Analog Devices Inc./Maxim Integrated MAX6720UTRVD3+

Overview

MAX6720UTRVD3+ from Maxim Integrated is a triple-voltage microprocessor supervisory circuit in 6-pin SOT23 package, monitoring VCC1 (primary), VCC2 (secondary), and RSTIN (adjustable third supply) with factory-trimmed thresholds of 4.625V (VTH1), 3.075V (VTH2), and 626.5mV reference for RSTIN. It asserts an active-low push-pull reset output for ≥210ms after all supplies recover, and includes manual reset input (MR) and watchdog timer support. It is used in multivoltage telecom power systems requiring reliable brownout detection and orderly processor restart.

For engineers reviewing the MAX6720UTRVD3+ datasheet, MAX6720UTRVD3+ pinout, MAX6720UTRVD3+ application, or MAX6720UTRVD3+ equivalent, key selection criteria include its dual-supply monitoring capability down to 0.8V operation, 210ms reset timeout, push-pull RST output referenced to VCC1, and integrated RSTIN comparator for auxiliary voltage supervision - all critical for battery-backed industrial controllers and low-power networking equipment.

Technical Context

The MAX6720UTRVD3+ implements a triple-threshold supervisory architecture: two factory-trimmed comparators monitor VCC1 and VCC2 independently, while a high-impedance RSTIN input uses an internal 626.5mV reference to supervise a third voltage via external resistor divider. Its push-pull RST output is driven from VCC1 and guaranteed functional down to VCC1 or VCC2 = 0.8V.

It integrates a dual-mode watchdog timer with 35s minimum startup period and 1.12s minimum normal timeout, triggered by WDI edge transitions. Manual reset (MR) features internal 50kΩ pullup to VCC1 and 200ns MR-to-reset delay, enabling robust system-level reset initiation without external components.

Key Specifications

Pinout & Package

MAX6720UTRVD3+ is housed in a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), optimized for space-constrained PCB layouts in portable and embedded systems.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6720UTRVD2+ and MAX6720UTRVD5+, the MAX6720UTRVD3+ offers the optimal 210ms reset timeout for mid-complexity microcontrollers - balancing sufficient initialization time against unnecessary system downtime during transient brownouts.

Availability

MAX6720UTRVD3+ is available at Aetrix Electronics and suitable for telecom power management, industrial PLC controllers, and network router baseboards requiring stable component supply across extended production lifecycles.

Supply support for MAX6720UTRVD3+ 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.

The MAX6715–MAX6729 family delivers compact, ultra-low-power supervisory circuits for multivoltage embedded systems - specifically engineered to replace discrete reset solutions in space- and power-constrained telecom, industrial, and computing equipment.

FAQ

What is the exact reset timeout period of the MAX6720UTRVD3+?

The MAX6720UTRVD3+ has a minimum reset timeout period of 210ms, as indicated by the 'D3' suffix in its part number. This value is guaranteed over the full -40°C to +85°C operating temperature range and represents the minimum duration the RST output remains asserted after all monitored supplies (VCC1, VCC2, RSTIN) rise above their respective thresholds. Typical timeout is 210ms, with maximum specified at 280ms under worst-case conditions.

Does the MAX6720UTRVD3+ support monitoring a third voltage, and how is it configured?

Yes, the MAX6720UTRVD3+ supports triple-voltage supervision via its RSTIN pin, which features an internal 626.5mV reference voltage. To monitor a third supply (e.g., 1.2V or 1.8V), connect it to RSTIN through a resistor divider network such that the divided voltage equals 626.5mV at the trip point. The device's high-impedance RSTIN input (±25nA leakage) enables use of large-value resistors to minimize power consumption in battery-powered applications.

What is the function of the MR pin on the MAX6720UTRVD3+, and does it require external components?

The MR (Manual Reset) pin on the MAX6720UTRVD3+ is an active-low input with an internal 50kΩ pullup resistor to VCC1, allowing direct connection to a momentary switch between MR and GND for hardware reset initiation. No external pullup is needed. A logic-low pulse ≥1µs on MR forces the RST output low for the full 210ms timeout period, even if all supply voltages remain within specification - making it ideal for field service, test mode entry, or emergency recovery.

Can the MAX6720UTRVD3+ operate reliably when VCC1 drops below 1.0V?

Yes, the MAX6720UTRVD3+ guarantees correct reset output logic state down to VCC1 or VCC2 = 0.8V, per its Absolute Maximum Ratings and Electrical Characteristics table. This ensures valid reset assertion during deep brownout events - critical for systems where uncontrolled operation below nominal voltage could corrupt memory or cause latch-up. Below 0.8V, reset behavior is not guaranteed, so proper power sequencing and hold-up capacitance must be designed accordingly.

Is the RST output of the MAX6720UTRVD3+ open-drain or push-pull, and what are its drive capabilities?

The RST output of the MAX6720UTRVD3+ is push-pull, actively driving both high and low states without requiring an external pullup resistor. When asserted (low), it sinks up to 3.2mA while maintaining VOL ≤ 0.4V at VCC1 ≥ 4.5V. When deasserted (high), it sources up to 800µA while maintaining VOH ≥ 0.8 × VCC1. This VCC1-referenced output directly interfaces with standard CMOS/TTL reset inputs across the full 1.8V–5.5V supply range.