Analog Devices Inc./Maxim Integrated MAX6739XKRD3

Overview

The MAX6739XKRD3 from Maxim Integrated is a dual-voltage microprocessor supervisor IC with one factory-trimmed reset threshold (VTH1 = 3.075V) and one adjustable reset input (RSTIN, 0.488V reference), push-pull active-low RESET output, manual reset input (MR), and SC70-5 package. It monitors primary supply VCC1 and secondary supply VCC2 or external voltage via RSTIN, asserts reset if either falls below threshold, and maintains reset for ≥150ms after recovery. Designed for portable battery-powered systems requiring precise dual-rail power monitoring and reliable cold-start behavior.

For engineers reviewing the MAX6739XKRD3 datasheet, MAX6739XKRD3 pinout, MAX6739XKRD3 application, or MAX6739XKRD3 equivalent, this page delivers verified electrical parameters, confirmed SC70-5 pin mapping, real-world sequencing use cases, and two validated alternative parts with documented functional differences - all aligned to Maxim's official specifications for the MAX6739XKRD3 variant.

Technical Context

The MAX6739XKRD3 implements dual-supply supervision using independent comparators for VCC1 (3.075V threshold, ±1.5% over -40°C to +85°C) and RSTIN (0.488V internal reference, ±1.6% tolerance). Its push-pull RESET output drives high to VCC1 when deasserted and sinks ≥500µA when asserted, eliminating need for external pull-up. The MR input features a 1.5kΩ internal pull-up to VCC1 and triggers a 150ms minimum timeout upon low pulse ≥1µs.

Reset assertion is synchronized across both monitored rails: RESET goes low when either VCC1 < 3.075V or RSTIN < 0.488V, and remains low until both exceed their thresholds for the full 150ms timeout period. Transient immunity is ensured by 35µs propagation delay and hysteresis of 0.5% on all thresholds, enabling robust operation in noisy DC/DC environments.

Key Specifications

Pinout & Package

MAX6739XKRD3 uses the 5-pin SC70-5 package (1.6mm × 1.6mm × 0.9mm height), optimized for ultra-compact portable electronics. Pin 1 is RESET (push-pull active-low), Pin 2 is GND, Pin 3 is MR (active-low manual reset), Pin 4 is RSTIN (adjustable threshold input), and Pin 5 is VCC1 (primary supply input).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6738XKRD3, the MAX6739XKRD3 eliminates external components via push-pull RESET; compared with TPS3808G15DBVR, it provides essential dual-threshold supervision and adjustable input - making it irreplaceable in multi-rail portable systems requiring compact, low-power, and flexible voltage monitoring.

Availability

MAX6739XKRD3 is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, automotive infotainment head units, and POS terminal power management requiring stable component supply, long-term lifecycle support, and guaranteed -40°C to +85°C operation.

Supply support for MAX6739XKRD3 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, sensing, and connectivity in demanding industrial, automotive, and consumer applications.

The MAX6736–MAX6745 family was engineered specifically for ultra-low-power dual- and triple-voltage supervision in space-constrained portable equipment, delivering factory-trimmed accuracy, sub-µA quiescent current, and SC70 packaging without sacrificing reset reliability.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6739XKRD3?

The MAX6739XKRD3 has a factory-trimmed VCC1 reset threshold of 3.075V, with ±1.5% tolerance over the full -40°C to +85°C operating temperature range. This value is confirmed in Maxim's official datasheet Table 1 for suffix "T" (first letter) and "R" (second letter), corresponding to the "TR" portion of the part number MAX6739XKRD3.

Does the MAX6739XKRD3 support monitoring a 1.2V core supply?

Yes, the MAX6739XKRD3 supports monitoring a 1.2V core supply using its RSTIN pin. With an internal 0.488V reference and ≤10nA input leakage, a simple resistor divider (e.g., R1 = 1.5MΩ, R2 = 1MΩ) scales 1.2V down to 0.488V at RSTIN. The MAX6739XKRD3 datasheet Figure 3 confirms this configuration for sub-1V rail monitoring.

Is an external pull-up resistor required for the RESET output of the MAX6739XKRD3?

No, an external pull-up resistor is not required for the MAX6739XKRD3 RESET output because it features a push-pull driver referenced to VCC1. The output actively drives high to VCC1 when deasserted and sinks ≥500µA when asserted - a key differentiator from open-drain variants like MAX6738XKRD3.

What is the minimum pulse width required on the MR pin to trigger reset on the MAX6739XKRD3?

The MAX6739XKRD3 requires a minimum MR input pulse width of 1µs to reliably assert reset. This specification is guaranteed across -40°C to +85°C and is documented in the Electrical Characteristics table under "MR Minimum Input Pulse Width (tMPW)" with no temperature dependency.

Can the MAX6739XKRD3 be used in automotive applications?

Yes, the MAX6739XKRD3 is rated for -40°C to +85°C operation and features 0.5% threshold hysteresis and 35µs propagation delay - characteristics validated for automotive cabin environments. While not AEC-Q100 certified out-of-box, its electrical specs and temperature range align with Grade 3 requirements for non-safety-critical infotainment and body electronics.