Analog Devices Inc./Maxim Integrated MAX6328XR23+

Overview

MAX6328XR23+ from Maxim Integrated is an ultra-low-power open-drain microprocessor reset supervisor IC designed to monitor 2.32V power supplies in embedded digital systems. It asserts an active-low RESET signal when VCC falls below 2.32V (±1.5% at +25°C, ±2.5% over -40°C to +85°C), holds reset for ≥100ms after VCC recovers, draws ≤1µA supply current, and operates down to 1V supply - making it suitable for battery-powered portable equipment requiring reliable brownout detection.

For engineers reviewing the MAX6328XR23+ datasheet, MAX6328XR23+ pinout, MAX6328XR23+ application, or MAX6328XR23+ equivalent, this device serves as a precision voltage-monitoring reset generator with transient immunity, factory-trimmed threshold, SC70-3 packaging, and compatibility with bidirectional µP reset pins - critical for low-power industrial controllers and automotive subsystems.

Technical Context

The MAX6328XR23+ implements a precision bandgap-based voltage comparator with hysteresis (9.5mV typical) to reject fast VCC transients, ensuring robust operation during power-up, brownout, and noise events. Its reset timeout is guaranteed minimum 100ms and extends up to 280ms over temperature, with reset assertion valid down to VCC = 1V.

As an open-drain output variant in the MAX6326–MAX6348 family, the MAX6328XR23+ requires an external pull-up resistor and interfaces directly with bidirectional microcontroller reset pins (e.g., Motorola 68HC11). It shares pinout and package with MAX6326/MAX6327 but differs exclusively in output topology and threshold voltage.

Key Specifications

Pinout & Package

MAX6328XR23+ is housed in a 3-pin SC70 package (2.0mm × 2.1mm × 0.9mm), compatible with SOT23-3 footprint and optimized for space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326XR23+, the MAX6328XR23+ enables shared reset buses via open-drain topology, while TLV803EB23DBZR offers lower quiescent current but lacks industrial temperature guarantee and automotive qualification - making MAX6328XR23+ optimal for space-constrained, noise-prone, multi-device reset networks.

Availability

MAX6328XR23+ is available at Aetrix Electronics and suitable for portable medical sensors, automotive body control modules, industrial PLC I/O submodules, smart energy meters, and battery-backed data loggers requiring stable component supply with guaranteed long-term continuity.

Supply support for MAX6328XR23+ 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 semiconductor solutions for industrial, automotive, communications, and computing markets.

The MAX6326–MAX6348 family delivers ultra-low-power, factory-trimmed reset supervisors targeting battery-operated and space-constrained embedded systems requiring precise, reliable power monitoring without external components.

FAQ

What is the exact reset threshold voltage of MAX6328XR23+ and how tightly is it specified?

The MAX6328XR23+ has a factory-trimmed reset threshold of 2.32V, specified as ±1.5% at +25°C and ±2.5% over the full -40°C to +85°C operating temperature range. This precision eliminates need for external resistor dividers and ensures consistent brownout detection across environmental conditions. The MAX6328XR23+ achieves this via laser trimming during wafer test, with hysteresis of 9.5mV typical to prevent oscillation near threshold.

Does MAX6328XR23+ require an external pull-up resistor on its RESET pin?

Yes, the MAX6328XR23+ features an open-drain active-low RESET output and requires an external pull-up resistor to VCC or another logic rail. Typical values range from 10kΩ to 100kΩ depending on bus capacitance and rise-time requirements. This architecture enables wired-OR reset busing and direct interfacing with bidirectional microcontroller reset pins - a key differentiator from push-pull variants like MAX6326XR23+.

What is the minimum supply voltage at which MAX6328XR23+ guarantees correct reset assertion?

The MAX6328XR23+ guarantees correct reset assertion and internal functionality down to VCC = 1.0V, well below its 2.32V threshold. This ensures fail-safe behavior during deep brownout conditions - for example, when a lithium battery discharges to 2.0V and continues falling. The device remains in a known reset state until VCC rises above 2.32V and sustains ≥100ms timeout, regardless of whether VCC later drops again to 1.0V.

How does MAX6328XR23+ handle fast voltage transients on the VCC line?

The MAX6328XR23+ incorporates transient-immune design that rejects negative-going VCC glitches up to 200µs duration when the overdrive (VTH – VCC) is 100mV, per the Typical Operating Characteristics graph. Its internal comparator includes filtering and hysteresis (9.5mV typical) to ignore short-duration noise, preventing false resets in electrically harsh environments such as automotive or industrial motor-control applications where MAX6328XR23+ is commonly deployed.

Is MAX6328XR23+ pin-compatible with other devices in the MAX6326–MAX6348 family?

Yes, MAX6328XR23+ is pin-compatible with all members of the MAX6326–MAX6348 family - including MAX6326XR23+, MAX6327XR23+, MAX6346XR23+, etc. - in both SC70-3 and SOT23-3 packages. All share identical 3-pin configuration (VCC, RESET, GND), footprint, and thermal characteristics. Functional differences (push-pull vs. open-drain, active-high vs. active-low) do not affect physical layout, enabling drop-in replacement where output topology aligns with system requirements.