Analog Devices Inc./Maxim Integrated MAX6328XR28+T

Overview

MAX6328XR28+T from Maxim Integrated is an open-drain, active-low microprocessor supervisory circuit in SC70-3 package, monitoring VCC supply voltage with a factory-trimmed reset threshold of 2.800V (±1.5% at +25°C, ±2.5% over -40°C to +85°C), 100ms minimum reset timeout, and ultra-low 1µA max supply current - used for reliable power-on/brownout reset assertion in portable 3.3V digital systems.

For engineers reviewing the MAX6328XR28+T datasheet, MAX6328XR28+T pinout, MAX6328XR28+T application, or MAX6328XR28+T equivalent, key selection criteria include its open-drain RESET output compatibility with bidirectional µP reset pins (e.g., Motorola 68HC11), immunity to fast VCC transients, and guaranteed correct operation down to 1.2V VCC.

Technical Context

The MAX6328XR28+T implements a precision bandgap-based reset comparator with 40ppm/°C tempco and 6.3mV hysteresis, asserting RESET low when VCC drops below 2.800V and holding it for ≥100ms after VCC rises above threshold. It requires no external components and operates across -40°C to +85°C.

VCC-to-RESET delay is ≤20µs under transient conditions; open-drain RESET output supports 1.6mA sink current with VOL ≤0.3V at VCC > 2.1V, and exhibits <0.1µA leakage when inactive - enabling direct interface with pull-up resistors on shared reset buses.

Key Specifications

Pinout & Package

MAX6328XR28+T is housed in a 3-pin SC70-3 package (outline X3-2, land pattern 90-0208), measuring 2.0mm × 2.1mm × 0.95mm, RoHS-compliant with lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6328UR28+T, the MAX6328XR28+T saves PCB area with SC70-3 but has lower thermal headroom; versus MAX6348XR28+T, it provides pure reset supervision without added watchdog complexity or cost - ideal for cost-sensitive, space-constrained 3.3V portable designs.

Availability

MAX6328XR28+T 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-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6328XR28+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, communications, and computing applications.

The MAX6328XR28+T belongs to the MAX6326/MAX6327/MAX6328 family of ultra-low-power µP supervisors - engineered specifically for battery-operated and space-constrained systems needing reliable, zero-component reset generation.

FAQ

What is the exact reset threshold voltage of MAX6328XR28+T and how tightly is it specified?

The MAX6328XR28+T has a factory-trimmed nominal reset threshold of 2.800V, guaranteed within ±1.5% at +25°C and ±2.5% over the full -40°C to +85°C operating range. This specification is measured and binned during production, ensuring consistent brownout detection behavior across all units of MAX6328XR28+T without user calibration.

Does MAX6328XR28+T require any external components to operate?

No, MAX6328XR28+T requires no external components - it integrates the voltage reference, comparator, timer, and output driver in a single SC70-3 package. Only a standard pull-up resistor on the open-drain RESET pin is needed for proper logic-level translation, making MAX6328XR28+T a true "zero-component" supervisory solution.

How does the open-drain output of MAX6328XR28+T benefit system design?

The open-drain RESET output of MAX6328XR28+T enables wired-OR connection with other reset sources (e.g., manual reset buttons or other supervisors) and native compatibility with microprocessors featuring bidirectional reset pins like the Motorola 68HC11 - eliminating level-shifting circuitry and simplifying multi-source reset arbitration in MAX6328XR28+T-based designs.

What is the maximum VCC transient duration that MAX6328XR28+T can ignore without asserting reset?

At a 100mV overdrive (i.e., VCC dropping 100mV below 2.800V threshold), MAX6328XR28+T ignores transients up to 200µs - verified in Typical Operating Characteristics graphs. This immunity prevents false resets from common switching regulator noise or EMI spikes, ensuring robust operation in electrically noisy environments where MAX6328XR28+T is deployed.

Is MAX6328XR28+T compatible with 1.8V or 2.5V supply rails?

Yes, MAX6328XR28+T operates with VCC from 1.2V to 5.5V and remains fully functional down to 1.2V - including correct reset assertion and timing. While its 2.800V threshold is optimized for 3.3V systems, MAX6328XR28+T can supervise lower rails if paired with appropriate external voltage dividers (though not required per datasheet, as internal design supports direct connection).