Analog Devices Inc./Maxim Integrated MAX6339KUT-T

Overview

MAX6339KUT-T from Maxim Integrated is a quad voltage supervisory IC that monitors four independent supply rails-including two user-adjustable thresholds (IN1 and IN4)-with precision factory-trimmed thresholds for +3.3V (−10%) and +2.5V (−10%), all in a 6-pin SOT23 package. It asserts a single active-low open-drain RESET output when any monitored voltage falls below its threshold, with guaranteed operation down to IN1 or IN2 ≥ 1V and a minimum 140ms reset timeout period. It is used in telecom power sequencing and industrial multi-rail systems requiring compact, low-power supervision.

For engineers reviewing the MAX6339KUT-T datasheet, MAX6339KUT-T pinout, MAX6339KUT-T application, or MAX6339KUT-T equivalent, key selection criteria include its dual adjustable input architecture, −10% tolerance on fixed 3.3V/2.5V monitoring, 55µA supply current, 0.3% threshold hysteresis, and immunity to short-duration supply transients-critical for reliable boot-up in embedded controllers and network equipment.

Technical Context

The MAX6339KUT-T implements four independent comparators referenced to a stable 1.23V internal bandgap, with two inputs (IN1 and IN4) configured for user-adjustable thresholds via external resistor dividers, while IN2 and IN3 are factory-set to +3.3V (−10%) and +2.5V (−10%). Its power is derived solely from IN2, enabling self-powered supervision of up to four rails without auxiliary biasing.

Reset assertion is synchronized across all inputs using a NOR-gated logic structure, ensuring a single active-low RESET output remains asserted until all four voltages exceed their respective thresholds and then sustains the 140ms minimum timeout. The open-drain RESET features a 10µA internal pullup to IN2 and supports external pullup to any voltage ≤ +5.5V without reverse current flow.

Key Specifications

Pinout & Package

MAX6339KUT-T is housed in a 6-pin SOT23-6 package (JEDEC MO-178AA), measuring 2.9mm × 1.6mm × 1.1mm, with gull-wing leads and lead-free (RoHS-compliant) finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6340KUT-T and TPS3307-33D, the MAX6339KUT-T uniquely balances quad monitoring, dual adjustability, and −10% fixed thresholds in a single SOT23-6 package-enabling full multi-rail supervision without supplemental components or board area penalty.

Availability

MAX6339KUT-T is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, network equipment, and medical imaging subsystems requiring stable component supply and long-term production continuity.

Supply support for MAX6339KUT-T 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, mixed-signal, and power management ICs for demanding industrial, communications, and computing applications.

The MAX6339KUT-T belongs to Maxim's µP supervisory product line, engineered specifically for space-constrained, multi-rail systems needing reliable, low-power, and configurable voltage monitoring without external passive components.

FAQ

What is the function of the IN2 pin on the MAX6339KUT-T?

The IN2 pin on the MAX6339KUT-T serves as both the primary power supply input for the IC and the internal pullup target for the open-drain RESET output. It must be connected to a stable voltage between 1.0V and 5.5V; the device draws 55µA from IN2 under typical conditions, and RESET remains valid as long as IN2 (or IN1) stays above 1V. This dual role eliminates the need for a separate V_CC rail.

Can the MAX6339KUT-T monitor a −12V supply?

Yes, the MAX6339KUT-T can monitor a −12V supply using its adjustable IN4 input. Since IN4 references an internal 1.23V threshold, a resistor-divider network must scale −12V to −1.23V at the pin. For example, with R2 = 2.49kΩ and V_INTH = −11.1V (−10% of −12V), R1 ≈ 3.48kΩ achieves the required ratio. The MAX6339KUT-T's absolute maximum rating for IN4 allows −6V to +0.3V, so the divider must ensure the pin voltage stays within this range.

How does the reset timeout period behave if one supply recovers before others?

The MAX6339KUT-T's reset timeout period begins only after all four monitored inputs (IN1–IN4) have risen above their respective thresholds. Until then, RESET remains asserted low. Once all thresholds are satisfied, RESET stays low for a minimum of 140ms-guaranteed across −40°C to +85°C-before going high. This ensures the microprocessor receives a clean, extended reset pulse regardless of individual rail recovery timing.

What is the maximum resistor value allowed for the external divider on MAX6339KUT-T adjustable inputs?

The MAX6339KUT-T adjustable inputs (IN1 and IN4) guarantee input current ≤ ±0.1µA, allowing resistor values up to 100kΩ for R2 with less than 1% error due to leakage. For example, using R2 = 100kΩ and R1 calculated per V_INTH = 1.23V × (R1+R2)/R2 yields accurate threshold setting without significant loading error. Higher values increase noise susceptibility and should be avoided unless layout and shielding mitigate interference.

Is the MAX6339KUT-T RoHS-compliant and lead-free?

Yes, the MAX6339KUT-T is RoHS-compliant and supplied in lead-free packaging. The "-T" suffix in the part number denotes tape-and-reel packaging with lead-free terminations, meeting JEDEC J-STD-020 moisture sensitivity level 1 requirements. Maxim's official documentation confirms compliance with EU RoHS Directive 2011/65/EU and China RoHS, with no exemptions applied to this variant.