Analog Devices Inc./Maxim Integrated MAX6319LHUK29B+T

Overview

MAX6319LHUK29B+T from Maxim Integrated is a 5-pin SOT23 microprocessor supervisory circuit with active-low push/pull reset output, manual reset input, and factory-trimmed 2.93V reset threshold. It provides 140ms minimum power-on reset timeout, operates from 1.0V to 5.5V supply, and guarantees valid reset down to V_CC = 1V. It is used in battery-powered embedded controllers to prevent code-execution errors during brownout.

For engineers reviewing the MAX6319LHUK29B+T datasheet, MAX6319LHUK29B+T pinout, MAX6319LHUK29B+T application, or MAX6319LHUK29B+T equivalent, key selection criteria include reset threshold accuracy (±1.5% at +25°C), MR input glitch rejection (100ns), supply current (≤12µA at 3.6V), and AEC-Q100 qualification for automotive-adjacent industrial use.

Technical Context

The MAX6319LHUK29B+T implements a precision voltage monitor with factory-laser-trimmed resistor divider setting V_RST = 2.93V (±1.5% at +25°C, ±2.5% over –40°C to +125°C) and 40ppm/°C temperature coefficient. It asserts reset when V_CC falls below V_RST, when MR is pulled low, or after reset timeout expires - but lacks watchdog functionality (WDI pin absent per Selector Guide).

Its active-low push/pull RESET output sources/sinks current (V_OL ≤ 0.3V at I_SINK = 1.2mA, V_OH ≥ 0.8×V_CC at I_SOURCE = 500µA), supports bidirectional reset bus compatibility via fast rise time (5–25ns, CL = 5pF), and features internal MR pullup (52kΩ) with 1.5µs minimum pulse width requirement at full temperature range.

Key Specifications

Pinout & Package

MAX6319LHUK29B+T is housed in a RoHS-compliant 5-pin SOT23 package (package code U5+2A, outline 21-0057), footprint-compatible with JEDEC MO-178AB, thermal resistance θ_JA = 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 MAX6319MHUK29B+T and TPS3808G18DBVR, MAX6319LHUK29B+T uniquely combines 2.93V precision threshold, 140ms timeout, MR input, and push/pull drive in a single SOT23 package - making it the most direct fit for 3.0V embedded controllers requiring manual reset and minimal external components.

Availability

MAX6319LHUK29B+T is available at Aetrix Electronics and suitable for portable instrumentation, industrial controllers, and battery-powered embedded systems requiring stable component supply, AEC-Q100 reliability, and precise 2.93V brownout detection.

Supply support for MAX6319LHUK29B+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 high-performance analog and mixed-signal ICs for industrial, automotive, and computing applications.

The MAX6316–MAX6322 family delivers compact, factory-trimmed supervisory circuits targeting space-constrained embedded systems needing guaranteed reset behavior across wide voltage and temperature ranges.

FAQ

What is the exact reset threshold voltage of MAX6319LHUK29B+T and how tightly is it specified?

The MAX6319LHUK29B+T has a factory-trimmed nominal reset threshold of 2.93V. At +25°C, it is specified as 2.93V ±1.5% (i.e., 2.886V to 2.974V). Over the full operating temperature range (–40°C to +125°C), the tolerance widens to ±2.5%, yielding 2.857V to 3.000V. This precision eliminates need for external calibration and ensures consistent brownout response in 3.0V systems.

Does MAX6319LHUK29B+T include a watchdog timer function?

No, MAX6319LHUK29B+T does not include a watchdog timer. Per the Selector Guide and device marking "LH" (indicating "L" = no watchdog, "H" = active-high reset output variant), this variant omits the WDI pin and associated watchdog circuitry. The MAX6319LHUK29B+T relies solely on V_CC monitoring and manual reset (MR) for fault detection.

What is the function of pin 4 on MAX6319LHUK29B+T, and can it be left floating?

Pin 4 on MAX6319LHUK29B+T is a no-connect (NC) terminal. The Pin Description table explicitly lists it as "-" for all MAX6319 variants, and the functional diagram confirms no internal connection. It may be left unconnected or tied to GND for mechanical stability - neither action affects electrical performance.

How does the manual reset (MR) input behave when left unconnected on MAX6319LHUK29B+T?

When left unconnected, the MR input on MAX6319LHUK29B+T is internally pulled up to V_CC via a 52kΩ resistor, holding it at logic high and disabling manual reset assertion. No external pullup is needed. Driving MR low for ≥1.5µs (over full temperature range) forces a reset that persists for the full 140ms timeout period after MR returns high.

Is MAX6319LHUK29B+T compatible with 1.8V microcontrollers?

Yes, MAX6319LHUK29B+T operates with V_CC as low as 1.0V and its RESET output is guaranteed functional down to V_CC = 1V. However, its 2.93V reset threshold is intended for 3.0V/3.3V systems. For 1.8V logic, the reset signal remains valid (V_OH ≥ 0.8×V_CC), but the threshold voltage is mismatched - use only if brownout detection at ~2.9V is acceptable for the 1.8V domain.