Analog Devices Inc./Maxim Integrated MAX6320PUK45CY+T

Overview

MAX6320PUK45CY+T from Maxim Integrated is a 5-pin SOT23 microprocessor supervisory circuit with active-low open-drain reset output, manual reset input, and watchdog timer. It features a factory-trimmed 4.5V reset threshold (±2.5% over -40°C to +125°C), 140ms minimum reset timeout, and 1.6s typical watchdog timeout. Used in embedded control systems to ensure reliable power-on initialization and fault recovery.

For engineers reviewing the MAX6320PUK45CY+T datasheet, MAX6320PUK45CY+T pinout, MAX6320PUK45CY+T application, or MAX6320PUK45CY+T equivalent, key selection criteria include its open-drain reset architecture, guaranteed reset validity down to VCC = 1V, immunity to short negative VCC transients, and AEC-Q100 qualification for automotive-adjacent industrial use.

Technical Context

The MAX6320PUK45CY+T implements a voltage-monitoring reset generator with independent manual reset (MR) and watchdog input (WDI) logic. Its open-drain RESET output requires an external pullup resistor (e.g., 10kΩ) to any supply up to 6V and sinks ≤3.2mA at VCC ≥ 4.5V while maintaining VOL ≤ 0.4V.

Reset assertion occurs when VCC falls below 4.5V (±2.5%), MR is pulled low, or WDI remains static beyond 1.6s. Reset remains active for ≥140ms after VCC recovers or MR releases, and the watchdog clears on any WDI edge (≥50ns pulse width).

Key Specifications

Pinout & Package

SOT23-5 package (outline 21-0057, land pattern 90-0174), RoHS-compliant, lead-free (+T suffix). Thermal resistance θJA = 255.9°C/W (multi-layer board).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6320PUK45CY+T, the MAX6320PUK46CY+T offers identical functionality with a higher reset threshold for tighter 4.7V rail monitoring, while the TPS3808G33DBVR sacrifices watchdog, manual reset, and open-drain flexibility for lower cost in basic 3.3V applications.

Availability

MAX6320PUK45CY+T is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, portable medical monitors, and battery-powered IoT sensor nodes requiring stable component supply across extended temperature ranges.

Supply support for MAX6320PUK45CY+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, mixed-signal, and power management ICs for demanding industrial, automotive, and computing applications.

The MAX6316–MAX6322 family delivers highly integrated μP supervisory functions - combining reset generation, watchdog monitoring, and manual reset in miniature SOT23 packages for space- and reliability-critical embedded systems.

FAQ

What is the exact reset threshold voltage of MAX6320PUK45CY+T and how does it vary with temperature?

The MAX6320PUK45CY+T has a factory-trimmed nominal reset threshold of 4.5V, specified as ±1.5% at +25°C and ±2.5% over the full operating range of -40°C to +125°C. Its temperature coefficient is 40ppm/°C, meaning drift is linear and predictable - for example, at +125°C, deviation remains within the guaranteed ±2.5% band relative to the 4.5V nominal value. This precision eliminates need for external trimming.

Does MAX6320PUK45CY+T require an external pullup resistor on the RESET pin, and what value is recommended?

Yes, MAX6320PUK45CY+T requires an external pullup resistor on the RESET pin because it uses an open-drain NMOS output structure. A 10kΩ resistor to the target logic supply (up to 6V) is recommended: it ensures VOL ≤ 0.4V when sinking 3.2mA at VCC ≥ 4.5V and guarantees VOH > 0.7×VCC for proper logic-high recognition across load conditions.

Can MAX6320PUK45CY+T operate reliably during severe supply brownout, and down to what VCC level does reset remain valid?

Yes, MAX6320PUK45CY+T guarantees valid reset signaling down to VCC = 1.0V - meaning RESET remains a well-defined logic low (VOL ≤ 0.4V) and functional reset assertion continues even as the supply collapses. This ensures deterministic behavior during deep brownout events where other supervisors may release reset prematurely.

How does the watchdog timer in MAX6320PUK45CY+T respond to WDI signal transitions, and what is the minimum pulse width it detects?

The MAX6320PUK45CY+T watchdog timer clears on any rising or falling edge at the WDI pin. It detects pulses as narrow as 50ns (measured at VIL = 0.3×VCC and VIH = 0.7×VCC), enabling robust software supervision even in high-speed code paths. Leaving WDI unconnected disables the watchdog by causing internal periodic servicing.

Is MAX6320PUK45CY+T qualified for automotive applications, and what standards does it meet?

MAX6320PUK45CY+T is AEC-Q100 qualified, meeting stress test requirements for Grade 1 (-40°C to +125°C ambient) operation. While not an automotive-specific part (lacking /V suffix), its qualification confirms reliability under thermal cycling, humidity, and vibration conditions typical of under-hood and cabin electronics - making it suitable for industrial and automotive-adjacent designs.