Analog Devices Inc./Maxim Integrated MAX6739XKLD3+T

Overview

The MAX6739XKLD3+T from Maxim Integrated is a dual-voltage microprocessor supervisor IC with one factory-trimmed reset threshold (VTH1 = 4.625V) 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 I/O supply (VCC1) and secondary core supply (VCC2 = 3.075V), asserts reset within 35µs on undervoltage, and maintains reset for ≥150ms after recovery - ideal for portable battery-powered systems requiring precise dual-rail power sequencing and fault detection.

For engineers reviewing the MAX6739XKLD3+T datasheet, MAX6739XKLD3+T pinout, MAX6739XKLD3+T application, or MAX6739XKLD3+T equivalent, key selection criteria include its 4.625V/3.075V fixed-adjustable dual-threshold configuration, 6µA quiescent current, -40°C to +85°C operation, SC70-5 footprint, and compatibility with low-voltage µPs in space-constrained embedded designs.

Technical Context

The MAX6739XKLD3+T implements two independent voltage monitoring channels: VCC1 (primary I/O rail) uses a precision factory-trimmed 4.625V threshold with ±1.5% tolerance over temperature, while VCC2 (secondary core rail) uses a 3.075V factory-set threshold. The RSTIN pin accepts an external resistor-divider to monitor a third voltage down to 0.488V, enabling flexible multi-rail supervision without additional components.

Its push-pull RESET output drives high to VCC1 (≥0.8×VCC1 at 800µA source) and low to ≤0.4V (at 3.2mA sink), eliminating need for external pull-up resistors. Manual reset is supported via MR input with internal 1.5kΩ pull-up and 150ms timeout, and the device features 0.5% reset threshold hysteresis and 100ns glitch rejection on MR.

Key Specifications

Pinout & Package

MAX6739XKLD3+T is housed in a 5-pin SC70-5 package (2.0mm × 1.25mm × 0.95mm height), optimized for high-density portable designs. Pin 1 is RESET (push-pull active-low), Pin 2 is GND, Pin 3 is MR (manual reset input), Pin 4 is VCC2 (secondary supply 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 MAX6738XKLD3+T, the MAX6739XKLD3+T eliminates external pull-up components and simplifies layout, while TPS3808G15DBVR offers lower current but cannot replace dual-rail supervision - making MAX6739XKLD3+T the optimal choice for integrated I/O+core monitoring in compact portable designs.

Availability

MAX6739XKLD3+T is available at Aetrix Electronics and suitable for portable medical sensors, industrial handheld terminals, GPS tracking modules, and notebook power sequencing requiring stable component supply and guaranteed long-term availability.

Supply support for MAX6739XKLD3+T 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, communications, and consumer markets.

The MAX6736–MAX6745 family was designed specifically for ultra-low-power dual- and triple-voltage microprocessor supervision in space-constrained portable and battery-operated systems, emphasizing precision thresholds, minimal quiescent current, and SC70 packaging.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6739XKLD3+T?

The MAX6739XKLD3+T has a factory-trimmed VCC1 reset threshold of 4.625V, with ±1.5% tolerance over the full -40°C to +85°C temperature range. This value is confirmed in Table 1 of the datasheet under suffix "LT", and applies specifically to the MAX6739XKLD3+T - not inferred from other variants in the MAX6736–MAX6745 family.

Does the MAX6739XKLD3+T support monitoring a 1.2V core supply?

Yes, the MAX6739XKLD3+T supports monitoring a 1.2V core supply via its RSTIN pin, which references an internal 0.488V comparator. Using a resistor divider (e.g., R1 = 1.5MΩ, R2 = 1MΩ), the effective threshold becomes 1.22V - matching typical 1.2V core rails. The MAX6739XKLD3+T datasheet explicitly confirms RSTIN operation down to 0.488V with <10nA input current.

What is the function of the MR pin on the MAX6739XKLD3+T?

The MR (Manual Reset) pin on the MAX6739XKLD3+T is an active-low input that forces the RESET output low when pulled to GND for ≥1µs. After release, RESET remains asserted for a guaranteed 150ms timeout period (D3 suffix). An internal 1.5kΩ pull-up to VCC1 allows direct connection to a momentary switch without external components - a feature validated in the Pin Description section for MAX6739.

Is the RESET output of the MAX6739XKLD3+T push-pull or open-drain?

The RESET output of the MAX6739XKLD3+T is push-pull, as confirmed in the Selector Guide (row MAX6739 shows "X" under "PUSH-PULL RESET") and Pin Description (RESET pin function states "push-pull" for MAX6739). It actively drives high to ≥0.8×VCC1 and low to ≤0.4V, eliminating need for external pull-up resistors - unlike open-drain variants such as MAX6738.

What package type and dimensions does the MAX6739XKLD3+T use?

The MAX6739XKLD3+T uses a 5-pin SC70-5 package measuring 2.0mm × 1.25mm × 0.95mm (L×W×H), with standard lead-free +T suffix. This is explicitly stated in the Ordering Information table and Pin Configurations diagram, confirming physical compatibility with SC70 footprints and distinguishing it from SOT-23 or µDFN alternatives.