Analog Devices Inc./Maxim Integrated MAX6709AUB+

Overview

The MAX6709AUB+ from Maxim Integrated is a quad voltage monitor IC designed for multivoltage system supervision, 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 fourth input (IN4) down to 0.62V. It operates from 2.0V to 5.5V supply, consumes only 35µA typical supply current, and delivers precise monitoring in telecom servers and desktop computers.

For engineers reviewing the MAX6709AUB+ datasheet, MAX6709AUB+ pinout, MAX6709AUB+ application, or MAX6709AUB+ equivalent, key selection considerations include its 10-pin µMAX package, -40°C to +85°C temperature range, 0.3% threshold hysteresis, internal 10µA pullup per output, and immunity to supply transients without external components.

Technical Context

The MAX6709AUB+ integrates four precision comparators with an internal 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 (0.62V base). Each comparator drives an independent active-low open-drain output with weak 10µA internal pullup to VCC, enabling wire-ORed power-good signaling.

An undervoltage lockout circuit forces all PWRGD_ outputs low when VCC drops below 2.0V, and built-in 0.3% threshold hysteresis eliminates need for external feedback resistors. The device supports multivoltage sequencing in systems where simultaneous monitoring of 5V, 3.3V, and 2.5V rails-plus one user-defined rail-is required with ±2.0% accuracy across temperature.

Key Specifications

Pinout & Package

Package: 10-pin µMAX (3.0mm × 3.0mm, 0.6mm height, 0.5mm pitch), lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3307-33DGNR and ADM1066ACPZ, the MAX6709AUB+ delivers optimal balance of integration, size, and simplicity for fixed-threshold quad monitoring-requiring zero configuration, occupying 3×3mm area, and consuming 35µA versus 120µA (TPS3307) or 500µA (ADM1066).

Availability

MAX6709AUB+ is available at Aetrix Electronics and suitable for telecommunications infrastructure, server power management, and notebook PC motherboard designs requiring stable component supply and long-term industrial lifecycle support.

Supply support for MAX6709AUB+ 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, computing, and communications markets.

The MAX6709AUB+ belongs to Maxim's precision voltage supervisor product line, engineered specifically for compact, low-power multivoltage system monitoring where reliability, accuracy, and minimal external components are critical.

FAQ

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

The IN4 pin on the MAX6709AUB+ is an adjustable voltage monitor input referenced to an internal 0.623V threshold. It requires an external resistor divider to scale higher supply voltages (e.g., 1.2V, 1.8V) down to the internal reference level. When the divided voltage falls below 0.623V, the corresponding PWRGD4 output asserts low. This design allows flexible monitoring of nonstandard rails without changing the IC.

Does the MAX6709AUB+ require external pullup resistors on its PWRGD outputs?

The MAX6709AUB+ includes internal 10µA pullup current sources to VCC on all four PWRGD outputs, eliminating the need for external pullups in most 3.3V or 5V logic interfaces. However, if interfacing to a logic supply higher than VCC (e.g., 5V logic while VCC = 3.3V), an external pullup to that higher voltage is required-and internal circuitry prevents reverse current flow into VCC.

How does the MAX6709AUB+ handle supply voltage transients?

The MAX6709AUB+ incorporates inherent immunity to short-duration supply transients: its internal architecture rejects disturbances under 120µs on VCC, preventing false triggering during switching regulator noise or load-step events. This is achieved through proprietary filtering and comparator hysteresis (0.3% of threshold), ensuring stable PWRGD assertion without external RC networks.

What is the operating temperature range specified for the MAX6709AUB+?

The MAX6709AUB+ is fully specified over the extended industrial temperature range of -40°C to +85°C. All electrical parameters-including threshold accuracy (±2.0%), supply current (35µA typ), and propagation delay (5µs)-are guaranteed across this range without derating, making it suitable for deployment in uncontrolled environments like telecom cabinets and server racks.

Can the MAX6709AUB+ monitor a 1.2V supply rail?

Yes, the MAX6709AUB+ can monitor a 1.2V supply rail using the adjustable IN4 input. By configuring an external resistor divider where R1 = R2 × ((1.2V / 0.623V) − 1) ≈ R2 × 0.925, the 1.2V input is scaled to 0.623V at the comparator input. When the 1.2V rail drops below its trip point (e.g., 1.14V for −5% tolerance), PWRGD4 asserts low-enabling precise low-voltage rail supervision.