Analog Devices Inc./Maxim Integrated MAX6444US16L+T

Overview

MAX6444US16L+T from Maxim Integrated is a single-supply, fixed-threshold microprocessor reset supervisor IC with one extended-setup manual reset input (MR1), active-low open-drain RESET output, 1.575V VCC reset threshold, and 6.72s manual reset setup period. It monitors VCC only, asserts RESET when VCC drops below threshold or MR1 is held low ≥6.72s, and guarantees valid reset operation down to VCC = 1.0V. Used in set-top boxes and consumer electronics for reliable power-on and brownout reset control.

For engineers reviewing the MAX6444US16L+T datasheet, MAX6444US16L+T pinout, MAX6444US16L+T application, or MAX6444US16L+T equivalent, key selection criteria include its 1.575V factory-set reset threshold, 6.72s extended MR1 setup time to prevent nuisance resets, 6µA supply current, SOT143-4 package, and open-drain RESET logic compatible with 0–6V pullup voltages.

Technical Context

This device implements a precision voltage monitor with ±0.075V threshold accuracy over -40°C to +85°C and 60ppm/°C tempco. Its internal comparator continuously compares VCC against a trimmed 1.575V reference, triggering a 210ms typical (140ms min) one-shot RESET pulse on threshold violation.

The MR1 input features an internal 50kΩ pullup and requires ≥6.72s low assertion before generating a RESET pulse-enabling use of front-panel pushbuttons without external debounce circuitry. RESET remains asserted for the full timeout period regardless of MR1 release timing, and the open-drain output supports level-shifting via external pullup to any voltage ≤6V.

Key Specifications

Pinout & Package

MAX6444US16L+T is housed in a 4-pin SOT143 package (1.3mm × 2.1mm footprint) with gull-wing leads, optimized for space-constrained consumer PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6444US16K+T, the MAX6444US16L+T offers faster user-initiated reset response (6.72s vs. 10.08s), while versus TPS3808G16DBVR it provides integrated long-duration manual reset without external components-reducing BOM count and layout area in consumer UI designs.

Availability

MAX6444US16L+T is available at Aetrix Electronics and suitable for set-top boxes, DVD players, and cable modems requiring stable component supply, long-term industrial availability, and RoHS-compliant packaging.

Supply support for MAX6444US16L+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 industrial, communications, and consumer applications.

The MAX6443–MAX6452 family delivers highly reliable, low-power microprocessor supervisory circuits optimized for consumer electronics and industrial equipment where immunity to short transients and nuisance-free manual reset are critical.

FAQ

What is the exact reset threshold voltage of the MAX6444US16L+T?

The MAX6444US16L+T has a factory-trimmed VCC reset threshold of 1.575V, with guaranteed limits of 1.52V (min) and 1.62V (max) over the full -40°C to +85°C operating temperature range. This value is confirmed in the Electrical Characteristics table under "VCC Reset Threshold" with suffix "16", and applies exclusively to the VCC supply monitor-not RSTIN, which is unused in this variant.

Does the MAX6444US16L+T support dual manual reset inputs?

No, the MAX6444US16L+T supports only a single extended-setup manual reset input (MR1). It belongs to the MAX6443/MAX6444 subgroup, which lacks MR2 and RSTIN pins. Dual manual reset capability is exclusive to MAX6445–MAX6448 and MAX6449–MAX6452 variants, as clearly indicated in the Pin Description and Selector Guide sections of the datasheet.

What package type and pin count does the MAX6444US16L+T use?

The MAX6444US16L+T uses a 4-pin SOT143 package (outline 21-0052), with pin 1 = GND, pin 2 = VCC, pin 3 = MR1, and pin 4 = RESET. This is explicitly stated in the Ordering Information table and confirmed in the Pin Configurations diagram on page 10 of the datasheet.

Is the RESET output of the MAX6444US16L+T push-pull or open-drain?

MAX6444US16L+T features an active-low open-drain RESET output, as confirmed by the "Open-Drain RESET Outputs" feature bullet and the Ordering Information table row specifying "MAX6444… - ✔" under the "OPEN-DRAIN RESET" column. A minimum 20kΩ external pullup resistor to VCC or another logic rail is required for proper operation.

What is the guaranteed minimum reset timeout period for the MAX6444US16L+T?

The MAX6444US16L+T guarantees a minimum reset timeout period of 140ms, with a typical value of 210ms and maximum of 280ms. This is specified in the Electrical Characteristics table under "Reset Timeout Period (tRP)" and applies to both power-on reset and manual reset assertion events.