Analog Devices Inc./Maxim Integrated MAX6323BUT26

Overview

MAX6323BUT26 from Maxim Integrated is a microprocessor supervisory circuit with windowed (min/max) watchdog, manual reset, and precision +2.63V reset threshold (±2.5% accuracy). It features push-pull RESET output, 100ms minimum reset timeout, guaranteed operation down to VCC = +1.2V, and operates over -40°C to +125°C in SOT23-6 package. Used in automotive engine control units to detect firmware hangs during cold-cranking conditions.

For engineers reviewing the MAX6323BUT26 datasheet, MAX6323BUT26 pinout, MAX6323BUT26 application, or MAX6323BUT26 equivalent, key selection criteria include its factory-trimmed 2.63V reset threshold, 10ms/100ms dual watchdog timeout window (B-suffix), push-pull RESET drive capability, and guaranteed reset assertion at VCC ≥ 1.2V for brownout resilience.

Technical Context

The MAX6323BUT26 implements a true windowed watchdog timer that detects both fast faults (WDI falling edges <10ms apart) and slow faults (no WDI edge >100ms), using internal laser-trimmed timing. Its VCC monitor employs a precision bandgap reference and comparator with hysteresis to ensure stable reset assertion/deassertion.

RESET is push-pull with VOH ≥ 0.8×VCC (at 500µA sink) and VOL ≤ 0.4V (at 1.2mA sink), enabling direct interface with 3.3V/5V µPs without external pullups. The MR input includes internal pullup and 100ns glitch immunity, requiring only a 1µs minimum low pulse width to trigger reset.

Key Specifications

Pinout & Package

MAX6323BUT26 uses a 6-pin SOT23-6 package with standard pinout: Pin 1 = MR (manual reset input), Pin 2 = GND, Pin 3 = WDI (watchdog input), Pin 4 = VCC (supply), Pin 5 = WDPO (open-drain watchdog pulse output), Pin 6 = RESET (push-pull active-low reset output).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6323CUT26 and TPS3808G33, the MAX6323BUT26 uniquely delivers tight 10ms/100ms windowed watchdog timing essential for real-time firmware validation, while maintaining identical +2.63V reset accuracy and push-pull RESET drive-making it irreplaceable in safety-critical automotive and medical designs requiring precise timing fault detection.

Availability

MAX6323BUT26 is available at Aetrix Electronics and suitable for automotive engine control, industrial PLC modules, and medical infusion pump controllers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6323BUT26 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for demanding industrial, automotive, and medical applications.

The MAX6323 family was designed specifically for microprocessor supervision in harsh environments, emphasizing precision voltage monitoring, windowed watchdog reliability, and guaranteed operation across -40°C to +125°C.

FAQ

What is the exact reset threshold voltage of MAX6323BUT26 and how accurate is it?

The MAX6323BUT26 has a nominal reset threshold of +2.63V with ±2.5% accuracy over the full -40°C to +125°C temperature range. This value is laser-trimmed at wafer test and guaranteed per datasheet Electrical Characteristics table. The MAX6323BUT26 maintains this accuracy without external components, eliminating calibration overhead in production.

Does MAX6323BUT26 support windowed watchdog functionality, and what are its timeout values?

Yes, the MAX6323BUT26 implements true windowed (min/max) watchdog functionality. Its B-suffix configuration provides a fast timeout of 10ms (minimum interval between WDI falling edges) and a slow timeout of 100ms (maximum interval). These values are factory-trimmed and specified in the Watchdog Timeout table of the MAX6323/MAX6324 datasheet.

What is the RESET output type of MAX6323BUT26, and does it require an external pullup resistor?

The MAX6323BUT26 features a push-pull RESET output, meaning it actively drives both high and low states. No external pullup resistor is required-unlike open-drain variants such as MAX6324. The MAX6323BUT26 can source ≥500µA at VOH ≥ 0.8×VCC and sink ≥1.2mA at VOL ≤ 0.4V, enabling direct interface with most µP reset inputs.

Can MAX6323BUT26 operate reliably during severe brownout conditions?

Yes, the MAX6323BUT26 guarantees valid RESET output down to VCC = +1.2V, making it highly resilient during brownout events. Below +1.2V, the RESET output becomes high-impedance-but since most µPs are nonfunctional below this voltage, system integrity is preserved. This behavior is explicitly characterized and guaranteed in the datasheet.

What package type and pin count does MAX6323BUT26 use, and is it RoHS-compliant?

The MAX6323BUT26 uses a 6-pin SOT23-6 package (2.9mm × 1.6mm footprint) with standard pinout. It is available in both leaded and lead-free versions; the "-T" suffix denotes lead-free packaging compliant with RoHS Directive 2011/65/EU. Lead-free ordering replaces "-T" with "+T", e.g., MAX6323BUT26+T.