Analog Devices Inc./Maxim Integrated MAX6324FUT26+T

Overview

MAX6324FUT26+T from Maxim Integrated is an open-drain microprocessor supervisory IC with windowed (min/max) watchdog, 2.63V ±2.5% reset threshold, and factory-trimmed fast/slow timeout windows (F = 17–23ms / 47–63ms). It monitors +2.5V supply rails in automotive and industrial control systems and guarantees valid RESET output down to VCC = +1.2V.

For engineers reviewing the MAX6324FUT26+T datasheet, MAX6324FUT26+T pinout, MAX6324FUT26+T application, or MAX6324FUT26+T equivalent, key selection criteria include open-drain RESET compatibility with bidirectional μP reset pins, guaranteed low-voltage reset assertion, 1ms WDPO fault pulse timing, and AEC-Q100-qualified variants for automotive use.

Technical Context

The MAX6324FUT26+T implements a dual-window watchdog that detects both fast faults (WDI falling edges <23ms apart) and slow faults (no WDI edge >63ms), with internal timer reset on WDI falling edge, RESET deassertion, or WDPO deassertion. Its VCC monitor uses a precision bandgap reference to maintain ±2.5% reset threshold accuracy over −40°C to +125°C.

RESET is open-drain and requires external pullup; WDPO is also open-drain and pulses low for 1ms upon fault detection. The MR input features internal 50–85kΩ pullup, 1μs minimum pulse width, and 100ns glitch immunity - enabling direct switch connection without external debounce circuitry.

Key Specifications

Pinout & Package

MAX6324FUT26+T is housed in a 6-pin SOT23 package (package code U6+1A, outline 21-0058), with 1.3mm × 2.2mm footprint and 0.95mm height - suitable for space-constrained PCB layouts in automotive ECUs and portable instrumentation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6324FUT26+T, MAX6324HUT44/V+T offers automotive qualification and higher reset voltage but requires redesign for 4.38V monitoring and longer watchdog periods; TPS3808G33DBVR provides lower-cost supervision without windowed watchdog capability or open-drain outputs, limiting its use in multi-supply or safety-critical contexts.

Availability

MAX6324FUT26+T is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLC I/O modules, medical infusion pump controllers, and railway signaling interface boards requiring stable component supply across extended temperature and long product lifecycles.

Supply support for MAX6324FUT26+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 demanding industrial, automotive, and medical applications - emphasizing reliability, low power, and high accuracy.

The MAX6323/MAX6324 family delivers microprocessor supervision with windowed watchdog functionality specifically for safety-critical embedded systems where deterministic response to software timing faults is mandatory.

FAQ

What is the exact reset threshold voltage of MAX6324FUT26+T?

The MAX6324FUT26+T has a nominal reset threshold of 2.63V with ±2.5% accuracy, resulting in a guaranteed range of 2.55V to 2.70V across −40°C to +125°C. This value is laser-trimmed at wafer test and applies specifically to the UT26 suffix variant - confirmed in the Electrical Characteristics table on page 2 of the MAX6323/MAX6324 datasheet revision 8.

Does MAX6324FUT26+T support windowed watchdog functionality?

Yes, MAX6324FUT26+T implements true min/max (windowed) watchdog detection. With F-suffix timing, it triggers WDPO on fast faults (WDI falling edges <23ms apart) or slow faults (no WDI edge >63ms). This dual-window behavior is explicitly documented in the Watchdog Timeout table and Figure 1 of the MAX6323/MAX6324 datasheet.

What is the function of the WDPO pin on MAX6324FUT26+T?

The WDPO pin on MAX6324FUT26+T is an open-drain watchdog pulse output that asserts low for 1ms (typical) upon detection of either a fast or slow watchdog fault. It remains inactive while RESET is asserted and requires an external pullup resistor to any supply ≤+6V - enabling flexible interfacing with NMI inputs or logic analyzers for fault diagnostics.

Can MAX6324FUT26+T operate with VCC below 1.5V?

Yes, MAX6324FUT26+T guarantees valid RESET output down to VCC = +1.2V, as stated in the General Description and Electrical Characteristics. Below 1.2V, RESET becomes high-impedance (open-circuit), but the device continues to monitor VCC and assert RESET as soon as VCC rises above the 2.63V threshold - making it suitable for deep brownout recovery scenarios.

Is MAX6324FUT26+T pin-compatible with other MAX6324 variants?

Yes, all MAX6324 variants - including MAX6324FUT26+T - share identical 6-pin SOT23 pinout, electrical interface, and functional block diagram. Differences are limited to factory-trimmed reset threshold (UT26) and watchdog timeout (F-suffix), with no changes to pin assignment, voltage ratings, or timing behavior outside those trimmed parameters.