Analog Devices Inc./Maxim Integrated MAX6709DUB

Overview

The MAX6709DUB 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 (−5%), 3.3V (−5%), and 1.8V (−5%) supplies, and an adjustable fourth input (0.62V reference). It operates from 2.0V to 5.5V, consumes only 35µA typical supply current, and delivers ±2.0% threshold accuracy across −40°C to +85°C - enabling reliable power sequencing in desktop computers and telecom equipment.

For engineers reviewing the MAX6709DUB datasheet, MAX6709DUB pinout, MAX6709DUB application, or MAX6709DUB equivalent, this device supports precise, component-free monitoring of three fixed-voltage rails plus one scalable rail in space-constrained embedded systems - with wire-ORable outputs, built-in hysteresis (0.3% of VTH), and immunity to supply transients.

Technical Context

The MAX6709DUB integrates four precision comparators with an internal 0.62V bandgap reference and factory-laser-trimmed resistor-divider networks for IN1–IN3, delivering fixed −5% trip points at 5.0V, 3.3V, and 1.8V nominal supplies. Its fourth input (IN4) bypasses internal dividers and connects directly to a comparator input, supporting adjustable monitoring down to 0.62V via external resistor networks.

All outputs are active-low, open-drain with weak 10µA internal pullups to VCC, enabling direct wire-ORing without external components. An undervoltage lockout circuit forces all PWRGD_ outputs low when VCC drops below 2.0V, ensuring deterministic behavior down to 1V operation - critical for brownout detection in industrial and computing platforms.

Key Specifications

Pinout & Package

MAX6709DUB is housed in a 10-pin µMAX package (3mm × 3mm, 0.5mm pitch), RoHS-compliant, with exposed pad for thermal enhancement. Pin 5 is GND; Pin 10 is VCC; Pins 1–4 are voltage inputs (IN1–IN4); Pins 6–9 are corresponding open-drain outputs (PWRGD4–PWRGD1).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6714DUB and TPS3307-33D, the MAX6709DUB uniquely provides four independent, pullup-equipped PWRGD_ outputs in a single µMAX package - making it the only solution that satisfies simultaneous, wire-ORable, four-rail power-good monitoring without external components or secondary ICs.

Availability

MAX6709DUB is available at Aetrix Electronics and suitable for desktop computers, telecom line cards, and industrial embedded controllers requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for MAX6709DUB 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 MAX6709DUB belongs to Maxim's precision voltage supervisor product line, engineered specifically for multivoltage system power integrity assurance - emphasizing low quiescent current, factory-trimmed accuracy, and minimal external component count.

FAQ

What voltage rails does the MAX6709DUB monitor by default?

The MAX6709DUB monitors 5.0V (−5%, 4.75V trip), 3.3V (−5%, 3.15V trip), and 1.8V (−5%, 1.71V trip) on IN1–IN3, with IN4 configured as an adjustable input referenced to 0.623V. This configuration is fixed per the DUB suffix and cannot be altered post-manufacture - users must select the correct variant (e.g., MAX6709CUB for −10% tolerance) at order time.

Does the MAX6709DUB require external pullup resistors on its PWRGD_ outputs?

No, the MAX6709DUB includes 10µA internal pullup current sources to VCC on all four PWRGD_ outputs, eliminating the need for external pullups in most 3.3V/5V logic interfaces. External pullups are only required when interfacing to logic supplies outside the 2.0V–5.5V range - and internal circuitry blocks reverse current flow from such external sources back into VCC.

Can the MAX6709DUB monitor a 12V supply?

Yes - the MAX6709DUB's IN4 input is adjustable and referenced to an internal 0.623V threshold. To monitor 12V, use a resistor divider (e.g., R1 = 18.3kΩ, R2 = 1kΩ) so that 12V at the divider tap equals 0.623V. The MAX6709DUB datasheet provides the exact formula: R1 = R2 × ((V_INTH/0.623V) − 1), ensuring accurate scaling without calibration.

How does the MAX6709DUB handle supply transients during operation?

The MAX6709DUB is explicitly designed to be immune to supply transients, with built-in hysteresis (0.3% of threshold voltage) and fast propagation delay (5µs typical) that reject short-duration noise spikes. Its comparator architecture and internal bandgap reference ensure stable trip points even during 100mV overdrive events - validated in Figures 10–12 of the MAX6709/MAX6714 datasheet.

Is the MAX6709DUB pin-compatible with other variants in the MAX6709 family?

Yes - all MAX6709 variants (e.g., MAX6709AUB, MAX6709BUB, MAX6709DUB) share identical 10-pin µMAX packaging, pinout, and electrical interface. Only the factory-trimmed threshold values differ between suffixes; no PCB layout change is needed when substituting within the MAX6709 family for different voltage or tolerance requirements.