Analog Devices Inc./Maxim Integrated MAX6741XKSHD3+T

Overview

MAX6741XKSHD3+T from Maxim Integrated is a dual-voltage microprocessor supervisor IC with open-drain reset output, VCC1 power-OK (POK1) output, and factory-trimmed reset thresholds of 2.925V (VCC1) and 2.188V (VCC2). It operates from -40°C to +85°C in a 5-pin SC70 package, draws only 6µA supply current, and provides 150ms minimum reset timeout - ideal for power-supply sequencing in portable multivoltage systems.

For engineers reviewing the MAX6741XKSHD3+T datasheet, MAX6741XKSHD3+T pinout, MAX6741XKSHD3+T application, or MAX6741XKSHD3+T equivalent, key selection considerations include its POK1-driven VCC1-to-VCC2 sequencing capability, dual fixed-threshold monitoring down to 0.9V core supplies, open-drain RESET with internal 50kΩ pullup, and compatibility with battery-powered controllers requiring precise voltage supervision and low quiescent current.

Technical Context

The MAX6741XKSHD3+T implements two independent voltage comparators with precision factory-set thresholds (VTH1 = 2.925V, VTH2 = 2.188V), each referenced to a stable bandgap reference. Its POK1 output asserts high after VCC1 exceeds VTH1 for 37.5–75.0ms, enabling controlled enablement of downstream VCC2 regulators.

RESET is asserted low when either VCC1 or VCC2 falls below its threshold, and remains low for ≥150ms after both supplies recover. The open-drain RESET includes an internal 50kΩ pullup to VCC1, supporting manual reset detect functionality without external components.

Key Specifications

Pinout & Package

MAX6741XKSHD3+T is housed in a 5-pin SC70-5 package (2.0mm × 1.25mm, 0.65mm pitch), optimized for high-density portable PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-voltage supervisor applications.

Compared with MAX6744XKSHD3+T, MAX6741XKSHD3+T offers manual reset detect via internal pullup but requires external pullup for standard logic interfacing; versus TPS3808G18DBVR, it delivers integrated dual-rail supervision and hardware-enforced sequencing - reducing design complexity and component count in multivoltage systems.

Availability

MAX6741XKSHD3+T is available at Aetrix Electronics and suitable for portable/battery-powered equipment, notebook computers, and industrial PLC I/O modules requiring stable component supply with guaranteed lead-free compliance and extended temperature support.

Supply support for MAX6741XKSHD3+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 power management, sensing, and interface applications.

The MAX6736–MAX6745 family was developed specifically for low-power, space-constrained multivoltage systems requiring accurate, factory-calibrated reset supervision and hardware-based power sequencing - targeting portable, industrial, and computing applications.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6741XKSHD3+T?

The MAX6741XKSHD3+T has factory-trimmed reset thresholds of 2.925V for VCC1 and 2.188V for VCC2, with ±1.5% tolerance over -40°C to +85°C. These values are defined by the "SH" suffix per Maxim's Table 1 and are not user-adjustable. Both thresholds are referenced to an internal bandgap, ensuring stability across temperature and supply variation - critical for reliable µP reset behavior in the MAX6741XKSHD3+T.

Does the MAX6741XKSHD3+T provide power-fail detection capability?

No, the MAX6741XKSHD3+T does not include power-fail input/output (PFI/PFO) functionality. That feature is exclusive to the MAX6742/MAX6745 variants. The MAX6741XKSHD3+T is configured specifically for dual-voltage supervision with POK1 sequencing - it contains VCC1, VCC2, RESET, POK1, and GND pins only. For power-fail monitoring, engineers must select MAX6742XKSHD3+T or MAX6745XKSHD3+T instead of the MAX6741XKSHD3+T.

How does the POK1 output function in the MAX6741XKSHD3+T, and what is its timing behavior?

The POK1 output on the MAX6741XKSHD3+T is an open-drain, active-high signal that remains low while VCC1 is below 2.925V. Once VCC1 exceeds this threshold, POK1 transitions high after a 37.5–75.0ms timeout period (tPOKP), independent of VCC2 or MR status. This delay ensures VCC1 is fully stabilized before enabling downstream circuitry - for example, using POK1 to gate a VCC2 regulator's EN pin. The MAX6741XKSHD3+T guarantees this behavior across temperature and supply conditions.

Can the MAX6741XKSHD3+T be used with a bidirectional microprocessor reset pin?

Yes, the MAX6741XKSHD3+T's open-drain RESET output is compatible with bidirectional µP reset pins. To prevent contention, connect a 4.7kΩ series resistor between the MAX6741XKSHD3+T RESET pin and the µP's reset I/O port, as documented in Maxim's Figure 5. This configuration allows the µP to drive the line low for its own reset requests while still receiving supervision asserts from the MAX6741XKSHD3+T - a verified interface method confirmed in the MAX6741XKSHD3+T functional documentation.

What is the purpose of the internal 50kΩ pullup on the RESET pin of the MAX6741XKSHD3+T?

The internal 50kΩ pullup resistor on the MAX6741XKSHD3+T's RESET pin enables manual reset detect functionality: when a pushbutton connects RESET to GND, the output goes low and remains low for the full 150ms reset timeout after release - eliminating need for external debounce circuitry. This pullup is referenced to VCC1, so RESET floats high when not asserted. It is a defining feature of the MAX6741XKSHD3+T (and MAX6740/MAX6742) that distinguishes it from variants like MAX6736/MAX6738 which require external pullups - directly supporting simplified pushbutton integration in the MAX6741XKSHD3+T.