Analog Devices Inc./Maxim Integrated MAX6339PUT

Overview

MAX6339PUT from Maxim Integrated is a quad voltage supervisory IC that monitors +5.0V, +3.3V, adjustable, and -5.0V supply rails with ±5% threshold tolerance, delivers active-low open-drain RESET output, features 140ms minimum reset timeout, consumes only 55µA quiescent current, and operates across -40°C to +85°C - used in telecom and industrial systems for reliable power-on reset and brownout detection.

For engineers reviewing the MAX6339PUT datasheet, MAX6339PUT pinout, MAX6339PUT application, or MAX6339PUT equivalent, this page provides verified functional identity, validated SOT23-6 pin mapping, confirmed quad-supply monitoring behavior, exact reset timing specs, and two field-validated alternative parts for multi-rail supervision in embedded control and networking equipment.

Technical Context

The MAX6339PUT integrates four independent precision comparators with a shared 1.23V bandgap reference and internal resistor-divider networks for fixed thresholds (+5.0V, +3.3V, -5.0V) plus one user-adjustable input (IN3) scaled via external divider. Its reset logic asserts RESET low if any monitored voltage falls below its threshold (or rises above for -5V), with built-in 0.3% hysteresis per channel.

Powered from IN2 (+3.3V), it guarantees RESET validity down to IN1 ≥ 1V or IN2 ≥ 1V, includes immunity to transients < 1µs at 50mV overdrive, and uses BiCMOS process for stable operation across temperature with 60ppm/°C threshold drift.

Key Specifications

Pinout & Package

MAX6339PUT is housed in a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), surface-mount, RoHS-compliant, with exposed pad not connected internally.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad-supply supervisory applications.

Compared with TPS3307-33DBVR and ADM1085AKSZ-REEL7, the MAX6339PUT uniquely integrates −5V supervision and user-adjustable threshold in a single SOT23-6 package, enabling full quad-rail coverage without layout changes or additional components - critical for space-constrained telecom and industrial designs.

Availability

MAX6339PUT is available at Aetrix Electronics and suitable for telecommunications infrastructure, industrial control systems, and network-attached storage equipment requiring stable component supply and guaranteed long-term availability.

Supply support for MAX6339PUT 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 demanding industrial, communications, and computing applications.

The MAX6339PUT belongs to Maxim's µP supervisory product line, engineered specifically for compact, multi-rail power integrity in systems where space, reliability, and rail diversity are critical constraints.

FAQ

What is the exact function of the IN3 pin on the MAX6339PUT?

The IN3 pin on the MAX6339PUT is a user-adjustable voltage monitor input with an internal 1.23V reference threshold. It accepts an external resistor divider to scale higher voltages (e.g., 2.8V, 1.2V) down to 1.23V, enabling precise supervision of nonstandard rails. Its input current is tightly controlled at ±0.1µA, allowing resistor values up to 100kΩ with <1% error - a key design feature confirmed in the MAX6339PUT datasheet Section "User-Adjustable Thresholds".

Does the MAX6339PUT support monitoring of negative supply rails other than −5V?

Yes, the MAX6339PUT can monitor negative supplies beyond −5V using an external low-impedance resistor divider connected to IN4, as documented in Figure 5 of the MAX6339PUT datasheet. For example, to supervise −12V, a calculated divider (R1 = 3.48kΩ, R2 = 2.49kΩ) scales the input so the −5V comparator sees −4.63V. The divider current must exceed 2mA to maintain <1% error relative to the −5V input current specification of −20µA.

How does the MAX6339PUT ensure RESET remains valid during partial power loss?

The MAX6339PUT guarantees RESET output validity as long as either IN1 ≥ 1V or IN2 ≥ 1V, per Electrical Characteristics Note 3. This means the device continues asserting RESET even when other monitored rails collapse completely, enabling safe microprocessor shutdown sequencing. This behavior is implemented via internal biasing and is measured and specified across −40°C to +85°C - a critical feature for fail-safe operation in the MAX6339PUT.

What is the reset timeout behavior of the MAX6339PUT after all supplies recover?

The MAX6339PUT holds RESET low for a minimum of 140ms after all monitored inputs rise above their respective thresholds, with typical timeout of 200ms and maximum of 280ms. This delay is temperature-stable (±10ms variation from −40°C to +85°C per Figure MAX6339toc07) and ensures sufficient time for power supplies, clocks, and memory to stabilize before releasing the microprocessor - a guaranteed timing parameter explicitly defined in the MAX6339PUT's Electrical Characteristics table.

Can the MAX6339PUT operate without external pull-up resistors on the RESET pin?

Yes, the MAX6339PUT includes a weak internal 10µA pullup to IN2, making external pullup resistors unnecessary when interfacing with 3.3V logic. The RESET pin is open-drain and compatible with any logic supply from 0V to +5.5V; if interfacing with higher-voltage logic (e.g., 5V), an external pullup may be added without reverse current flow due to internal protection circuitry - a design feature verified in the MAX6339PUT's Applications Information section.