Analog Devices Inc./Maxim Integrated MAX6337US23D1+T

Overview

MAX6337US23D1+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 supply voltage with a factory-trimmed 2.30V reset threshold, asserts active-low RESET during brownout or manual reset, and guarantees valid output down to VCC = 1.0V. Used in portable equipment and automotive controllers for reliable power-on reset generation.

For engineers reviewing the MAX6337US23D1+T datasheet, MAX6337US23D1+T pinout, MAX6337US23D1+T application, or MAX6337US23D1+T equivalent, key selection criteria include open-drain output compatibility with bidirectional µP reset pins, 1ms minimum reset timeout, 3.3µA quiescent current, and guaranteed operation at VCC ≥1.0V across –40°C to +125°C.

Technical Context

The MAX6337US23D1+T implements a precision bandgap-based reset comparator with ±1.8% (25°C) and ±3% (–40°C to +125°C) threshold accuracy over temperature. Its internal debounced manual-reset input (MR) features a 20kΩ pull-up resistor and 160µs minimum pulse width requirement.

Reset assertion is triggered by VCC falling below 2.30V or MR pulled low; RESET remains asserted for ≥1ms after VCC rises above threshold or MR is released. The open-drain output requires an external pull-up and supports interfacing with bidirectional µP reset pins such as those on Motorola 68HC11.

Key Specifications

Pinout & Package

MAX6337US23D1+T is housed in a 4-pin SOT143 package - compact, surface-mount, lead-free (RoHS-compliant), with 1.3mm × 1.3mm footprint and 0.95mm 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 MAX6336US23D1+T and MAX812TEUS23D3+T, the MAX6337US23D1+T uniquely supports open-drain operation for multi-drop reset buses and offers lowest quiescent current (3.3µA), making it optimal for battery-critical and bidirectional-interface applications.

Availability

MAX6337US23D1+T is available at Aetrix Electronics and suitable for battery-powered instrumentation, automotive body control modules, and industrial PLC I/O subsystems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6337US23D1+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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and computing markets.

The MAX633x family delivers ultra-low-voltage, low-power µP supervisory circuits targeting space- and energy-constrained applications where precision reset thresholds and guaranteed operation near minimum supply rails are essential.

FAQ

What is the factory-trimmed reset threshold voltage for MAX6337US23D1+T?

The MAX6337US23D1+T has a factory-trimmed reset threshold of 2.30V, with ±1.8% accuracy 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 "US23" suffix. The threshold is set at production and requires no external calibration.

Does MAX6337US23D1+T support operation below 1.8V supply voltage?

Yes, MAX6337US23D1+T is guaranteed to operate and assert valid RESET down to VCC = 1.0V, unlike the MAX6335/MAX6336 variants which guarantee down to 0.7V. Below 1.0V, reset behavior is not specified. This makes MAX6337US23D1+T suitable for brownout detection in 1.2V–1.8V auxiliary rails where 1.0V functional margin is acceptable.

What is the minimum reset timeout period for MAX6337US23D1+T?

The MAX6337US23D1+T has a nominal reset timeout period of 1ms minimum, indicated by the "D1" suffix in the part number. This is verified in the Electrical Characteristics table under parameter tRP, with typical values of 1ms at +25°C and guaranteed minimum across temperature. It ensures sufficient hold time for basic µP initialization sequences.

Why does MAX6337US23D1+T use an open-drain output instead of push/pull?

The open-drain output of MAX6337US23D1+T enables wired-OR reset bus configurations and direct interfacing with microcontrollers that have bidirectional reset pins (e.g., Motorola 68HC11). Unlike push/pull outputs, it avoids contention when multiple devices drive the same reset line and simplifies level translation across different voltage domains - a key design advantage in multi-IC systems.

Is an external pull-up resistor required for MAX6337US23D1+T's RESET pin?

Yes, an external pull-up resistor is mandatory for MAX6337US23D1+T's open-drain RESET output to establish a defined high state when not asserted. Typical values range from 10kΩ to 100kΩ, selected based on rise-time requirements and bus loading. The pull-up may connect to VCC or another logic rail - enabling flexible voltage-level interfacing without additional components.