Analog Devices Inc./Maxim Integrated MAX6444US23L

Overview

MAX6444US23L from Maxim Integrated is a single-supply microprocessor supervisory circuit with fixed 2.313V reset threshold, active-low open-drain RESET output, and extended manual reset setup period (6.72s). It monitors VCC only, asserts reset when VCC drops below threshold or MR1 is held low ≥6.72s, and guarantees valid reset down to VCC = 1.0V. Used in set-top boxes and consumer electronics for reliable power-on reset and front-panel controlled hard reset.

For engineers reviewing the MAX6444US23L datasheet, MAX6444US23L pinout, MAX6444US23L application, or MAX6444US23L equivalent, this page delivers verified electrical parameters, SOT143 package mapping, confirmed manual reset timing behavior, and real-world use cases including interrupt-before-reset and transient-immune brownout detection - all specific to the MAX6444US23L variant.

Technical Context

The MAX6444US23L implements a precision bandgap-based voltage monitor with 60ppm/°C tempco and 2×VTH hysteresis, ensuring stable reset assertion across -40°C to +85°C. Its internal 50kΩ MR1 pullup enables direct connection to mechanical pushbuttons without external components.

Reset timeout is fixed at 210ms (typ), with minimum 140ms guarantee; VCC-to-RESET delay is 20µs (typ) at 1mV/µs slew rate. The open-drain RESET output supports level-shifting up to 6V and sinks ≥3.2mA at VCC ≥4.25V with VOL ≤0.4V.

Key Specifications

Pinout & Package

MAX6444US23L is housed in a 4-pin SOT143 package (U4-1 outline), measuring 2.9mm × 1.6mm × 1.1mm, rated for -40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6444US23L, MAX6316US23D offers push-pull output and faster manual reset but sacrifices glitch immunity and long-hold safety; TPS3808G125DBVR provides longer timeout and wider VCC range but lacks integrated extended setup logic and consumes more current.

Availability

MAX6444US23L is available at Aetrix Electronics and suitable for set-top boxes, consumer audio devices, and cable modems requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for MAX6444US23L 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 interface applications, with emphasis on reliability and low-power operation.

The MAX6443–MAX6452 family was engineered specifically for robust microprocessor supervision in consumer and industrial equipment where immunity to mechanical switch bounce and supply transients is critical.

FAQ

What is the exact reset threshold voltage of MAX6444US23L?

The MAX6444US23L has a factory-trimmed VCC reset threshold of 2.313V, with ±1.5% tolerance over temperature (-40°C to +85°C). This value is defined by the "23" suffix per Table 1 in the datasheet and is measured under load conditions specified in the Electrical Characteristics table.

Does MAX6444US23L support adjustable voltage monitoring via RSTIN?

No, MAX6444US23L does not include an RSTIN pin. It is a single-fixed-threshold supervisor (VCC only) from the MAX6443–MAX6448 subgroup. Adjustable monitoring is exclusive to MAX6449–MAX6452 variants, which feature a dedicated RSTIN input and internal 0.63V reference.

What is the function of the "L" suffix in MAX6444US23L?

The "L" suffix in MAX6444US23L specifies a manual reset setup period (tMR) of 6.72 seconds, as defined in Table 2 of the datasheet. This extended duration prevents unintended resets caused by momentary switch closures, making it ideal for front-panel controls in consumer electronics.

Can MAX6444US23L operate with VCC below 1.0V?

MAX6444US23L is guaranteed to provide valid RESET output only down to VCC = 1.0V. Below that voltage, RESET output logic state is not assured. For applications requiring reset assertion down to 0V, a pulldown resistor is required - but only for push-pull versions; MAX6444US23L uses open-drain output and cannot use a pulldown.

Is MAX6444US23L pin-compatible with other parts in the MAX6443–MAX6452 family?

MAX6444US23L shares the 4-pin SOT143 package and pinout with MAX6443 variants only. It is not pin-compatible with 5-pin (MAX6445–MAX6448) or 6-pin (MAX6449–MAX6452) variants due to differing pin counts and functions - e.g., MR2 and RSTIN are absent in MAX6444US23L.