Analog Devices Inc./Maxim Integrated MAX6452UT26L+T

Overview

The MAX6452UT26L+T from Maxim Integrated is a dual-supply microprocessor reset supervisor IC with one fixed-threshold (2.625V) and one adjustable-threshold (0.63V reference) voltage monitor, extended manual reset setup period (6.72s), 140ms min reset timeout, and open-drain active-low RESET output in SOT23-6 package. It prevents nuisance resets in set-top boxes and industrial equipment by requiring sustained button press before asserting reset.

For engineers reviewing the MAX6452UT26L+T datasheet, MAX6452UT26L+T pinout, MAX6452UT26L+T application, or MAX6452UT26L+T equivalent, key selection criteria include its dual manual reset architecture (MR1 extended + MR2 immediate), RSTIN-adjustable monitoring down to 0.63V, guaranteed reset validity at VCC ≥ 1.0V, and AEC-Q100-qualified variants for automotive use.

Technical Context

The MAX6452UT26L+T integrates two independent reset comparators: one monitors VCC against a factory-set 2.625V threshold (±1.5% over -40°C to +85°C), while the second monitors RSTIN against a precise 0.630V internal reference (±0.015V, ±2.5mV hysteresis). Its dual manual reset inputs operate asymmetrically-MR1 requires 6.72s low assertion to trigger a one-shot 140ms–280ms reset pulse, whereas MR2 responds immediately to a rising edge with debounced 210ms deassertion timing.

This architecture enables interrupt-before-reset functionality: brief MR1 closure triggers processor interrupt only, while prolonged press initiates full system reset. The RSTIN input supports high-impedance external resistor-divider configuration for custom voltage thresholds as low as 0.63V, with leakage current ≤25nA and propagation delay ≤15µs (RSTIN falling at 1mV/µs).

Key Specifications

Pinout & Package

Package: SOT23-6 (6-pin, 1.6mm × 2.9mm, 0.95mm height), RoHS-compliant lead(Pb)-free, tape-and-reel packaging.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor reset applications.

Compared with MAX6451UT26L+T, the MAX6452UT26L+T offers level-shifting flexibility via open-drain output but requires an external pullup; versus MAX6448UK26L+T, it adds RSTIN-based auxiliary rail monitoring and MR2 immediate reset-critical for multi-rail systems needing both precision supervision and responsive service recovery.

Availability

MAX6452UT26L+T is available at Aetrix Electronics and suitable for set-top boxes, DVD players, and industrial modems requiring stable component supply, long-term lifecycle support, and guaranteed performance across -40°C to +85°C.

Supply support for MAX6452UT26L+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 and mixed-signal ICs for power management, sensing, and interface applications, with emphasis on reliability and low-power operation.

The MAX6443–MAX6452 family delivers robust microprocessor supervision for consumer, industrial, and automotive systems, featuring extended manual reset setup periods to eliminate false resets in noisy or mechanically actuated environments.

FAQ

What is the exact VCC reset threshold voltage for the MAX6452UT26L+T?

The MAX6452UT26L+T has a factory-set VCC reset threshold of 2.625V, specified with ±1.5% tolerance over the full -40°C to +85°C operating temperature range. This value is confirmed in Table 1 of the datasheet under suffix "26", and applies to the primary supply monitoring function of the MAX6452UT26L+T. The threshold exhibits 60ppm/°C tempco and 2×VTH hysteresis for noise immunity.

How does the MR2 input on the MAX6452UT26L+T differ from MR1 in terms of reset triggering?

The MR2 input on the MAX6452UT26L+T responds to a rising edge with immediate RESET assertion (140ms min timeout), while MR1 requires a sustained low state for 6.72 seconds. MR2 also features 210ms internal debouncing on the falling edge to prevent false releases, making it ideal for smart-card detect or service reset functions. This dual-input behavior is unique to the MAX6452UT26L+T within the MAX6443–MAX6452 family.

Can the MAX6452UT26L+T monitor a 1.2V supply, and if so, how?

Yes, the MAX6452UT26L+T can monitor a 1.2V supply using its RSTIN pin with an external resistor divider. With a 0.630V internal reference, a 1.2V rail requires R1 = R2 × (1.2V / 0.63V − 1) ≈ 0.905 × R2. Using R2 = 250kΩ yields R1 ≈ 226kΩ. The MAX6452UT26L+T's RSTIN input draws ≤25nA, enabling high-resistance dividers that minimize current drain while maintaining accuracy.

What is the minimum VCC voltage at which the MAX6452UT26L+T guarantees valid RESET output operation?

The MAX6452UT26L+T guarantees valid RESET output operation down to VCC = 1.0V, as stated in the Electrical Characteristics table and Detailed Description section. Below this voltage, current-sinking capability declines, but the device ensures correct logic state assertion throughout its specified operating range. This specification is critical for brownout detection in battery-powered applications using the MAX6452UT26L+T.

Does the MAX6452UT26L+T require an external pullup resistor on the RESET pin, and why?

Yes, the MAX6452UT26L+T requires an external pullup resistor (minimum 20kΩ) on the RESET pin because it features an open-drain output configuration. Without this resistor, the RESET signal cannot achieve a defined high state, preventing proper communication with the microprocessor's reset input. The pullup may connect to VCC or another logic rail up to 6V, enabling level-shifting functionality unique to the MAX6452UT26L+T's open-drain architecture.