Analog Devices Inc./Maxim Integrated MAX6337US22D2+T

Overview

MAX6337US22D2+T from Maxim Integrated is an ultra-low-voltage, open-drain microprocessor supervisory circuit designed for 1.8V–3.3V digital systems. It asserts an active-low RESET signal when VCC falls below 2.20V (±3% over temperature) or when the debounced manual-reset input (MR) is asserted, with a guaranteed minimum timeout of 20ms after recovery. Its 4-pin SOT143 package and 3.3µA supply current support space- and power-constrained applications such as portable instrumentation and automotive control modules.

For engineers reviewing the MAX6337US22D2+T datasheet, MAX6337US22D2+T pinout, MAX6337US22D2+T application, or MAX6337US22D2+T equivalent, key selection criteria include its open-drain output architecture, VCC operating down to 1.0V, factory-trimmed 2.20V reset threshold, 20ms minimum reset timeout, and guaranteed reset validity across –40°C to +125°C.

Technical Context

The MAX6337US22D2+T implements a precision voltage-monitoring comparator with factory-trimmed 2.20V threshold (±1.8% at +25°C, ±3% over –40°C to +125°C), immune to fast VCC transients up to 24µs at 10V/ms slew rate. Its internal MR input includes a 20kΩ pull-up resistor and 160µs minimum pulse width requirement, eliminating external debounce components.

This device uses an open-drain RESET output requiring an external pull-up resistor, enabling wired-OR interfacing with bidirectional µP reset pins (e.g., Motorola 68HC11). It guarantees valid RESET assertion only down to VCC = 1.0V-not 0.7V like push-pull variants-due to reduced sink capability at ultra-low supply voltages.

Key Specifications

Pinout & Package

MAX6337US22D2+T is housed in a lead-free 4-pin SOT143 package (1.3mm × 2.1mm footprint, 1.1mm height), optimized for high-density PCB layouts in portable and automotive electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6337US22D2+T, the MAX6336US22D2+T provides stronger low-VCC reset assurance but lacks wired-OR capability, while the MAX6315US22D2+T offers identical timing and threshold with broader VCC compatibility-making both suitable alternatives depending on output topology and voltage-margin requirements.

Availability

MAX6337US22D2+T is available at Aetrix Electronics and suitable for automotive engine control units, portable medical instrumentation, industrial programmable logic controllers, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6337US22D2+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) is a semiconductor company specializing in analog, mixed-signal, and power-management ICs for industrial, automotive, and communications applications.

The MAX633x series delivers ultra-low-voltage microprocessor supervisory functions with factory-trimmed thresholds and minimal external components-designed specifically for reliability-critical embedded systems operating across harsh thermal and electrical environments.

FAQ

What is the exact reset threshold voltage for MAX6337US22D2+T?

The MAX6337US22D2+T features a factory-trimmed reset threshold of 2.20V, 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 official datasheet and applies specifically to the "US22" suffix variant, ensuring precise brownout detection for 2.5V and 1.8V supply rails without external calibration.

Does MAX6337US22D2+T support operation below 1.0V VCC?

No. The MAX6337US22D2+T is guaranteed to maintain correct reset state only down to VCC = 1.0V, unlike the MAX6335/MAX6336 variants which operate down to 0.7V. Below 1.0V, the open-drain output's sinking capability degrades, risking indeterminate RESET levels-so it must not be used in applications requiring reset assertion below 1.0V.

What is the minimum reset timeout period for MAX6337US22D2+T?

The MAX6337US22D2+T has a nominal reset timeout period of 20ms, with a guaranteed minimum of 20ms and maximum of 40ms over temperature. This value is fixed by the "D2" suffix in the part number and is fully specified across –40°C to +125°C, meeting boot-time hold requirements for most 8-/16-bit microcontrollers.

Is an external pull-up resistor required for MAX6337US22D2+T's RESET pin?

Yes. Because MAX6337US22D2+T features an open-drain active-low RESET output, an external pull-up resistor (typically 10kΩ–100kΩ to VCC or another logic rail) is mandatory to establish a defined high state when RESET is deasserted. This enables wired-OR configurations and compatibility with bidirectional microcontroller reset pins.

Can MAX6337US22D2+T replace MAX6315US22D2+T in an existing design?

Not directly. While both share the same 2.20V threshold and 20ms timeout, MAX6337US22D2+T has an open-drain output versus MAX6315US22D2+T's push/pull output. Swapping requires adding a pull-up resistor and verifying that the target µP accepts open-drain reset signaling-especially critical for systems relying on RESET sourcing capability during power-up.