Analog Devices Inc./Maxim Integrated MAX6328UR30

Overview

MAX6328UR30 from Maxim Integrated is an ultra-low-power open-drain microprocessor supervisory circuit that monitors VCC supply voltage and asserts an active-low reset signal when voltage falls below 3.00V (±2.5% over temperature), maintaining reset for ≥100ms after recovery. It operates from 1.2V to 5.5V, draws ≤1.0µA at 3V, and is housed in a 3-pin SOT23 package for space-constrained portable and battery-powered systems.

For engineers reviewing the MAX6328UR30 datasheet, MAX6328UR30 pinout, MAX6328UR30 application, or MAX6328UR30 equivalent, this device is selected for precision brownout detection in low-voltage µP systems where open-drain reset output enables bidirectional reset pin interfacing (e.g., Motorola 68HC11), transient immunity, and minimal board footprint.

Technical Context

The MAX6328UR30 implements a factory-trimmed bandgap-based reset comparator with 3.00V threshold (±1.5% at +25°C, ±2.5% over −40°C to +85°C) and 6.3mV hysteresis. Its open-drain RESET output supports external pull-up voltages up to 6V and sinks ≥1.6mA while asserted, enabling flexible logic-level translation and wired-OR reset bus configurations.

Designed for robust power monitoring, it ignores fast VCC transients (up to 100V/µs slew rate) and guarantees correct reset state down to VCC = 1.2V. The 100ms minimum reset timeout is internally timed and fully specified across temperature without external components.

Key Specifications

Pinout & Package

MAX6328UR30 is packaged in a 3-pin SOT23-3 (U3-1) surface-mount package with 0.95mm pitch, compatible with standard reflow profiles and IPC-7351 land pattern 90-0179.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TR30D and TPS3808G30DBVR, the MAX6328UR30 delivers the lowest ICC (1.0µA) and retains full open-drain functionality in the same SOT23-3 package-critical for battery longevity and µP interface compatibility where reset bus sharing or bidirectional pin support is required.

Availability

MAX6328UR30 is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, and smart meter data loggers requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MAX6328UR30 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 power, sensing, connectivity, and security applications.

The MAX6326/MAX6327/MAX6328 family targets ultra-low-power microprocessor supervision in space- and energy-constrained systems, emphasizing precision threshold accuracy, minimal ICC, and robust transient immunity without external components.

FAQ

What is the exact reset threshold voltage of MAX6328UR30 and how does it vary with temperature?

The MAX6328UR30 has a nominal reset threshold of 3.00V, factory-trimmed with ±1.5% tolerance at +25°C and ±2.5% over the full −40°C to +85°C operating range. Its temperature coefficient is 40ppm/°C, resulting in a maximum deviation of approximately ±15mV across temperature-ensuring stable brownout detection in varying environmental conditions. This specification is guaranteed and tested per the datasheet Electrical Characteristics table.

Does MAX6328UR30 require any external components to function?

No, the MAX6328UR30 operates autonomously with no external timing components. Only a single external pull-up resistor on the open-drain RESET pin is required to define the logic-high voltage level and sink current capability. No capacitors, resistors, or trimming elements are needed-reducing BOM count, PCB area, and qualification effort compared to discrete reset solutions.

Can MAX6328UR30 interface directly with a microcontroller that has a bidirectional reset pin?

Yes, the MAX6328UR30's open-drain RESET output is specifically designed for this use case. When connected to a bidirectional µP reset pin (e.g., Motorola 68HC11) with a single external pull-up resistor, either the MAX6328UR30 or the µP can assert reset-enabling coordinated system-level reset initiation without additional logic or isolation components.

What is the minimum VCC voltage at which MAX6328UR30 remains functional and asserts reset correctly?

The MAX6328UR30 guarantees correct reset assertion and state retention down to VCC = 1.2V over the full −40°C to +85°C temperature range. This allows reliable operation during deep brownout conditions and ensures the reset signal remains valid even as the supply collapses-critical for safeguarding firmware execution in low-voltage portable and battery-powered applications using the MAX6328UR30.

How does MAX6328UR30 handle fast voltage transients on the VCC line?

The MAX6328UR30 incorporates internal filtering and comparator design features that reject fast VCC transients up to 100V/µs slew rate. Its reset comparator is engineered to ignore short-duration negative-going glitches-preventing spurious resets caused by switching noise, ESD coupling, or regulator instability-while still responding accurately to sustained brownout events as defined by the 3.00V threshold and 100ms timeout.