Analog Devices Inc./Maxim Integrated MAX6703LKA+T

Overview

MAX6703LKA+T from Maxim Integrated is a low-voltage microprocessor supervisory circuit in an 8-pin SOT23 package, providing active-low open-drain reset output, manual reset input, watchdog timer with independent output, and power-fail monitoring via PFI/PFO. It monitors three supply voltages (one fixed V_CC threshold + two adjustable via RST_IN1/RST_IN2), guarantees reset validity down to V_CC = 1V, and delivers 140ms reset timeout - used in critical µP power monitoring for white goods and telecom systems.

For engineers reviewing the MAX6703LKA+T datasheet, MAX6703LKA+T pinout, MAX6703LKA+T application, or MAX6703LKA+T equivalent, key selection criteria include its L-suffix 4.63V V_CC reset threshold, open-drain RESET output, dual adjustable reset inputs for triple-voltage supervision, 1.6s watchdog timeout, and -40°C to +125°C operating range.

Technical Context

The MAX6703LKA+T implements a triple-supply monitoring architecture: primary V_CC detection at 4.63V (L-suffix), plus two user-adjustable thresholds (0.62V reference) on RST_IN1 and RST_IN2 pins for secondary/tertiary rails. Its reset generator asserts active-low open-drain RESET for ≥140ms after any undervoltage event on V_CC, RST_IN1, or RST_IN2.

The integrated watchdog operates independently with 1.6s timeout (typ), asserting active-low open-drain WDO upon overflow or V_CC/RST_INx undervoltage; WDO deasserts only on valid WDI edge or MR assertion. Power-fail comparator uses internal 0.62V reference with PFI input and PFO output, supporting early warning and orderly shutdown.

Key Specifications

Pinout & Package

MAX6703LKA+T is housed in an 8-pin SOT23 package (package code K8+2), measuring 2.9mm × 1.6mm × 1.1mm, RoHS-compliant and lead-free (indicated by "+T" suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6703LKA+T, MAX6703LKA-T offers identical electrical performance but requires Pb-based soldering, while MAX6705LKA+T simplifies design by removing dual adjustable inputs - trading triple-rail coverage for lower cost and smaller footprint in single-rail applications.

Availability

MAX6703LKA+T is available at Aetrix Electronics and suitable for critical µP power monitoring, white goods control, and telecommunications infrastructure requiring stable component supply across extended temperature ranges.

Supply support for MAX6703LKA+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 communications applications.

The MAX6701–MAX6708 family targets high-reliability microprocessor supervision, delivering integrated reset, watchdog, power-fail warning, and multi-rail monitoring in minimal SOT23 footprint.

FAQ

What is the reset threshold voltage for MAX6703LKA+T?

The MAX6703LKA+T has a nominal V_CC reset threshold of 4.63V (L-suffix), specified from 4.47V (min) to 4.78V (max) over the full -40°C to +125°C temperature range. This threshold is factory-trimmed and guaranteed, making it suitable for precise +5V supply monitoring in industrial and telecom equipment where tight tolerance is required.

Does MAX6703LKA+T support triple-voltage supervision?

Yes, MAX6703LKA+T supports triple-voltage supervision: primary V_CC at 4.63V, plus two user-adjustable rails via RST_IN1 and RST_IN2 pins. Each adjustable input references the internal 0.62V comparator, allowing external resistor dividers to set custom thresholds - enabling coordinated reset across +5V, +3.3V, and +1.8V rails in a single IC.

What type of reset output does MAX6703LKA+T provide?

MAX6703LKA+T provides an active-low open-drain RESET output (pin 7). This configuration allows flexible pull-up voltage selection (e.g., to 3.3V or 5V), supports wired-OR connection with other reset sources, and eliminates shoot-through current in multi-supply systems - critical for robust reset signaling in complex embedded designs.

How does the watchdog function operate in MAX6703LKA+T?

The MAX6703LKA+T watchdog asserts active-low open-drain WDO (pin 8) if the WDI input (pin 6) remains static for >1.6s (typ). WDO deasserts on any valid WDI edge or when MR is pulled low. Unlike MAX6704, it provides independent watchdog signaling without affecting RESET timing - enabling NMI-based fault recovery without disrupting system boot sequence.

Can MAX6703LKA+T monitor power-fail conditions on auxiliary rails?

Yes, MAX6703LKA+T monitors auxiliary rails via its PFI (pin 4) and PFO (pin 5) interface. The internal 0.62V comparator allows external resistor dividers to scale higher voltages (e.g., 12V, 24V) down to the detection threshold. When PFI falls below 0.62V, PFO goes low - enabling early warning and µP-initiated graceful shutdown before main supply collapse.