Analog Devices Inc./Maxim Integrated MAX6709MUB+

Overview

The MAX6709MUB+ from Maxim Integrated is a low-power, quad voltage monitor IC designed for multivoltage system supervision. It provides four independent active-low open-drain power-good outputs with 10µA internal pullups to VCC, monitors adjustable thresholds down to 0.62V (via external resistor dividers), supports ±2.0% threshold accuracy, and operates across 2.0V–5.5V supply with 35µA typical supply current. It is used in desktop/notebook computers and telecom equipment for reliable power-rail sequencing and fault detection.

For engineers reviewing the MAX6709MUB+ datasheet, MAX6709MUB+ pinout, MAX6709MUB+ application, or MAX6709MUB+ equivalent, key selection criteria include factory-trimmed or adjustable input thresholds (e.g., 3.0V nominal with 10% tolerance), quad independent outputs, µMAX-10 package compatibility, and operation over –40°C to +85°C without external components.

Technical Context

The MAX6709MUB+ integrates four precision comparators with an internal 0.62V bandgap reference and factory-trimmed resistor-divider networks for fixed-threshold monitoring (e.g., 3.0V nominal), while two inputs are designated as adjustable-accepting external resistor dividers to scale higher voltages down to the 0.62V comparator threshold. Its hysteresis is fixed at 0.3×V_TH, eliminating need for external feedback.

It features undervoltage lockout that forces all PWRGD outputs low when VCC drops below 2.0V, and all outputs are open-drain with weak 10µA internal pullups to VCC-enabling wire-ORed power-good signaling and interoperability with mixed-voltage logic systems without external pullup resistors.

Key Specifications

Pinout & Package

Package: 10-pin µMAX (3.0mm × 3.0mm, 0.6mm height, exposed pad). Pin pitch: 0.5mm. RoHS-compliant, lead-free (indicated by '+' suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6714CUB+, the MAX6709MUB+ delivers true quad independent PWRGD signaling ideal for rail arbitration-not reset assertion-while TPS3307-33DGNR trades configurability for lower cost and smaller footprint in homogeneous 3.3V applications.

Availability

MAX6709MUB+ is available at Aetrix Electronics and suitable for desktop computers, telecom line cards, industrial PLCs, and notebook computer designs requiring stable component supply, long-term manufacturability, and guaranteed RoHS-compliant sourcing.

Supply support for MAX6709MUB+ 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 MAX6709 belongs to Maxim's voltage supervisor product line, engineered specifically for multivoltage system power integrity-emphasizing low ICC, factory-trimmed accuracy, and flexible threshold configuration without external passive components.

FAQ

What is the exact threshold voltage for the fixed 3.0V input (IN2) on the MAX6709MUB+?

The MAX6709MUB+ has IN2 factory-trimmed for 3.0V nominal with 10% tolerance, resulting in a guaranteed trip threshold range of 2.70V to 2.85V (min to max) at TA = –40°C to +85°C. This is confirmed in the Electrical Characteristics table under "3.0V (–10%)" for V_TH, with typical value 2.78V. The MAX6709MUB+ datasheet specifies this as the only fixed-threshold input in its variant.

Does the MAX6709MUB+ require external pullup resistors on its PWRGD outputs?

No, the MAX6709MUB+ does not require external pullup resistors. Each PWRGD output features a 10µA internal current-source pullup to VCC, sufficient to drive standard CMOS/TTL logic inputs. External pullups are optional-only needed when interfacing to logic supplies different from VCC (e.g., pulling PWRGD to 1.8V while VCC = 3.3V), and internal circuitry prevents reverse current flow.

Can all four inputs of the MAX6709MUB+ be configured for adjustable thresholds?

No-only IN1, IN3, and IN4 are adjustable on the MAX6709MUB+. IN2 is fixed at 3.0V ±10%. This is defined in the Selector Guide: MAX6709MUB+ is specified as "Adj*/3/Adj*/Adj*" meaning IN1=adjustable, IN2=3.0V, IN3=adjustable, IN4=adjustable. The internal resistor network for IN2 is trimmed permanently; it cannot be reconfigured as adjustable.

What is the propagation delay of the MAX6709MUB+ when monitoring a fast-ramping supply?

The MAX6709MUB+ propagation delay is 5µs (typical) for rising-edge detection (IN_ rising from V_TH to V_TH + 50mV at 10mV/µs slew rate), and 30µs for falling-edge detection (IN_ falling from V_TH to V_TH – 50mV). These values are measured under VCC = 5V, TA = +25°C, and apply to all inputs including IN2 (3.0V) and adjustable channels.

How does the MAX6709MUB+ handle supply transients, and is external filtering required?

The MAX6709MUB+ is explicitly characterized as "immune to supply transients" per its Features list and Applications Information section. Its internal comparator design and 0.3×V_TH hysteresis suppress false triggering from short-duration noise spikes. No external RC filtering is required-though a 0.1µF ceramic bypass capacitor on VCC (as recommended) improves overall noise immunity in high-EMI environments.