Analog Devices Inc./Maxim Integrated MAX6743XKZWD3+

Overview

The MAX6743XKZWD3+ from Maxim Integrated is a triple-voltage microprocessor supervisor IC with two factory-trimmed reset thresholds (VTH1 = 2.925V, VTH2 = 1.665V) and one user-adjustable RSTIN input (488mV threshold), push-pull active-low RESET output, no manual reset pin, and no power-fail or POK functionality. It operates from 1.2V to 5.5V supply, draws only 6µA quiescent current, and is used in multivoltage portable systems requiring precise, low-power supply monitoring and reliable reset assertion.

For engineers reviewing the MAX6743XKZWD3+ datasheet, MAX6743XKZWD3+ pinout, MAX6743XKZWD3+ application, or MAX6743XKZWD3+ equivalent, key selection considerations include its SC70-5 package footprint, 150ms minimum reset timeout, dual fixed + adjustable voltage monitoring architecture, and absence of MR/PFI/POK pins - distinguishing it from other members of the MAX6736–MAX6745 family.

Technical Context

The MAX6743XKZWD3+ implements a triple-supply supervisory architecture with independent comparators for VCC1 (primary I/O supply), VCC2 (secondary core supply), and RSTIN (user-defined third supply). All three inputs feed into a shared reset timer that asserts RESET low if any monitored voltage falls below its respective threshold and holds it low for ≥150ms after all voltages recover.

Its push-pull RESET output is referenced to VCC1 and drives high to ≥0.8×VCC1 when deasserted; no external pullup is required. The device lacks MR, PFI, PFO, and POK1 pins - confirmed by its SC70-5 pinout (RESET, GND, VCC2, RSTIN, VCC1) and Selector Guide entry - making it functionally distinct from MAX6740/MAX6741/MAX6742 variants.

Key Specifications

Pinout & Package

MAX6743XKZWD3+ uses a 5-pin SC70-5 package with exposed pad (not electrically connected). Pin assignments are fixed per functional variant and verified against 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 MAX6743XKZWD3+, MAX6740XKZWD3+ adds manual reset capability at the cost of open-drain output requiring pullup, while TPS3808G33DBVR offers lower quiescent current but omits the third adjustable input and exact threshold match - making MAX6743XKZWD3+ optimal for compact triple-rail designs needing push-pull drive and precise 2.925V/1.665V supervision.

Availability

MAX6743XKZWD3+ is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, and smart meter data acquisition units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6743XKZWD3+ 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, mixed-signal, and power management ICs for demanding industrial, automotive, and computing applications.

The MAX6736–MAX6745 product line delivers low-power, multi-rail µP supervisors in ultra-small packages - engineered specifically for space-constrained, battery-operated, and multivoltage embedded systems where reliability and quiescent current are critical.

FAQ

What is the reset timeout period for MAX6743XKZWD3+?

The MAX6743XKZWD3+ has a minimum reset timeout period of 150ms (D3 suffix), guaranteed over -40°C to +85°C. This timeout begins after all monitored supplies (VCC1, VCC2, RSTIN) rise above their respective thresholds and ensures the microprocessor remains held in reset long enough for full power stabilization before resuming operation. The actual timeout may extend up to 300ms depending on process and temperature variation.

Does MAX6743XKZWD3+ support manual reset functionality?

No, MAX6743XKZWD3+ does not include a manual reset (MR) input. Its pinout (RESET, GND, VCC2, RSTIN, VCC1) confirms the absence of an MR pin, and the Selector Guide explicitly lists "-" under the MANUAL RESET column for MAX6743. Systems requiring hardware reset buttons should consider MAX6740XKZWD3+ instead, which shares identical thresholds and timeout but adds MR and open-drain RESET.

What are the factory-trimmed voltage thresholds for MAX6743XKZWD3+?

The MAX6743XKZWD3+ has two factory-trimmed thresholds: VTH1 = 2.925V for VCC1 (I/O supply) and VTH2 = 1.665V for VCC2 (core supply), both specified over -40°C to +85°C with ±75mV and ±72mV tolerance respectively. These values correspond to the "ZW" suffix in Table 1 of the datasheet and are laser-trimmed during production for high accuracy without external calibration.

Can MAX6743XKZWD3+ monitor a 0.9V supply rail?

Yes, MAX6743XKZWD3+ can monitor a 0.9V rail using its RSTIN pin. With a typical internal reference of 488mV, an external resistor divider (e.g., R1 = 453kΩ, R2 = 511kΩ) scales the 0.9V rail down to ~488mV at RSTIN. The device's ±39mV RSTIN threshold tolerance over temperature ensures reliable detection, and its <10nA input leakage allows use of high-value resistors to minimize power draw in battery-critical applications.

Is MAX6743XKZWD3+ pin-compatible with other SC70-5 supervisors?

MAX6743XKZWD3+ is not pin-compatible with generic SC70-5 supervisors due to its unique pin assignment: Pin 1 = RESET (push-pull), Pin 2 = GND, Pin 3 = VCC2, Pin 4 = RSTIN, Pin 5 = VCC1. This differs from common dual-supply supervisors (e.g., TPS3808) that place GND on Pin 2 and VCC on Pin 5 but assign different functions to Pins 3 and 4. Layout reuse requires verification against the MAX6743XKZWD3+ specific pinout diagram on page 15 of the datasheet.