Analog Devices Inc./Maxim Integrated MAX6337US24D3-T

Overview

MAX6337US24D3-T 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 a 100ms minimum reset timeout, draws only 3.3µA at 2.5V, and operates down to 1.0V VCC - used in portable equipment, automotive controllers, and critical µP power monitoring.

For engineers reviewing the MAX6337US24D3-T datasheet, MAX6337US24D3-T pinout, MAX6337US24D3-T application, or MAX6337US24D3-T equivalent, key selection criteria include its open-drain output architecture, factory-trimmed 2.40V reset threshold, guaranteed operation to 1.0V VCC, transient-immune reset comparator, and SOT143 package compatibility with MAX811/MAX812 and MAX6314/MAX6315.

Technical Context

The MAX6337US24D3-T 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 20µs at 100mV overdrive. Its internal debounced manual-reset input (MR) features a 20kΩ pull-up resistor and requires only a 160µs minimum pulse width at 2.6V.

This device uses an open-drain RESET output requiring an external pull-up resistor, enabling bidirectional interface with µPs like the Motorola 68HC11. The 100ms nominal reset timeout period is factory-programmed and remains stable across temperature (±15% variation over -40°C to +125°C), with propagation delay under 24µs during VCC fall at 10V/ms.

Key Specifications

Pinout & Package

MAX6337US24D3-T is housed in a 4-pin SOT143 surface-mount package (1.3mm × 2.1mm footprint, 1.0mm height), optimized for space-constrained portable and automotive PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6337US24D3-T, the MAX6336US24D3-T offers lower VCC operational limit (0.7V vs. 1.0V) but lacks open-drain flexibility, while the MAX811TEUS24D3-T trades higher current and no MR debounce for pin-for-pin legacy replacement in existing designs.

Availability

MAX6337US24D3-T is available at Aetrix Electronics and suitable for portable power management, automotive body control modules, and industrial sensor nodes requiring stable component supply with guaranteed long-term availability.

Supply support for MAX6337US24D3-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 interface applications in industrial, automotive, and communications markets.

The MAX6335/MAX6336/MAX6337 family delivers ultra-low-voltage, low-power µP supervisory circuits targeting space- and power-constrained embedded systems requiring reliable reset generation without external components.

FAQ

What is the exact reset threshold voltage for MAX6337US24D3-T?

The MAX6337US24D3-T has a factory-trimmed reset threshold of 2.40V, with ±1.8% tolerance at +25°C and ±3% over the full -40°C to +125°C operating range. This value is confirmed in Table 1 of the datasheet and applies specifically to the "US24" suffix variant, ensuring accurate brownout detection for 2.5V systems.

Does MAX6337US24D3-T require an external pull-up resistor on the RESET pin?

Yes, MAX6337US24D3-T requires an external pull-up resistor on the RESET pin because it features an open-drain output. The datasheet specifies that a pull-up to VCC (or another appropriate rail) is necessary to establish a defined high logic level when RESET is not asserted - no internal pull-up is provided.

What is the minimum VCC voltage at which MAX6337US24D3-T guarantees correct RESET output behavior?

MAX6337US24D3-T guarantees correct RESET/RESET output behavior down to VCC = 1.0V. This differs from the MAX6335/MAX6336 variants, which guarantee operation to 0.7V. Below 1.0V, the open-drain output may not maintain a valid low state due to reduced sink capability.

Can the manual-reset input (MR) of MAX6337US24D3-T be left floating?

Yes, the MR pin of MAX6337US24D3-T can be left unconnected because it includes an internal 20kΩ pull-up resistor to VCC. When unused, this ensures MR remains at logic high and does not inadvertently trigger reset - no external components are required for default operation.

What is the reset timeout period for MAX6337US24D3-T, and how stable is it over temperature?

MAX6337US24D3-T has a factory-programmed nominal reset timeout period of 100ms, with a minimum guaranteed value of 100ms. Over the full -40°C to +125°C temperature range, the timeout varies by ±15%, remaining within 85ms to 115ms - verified in the Typical Operating Characteristics graph "Normalized Reset Timeout Period vs. Temperature".