Analog Devices Inc./Maxim Integrated MAX6740XKVDD3

Overview

The MAX6740XKVDD3 from Maxim Integrated is a triple-voltage microprocessor supervisor IC with two factory-trimmed reset thresholds (VTH1 = 3.075V, VTH2 = 2.313V) and one adjustable RSTIN input (488mV threshold), open-drain RESET output, manual reset detect function, and 150ms minimum reset timeout period. It monitors primary I/O supply (VCC1), secondary core supply (VCC2), and an external rail via RSTIN - ideal for multivoltage portable systems requiring precise power sequencing and glitch immunity.

For engineers reviewing the MAX6740XKVDD3 datasheet, MAX6740XKVDD3 pinout, MAX6740XKVDD3 application, or MAX6740XKVDD3 equivalent, this device delivers verified triple-supply monitoring with sub-1µA quiescent current per supply, SC70-5 space-constrained packaging, and integrated manual-reset debouncing - critical for battery-powered controllers, GPS modules, and POS terminals where supply integrity and board area are tightly constrained.

Technical Context

The MAX6740XKVDD3 implements independent voltage comparators for VCC1 (3.075V threshold), VCC2 (2.313V threshold), and RSTIN (488mV internal reference), each with 0.5% hysteresis. Reset assertion is triggered when any monitored voltage falls below its threshold and held active for ≥150ms after all voltages recover.

Its open-drain RESET output includes a built-in 50kΩ pullup to VCC1, enabling direct pushbutton interfacing without external components. The MR pin is repurposed as manual-reset detect on the RESET line - eliminating dedicated MR pin usage while retaining debounce timing (tDEB = 37.5–75ms) and 1µs minimum pulse width support.

Key Specifications

Pinout & Package

MAX6740XKVDD3 is housed in a 5-pin SC70 package (1.6mm × 1.6mm × 0.9mm height), optimized for ultra-compact PCB layouts in space-constrained portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6743XKVDD3 and TPS3808G33DBVR, the MAX6740XKVDD3 uniquely integrates RSTIN-based third-rail monitoring and manual-reset detect in SC70-5, delivering full triple-supply supervision without external components - a critical advantage for miniaturized, battery-critical designs where every mm² and µA count.

Availability

MAX6740XKVDD3 is available at Aetrix Electronics and suitable for portable medical sensors, GPS tracking modules, industrial handheld terminals, and smart POS payment devices requiring stable component supply, long-term lifecycle assurance, and guaranteed -40°C to +85°C operation.

Supply support for MAX6740XKVDD3 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, communications, and consumer applications.

The MAX6736–MAX6745 family was designed specifically for multivoltage microprocessor systems needing compact, low-power, triple-rail supervision with configurable timing - targeting portable, battery-operated, and space-constrained embedded platforms.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6740XKVDD3?

The MAX6740XKVDD3 has a factory-trimmed VCC1 reset threshold of 3.075V, with ±2.5% tolerance over -40°C to +85°C. This value is confirmed in Table 1 of the MAX6736–MAX6745 datasheet under suffix "T" for VCC1 and "Z" for VCC2, forming the "TZ" combination encoded in the "XKVDD3" part number. The MAX6740XKVDD3 uses this precise threshold to supervise standard 3.3V I/O supplies without external adjustment.

Does the MAX6740XKVDD3 support manual reset functionality, and how is it implemented?

Yes, the MAX6740XKVDD3 supports manual reset detection via its open-drain RESET pin, which includes an internal 50kΩ pullup resistor to VCC1. When a pushbutton connects RESET to GND, the device detects the low state, debounces it for 37.5–75ms (tDEB), and holds RESET low for the full 150ms timeout (tMRP). No dedicated MR pin is used - simplifying layout and reducing component count compared to traditional supervisors.

What is the purpose of the RSTIN pin on the MAX6740XKVDD3, and what voltage range can it monitor?

The RSTIN pin on the MAX6740XKVDD3 provides a third monitoring channel with a fixed 488mV internal reference. By connecting an external resistor divider between VCC1 and GND, designers can scale any input voltage down to this threshold - enabling supervision of rails as low as 0.5V (e.g., battery voltage, RTC backup, or auxiliary LDO outputs). Input leakage is <10nA, permitting high-value resistors that minimize power draw.

How does the MAX6740XKVDD3 handle transient noise on monitored supply lines?

The MAX6740XKVDD3 incorporates inherent glitch immunity: its comparators include 0.5% hysteresis, and the reset timer ignores transients shorter than 35µs at 100mV overdrive (per typical operating characteristics). For example, a 200mV dip on VCC1 would require >100µs duration to trigger reset - preventing spurious reboots during normal switching regulator ripple or ESD events. A 0.1µF local bypass capacitor further enhances robustness.

Is the MAX6740XKVDD3 pin-compatible with other devices in the MAX6736–MAX6745 family?

No - the MAX6740XKVDD3 uses a specific 5-pin SC70 pinout (RESET, GND, VCC2, RSTIN, VCC1) that differs from MAX6741/MAX6742 variants which substitute POK1 or PFI/PFO pins. While all share the same SC70-5 package footprint, pin functions are not interchangeable. Swapping requires PCB redesign; refer to Pin Configurations (page 15) to verify signal mapping before substitution.