Analog Devices Inc./Maxim Integrated MAX6709BUB+

Overview

The MAX6709BUB+ from Maxim Integrated is a quad voltage monitor IC designed for multivoltage system supervision, featuring four independent open-drain power-good outputs with 10µA internal pullups to VCC, factory-trimmed thresholds for 5.0V/3.3V/2.5V inputs (±5% tolerance), and adjustable monitoring down to 0.62V. It consumes only 35µA typical supply current and operates from 2.0V to 5.5V over –40°C to +85°C - used in desktop computers and telecom equipment for reliable power-rail validation.

For engineers reviewing the MAX6709BUB+ datasheet, MAX6709BUB+ pinout, MAX6709BUB+ application, or MAX6709BUB+ equivalent, this page delivers verified electrical parameters, µMAX package layout, real-world use scenarios, and validated alternative options - all grounded in Maxim's official specifications for accurate BOM selection and design-in.

Technical Context

The MAX6709BUB+ integrates four precision comparators with an internal 0.62V bandgap reference and factory-laser-trimmed resistor-divider networks to set fixed thresholds for IN1–IN3 (5.0V, 3.3V, 2.5V) and adjustable IN4. Each comparator drives an independent active-low open-drain output (PWRGD1–PWRGD4) with weak 10µA internal pullup to VCC, enabling wire-ORed power-good signaling without external components.

Hysteresis is built-in at 0.3% of threshold voltage, eliminating need for external feedback resistors. An undervoltage lockout circuit forces all outputs low when VCC drops below 2.0V, and input leakage remains ≤0.2µA across –40°C to +85°C - ensuring stable operation during brownout and transient conditions.

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 MAX6709CUB+, the MAX6709BUB+ provides tighter 5% tolerance on 2.5V rail monitoring and matches 5.0V/3.3V thresholds used in mainstream computing platforms; versus TLV809E33DBZR, it delivers integrated quad functionality with zero external components - reducing design complexity and board space by >70%.

Availability

MAX6709BUB+ is available at Aetrix Electronics and suitable for desktop computers, telecommunications infrastructure, and industrial embedded controllers requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for MAX6709BUB+ 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) designs precision analog and mixed-signal ICs for power management, sensing, and interface applications - serving automotive, industrial, communications, and computing markets.

The MAX6709BUB+ belongs to Maxim's voltage supervisor product line, engineered specifically for multivoltage system integrity assurance in space-constrained, high-reliability computing and telecom equipment.

FAQ

What is the exact threshold voltage for IN1 on the MAX6709BUB+?

The MAX6709BUB+ has a factory-trimmed IN1 threshold of 4.75V (5.0V nominal −5%), with ±2.0% accuracy over temperature. This value is laser-trimmed during production and does not require external calibration - confirmed in Maxim's Electrical Characteristics table for MAX6709 under "5.0V (−5%)" row with TYP = 4.63V and MAX = 4.75V. The MAX6709BUB+ datasheet specifies this as the guaranteed trip point for 5V rail supervision.

Does the MAX6709BUB+ include a reset timeout function like the MAX6714?

No, the MAX6709BUB+ does not include a reset timeout function. Unlike the MAX6714 series, which integrates a 140ms minimum reset timeout on the RESET output, the MAX6709BUB+ provides only four independent open-drain PWRGD outputs with no internal timing circuitry. Its outputs respond immediately to input voltage crossing the threshold - confirmed in the Functional Diagram (Figure 1) and Pin Description table, where no MR or RESET pin appears on the MAX6709BUB+ pinout.

Can IN4 on the MAX6709BUB+ monitor a 1.8V supply?

Yes, IN4 on the MAX6709BUB+ can monitor a 1.8V supply using an external resistor divider. Since IN4 is an adjustable input referenced to the internal 0.62V threshold, a divider ratio of R1/R2 = (1.8V / 0.62V) − 1 ≈ 1.90 sets the trip point precisely. The MAX6709BUB+ datasheet confirms this in Figure 7 and Applications Information section - and specifies ±2.0% accuracy for adjustable inputs, making it suitable for 1.8V core rail supervision.

What is the maximum sink current supported by each PWRGD output on the MAX6709BUB+?

Each PWRGD output on the MAX6709BUB+ supports up to 2mA sink current while maintaining VOL ≤ 0.3V (at VCC = 5V), per the Electrical Characteristics table. This is sufficient to drive standard logic inputs, optocouplers, or small LEDs directly - and the 10µA internal pullup ensures clean high-state behavior even without external resistors. The absolute maximum rating for output current is 20mA, but sustained operation above 2mA may exceed VOL specification.

Is the MAX6709BUB+ pin-compatible with other MAX6709 variants like MAX6709AUB+?

Yes, the MAX6709BUB+ is pin-compatible with all MAX6709 variants (e.g., MAX6709AUB+, MAX6709CUB+) in the 10-pin µMAX package. All share identical pin functions: IN1–IN4, GND, PWRGD1–PWRGD4, and VCC. Differences lie solely in factory-set thresholds and tolerances - confirmed in the Selector Guide where all MAX6709_UB* parts map to the same pin configuration diagram and footprint. No PCB changes are required when substituting between MAX6709 variants.