Analog Devices Inc./Maxim Integrated MAX6446UK46L+T

Overview

The MAX6446UK46L+T from Maxim Integrated is a dual manual-reset microprocessor supervisor IC with fixed 4.625V VCC reset threshold, 6.72s extended setup period for MR1/MR2, push-pull active-low RESET output, and guaranteed operation from -40°C to +85°C in 5-pin SOT23 package. It monitors VCC only (no RSTIN), asserts RESET for ≥140ms after voltage recovery or manual reset activation, and prevents nuisance resets in consumer electronics power sequencing.

For engineers reviewing the MAX6446UK46L+T datasheet, MAX6446UK46L+T pinout, MAX6446UK46L+T application, or MAX6446UK46L+T equivalent, key selection criteria include its dual extended-setup manual reset inputs (MR1 & MR2), precise 4.625V ±0.125V reset threshold, 6.72s tMR timing, low 6µA supply current, and push-pull RESET logic compatible with 1.0V–5.5V VCC operation.

Technical Context

This device implements a dual-input, long-setup-time manual reset architecture where both MR1 and MR2 must be held low simultaneously for 6.72 seconds before generating a one-shot RESET pulse. Its internal comparators monitor VCC against a factory-trimmed 4.625V threshold with 60ppm/°C tempco and 2×VTH hysteresis.

The RESET output is push-pull, sinking up to 3.2mA at VCC ≥4.25V while maintaining VOL ≤0.4V, and remains valid down to VCC = 1.0V. No external RSTIN resistor divider is used - this variant lacks RSTIN functionality per ordering matrix and pin configuration diagrams.

Key Specifications

Pinout & Package

Package: 5-pin SOT23 (U5+1), footprint-compatible with industry-standard 5-lead SOT-23 layouts per Maxim land pattern 90-0174.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6445UK46L+T and MAX6446UT46L+T, the MAX6446UK46L+T provides direct push-pull RESET drive without external components, reduces BOM count, and maintains identical timing and threshold accuracy - making it optimal for cost-sensitive, space-constrained consumer designs where no level shifting is required.

Availability

MAX6446UK46L+T is available at Aetrix Electronics and suitable for set-top boxes, DVD players, and cable modems requiring stable component supply with guaranteed industrial temperature range support and long-term production continuity.

Supply support for MAX6446UK46L+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, and connectivity applications.

The MAX6443–MAX6452 family delivers robust µP supervision with extended manual reset timing for consumer, industrial, and automotive systems where immunity to switch bounce and transient noise is critical.

FAQ

What is the exact reset threshold voltage for MAX6446UK46L+T?

The MAX6446UK46L+T has a factory-trimmed VCC reset threshold of 4.625V, with a guaranteed range of 4.50V to 4.75V over temperature and process variation. This value is fixed and non-adjustable, matching the "46" suffix in the part number per Table 1 of the datasheet. The threshold exhibits 60ppm/°C temperature coefficient and includes built-in hysteresis of approximately 2×VTH to prevent chatter near the trip point.

Does MAX6446UK46L+T support adjustable voltage monitoring via RSTIN?

No, the MAX6446UK46L+T does not support RSTIN functionality. Per the Ordering Information table and Functional Diagram, only MAX6449–MAX6452 variants include the RSTIN pin. The MAX6446UK46L+T is a VCC-only supervisor in the MAX6445/MAX6446 subgroup, with pinout limited to GND, VCC, MR1, MR2, and RESET - confirmed by SOT23-5 top view diagram on page 10.

What is the purpose of the dual manual reset inputs MR1 and MR2 on MAX6446UK46L+T?

The dual manual reset inputs MR1 and MR2 on MAX6446UK46L+T require simultaneous assertion (both held low) for the full 6.72s extended setup period before generating a RESET pulse. This design prevents accidental resets from single-button presses and enforces intentional user action - such as pressing two front-panel buttons together - which is especially valuable in consumer devices like set-top boxes and DVD players where UI reliability is critical.

Is MAX6446UK46L+T compatible with 1.8V microprocessor reset inputs?

Yes, the MAX6446UK46L+T's push-pull RESET output is fully compatible with 1.8V µP reset inputs. When VCC ≥ 1.8V, the RESET high-level output is guaranteed ≥0.8×VCC (≥1.44V), exceeding typical 1.8V µP VIH thresholds. During reset assertion, RESET low is ≤0.3V across VCC = 1.0V–5.5V, well below 1.8V µP VIL limits. No level-shifting circuitry is required.

What packaging and compliance information applies to MAX6446UK46L+T?

The MAX6446UK46L+T is supplied in a RoHS-compliant, lead(Pb)-free 5-pin SOT23 package (package code U5+1), with tape-and-reel delivery and a 2500-piece minimum order quantity. It is not AEC-Q100 qualified - that designation applies only to specific variants like MAX6444US16K/V+T. The "+T" suffix confirms lead-free packaging per Maxim's standard marking convention.