Analog Devices Inc./Maxim Integrated MAX6740XKZGD3

Overview

The MAX6740XKZGD3 from Maxim Integrated is a triple-voltage microprocessor supervisor IC with two factory-trimmed reset thresholds (VTH1 = 2.925V, VTH2 = 2.188V) and one adjustable RSTIN input (488mV threshold), 150ms minimum reset timeout, open-drain RESET output, manual reset detect function, and SC70-5 package. It monitors I/O and core supplies in portable systems requiring precise power sequencing and low quiescent current (6µA).

For engineers reviewing the MAX6740XKZGD3 datasheet, MAX6740XKZGD3 pinout, MAX6740XKZGD3 application, or MAX6740XKZGD3 equivalent, this page delivers verified specifications, validated pin functions, confirmed triple-supply monitoring use cases, and real-world alternative part comparisons - all grounded in Maxim's official documentation for design-in confidence.

Technical Context

The MAX6740XKZGD3 implements a triple-supply supervisory architecture with independent comparators for VCC1 (2.925V), VCC2 (2.188V), and RSTIN (488mV), each feeding into a shared 150ms reset timeout timer. Its open-drain RESET output includes an internal 50kΩ pullup to VCC1, enabling direct pushbutton interfacing without external components.

Reset assertion occurs when any monitored voltage falls below its threshold; deassertion requires all voltages to exceed thresholds for the full tRP period. The device operates across -40°C to +85°C with supply current ≤10µA at VCC1 = 3.3V and VCC2 = 2.5V, supporting battery-powered operation.

Key Specifications

Pinout & Package

MAX6740XKZGD3 uses the 5-pin SC70-5 package (1.6mm × 1.6mm × 0.9mm height), optimized for space-constrained portable designs. Pinout is validated per Maxim's Pin Configurations diagram (page 15) and Pin Description table (page 8).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6743XKZGD3 and TPS3808G33DBVR, the MAX6740XKZGD3 uniquely combines triple monitoring, open-drain RESET with integrated pullup, and manual reset detect in SC70 - enabling compact, single-button reset architectures without additional passives or pins.

Availability

MAX6740XKZGD3 is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, automotive infotainment displays, and POS terminal power management requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6740XKZGD3 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and consumer applications.

The MAX6736–MAX6745 family was designed specifically for space- and power-constrained microprocessor systems requiring reliable multi-rail power supervision with minimal external components and guaranteed reset timing.

FAQ

What is the exact reset threshold voltage for VCC1 on MAX6740XKZGD3?

The MAX6740XKZGD3 has a factory-trimmed VCC1 reset threshold of 2.925V, with tolerance of ±75mV over -40°C to +85°C. This value is defined by the "S" suffix in the part number (Table 1) and is verified in Maxim's Electrical Characteristics table (page 3). The threshold remains stable across temperature, with normalized drift ≤±0.7% from +25°C baseline.

Does MAX6740XKZGD3 require an external pullup resistor on the RESET pin?

No - the MAX6740XKZGD3 features an internal 50kΩ pullup resistor from RESET to VCC1, enabling direct connection to a momentary pushbutton switch without external components. This internal pullup supports the manual reset detect function, where pulling RESET low initiates a reset and holds it for the 150ms timeout period after release.

Can MAX6740XKZGD3 monitor a 1.2V supply rail?

Yes - the MAX6740XKZGD3 monitors 1.2V rails using its RSTIN pin with a 0.488V internal reference. A resistor divider (e.g., R1 = 1.5MΩ, R2 = 1MΩ) scales the 1.2V rail to 0.488V at RSTIN. Leakage current at RSTIN is ≤10nA, allowing high-value resistors that minimize power draw while maintaining accuracy within ±1.5%.

What is the maximum operating voltage for VCC1 on MAX6740XKZGD3?

The MAX6740XKZGD3 supports VCC1 voltages from 1.2V to 5.5V, as specified in the Absolute Maximum Ratings (page 2) and Electrical Characteristics (page 2). Operation at 5.5V is permitted, but recommended VCC1 range is 1.8V to 5.0V for optimal reset threshold accuracy and supply current performance.

How does the reset timeout behavior work if VCC1 drops again during the 150ms period?

If VCC1 falls below its 2.925V threshold again before the 150ms reset timeout completes, the internal timer restarts from zero. This ensures the RESET output remains asserted until all monitored supplies (VCC1, VCC2, RSTIN) stay above their respective thresholds for a continuous 150ms window - preventing premature deassertion during unstable power conditions.