Analog Devices Inc./Maxim Integrated MAX6709AUB+T

Overview

The MAX6709AUB+T from Maxim Integrated is a quad voltage monitor IC for multivoltage systems, featuring four independent open-drain power-good outputs (PWRGD1–PWRGD4), factory-trimmed thresholds for 5.0V/3.3V/2.5V inputs with ±10% tolerance, and an adjustable input (IN4) supporting down to 0.62V via external resistor divider. It consumes only 35µA typical supply current and operates from 2.0V to 5.5V over –40°C to +85°C - used in server power sequencing and telecom board-level supervision.

For engineers reviewing the MAX6709AUB+T datasheet, MAX6709AUB+T pinout, MAX6709AUB+T application, or MAX6709AUB+T equivalent, key selection criteria include its 10-pin µMAX package, independent active-low open-drain outputs with 10µA internal pullup to VCC, ±2.0% threshold accuracy, immunity to supply transients, and support for wire-ORed power-good signaling in high-reliability embedded systems.

Technical Context

The MAX6709AUB+T integrates four precision comparators with an internal 0.62V bandgap reference and factory-laser-trimmed resistor-divider networks to set fixed thresholds for IN1 (5.0V), IN2 (3.3V), IN3 (2.5V), and adjustable IN4. Each comparator drives a dedicated open-drain output with weak 10µA internal pullup to VCC, enabling direct interfacing with 1.8V–5.5V logic without external pullups.

An undervoltage lockout circuit forces all PWRGD_ outputs low when VCC drops below 2.0V, and built-in 0.3% threshold hysteresis eliminates noise-induced oscillation without external components. The device uses BiCMOS process technology (1029 transistors) and is fully specified across –40°C to +85°C with <60 ppm/°C threshold temperature coefficient.

Key Specifications

Pinout & Package

The MAX6709AUB+T is housed in a 10-pin µMAX package (3.0mm × 3.0mm, 0.6mm height), lead-free, with exposed pad for thermal performance. Pin 1 is top-left corner (notch-marked), pin 10 is bottom-right.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad voltage monitoring applications.

Compared with MAX6709BUB+T, the MAX6709AUB+T offers wider threshold margins for legacy or loosely regulated supplies, while versus TPS3307-33DGNR it delivers full quad monitoring in identical µMAX footprint without compromising on adjustability or ultra-low current draw.

Availability

The MAX6709AUB+T is available at Aetrix Electronics and suitable for telecommunications infrastructure, server motherboard design, and high-end printer power management requiring stable component supply and long-term production continuity.

Supply support for MAX6709AUB+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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The MAX6709AUB+T belongs to Maxim's precision voltage supervisor product line, engineered specifically for multivoltage system power integrity assurance in space- and power-constrained applications.

FAQ

What is the function of the IN4 pin on the MAX6709AUB+T?

The IN4 pin on the MAX6709AUB+T is an adjustable voltage monitor input referenced to an internal 0.62V threshold. When used with an external resistor divider, it supports custom monitoring of voltages as low as 0.62V - for example, setting IN4 to detect a 1.2V rail by selecting R1/R2 such that V_INTH = 0.62V × (R1 + R2)/R2 = 1.2V. This flexibility makes the MAX6709AUB+T adaptable to nonstandard supply voltages not covered by its fixed thresholds.

Does the MAX6709AUB+T provide reset timing or manual reset capability?

No, the MAX6709AUB+T does not include reset timing or manual reset functionality. It is a pure quad voltage monitor with four independent open-drain PWRGD outputs. For reset generation with timeout and MR support, the pin-compatible MAX6714 series (e.g., MAX6714AUB+T) should be used instead. The MAX6709AUB+T outputs assert only in response to monitored voltage deviations and lack internal timing circuitry or MR input pins.

Can the MAX6709AUB+T outputs drive standard CMOS logic directly?

Yes, the MAX6709AUB+T's PWRGD outputs can interface directly with standard CMOS logic. Each output is open-drain with a 10µA internal pullup to VCC, producing VOH ≥ 0.8 × VCC when unasserted and VOL ≤ 0.3V when asserted (at ISINK = 2mA). Since VCC ranges from 2.0V to 5.5V, this ensures compatibility with 1.8V, 2.5V, 3.3V, and 5V logic families - no external pullup is required unless interfacing to a voltage higher than VCC.

What is the temperature coefficient of the threshold voltage for the MAX6709AUB+T?

The MAX6709AUB+T has a threshold voltage temperature coefficient (TCVTH) of 60 ppm/°C, measured across the full operating range of –40°C to +85°C. This low drift ensures stable trip points despite ambient or self-heating variations - critical for maintaining accurate power-good assertion timing in thermally dynamic environments such as telecom chassis or high-density servers.

How does the MAX6709AUB+T handle undervoltage conditions on its own VCC supply?

The MAX6709AUB+T incorporates an internal undervoltage lockout (UVLO) circuit that forces all four PWRGD outputs low whenever VCC drops below 2.0V. This behavior prevents erratic output states during power ramp-up or brownout events. The UVLO remains active down to VCC = 1V (guaranteed from 0°C to +70°C), ensuring clean, predictable deassertion of all power-good signals even under severe supply collapse - a key reliability feature for fail-safe system initialization.