Analog Devices Inc./Maxim Integrated MAX6709KUB+

Overview

The MAX6709KUB+ from Maxim Integrated is a quad voltage monitor IC for multivoltage systems, featuring four independent active-low open-drain outputs with 10µA internal pullup to VCC, factory-trimmed thresholds for 3.3V and 1.8V nominal supplies (±10% tolerance), and adjustable inputs down to 0.62V. It operates from 2.0V to 5.5V supply, consumes only 35µA typical supply current, and delivers precise undervoltage detection in telecom power management and server board monitoring.

For engineers reviewing the MAX6709KUB+ datasheet, MAX6709KUB+ pinout, MAX6709KUB+ application, or MAX6709KUB+ equivalent, this page provides verified functional identity, confirmed µMAX-10 package mapping, exact threshold configuration (IN1/IN4 adjustable, IN2 = 3.3V, IN3 = 1.8V, ±10%), real-world timing behavior (30µs propagation delay, 0.3% hysteresis), and validated alternative options for multivoltage supervisory designs.

Technical Context

The MAX6709KUB+ implements four independent precision comparators with an internal 0.62V bandgap reference and factory-laser-trimmed resistor-divider networks for fixed thresholds. Its adjustable inputs (IN1, IN4) connect directly to comparator noninverting inputs, requiring external resistor dividers to scale higher voltages to the 0.62V reference.

All outputs are active-low open-drain with weak 10µA internal pullups to VCC, enabling wire-ORed power-good signaling. An integrated undervoltage lockout forces all outputs low when VCC drops below 2.0V, and hysteresis is built-in at 0.3% of threshold voltage-no external components required.

Key Specifications

Pinout & Package

Package: 10-pin µMAX (3.0mm × 3.0mm, 0.6mm height, 0.5mm pitch), lead-free, RoHS-compliant, rated for -40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6714CUB+, the MAX6709KUB+ provides four independent status outputs ideal for complex power sequencing, while TPS3307-33DBTR trades channel count for compactness-neither offers pin compatibility, so PCB redesign is required for substitution.

Availability

The MAX6709KUB+ is available at Aetrix Electronics and suitable for telecommunications infrastructure, server motherboard design, and high-end printer logic control requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6709KUB+ 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, and computing markets.

The MAX6709KUB+ belongs to Maxim's precision voltage supervisor product line, engineered specifically for multivoltage system integrity assurance in space- and power-constrained embedded platforms.

FAQ

What is the exact threshold configuration for MAX6709KUB+?

The MAX6709KUB+ is configured per Maxim's Selector Guide: IN1 and IN4 are adjustable inputs (0.62V base), IN2 monitors 3.3V ±10% (trip at 2.97V), and IN3 monitors 1.8V ±10% (trip at 1.62V). This specific variant supports systems requiring two customizable rails alongside standard I/O and core voltage supervision. The MAX6709KUB+ datasheet confirms these thresholds are factory-laser-trimmed and do not require external components.

Does MAX6709KUB+ include a reset timeout function like MAX6714?

No, the MAX6709KUB+ does not include a reset timeout or manual reset (MR) input. It is a pure quad voltage monitor with four independent PWRGD outputs. Unlike the MAX6714 series-which integrates a timed RESET output and MR pin-the MAX6709KUB+ asserts outputs immediately upon threshold breach with no built-in delay. For timeout functionality, external RC timing or a separate supervisor like MAX6714CUB+ must be used alongside MAX6709KUB+.

Can unused inputs on MAX6709KUB+ be left floating?

No-only the adjustable inputs (IN1 and IN4 on MAX6709KUB+) must be tied to GND if unused; fixed-threshold inputs (IN2, IN3) are internally terminated and may float safely. Leaving IN1 or IN4 unconnected risks noise coupling and false triggering due to their high-impedance comparator inputs. The MAX6709KUB+ datasheet explicitly requires grounding unused adjustable inputs to ensure stable operation and avoid erratic PWRGD behavior.

What is the maximum sink current supported by MAX6709KUB+ outputs?

The MAX6709KUB+ open-drain outputs support up to 2mA sink current while maintaining VOL ≤ 0.3V (tested at VCC = 5V). This is sufficient to drive standard TTL/CMOS inputs, LEDs (with series resistor), or optocouplers directly. The 10µA internal pullup remains active during sinking, but external pullups can override it-enabling interoperability with 1.8V, 3.3V, or 5V logic domains without level shifters. Performance is fully specified from -40°C to +85°C.

How does MAX6709KUB+ handle supply transients during operation?

The MAX6709KUB+ is designed to reject short-duration supply transients: its built-in 0.3% hysteresis and 30µs propagation delay prevent false triggering from spikes <100µs wide. The internal bandgap reference and comparator architecture ensure stable threshold tracking across VCC variations from 2.0V to 5.5V. As confirmed in the MAX6709KUB+ datasheet, it remains immune to typical board-level noise-no external filtering is required beyond standard 0.1µF VCC bypassing.