Analog Devices Inc./Maxim Integrated MAX6743XKLTD3

Overview

The MAX6743XKLTD3 from Maxim Integrated is a triple-voltage microprocessor supervisor IC with two factory-trimmed reset thresholds (VTH1 = 4.625V, VTH2 = 3.075V) and one user-adjustable RSTIN input (488mV threshold), push-pull active-low RESET output, no manual reset pin, and 150ms minimum reset timeout period. It monitors primary I/O supply (VCC1), secondary core supply (VCC2), and an external voltage via RSTIN in portable, multivoltage embedded systems.

For engineers reviewing the MAX6743XKLTD3 datasheet, MAX6743XKLTD3 pinout, MAX6743XKLTD3 application, or MAX6743XKLTD3 equivalent, this device serves as a space-constrained, ultra-low-power (6µA) supervisory solution for dual-rail power sequencing, battery-backed systems, and precision voltage monitoring where guaranteed reset assertion during brownout and clean power-up timing are critical.

Technical Context

The MAX6743XKLTD3 implements independent comparators for VCC1, VCC2, and RSTIN, each referenced to precision internal bandgap references (4.625V, 3.075V, and 0.488V respectively), with hysteresis of 0.5% of threshold. Its reset logic asserts RESET low if any monitored input falls below its threshold and holds it low for ≥150ms after all inputs exceed their thresholds.

It uses BiCMOS process technology (249 transistors), operates over –40°C to +85°C, and guarantees valid RESET output while either VCC1 or VCC2 remains above 1.2V. The push-pull RESET output drives high to ≥0.8×VCC1 (ISOURCE = 800µA) and low to ≤0.4V (ISINK = 3.2mA), eliminating need for external pullup.

Key Specifications

Pinout & Package

MAX6743XKLTD3 is housed in a 5-pin SC70 package (1.6mm × 1.6mm × 0.9mm height), optimized for space-constrained portable designs. Pin 1 is RESET (push-pull active-low), Pin 2 is GND, Pin 3 is VCC2, Pin 4 is RSTIN, and Pin 5 is VCC1 - confirmed 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 MAX6740XKLTD3 and TPS3808G33DBVR, the MAX6743XKLTD3 uniquely delivers triple-supply supervision with push-pull RESET and zero external components in the smallest footprint - making it optimal for space- and power-constrained multivoltage systems requiring guaranteed reset integrity.

Availability

MAX6743XKLTD3 is available at Aetrix Electronics and suitable for industrial PLCs, portable medical devices, notebook embedded controllers, and POS terminal power management requiring stable component supply, long-term lifecycle support, and guaranteed performance across –40°C to +85°C.

Supply support for MAX6743XKLTD3 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 computing markets.

The MAX6736–MAX6745 family was designed specifically for ultra-low-power, multivoltage microprocessor supervision in portable and battery-operated equipment - emphasizing precision thresholds, minimal board area, and guaranteed reset behavior under transient conditions.

FAQ

What is the function of the RSTIN pin on the MAX6743XKLTD3?

The RSTIN pin on the MAX6743XKLTD3 is an adjustable reset threshold input referenced to an internal 0.488V comparator. When the voltage at RSTIN falls below this level - typically set via an external resistor divider - the device asserts the RESET output. This enables monitoring of a third supply (e.g., battery or auxiliary rail) down to 0.5V, with leakage current < ±10nA to minimize power loss in divider networks.

Does the MAX6743XKLTD3 include a manual reset input (MR)?

No, the MAX6743XKLTD3 does not include a manual reset input. Per the Selector Guide (page 14) and Pin Configurations (page 15), MAX6743 variants omit the MR pin - unlike MAX6736–MAX6739 or MAX6740–MAX6742. The MAX6743XKLTD3 relies solely on supply- and RSTIN-triggered reset assertion, with no provision for external pushbutton reset initiation.

What are the exact reset threshold voltages for MAX6743XKLTD3?

The MAX6743XKLTD3 has two factory-trimmed reset thresholds: VTH1 = 4.625V (for VCC1, monitoring 5V I/O rails) and VTH2 = 3.075V (for VCC2, monitoring 3.3V core supplies), both specified over –40°C to +85°C with ±75mV and ±50mV tolerances respectively. These values are confirmed in Table 1 (page 9) and the Ordering Information note (page 2).

Is the RESET output of MAX6743XKLTD3 push-pull or open-drain?

The RESET output of MAX6743XKLTD3 is push-pull active-low, as confirmed in the Selector Guide (page 14) and Pin Description (page 8). It drives high to ≥0.8×VCC1 (with 800µA source capability) and low to ≤0.4V (with 3.2mA sink capability), eliminating the need for an external pullup resistor and enabling direct connection to µP reset pins.

What is the reset timeout period for MAX6743XKLTD3?

The MAX6743XKLTD3 has a 150ms minimum reset timeout period, indicated by the "D3" suffix in its part number. This value is guaranteed over –40°C to +85°C and begins timing after all monitored supplies (VCC1, VCC2, RSTIN) exceed their respective thresholds. It is documented in Table 3 (page 10) and Electrical Characteristics (page 4, tRP parameter).