Analog Devices Inc./Maxim Integrated MAX6444US46L

Overview

MAX6444US46L from Maxim Integrated is a single-supply, fixed-threshold microprocessor supervisory circuit with one extended-setup manual reset input (MR1), 4.625V VCC reset threshold, and push-pull active-low RESET output in SOT143 package. It monitors VCC only, asserts RESET when VCC drops below 4.625V (±1.5% over -40°C to +85°C), holds RESET for 210ms (typ) after recovery, and requires MR1 to be held low ≥6.72s to trigger manual reset - preventing nuisance resets in consumer electronics power management.

For engineers reviewing the MAX6444US46L datasheet, MAX6444US46L pinout, MAX6444US46L application, or MAX6444US46L equivalent, this page delivers verified electrical parameters, SOT143 terminal mapping, real-world use cases including set-top box brownout protection and front-panel interrupt-before-reset, and two validated alternative parts with documented functional differences.

Technical Context

The MAX6444US46L implements a precision bandgap-based voltage monitor with 60ppm/°C tempco and 2×VTH hysteresis (≈9.25mV at 4.625V). Its internal timing circuit enforces a fixed 6.72s setup period on MR1 before asserting RESET, with no external components required.

RESET logic is push-pull active-low, guaranteed functional down to VCC = 1.0V, with VOL ≤0.3V at ISINK = 50µA and VOH ≥0.8×VCC at ISOURCE = 200µA. The device draws only 6µA (typ) supply current and operates across -40°C to +85°C.

Key Specifications

Pinout & Package

SOT143 package: 4-pin, surface-mount, lead-free compatible (RoHS), 1.3mm × 2.9mm body, 0.95mm height, gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6444US46D and TPS3808G33DBVR, the MAX6444US46L uniquely combines 4.625V precision monitoring, 6.72s intentional manual reset, and push-pull output in SOT143 - making it the sole fit for 4.5V+ consumer power rails demanding deliberate human-initiated reset.

Availability

MAX6444US46L is available at Aetrix Electronics and suitable for set-top boxes, DVD players, and industrial control panels requiring stable component supply, long-lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for MAX6444US46L 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 in industrial, automotive, and consumer markets.

The MAX6443–MAX6452 family was engineered specifically for robust microprocessor supervision in cost-sensitive consumer electronics, featuring extended manual reset timing to eliminate false triggers while maintaining ultra-low quiescent current.

FAQ

What is the exact reset threshold voltage of the MAX6444US46L?

The MAX6444US46L has a factory-trimmed VCC reset threshold of 4.625V, 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 and corresponds to the "46" suffix in the part number. The threshold exhibits 60ppm/°C tempco and includes 2×VTH hysteresis (≈9.25mV) to prevent chatter near the trip point. The MAX6444US46L does not monitor RSTIN - it is a single-supply-only device.

How does the manual reset function work on the MAX6444US46L?

The MAX6444US46L features one extended-setup manual reset input (MR1, Pin 3) that must be held low for a minimum of 6.72 seconds - defined by the "L" suffix - before the RESET output pulses low for 140ms (min). MR1 has an internal 50kΩ pull-up to VCC, so a simple SPST switch to ground suffices. Shorter presses are ignored, eliminating nuisance resets. This behavior is intrinsic to the MAX6444US46L silicon and requires no external timing components.

Is the RESET output of the MAX6444US46L push-pull or open-drain?

The MAX6444US46L has a push-pull active-low RESET output (Pin 2), as confirmed in the Selector Guide and Pin Description sections of the datasheet. This means it actively drives low and high without needing an external pull-up resistor. The MAX6444US46D variant offers open-drain instead. The push-pull configuration of the MAX6444US46L simplifies board layout and improves noise immunity in single-rail systems.

What package type and dimensions does the MAX6444US46L use?

The MAX6444US46L is supplied in a 4-pin SOT143 package (package code U4-1), measuring 1.3mm × 2.9mm with 0.95mm height and gull-wing leads. This compact outline is documented in the Package Information section and land pattern no. 90-0183. The SOT143 footprint allows high-density placement in space-constrained consumer electronics, and the device is available in both leaded and lead-free versions (suffix "-T" or "+T").

Does the MAX6444US46L support operation down to low VCC voltages?

Yes, the MAX6444US46L guarantees valid RESET output functionality down to VCC = 1.0V, as specified in the Electrical Characteristics table. At VCC ≥1.0V, RESET can sink ≥50µA with VOL ≤0.3V and source ≥200µA with VOH ≥0.8×VCC. This enables reliable supervision during deep brownout conditions where other supervisors cease operation. The MAX6444US46L does not function below 1.0V, and no external circuitry extends its range.