Analog Devices Inc./Maxim Integrated MAX6337US24D3

Overview

MAX6337US24D3 from Maxim Integrated is an ultra-low-voltage, open-drain microprocessor supervisory circuit designed for 1.8V–3.3V digital systems. It monitors VCC and asserts an active-low RESET signal when supply voltage falls below 2.40V (±3% over temperature), provides 100ms minimum reset timeout, operates down to 1.0V VCC, draws only 3.3µA at 2.5V, and features a debounced manual-reset input. It is used in portable battery-powered equipment requiring reliable power-on reset and brownout detection.

For engineers reviewing the MAX6337US24D3 datasheet, MAX6337US24D3 pinout, MAX6337US24D3 application, or MAX6337US24D3 equivalent, key selection considerations include its open-drain output architecture, factory-trimmed 2.40V reset threshold, guaranteed operation to 1.0V VCC, 100ms reset timeout, and SOT143 package compatibility with legacy supervisors like MAX811/MAX6314.

Technical Context

The MAX6337US24D3 implements a precision bandgap-based reset comparator with factory-trimmed 2.40V threshold (±1.8% at +25°C, ±3% over –40°C to +125°C) and built-in immunity to fast VCC transients-rejecting glitches up to 24µs at 100mV overdrive. Its internal MR pull-up resistor (20kΩ) enables direct connection of a momentary switch to GND without external components.

As an open-drain supervisor, it requires an external pull-up resistor for RESET logic level translation and supports bidirectional µP reset pins (e.g., Motorola 68HC11). The device guarantees valid RESET assertion only down to VCC = 1.0V-not 0V-due to reduced sink capability at ultra-low supply voltages.

Key Specifications

Pinout & Package

MAX6337US24D3 is housed in a 4-pin SOT143 surface-mount package (3.0mm × 1.6mm × 1.1mm), optimized for space-constrained PCB layouts in portable and automotive applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6337US24D3, MAX6314US24D3 offers simpler drive but less interface flexibility, while TLV809K24DBZR reduces current and size at the expense of MR support and open-drain capability-making MAX6337US24D3 optimal for robust, field-serviceable embedded systems requiring manual intervention and bus-sharing.

Availability

MAX6337US24D3 is available at Aetrix Electronics and suitable for portable medical sensors, automotive body control modules, and industrial PLC I/O submodules requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across temperature extremes.

Supply support for MAX6337US24D3 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) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and communications markets.

The MAX633x family was engineered specifically for ultra-low-voltage microprocessor supervision in battery-powered and harsh-environment systems-emphasizing guaranteed operation down to 1.0V, minimal quiescent current, and factory-trimmed accuracy without external calibration.

FAQ

What is the exact reset threshold voltage of MAX6337US24D3 and how does it vary with temperature?

The MAX6337US24D3 has a factory-trimmed nominal reset threshold of 2.40V. At +25°C, tolerance is ±1.8%; over the full –40°C to +125°C operating range, it widens to ±3%. This means the actual trip point falls between 2.33V and 2.47V across temperature, ensuring predictable brownout behavior in 2.5V systems without external adjustment.

Does MAX6337US24D3 support manual reset, and how is it implemented?

Yes, MAX6337US24D3 includes a debounced manual-reset input (MR) that asserts reset when pulled low. It features a 20kΩ internal pull-up resistor, so MR can be left unconnected if unused. To implement manual reset, connect a normally open momentary switch between MR and GND-no external RC network is needed due to on-chip debouncing.

Why does MAX6337US24D3 use an open-drain output instead of push-pull?

The open-drain output of MAX6337US24D3 enables wired-OR reset bus configurations and seamless interfacing with microcontrollers having bidirectional reset pins (e.g., Motorola 68HC11). It requires an external pull-up resistor, allowing flexible voltage translation-critical when RESET must drive logic referenced to a different rail than VCC.

What is the minimum supply voltage at which MAX6337US24D3 guarantees correct reset assertion?

MAX6337US24D3 guarantees correct reset assertion and deassertion behavior down to VCC = 1.0V. Below 1.0V, the internal circuitry may not maintain valid logic states. This differs from the MAX6335/MAX6336 variants, which guarantee operation to 0.7V-but those use push-pull outputs, not open-drain.

Can MAX6337US24D3 replace MAX811L in existing designs?

MAX6337US24D3 is pin-compatible with MAX811L in the SOT143 package and shares identical pinout (VCC, GND, RESET, MR). However, MAX811L has a 2.63V threshold and 140ms timeout, whereas MAX6337US24D3 offers 2.40V and 100ms. Direct replacement requires validation of system voltage margins and reset timing requirements.