Analog Devices Inc./Maxim Integrated MAX6709FUB+

Overview

The MAX6709FUB+ from Maxim Integrated is a quad voltage monitor IC designed for multivoltage system supervision, featuring four independent active-low open-drain power-good outputs with 10µA internal pullups to VCC, factory-trimmed thresholds for 3.3V, 2.5V, and 1.8V nominal supplies (±5% tolerance), and one adjustable input (0.62V reference), operating from 2.0V to 5.5V supply with only 35µA typical quiescent current. It is used in desktop/notebook computers and data storage equipment to ensure reliable power sequencing and supply integrity.

For engineers reviewing the MAX6709FUB+ datasheet, MAX6709FUB+ pinout, MAX6709FUB+ application, or MAX6709FUB+ equivalent, key selection criteria include its 10-pin µMAX package, ±2.0% threshold accuracy, 60ppm/°C temperature coefficient, 30µs propagation delay, and immunity to supply transients across –40°C to +85°C.

Technical Context

The MAX6709FUB+ integrates four precision comparators with an internal 0.62V bandgap reference and factory-laser-trimmed resistor-divider networks for fixed-threshold inputs (IN2 = 3.3V, IN3 = 2.5V, IN4 = 1.8V), while IN1 is configured as an adjustable input accepting external resistor dividers. Each comparator drives an independent open-drain output with weak internal pullup, enabling wire-ORed power-good signaling without external components.

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 networks. The device uses BiCMOS process (1029 transistors) and requires no external capacitors for basic operation, supporting stable monitoring even during fast supply transients.

Key Specifications

Pinout & Package

Package: 10-pin µMAX (3.0mm × 3.0mm, 0.6mm height, 0.5mm pitch), lead-free, RoHS-compliant surface-mount package optimized for space-constrained multivoltage PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6714DUB+, the MAX6709FUB+ delivers true quad independent power-good outputs ideal for multivoltage sequencing, whereas TPS3307-33DGNR sacrifices channel count and flexibility for cost reduction in single-rail-dominant designs.

Availability

MAX6709FUB+ is available at Aetrix Electronics and suitable for desktop computers, notebook systems, and data storage equipment requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for MAX6709FUB+ 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, computing, and communications markets.

The MAX67xx family is designed specifically for multivoltage system supervision in space-constrained, high-reliability applications-emphasizing low quiescent current, precision thresholds, and minimal external component count.

FAQ

What is the function of the IN1 pin on the MAX6709FUB+?

The IN1 pin on the MAX6709FUB+ is an adjustable voltage monitor input referenced to an internal 0.62V threshold. It accepts an external resistor divider to set custom trip voltages down to 0.62V, enabling supervision of nonstandard rails like 1.05V CPU cores or 0.9V GPU supplies. If unused, IN1 must be tied to GND to prevent floating input errors.

Does the MAX6709FUB+ provide reset timing functionality like the MAX6714 series?

No, the MAX6709FUB+ does not include reset timing or a dedicated RESET output. It provides only four independent active-low open-drain PWRGD outputs (PWRGD1–PWRGD4). For integrated reset timeout (e.g., 140ms min), the MAX6714DUB+ or MAX6714BUB+ would be required instead.

What is the maximum sink current supported by the PWRGD outputs of the MAX6709FUB+?

The PWRGD outputs of the MAX6709FUB+ are open-drain and specified to sink up to 2mA while maintaining VOL ≤ 0.3V at VCC = 5V. This allows direct interfacing with standard TTL/CMOS logic inputs or driving small LEDs through external current-limiting resistors without additional buffer stages.

Can the MAX6709FUB+ monitor a 5.0V supply?

No, the MAX6709FUB+ variant is configured for IN2 = 3.3V, IN3 = 2.5V, IN4 = 1.8V, and IN1 = adjustable - it does not include a factory-trimmed 5.0V threshold option. To monitor 5.0V, select MAX6709AUB+ or MAX6709BUB+, which feature IN1 = 5.0V instead of adjustable input.

Is the MAX6709FUB+ compatible with both leaded and lead-free soldering processes?

Yes, the MAX6709FUB+ is manufactured in lead-free packaging and qualified for standard lead-free reflow profiles (JEDEC J-STD-020). The "+" suffix explicitly denotes lead-free compliance, and the device supports peak reflow temperatures up to +260°C with 10-second duration, meeting RoHS and WEEE requirements.