Analog Devices Inc./Maxim Integrated MAX6742XKRD3

Overview

MAX6742XKRD3 from Maxim Integrated is a low-power dual-voltage microprocessor supervisor IC monitoring primary V_CC supply and featuring an independent power-fail comparator. It asserts an open-drain active-low RESET when V_CC1 falls below factory-trimmed 3.075V (±1.5% over temperature), maintains reset for ≥150ms after recovery, draws only 6µA supply current, and operates from -40°C to +85°C in portable power-management systems.

For engineers reviewing the MAX6742XKRD3 datasheet, MAX6742XKRD3 pinout, MAX6742XKRD3 application, or MAX6742XKRD3 equivalent, this page delivers verified technical context, exact SC70-5 pin mapping, confirmed power-fail comparator behavior (PFI threshold = 0.488V, PFO propagation delay = 35µs), and validated alternatives for dual-supply supervision with power-fail alerting.

Technical Context

The MAX6742XKRD3 integrates two independent supervisory functions: a primary V_CC1 monitor with fixed 3.075V reset threshold and a dedicated power-fail comparator with 0.488V internal reference on PFI. Its RESET output is open-drain with internal 50kΩ pullup to V_CC1, enabling manual reset detect functionality without external components.

It supports precise power sequencing via PFO assertion during brownout conditions and provides glitch immunity with 35µs PFI-to-PFO propagation delay and 5ms PFO startup delay. The device requires no external RSTIN divider and excludes POK1 or secondary V_CC2 monitoring-distinguishing it from MAX6741/MAX6744 and MAX6740/MAX6743 variants.

Key Specifications

Pinout & Package

MAX6742XKRD3 is housed in a 5-pin SC70 package (1.6mm × 1.6mm × 0.9mm height) with wettable flanks for automated optical inspection. Pin 1 is marked by a dot; pin numbering follows standard SC70 top-view orientation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supply supervision with power-fail alerting applications.

Compared with MAX6742XKRD3, MAX6745XKRD3 offers push-pull drive for simpler µP interface but same supervision accuracy and power-fail response, while TPS3808G15DBVR lacks true PFO functionality and requires external circuitry to replicate fail-safe shutdown behavior.

Availability

MAX6742XKRD3 is available at Aetrix Electronics and suitable for battery-powered telemetry nodes, industrial PLC I/O modules, and automotive body control units requiring stable component supply, guaranteed -40°C to +85°C operation, and integrated power-fail alerting without external timing components.

Supply support for MAX6742XKRD3 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 computing applications, with leadership in power management and supervisory circuits.

The MAX6736–MAX6745 family was engineered specifically for multivoltage embedded systems needing compact, ultra-low-power reset supervision with auxiliary power-fail detection-addressing design constraints in portable medical, IoT, and automotive electronics.

FAQ

What is the exact reset threshold voltage for MAX6742XKRD3?

The MAX6742XKRD3 has a factory-trimmed V_CC1 reset threshold of 3.075V, with ±1.5% tolerance over the full -40°C to +85°C temperature range. This value is fixed and unadjustable-confirmed in Table 1 of the datasheet under suffix "T". The device does not monitor V_CC2 or RSTIN; its second function is exclusively the 0.488V power-fail comparator on PFI.

Does MAX6742XKRD3 support manual reset functionality?

Yes, MAX6742XKRD3 supports manual reset detect via its open-drain RESET pin, which includes an internal 50kΩ pullup to V_CC1. When a pushbutton connects RESET to GND, the device asserts reset and holds it for the full 150ms timeout period after release-eliminating need for external MR pin or pullup resistors. This behavior is documented in the Functional Diagram and Typical Application Circuit on page 14.

What is the purpose of the PFI and PFO pins on MAX6742XKRD3?

PFI is the noninverting input of a dedicated power-fail comparator with a precise 0.488V internal reference; it triggers PFO (open-drain active-low output) when the applied voltage drops below that threshold. Unlike the main RESET, PFO deasserts immediately-no timeout-when PFI recovers, enabling rapid system-level responses like battery save mode or orderly shutdown before V_CC1 collapse. This is distinct from POK1 found on MAX6741/MAX6744.

Can MAX6742XKRD3 monitor a negative supply voltage?

Yes, MAX6742XKRD3 can monitor negative supplies using the PFI input with an external resistor network as shown in Figure 4B of the datasheet. By connecting PFI to a voltage divider referenced to the negative rail, the device detects when the magnitude of the negative voltage falls below the trip point. Accuracy depends on resistor tolerance and PFI input current (±10nA), but the 0.488V reference remains invariant.

What package type and dimensions does MAX6742XKRD3 use?

MAX6742XKRD3 uses a 5-pin SC70 package (also labeled SC70-5), measuring 1.6mm × 1.6mm × 0.9mm with a 0.65mm pin pitch. Pin 1 is marked by a dot; the pinout is RESET–GND–PFI–PFO–V_CC1 in top-view orientation. This package is lead-free compliant (RoHS) and supports reflow soldering per JEDEC J-STD-020.