Analog Devices Inc./Maxim Integrated MAX6337US22D1-T

Overview

MAX6337US22D1-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 reset timeout of 1ms and valid operation down to VCC = 1.0V. It is used in portable equipment, automotive controllers, and critical µP power monitoring where space-constrained SOT143 packaging and transient-immune reset generation are required.

For engineers reviewing the MAX6337US22D1-T datasheet, MAX6337US22D1-T pinout, MAX6337US22D1-T application, or MAX6337US22D1-T equivalent, key selection considerations include its 2.20V factory-trimmed reset threshold, 1ms minimum timeout, open-drain output structure for bidirectional µP reset pin interfacing (e.g., Motorola 68HC11), low 3.3µA supply current at 1.8V, and guaranteed reset validity down to VCC = 1.0V.

Technical Context

The MAX6337US22D1-T implements a precision voltage comparator with factory-trimmed 2.20V reset threshold (±1.8% at +25°C, ±3% over –40°C to +125°C), immune to fast VCC transients up to 24µs at 10mV overdrive. Its internal MR input includes a 20kΩ pull-up resistor and 160µs minimum pulse width requirement, eliminating external debounce components.

Reset assertion is sustained for ≥1ms after VCC rises above 2.20V or MR deasserts, with propagation delay <24µs during VCC fall at 10V/ms. The open-drain RESET output requires an external pull-up and supports bidirectional reset bus sharing, unlike push/pull variants (MAX6335/MAX6336).

Key Specifications

Pinout & Package

MAX6337US22D1-T is housed in a 4-pin SOT143 package (3.0mm × 1.6mm × 0.9mm), optimized for space-constrained PCB layouts in portable and automotive modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6337US22D1-T, the MAX6336US22D1-T offers simpler drive capability but forfeits bus-sharing flexibility, while the TLV803EB22DBZR reduces package size and cost but omits MR functionality and robust transient rejection-making MAX6337US22D1-T optimal for bidirectional reset architectures requiring manual intervention and noise resilience.

Availability

MAX6337US22D1-T is available at Aetrix Electronics and suitable for portable medical sensors, automotive body control modules, and industrial PLC I/O modules requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6337US22D1-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 industrial, automotive, and computing applications, with emphasis on power efficiency, reliability, and integration.

The MAX6335/MAX6336/MAX6337 family delivers ultra-low-voltage supervisory circuits targeting space- and power-constrained µP systems needing factory-trimmed thresholds, manual reset, and transient-hardened reset generation.

FAQ

What is the factory-trimmed reset threshold voltage for MAX6337US22D1-T?

The MAX6337US22D1-T has 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 laser-trimmed during production and specified in Table 1 of the datasheet; it ensures accurate brownout detection for 2.5V and 1.8V logic domains without external calibration components.

Does MAX6337US22D1-T support manual reset, and how is it implemented?

Yes, MAX6337US22D1-T supports manual reset via its MR pin (Pin 3), which is active-low and internally pulled up to VCC with a 20kΩ resistor. A logic-low pulse ≥160µs on MR asserts RESET and sustains it for the full timeout period (≥1ms) after MR returns high. No external debounce circuitry is needed, simplifying front-panel reset button integration in portable and industrial devices.

Why does MAX6337US22D1-T use an open-drain RESET output instead of push/pull?

The open-drain RESET output on MAX6337US22D1-T enables wired-OR reset bus configurations and direct interfacing with microcontrollers that have bidirectional reset pins (e.g., Motorola 68HC11). Unlike push/pull variants, it avoids contention when multiple devices share the same reset line and allows flexible pull-up voltage selection-critical for mixed-voltage system designs where RESET must coordinate across 3.3V and 1.8V domains.

What is the minimum supply voltage at which MAX6337US22D1-T guarantees correct reset behavior?

MAX6337US22D1-T guarantees correct reset assertion and deassertion down to VCC = 1.0V, unlike the MAX6335/MAX6336 variants which guarantee operation to 0.7V. This 1.0V limit ensures deterministic behavior during deep brownout conditions while maintaining compatibility with modern low-voltage µPs and avoiding false releases due to marginal supply collapse.

How does MAX6337US22D1-T handle fast transients on the VCC supply line?

MAX6337US22D1-T incorporates a transient-immune reset comparator that rejects negative-going VCC glitches up to 24µs in duration when the overdrive is 10mV, as shown in the "Maximum Transient Duration vs. Reset Comparator Overdrive" graph. This design prevents spurious resets during switching regulator noise or ESD-induced supply dips, enhancing system reliability in electrically noisy environments like automotive and industrial settings.