Analog Devices Inc./Maxim Integrated MAX6720AUTVDD3+T

Overview

MAX6720AUTVDD3+T from Maxim Integrated is a triple-voltage microprocessor supervisory IC monitoring VCC1 (primary), VCC2 (secondary), and an externally adjustable RSTIN input down to 0.626V. It asserts an active-low push-pull reset output for ≥210ms after any monitored supply falls below its threshold, and guarantees valid reset operation with VCC1 or VCC2 ≥ 0.8V. Used in multivoltage embedded systems requiring reliable power-up sequencing and brownout protection.

For engineers reviewing the MAX6720AUTVDD3+T datasheet, MAX6720AUTVDD3+T pinout, MAX6720AUTVDD3+T application, or MAX6720AUTVDD3+T equivalent, key selection criteria include dual-supply monitoring range (1.575V–4.625V on VCC1, 0.788V–3.075V on VCC2), 210ms min reset timeout, push-pull RST output, manual reset input with internal 50kΩ pullup, and guaranteed operation down to 0.8V supply.

Technical Context

The MAX6720AUTVDD3+T implements a dual-threshold voltage supervision architecture with factory-trimmed VCC1 and VCC2 reset comparators and a dedicated high-impedance RSTIN input referenced to a 626.5mV internal bandgap. Its reset logic combines asynchronous fault detection across three inputs (VCC1, VCC2, RSTIN) with a deterministic timeout counter that restarts on any new fault before timeout completion.

It features a push-pull RST output referenced to VCC1, an active-low manual reset input (MR) with 200ns delay and 1µs minimum pulse width, and operates over –40°C to +85°C in a 6-pin SOT23 package. Supply current is 14µA typical at 3.6V, with immunity to VCC transients ≤20µs when overdriven by ≥100mV.

Key Specifications

Pinout & Package

MAX6720AUTVDD3+T is housed in a 6-pin SOT23 package (2.9mm × 1.6mm × 1.1mm), surface-mount, RoHS-compliant, lead-free (+T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6720AUTVDD3+T, MAX6720AUTVD3+T offers matching functionality with a lower VCC2 threshold for 2.5V rails, while TPS3808G33DBVR provides lower quiescent current but sacrifices dual/third-supply monitoring and push-pull drive-making it unsuitable for direct replacement in multivoltage designs.

Availability

MAX6720AUTVDD3+T is available at Aetrix Electronics and suitable for industrial PLCs, telecom line cards, medical infusion pumps, and automotive ADAS camera modules requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for MAX6720AUTVDD3+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, communications, computing, and automotive markets.

The MAX6715–MAX6729 family was designed specifically for space-constrained, multivoltage embedded systems requiring precise, low-power, triple-rail supervision with guaranteed operation down to 0.8V supply.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6720AUTVDD3+T?

The MAX6720AUTVDD3+T has a factory-trimmed VCC1 reset threshold of 4.625V (typical), with a guaranteed range of 4.500V to 4.750V at +25°C. This value is encoded in the "VD" suffix per Maxim's Reset Voltage Threshold Suffix Guide and applies to the primary supply monitoring channel. The MAX6720AUTVDD3+T uses this threshold to assert reset when VCC1 falls below specification during power-up or brownout events.

Does the MAX6720AUTVDD3+T support monitoring a negative voltage supply?

Yes - the MAX6720AUTVDD3+T can monitor negative supplies using the RSTIN input with an appropriate resistor-divider network, as documented in Maxim's application circuits. The internal 626.5mV reference allows scaling of negative rails; for example, a –12V supply can be monitored by configuring R1/R2 to produce 626.5mV at RSTIN when –12V crosses its fail threshold. The MAX6720AUTVDD3+T itself must be powered by valid positive VCC1/VCC2 supplies.

What is the function of Pin 6 (RSTIN) on the MAX6720AUTVDD3+T, and how is it configured?

Pin 6 (RSTIN) is a high-impedance, adjustable reset comparator input referenced to a 626.5mV internal bandgap. To monitor a third voltage (e.g., 2.5V, 1.2V, or –5V), connect an external resistor divider between the target supply and ground, with the midpoint feeding RSTIN. The threshold is set by V_{EXT_TH} = 626.5mV × (R1 + R2)/R2. The MAX6720AUTVDD3+T asserts reset when RSTIN falls below 626.5mV, providing flexible triple-supply supervision without additional ICs.

Is the reset output of the MAX6720AUTVDD3+T push-pull or open-drain, and what are its drive capabilities?

The MAX6720AUTVDD3+T features an active-low push-pull RST output (Pin 1), eliminating the need for an external pullup resistor. It sinks up to 3.2mA while maintaining VOL ≤ 0.4V (at VCC1 ≥ 4.5V) and sources up to 800µA with VOH ≥ 0.8 × VCC1. This direct-drive capability ensures robust interfacing with µP reset pins across varying supply voltages and simplifies PCB layout compared to open-drain alternatives.

How does the manual reset input (MR) behave on the MAX6720AUTVDD3+T, and what is its internal pullup value?

The MR pin (Pin 3) is an active-low manual reset input with an internal 50kΩ pullup resistor to VCC1. Pulling MR low forces an immediate reset assertion, which remains active for the full 210ms timeout period after MR returns high. The MAX6720AUTVDD3+T specifies a 1µs minimum MR pulse width and 200ns propagation delay from MR low-to-RST low, enabling reliable board-level reset initiation via momentary switch or FPGA control without external components.