Analog Devices Inc./Maxim Integrated MAX6740XKWTD3

Overview

The MAX6740XKWTD3 from Maxim Integrated is a triple-voltage microprocessor supervisor IC with two factory-trimmed reset thresholds (VTH1 = 3.075V, VTH2 = 1.665V) and one adjustable RSTIN input (488mV threshold), open-drain RESET output, manual reset detect function, and 150ms minimum reset timeout period. It monitors I/O and core supplies in portable systems requiring precise power sequencing and low-quiescent-current supervision.

For engineers reviewing the MAX6740XKWTD3 datasheet, MAX6740XKWTD3 pinout, MAX6740XKWTD3 application, or MAX6740XKWTD3 equivalent, this device serves as a space-constrained, ultra-low-power (6µA) supervisory solution for multivoltage embedded systems where simultaneous VCC1/VCC2/RSTIN monitoring and pushbutton-initiated reset detection are required.

Technical Context

The MAX6740XKWTD3 implements a triple-supply monitoring architecture with independent comparators for VCC1 (3.075V threshold), VCC2 (1.665V threshold), and RSTIN (488mV internal reference). Reset assertion is triggered when any monitored voltage falls below its threshold and held for ≥150ms after all voltages recover.

It features an open-drain RESET output with integrated 50kΩ pullup to VCC1 enabling manual reset detect functionality, plus dedicated MR input handling with 150ms timeout and 100ns glitch rejection. All functions operate across –40°C to +85°C in a 5-pin SC70 package.

Key Specifications

Pinout & Package

MAX6740XKWTD3 is housed in a 5-pin SC70-5 package (2.0mm × 1.25mm footprint, 0.9mm height) with gull-wing leads, optimized for reflow soldering and compact portable applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6740XKWTD3, MAX6743XKTWD3 offers higher drive strength but sacrifices RSTIN flexibility, while TPS3808G33DBVR reduces current consumption by 77% but eliminates the third monitoring channel and requires PCB redesign due to different package and pin count.

Availability

MAX6740XKWTD3 is available at Aetrix Electronics and suitable for portable medical sensors, industrial handheld terminals, wearable fitness trackers, smart POS terminals, and other multivoltage embedded systems requiring stable component supply with guaranteed long-term availability.

Supply support for MAX6740XKWTD3 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 ultra-low-power, space-constrained multivoltage microprocessor supervision in battery-operated and portable electronics, emphasizing precision thresholds, minimal current draw, and integrated reset sequencing features.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6740XKWTD3?

The MAX6740XKWTD3 has a factory-trimmed VCC1 reset threshold of 3.075V, with a guaranteed tolerance of ±75mV over the full –40°C to +85°C operating temperature range. This value is confirmed in Table 1 of the datasheet under suffix "T" for VCC1 and "W" for VCC2, and applies specifically to the MAX6740XKWTD3 part number.

Does the MAX6740XKWTD3 support manual reset functionality, and how is it implemented?

Yes, the MAX6740XKWTD3 supports manual reset detection via its open-drain RESET pin, which includes an internal 50kΩ pullup resistor to VCC1. When the RESET line is pulled low externally (e.g., by a pushbutton to GND), the device detects this as a manual reset event, holds RESET low for 150ms, and debounces the input for 37.5ms - eliminating the need for a dedicated MR pin or external RC network.

What is the purpose of the RSTIN pin on the MAX6740XKWTD3, and what voltage does it monitor?

The RSTIN pin on the MAX6740XKWTD3 provides an adjustable third monitoring input with a precise 488mV internal reference threshold. It allows supervision of auxiliary voltages (e.g., battery, sensor bias, or analog rails) down to ~0.5V using an external resistor divider. The MAX6740XKWTD3 uses this pin to assert RESET when the divided voltage falls below 488mV, extending supervision beyond the two fixed rails.

What package type and dimensions does the MAX6740XKWTD3 use?

The MAX6740XKWTD3 is supplied in a 5-pin SC70-5 package measuring 2.0mm × 1.25mm × 0.9mm with gull-wing leads. This ultra-small outline package supports high-density PCB layouts and is compatible with standard reflow soldering processes, making it ideal for compact portable electronics where board space is at a premium.

How does the MAX6740XKWTD3 handle power supply transients to avoid false resets?

The MAX6740XKWTD3 incorporates inherent transient immunity: it ignores falling VCC transients shorter than ~100µs when overdriven by 100mV, as characterized in the "Maximum VCC1/VCC2 Transient Duration vs. Reset Threshold Overdrive" graph. Combined with a recommended 0.1µF bypass capacitor near VCC1, this ensures robust operation in noisy switching environments without spurious reset assertions.