mV × (R1 + R2)/R2, enabling monitoring down to 0.62V with minimal current draw (±25nA).

What is the function of the MR pin on the MAX6720AUTVHD3+T, and does it require external components?

The MR pin on the MAX6720AUTVHD3+T is an active-low manual reset input with an internal 50kΩ pullup resistor to VCC1. It requires no external components: pulling MR low forces reset assertion for the full 210ms timeout period, then holds reset for the timeout duration after MR returns high. Leaving MR unconnected defaults to inactive (pulled high).

How does the watchdog timer operate on the MAX6720AUTVHD3+T, and what are its two timeout modes?

The MAX6720AUTVHD3+T features a dual-mode watchdog timer: after any reset event (power-up, MR, or watchdog timeout), it enters a 35s minimum startup mode to allow full system boot. Upon detecting the first valid WDI transition (rising or falling edge), it switches to 1.12s minimum normal mode. This architecture prevents false timeouts during boot while ensuring rapid detection of runtime hangs.

Is the MAX6720AUTVHD3+T pin-compatible with other devices in the MAX6715–MAX6729 family?

The MAX6720AUTVHD3+T uses the 6-pin SOT23-6 package and shares identical pinout with MAX6715–MAX6722 variants in the same package (e.g., MAX6716, MAX6722). However, pin functions differ across family members - for example, MAX6715 has open-drain RST while MAX6720 has push-pull RST. Always verify reset output type and feature enablement (watchdog, RSTIN) before substitution.