Analog Devices Inc./Maxim Integrated MAX6720AUTRVD3+T

Overview

MAX6720AUTRVD3+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) for auxiliary supply monitoring down to 0.62V. It provides push-pull active-low reset output with 210ms minimum timeout, manual reset input, and operates from -40°C to +85°C. Used in multivoltage telecom and industrial systems requiring reliable power-up sequencing and brownout detection.

For engineers reviewing the MAX6720AUTRVD3+T datasheet, MAX6720AUTRVD3+T pinout, MAX6720AUTRVD3+T application, or MAX6720AUTRVD3+T equivalent, key selection factors include its dual factory-trimmed thresholds (VTH1 = 4.625V, VTH2 = 3.075V), 210ms reset timeout, push-pull RST output referenced to VCC1, guaranteed reset validity down to VCC1/VCC2 = 0.8V, and 14µA typical supply current at 3.6V.

Technical Context

The MAX6720AUTRVD3+T implements a dual-threshold voltage monitor with independent comparators for VCC1 and VCC2, plus a high-impedance RSTIN comparator referenced to a 626.5mV internal bandgap. Its reset logic asserts RST low when any monitored voltage falls below its threshold and holds for a fixed 210ms timeout after all voltages recover.

It features a manual reset input (MR) with internal 50kΩ pullup to VCC1, immune to sub-100ns glitches, and guarantees valid reset output state even when VCC1 or VCC2 drops to 0.8V - critical for low-voltage brownout detection in battery-powered systems.

Key Specifications

Pinout & Package

SOT23-6 package (2.9mm × 1.6mm × 1.1mm), surface-mount, lead-free (+T suffix), rated for -40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6720AUTRVD3+T, the MAX6720AUTRVD2+T offers identical monitoring capability with reduced timeout for faster recovery, while TPS3808G33DBVR trades multi-rail supervision for lower quiescent current in single-supply designs - neither is pin-compatible, and both require PCB layout changes.

Availability

MAX6720AUTRVD3+T is available at Aetrix Electronics and suitable for telecom infrastructure, industrial control systems, and battery-powered edge computing applications requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX6720AUTRVD3+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 high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and communications markets.

The MAX6715–MAX6729 family delivers compact, ultra-low-power supervisory solutions for multivoltage embedded systems, emphasizing factory-trimmed accuracy, wide supply range operation, and robust reset timing - designed specifically for reliability-critical power sequencing in space-constrained applications.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6720AUTRVD3+T?

The MAX6720AUTRVD3+T has a factory-trimmed VCC1 reset threshold of 4.625V (±1.5% over temperature), corresponding to the "T" suffix in the Reset Voltage Threshold Suffix Guide. This value is laser-trimmed during production and does not require external calibration. The threshold remains stable across the full -40°C to +85°C operating range with 20ppm/°C tempco, ensuring consistent brownout detection in the MAX6720AUTRVD3+T across environmental conditions.

Does the MAX6720AUTRVD3+T support monitoring a third voltage, and how is it configured?

Yes, the MAX6720AUTRVD3+T supports third-supply monitoring via its RSTIN pin, which compares the applied voltage against a precise 626.5mV internal reference. To monitor a higher voltage (e.g., 12V), connect an external resistor divider (R1/R2) between the supply and GND, with the midpoint fed to RSTIN. The threshold is calculated as VEXT_TH = 626.5mV × (R1 + R2)/R2. The MAX6720AUTRVD3+T's 25nA max RSTIN input current enables use of high-value resistors to minimize power loss in battery-sensitive designs.

What is the function of the MR pin on the MAX6720AUTRVD3+T, and what are its electrical characteristics?

The MR (Manual Reset) pin on the MAX6720AUTRVD3+T is an active-low input with an internal 50kΩ pullup resistor to VCC1. Pulling MR low forces an immediate reset assertion, held for the full 210ms timeout period after MR returns high. It accepts TTL/CMOS logic levels, rejects sub-100ns glitches, and requires no external debounce circuitry. The MAX6720AUTRVD3+T specifies MR minimum pulse width as 1µs, making it compatible with fast digital control signals and microcontroller GPIO outputs.

Is the reset output of the MAX6720AUTRVD3+T open-drain or push-pull, and what are its drive capabilities?

The MAX6720AUTRVD3+T features a push-pull active-low reset output (RST pin), referenced to VCC1. It sources up to 800µA and sinks up to 3.2mA while maintaining VOL ≤ 0.4V at VCC1 ≥ 4.5V. Unlike open-drain variants, it requires no external pullup resistor and can directly drive standard µP reset inputs. This architecture simplifies layout, reduces component count, and ensures fast rise/fall times - a key differentiator of the MAX6720AUTRVD3+T within the MAX6715–MAX6729 family.

How does the MAX6720AUTRVD3+T ensure reliable reset operation during low-voltage conditions?

The MAX6720AUTRVD3+T guarantees valid reset output logic state down to VCC1 or VCC2 = 0.8V - significantly lower than most supervisors. This is achieved through proprietary biasing and comparator design that maintains functional margins even near supply collapse. When VCC drops below 0.8V, the MAX6720AUTRVD3+T enters an undefined state, but the guaranteed 0.8V threshold ensures deterministic reset assertion during brownout recovery. This feature is critical for fail-safe operation in battery-backed systems and unregulated power supplies.