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 (MR), 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 embedded control systems to prevent code-execution errors during power-up, brownout, or software lockup.

For engineers reviewing the MAX6319LHUK29B-T datasheet, MAX6319LHUK29B-T pinout, MAX6319LHUK29B-T application, or MAX6319LHUK29B-T equivalent, key selection criteria include reset threshold accuracy (±2.5% over -40°C to +125°C), MR input compatibility with TTL/CMOS logic, absence of watchdog function, and guaranteed push/pull drive capability into 1.2mA loads at ≥2.7V.

Technical Context

The MAX6319LHUK29B-T implements a precision voltage monitor with laser-trimmed internal resistor divider setting V_RST = 2.93V (±2.5% over temperature), paired with a fixed 140ms reset timeout period (C-suffix). It features an active-low push/pull RESET output capable of sourcing/sinking current, and a manual reset input (MR) with 52kΩ internal pullup and 100ns glitch rejection.

No watchdog timer is integrated - the WDI pin is omitted per the Selector Guide and device marking suffix "LH" (indicating MR + active-low push/pull only). The circuit asserts RESET when V_CC falls below 2.93V or when MR is pulled low, holding RESET active for 140ms after V_CC recovery or MR release.

Key Specifications

Pinout & Package

MAX6319LHUK29B-T is housed in a RoHS-compliant 5-pin SOT23 package (package code U5+2A, outline 21-0057), measuring 2.9mm × 1.6mm × 1.1mm, with gull-wing leads optimized for automated assembly and thermal performance (θ_JA = 255.9°C/W on multilayer board).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6319LHUK29B-T, MAX6320PUK29CY-T adds watchdog and open-drain flexibility at the cost of losing MR, while TLV803EB29DBZR reduces supply current but removes MR entirely - both require revalidation of reset timing and drive strength in target systems.

Availability

MAX6319LHUK29B-T is available at Aetrix Electronics and suitable for industrial PLC controllers, medical infusion pumps, smart energy meters, and automotive body control modules requiring stable component supply, long-term lifecycle support, and AEC-Q100-qualified reliability.

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 precision analog and mixed-signal ICs for industrial, automotive, and communications applications, with emphasis on high-reliability, low-power, and small-footprint solutions.

The MAX6316–MAX6322 family delivers highly integrated μP supervisory circuits targeting space-constrained embedded systems needing robust power monitoring, manual reset, and precise reset timing - without external passive components.

FAQ

What is the reset threshold voltage of the MAX6319LHUK29B-T and how accurate is it?

The MAX6319LHUK29B-T has a factory-trimmed reset threshold of 2.93V, specified with ±1.5% tolerance at +25°C and ±2.5% over the full operating temperature range (-40°C to +125°C). This accuracy is achieved using laser-trimmed internal resistors and is documented in Table 1 of the datasheet. The MAX6319LHUK29B-T maintains this specification without requiring external calibration or compensation networks.

Does the MAX6319LHUK29B-T include a watchdog timer function?

No, the MAX6319LHUK29B-T does not include a watchdog timer. Its part number suffix "LH" denotes active-low push/pull RESET and manual reset (MR) only - confirmed by the Selector Guide and absence of WDI pin functionality. The MAX6319LHUK29B-T relies solely on V_CC monitoring and MR assertion for reset generation, making it suitable for applications where software supervision is handled externally or not required.

What is the function of Pin 4 on the MAX6319LHUK29B-T?

Pin 4 on the MAX6319LHUK29B-T is a no-connect (NC) terminal - it is not bonded internally and serves no electrical function. Per Maxim's pin description and SOT23 top-marking documentation, this pin must be left floating in the PCB layout. Tying it to GND is acceptable per standard practice but provides no functional benefit and is not required for operation of the MAX6319LHUK29B-T.

Can the MAX6319LHUK29B-T operate reliably during deep brownout conditions?

Yes, the MAX6319LHUK29B-T guarantees valid reset output down to V_CC = 1.0V, ensuring deterministic assertion of the active-low RESET signal even as the supply collapses. This behavior is explicitly tested and specified in the Electrical Characteristics table. The MAX6319LHUK29B-T continues to monitor V_CC and hold RESET low until V_CC rises above 2.93V and remains stable for 140ms, preventing erratic MCU operation during recovery.

How does the manual reset (MR) input work on the MAX6319LHUK29B-T?

The MR input on the MAX6319LHUK29B-T is an active-low signal with internal 52kΩ pullup to V_CC. Pulling MR below V_IL (0.3×V_CC) forces RESET low for the full 140ms timeout period, regardless of V_CC level. The MR pin rejects fast transients (<100ns) and accepts TTL/CMOS logic levels. When unused, MR may be left unconnected - the internal pullup ensures no spurious reset. This behavior is fully characterized and guaranteed for the MAX6319LHUK29B-T across temperature and voltage.