Analog Devices Inc./Maxim Integrated MAX6740XKRVD3+

Overview

The MAX6740XKRVD3+ 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 - used for reliable power-on reset and supply monitoring in multivoltage portable systems.

For engineers reviewing the MAX6740XKRVD3+ datasheet, MAX6740XKRVD3+ pinout, MAX6740XKRVD3+ application, or MAX6740XKRVD3+ equivalent, key selection considerations include its triple-supply monitoring capability, 6µA quiescent current, 0.488V adjustable threshold support, -40°C to +85°C operation, and compatibility with battery-powered I/O/core sequencing architectures.

Technical Context

The MAX6740XKRVD3+ integrates three independent voltage monitors: VCC1 (primary I/O supply), VCC2 (secondary core supply), and RSTIN (user-adjustable third input). It asserts an active-low open-drain RESET when any monitored voltage falls below its threshold and holds it for ≥150ms after all voltages recover.

Its internal 50kΩ pullup on RESET enables direct pushbutton interfacing without external components, and the manual reset detect function includes 37.5–75ms debounce and 150ms timeout - eliminating need for external RC timing networks in handheld device reset circuits.

Key Specifications

Pinout & Package

Package: 5-pin SC70 (2.0mm × 2.1mm, 0.65mm pitch), surface-mount, lead-free (indicated by '+' suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6743XKRVD3+, the MAX6740XKRVD3+ offers integrated manual reset detect and open-drain flexibility; versus TPS3808G33DBVR, it provides essential third-rail monitoring for complex SoC power domains but consumes higher quiescent current.

Availability

MAX6740XKRVD3+ is available at Aetrix Electronics and suitable for portable medical sensors, industrial handheld terminals, wearable fitness trackers, and smart POS payment terminals requiring stable component supply and long-term production continuity.

Supply support for MAX6740XKRVD3+ 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 in industrial, medical, and consumer markets.

The MAX6736–MAX6745 family delivers low-power, space-efficient µP supervision for multivoltage systems - specifically engineered to replace discrete reset solutions in battery-constrained portable electronics.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6740XKRVD3+?

The MAX6740XKRVD3+ has a factory-trimmed VCC1 reset threshold of 2.925V (±2.5%) over the full -40°C to +85°C temperature range. This value is encoded in the 'R' suffix per Table 1 of the datasheet and applies specifically to the MAX6740XKRVD3+ variant - not inferred from other MAX6740 family members with different suffixes.

Does the MAX6740XKRVD3+ support monitoring a 1.2V supply as the third voltage?

Yes, the MAX6740XKRVD3+ supports monitoring a 1.2V supply via its RSTIN pin using an external resistor divider. With a fixed 0.488V internal reference, a 1.2V rail can be scaled using R1 = 1.5MΩ and R2 = 1MΩ (VEXT_TH = 0.488V × (R1+R2)/R2), enabling accurate trip-point setting without additional ICs.

What is the function of the MR pin on the MAX6740XKRVD3+?

The MR pin on the MAX6740XKRVD3+ is an active-low manual reset input with internal 1.5kΩ pullup to VCC1. When pulled low for ≥1µs, it forces the open-drain RESET output low for 150ms (D3 timeout). Its debounce period (37.5–75ms) allows direct connection to mechanical pushbuttons without external filtering.

Can the MAX6740XKRVD3+ be used in a system with a 5V VCC1 rail?

No - the MAX6740XKRVD3+ is specified for VCC1 operation from 1.2V to 5.5V, but its factory-trimmed VCC1 threshold is 2.925V. A 5V rail exceeds the intended monitoring range and would not trigger reset. For 5V supervision, select a MAX6740 variant with 'L' suffix (4.625V threshold) such as MAX6740XKLTD3+.

Is the RESET output of the MAX6740XKRVD3+ compatible with bidirectional µP reset pins?

Yes - the open-drain RESET output of the MAX6740XKRVD3+ is fully compatible with bidirectional µP reset I/O pins. Its internal 50kΩ pullup to VCC1 ensures proper logic levels during µP reset assertion and release, and no external resistor is required unless higher drive strength is needed.