Analog Devices Inc./Maxim Integrated MAX6448UK26L+T

Overview

MAX6448UK26L+T from Maxim Integrated is a single-supply microprocessor supervisory circuit with one extended-setup manual reset input (MR1) and one immediate-assertion manual reset input (MR2), fixed 2.625V VCC reset threshold, 6.72s MR1 setup period, push-pull active-low RESET output, and guaranteed operation from -40°C to +85°C. It prevents nuisance resets in consumer electronics power-on sequencing and front-panel control interfaces.

For engineers reviewing the MAX6448UK26L+T datasheet, MAX6448UK26L+T pinout, MAX6448UK26L+T application, or MAX6448UK26L+T equivalent, key selection criteria include its dual-mode manual reset logic (extended vs. immediate), 2.625V precision reset threshold, 6.72s MR1 hold time, 140ms min reset timeout, and SOT23-5 package compatibility with space-constrained embedded designs.

Technical Context

The MAX6448UK26L+T implements a dual-input reset architecture: MR1 requires a sustained low state for 6.72s to trigger a one-shot 140ms–280ms RESET pulse, while MR2 asserts RESET immediately on a rising edge-debounced for 210ms to prevent false triggers during smart-card insertion/removal detection. Its internal 50kΩ pullup on MR1 enables direct connection to mechanical switches without external components.

VCC monitoring uses a factory-trimmed comparator with 2.625V threshold (±1.5% over temperature), 60ppm/°C tempco, and hysteresis of 2×VTH. RESET remains valid down to VCC = 1.0V, with VOL ≤ 0.3V at ISINK = 1.2mA, ensuring reliable microprocessor reset assertion even during brownout conditions.

Key Specifications

Pinout & Package

MAX6448UK26L+T is housed in a 5-pin SOT23 package (package code U5+1), footprint-compatible with industry-standard 5-lead SOT-23 layouts and suitable for automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6447UK26L+T, MAX6448UK26L+T offers identical supervision accuracy and timing but substitutes open-drain RESET for push-pull-enabling level-shifting to different logic families. Versus TPS3808G33DBVR, MAX6448UK26L+T provides unique dual-mode reset control critical for user-interface-rich devices requiring both momentary and intentional reset paths.

Availability

MAX6448UK26L+T is available at Aetrix Electronics and suitable for set-top boxes, DVD players, cable/DSL modems, MP3 players, and industrial equipment requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX6448UK26L+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, sensing, connectivity, and security applications in industrial, automotive, and consumer markets.

The MAX6443–MAX6452 family was engineered specifically for robust microprocessor supervision in noise-prone consumer and industrial environments, emphasizing immunity to switch bounce, transient glitches, and brownout conditions.

FAQ

What is the exact reset threshold voltage for MAX6448UK26L+T?

The MAX6448UK26L+T has a factory-set VCC reset threshold of 2.625V, with guaranteed tolerance of ±1.5% over the full -40°C to +85°C operating temperature range. This value is defined by the "26" suffix in the part number and confirmed in the Electrical Characteristics table under VTH parameter for the 26 threshold code.

Does MAX6448UK26L+T support both push-pull and open-drain RESET outputs?

No-MAX6448UK26L+T features an open-drain RESET output, as indicated by the "U" prefix in the package code (UK26L+T) and confirmed in the Ordering Information table and Pin Configurations section. The "K" suffix denotes open-drain logic; push-pull variants use "S" or no letter (e.g., MAX6447UK26L+T).

How does the MR2 pin function on MAX6448UK26L+T?

On MAX6448UK26L+T, MR2 is an active-low manual reset input that triggers an immediate one-shot RESET pulse on a rising edge. It is internally debounced for 210ms to suppress contact bounce, making it ideal for smart-card detect or test-mode activation without external filtering circuitry.

What is the minimum VCC voltage required for valid RESET assertion in MAX6448UK26L+T?

MAX6448UK26L+T guarantees valid RESET output logic down to VCC = 1.0V, as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. Below 1.0V, RESET behavior is not guaranteed; for operation down to 0V, a pulldown resistor is required-but only with push-pull variants, not the open-drain MAX6448UK26L+T.

Can MAX6448UK26L+T monitor a secondary voltage using RSTIN?

No-MAX6448UK26L+T does not include an RSTIN pin. It is a single-supply supervisor (MAX6447/MAX6448 series) with only VCC monitoring. Adjustable-threshold monitoring via RSTIN is exclusive to MAX6449–MAX6452 variants, which feature six-pin SOT23 packages and dedicated RSTIN terminals.