Analog Devices Inc./Maxim Integrated MAX6742XKTD7-T

Overview

The MAX6742XKTD7-T from Maxim Integrated is a low-power dual-voltage microprocessor supervisor IC that monitors a primary V_CC1 supply and provides an independent power-fail comparator (PFI/PFO). It features factory-trimmed reset thresholds (V_TH1 = 3.075V, V_TH2 = 2.313V), 1200ms minimum reset timeout, 6µA supply current, and operates in the -40°C to +85°C range. It is used in portable battery-powered systems requiring reliable power monitoring and orderly shutdown on power failure.

For engineers reviewing the MAX6742XKTD7-T datasheet, MAX6742XKTD7-T pinout, MAX6742XKTD7-T application, or MAX6742XKTD7-T equivalent, key selection criteria include its dedicated PFI/PFO functionality, SC70-5 package footprint, open-drain RESET output with internal 50kΩ pullup, and precise 0.488V power-fail threshold - all critical for low-voltage DC-DC converter supervision and battery voltage monitoring.

Technical Context

The MAX6742XKTD7-T implements a dual-supply supervisory architecture with one fixed V_CC1 monitor (3.075V) and one secondary V_CC2 monitor (2.313V), plus a separate power-fail comparator referenced to a 0.488V internal bandgap. Its reset assertion logic combines V_CC1, V_CC2, and manual reset inputs, while PFO responds instantaneously to PFI crossing the 0.488V threshold without timeout delay.

This device uses BiCMOS process technology (249 transistors) and delivers transient immunity up to 35µs for 100mV overdrive, with guaranteed valid RESET output when either V_CC1 or V_CC2 exceeds 1.2V. The internal 50kΩ pullup on RESET enables direct pushbutton interfacing without external components.

Key Specifications

Pinout & Package

Package: 5-pin SC70 (1.6mm × 1.6mm, 0.5mm pitch), surface-mount, lead-free compatible (-T suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supply supervisory applications.

Compared with MAX6742XKTD7-T, MAX6745XKTD7-T offers push-pull drive for simpler interface but sacrifices open-drain flexibility, while TPS3808G33DBVR reduces cost and current but eliminates critical power-fail detection - making MAX6742XKTD7-T uniquely suited for battery-backed or fail-safe systems.

Availability

MAX6742XKTD7-T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered IoT sensors, industrial data loggers, and handheld test equipment requiring stable component supply and long-term lifecycle support.

Supply support for MAX6742XKTD7-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, medical, and communications applications.

The MAX6736–MAX6745 family was engineered specifically for multivoltage microprocessor systems needing compact, low-power supervision with flexible reset and power-fail detection - targeting portable, battery-operated, and space-constrained embedded platforms.

FAQ

What is the function of the PFI and PFO pins on the MAX6742XKTD7-T?

The PFI (Power-Fail Input) pin on the MAX6742XKTD7-T accepts a scaled-down version of a monitored supply (e.g., battery voltage) via a resistor divider. When PFI falls below the internal 0.488V reference, the PFO (Power-Fail Output) pin asserts low immediately - with no timeout delay - to signal impending power loss. This allows the host system to initiate data save, suspend, or shutdown routines before V_CC collapses. The MAX6742XKTD7-T's PFI input draws less than 10nA, minimizing divider current drain.

Does the MAX6742XKTD7-T require external components to operate?

The MAX6742XKTD7-T requires no external components for basic dual-supply supervision: its V_CC1 and V_CC2 reset thresholds are factory-trimmed, and the RESET output includes an internal 50kΩ pullup to V_CC1. However, external resistors are needed on PFI to scale higher voltages (e.g., 12V battery) down to the 0.488V trip point, and an external pullup resistor is required on PFO since it is open-drain. A 0.1µF bypass capacitor on V_CC1 is recommended for transient immunity.

How does the 1200ms reset timeout (D7 suffix) affect system startup timing?

The 1200ms minimum reset timeout of the MAX6742XKTD7-T ensures the RESET signal remains asserted for at least 1.2 seconds after all monitored supplies (V_CC1, V_CC2) exceed their thresholds. This accommodates slow-ramping power supplies, such as those found in battery-charged systems or low-noise LDOs, and provides ample time for microcontroller firmware initialization, PLL lock, and peripheral configuration. The timeout begins only after both supplies are stable - not from power application - preventing premature release.

Can the MAX6742XKTD7-T monitor negative supply voltages?

Yes, the MAX6742XKTD7-T can monitor negative supplies using the PFI input with an appropriate resistor network. As shown in the datasheet Figure 4B, a voltage divider referenced to V_CC1 and connected to a negative rail generates a positive voltage at PFI proportional to the magnitude of the negative supply. When the negative voltage becomes less negative (i.e., rises toward zero), PFI drops below 0.488V and PFO asserts. Accuracy depends on resistor tolerance and PFI input offset, but the MAX6742XKTD7-T's 10nA max input current minimizes loading error.

What is the significance of the 'TD7' suffix in MAX6742XKTD7-T?

The 'TD7' suffix in MAX6742XKTD7-T decodes as follows: 'T' indicates V_CC1 reset threshold = 3.075V, 'D' indicates SC70-5 package, and '7' specifies the D7 reset timeout option (1200ms minimum). The 'XK' denotes the standard temperature grade (-40°C to +85°C), and '-T' confirms lead-free RoHS-compliant packaging. This full suffix uniquely identifies the device's electrical configuration, timing behavior, and environmental rating - critical for design-in and procurement accuracy.