Analog Devices Inc./Maxim Integrated MAX6328XR22

Overview

MAX6328XR22 from Maxim Integrated is an ultra-low-power open-drain microprocessor supervisory circuit designed to monitor VCC supply voltage and assert an active-low reset signal during power-up, brownout, or power-down events. It features a factory-trimmed 2.20V reset threshold (±1.5% at +25°C, ±2.5% over -40°C to +85°C), 100ms minimum reset timeout, 1µA maximum supply current at 3V, and operates from 1.2V to 5.5V. It is used in portable battery-powered systems requiring reliable, low-quiescent-power reset supervision.

For engineers reviewing the MAX6328XR22 datasheet, MAX6328XR22 pinout, MAX6328XR22 application, or MAX6328XR22 equivalent, this page delivers verified technical context, precise pin functionality, real-world use cases in µP-critical systems, and validated alternative options - all grounded in Maxim's official specifications for the SC70-3 packaged variant with R22 suffix.

Technical Context

The MAX6328XR22 implements a precision bandgap-based reset comparator with hysteresis (6.3mV) and internal timing circuitry to guarantee ≥100ms reset assertion after VCC rises above 2.20V. Its open-drain RESET output enables bidirectional reset interfacing-e.g., with Motorola 68HC11 µPs-using only an external pull-up resistor.

It is immune to fast VCC transients (up to 100V/µs slew rate), ignores negative-going glitches below defined overdrive-duration thresholds, and maintains valid reset state down to VCC = 1.2V across its full -40°C to +85°C operating range. Reset threshold temperature coefficient is 40ppm/°C.

Key Specifications

Pinout & Package

MAX6328XR22 is housed in a 3-pin SC70-3 package (outline X3-2, land pattern 90-0208), measuring 2.0mm × 2.1mm × 0.95mm, with gull-wing leads and RoHS-compliant lead-free finish (marked "EJAA" on top).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6328XR22, the MAX6328UR22-T offers identical supervision performance in a mechanically distinct but functionally interchangeable package, while the MAX809TR22D3T1G provides similar threshold accuracy but sacrifices open-drain flexibility and documented glitch rejection - making it unsuitable for µPs with shared reset buses.

Availability

MAX6328XR22 is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, and smart meter communication units requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6328XR22 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 high-performance analog and mixed-signal ICs for industrial, computing, and communications applications, with emphasis on power efficiency and integration.

The MAX6326/MAX6327/MAX6328 family was engineered specifically for ultra-low-power microprocessor reset supervision in space- and energy-constrained systems - delivering precision voltage monitoring without external components.

FAQ

What is the exact reset threshold voltage of MAX6328XR22 and how does it vary with temperature?

The MAX6328XR22 has a factory-trimmed nominal reset threshold of 2.20V. At +25°C, this is guaranteed within ±1.5% (2.145V to 2.250V). Over the full -40°C to +85°C operating range, tolerance widens to ±2.5%, resulting in a minimum threshold of 2.145V and maximum of 2.250V. Temperature coefficient is 40ppm/°C, contributing minimal drift relative to the base threshold.

Does MAX6328XR22 require any external components to operate?

No, MAX6328XR22 requires no external components. It integrates the voltage reference, comparator, timer, and open-drain output driver in a single SC70-3 package. Only an external pull-up resistor on the RESET pin is needed for proper logic-level translation - no capacitors, resistors, or trimming networks are necessary for basic reset supervision functionality.

Can MAX6328XR22 interface directly with a microprocessor that has a bidirectional reset pin?

Yes, MAX6328XR22 is explicitly designed for this use case. Its open-drain RESET output allows direct connection to bidirectional µP reset pins (e.g., Motorola 68HC11) using a single external pull-up resistor. Either the MAX6328XR22 or the µP can assert reset on the shared line - a capability not supported by push-pull reset supervisors.

What is the maximum supply voltage and minimum operating voltage for MAX6328XR22?

MAX6328XR22 operates from a VCC supply of 1.2V to 5.5V. It guarantees correct reset state (i.e., output reflects true VCC condition) down to 1.2V across the full -40°C to +85°C temperature range. Absolute maximum VCC is 6V, with terminal ratings specifying -0.3V to +6V for RESET and GND pins.

How does MAX6328XR22 handle fast voltage transients on the VCC line?

MAX6328XR22 is designed to ignore fast transients on VCC, with a specified maximum slew rate immunity of 100V/µs. Its internal comparator incorporates filtering and hysteresis (6.3mV) to prevent false resets during short-duration glitches. The Typical Operating Characteristics graph "Maximum Transient Duration vs. Reset Threshold Overdrive" quantifies allowable pulse width versus amplitude for non-reset-inducing events.