Analog Devices Inc./Maxim Integrated MAX6328XR29+T

Overview

MAX6328XR29+T 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 2.93V, holding reset for ≥100ms after recovery. It operates from 1.2V to 5.5V, draws ≤1µA supply current, and is housed in a 3-pin SC70 package. Used in portable battery-powered systems requiring reliable brownout detection.

For engineers reviewing the MAX6328XR29+T datasheet, MAX6328XR29+T pinout, MAX6328XR29+T application, or MAX6328XR29+T equivalent, key selection criteria include reset threshold accuracy (±2.5% over temperature), open-drain output compatibility with bidirectional µP reset pins, transient immunity up to 200µs at 100mV overdrive, and SC70 footprint suitability for space-constrained designs.

Technical Context

The MAX6328XR29+T implements a precision bandgap-based reset comparator with factory-trimmed 2.93V threshold and 6.3mV hysteresis, enabling stable operation across -40°C to +85°C. Its open-drain RESET output supports wired-OR configurations and interfaces directly with µPs like the Motorola 68HC11 using only an external pull-up resistor.

It features ultra-low ICC (≤1.0µA at 3V) and robust power-supply transient immunity-rejecting negative-going VCC glitches up to 200µs duration when VTH − VCC = 100mV-ensuring no spurious resets during noisy power transitions.

Key Specifications

Pinout & Package

MAX6328XR29+T is packaged in a 3-pin SC70 (X3-2 outline), with 0.65mm lead pitch and exposed pad not present. Pin 1 is GND, Pin 2 is open-drain RESET, Pin 3 is VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6328XR29+T, the MAX6328UR29+T offers identical functionality in a larger SOT23 package suitable for manual prototyping or high-current thermal scenarios, while the MAX809TRD3+T trades open-drain versatility for tighter threshold tolerance and stronger output drive-neither is pin-compatible, and both require layout or interface adaptation.

Availability

MAX6328XR29+T is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, smart meter communication units, and automotive body control modules requiring stable component supply with guaranteed long-term continuity.

Supply support for MAX6328XR29+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 is a semiconductor company specializing in analog and mixed-signal ICs for power, sensing, connectivity, and security applications.

The MAX632x family was designed specifically for ultra-low-power microprocessor supervision in battery-critical and space-constrained systems, emphasizing precision threshold stability, minimal ICC, and seamless µP interface compatibility.

FAQ

What is the exact reset threshold voltage of MAX6328XR29+T and how tightly is it specified?

The MAX6328XR29+T has a nominal reset threshold of 2.93V, with ±1.5% tolerance at +25°C and ±2.5% over the full -40°C to +85°C operating range. This specification is factory-trimmed and guaranteed-not typical-ensuring consistent brownout detection across temperature without external calibration. The MAX6328XR29+T achieves this via laser-trimmed internal resistive divider networks.

Does MAX6328XR29+T support operation down to 1V supply, and what is its minimum functional VCC?

The MAX6328XR29+T guarantees correct reset assertion state down to VCC = 1V, but its specified operating range begins at 1.2V (min) to 5.5V (max). Below 1.2V, the internal comparator may not reliably detect threshold crossings, though the output remains valid. For reliable supervision in ultra-low-VCC applications such as coin-cell backup, the MAX6328XR29+T must be operated within its 1.2V–5.5V range.

Can MAX6328XR29+T drive a reset line shared among multiple microcontrollers?

Yes-the MAX6328XR29+T features an open-drain RESET output, enabling direct wired-OR connection to a common reset bus. When multiple devices (e.g., MAX6328XR29+T and another supervisor or µP) share the line, each can assert reset independently using a single pull-up resistor. This eliminates contention and supports fail-safe system-level reset arbitration, a capability not available with push-pull-output supervisors like the MAX6326 series.

What is the maximum negative VCC transient duration that MAX6328XR29+T can ignore at 100mV overdrive?

At a VCC dip of 100mV below the 2.93V threshold (i.e., VCC = 2.83V), the MAX6328XR29+T can ignore transients up to 200µs in duration without issuing a false reset. This value is derived from the "Maximum Transient Duration vs. Reset Threshold Overdrive" graph in the datasheet and reflects typical performance under industrial-grade noise conditions. Longer transients will trigger the reset timeout timer.

Is MAX6328XR29+T RoHS-compliant and what does the "+T" suffix indicate?

Yes, MAX6328XR29+T is RoHS-compliant and lead-free. The "+T" suffix explicitly denotes lead-free packaging per JEDEC J-STD-609, replacing the legacy "-T" tape-and-reel designation. All MAX6328XR29+T units shipped by Aetrix Electronics meet current EU RoHS Directive 2011/65/EU Annex II substance restrictions and carry appropriate marking per IPC-1752A.