Analog Devices Inc./Maxim Integrated MAX6705ARKA+T

Overview

MAX6705ARKA+T from Maxim Integrated is a single-supply microprocessor supervisory IC in an 8-pin SOT23 package, providing active-low push-pull reset output, independent watchdog timer with 1.6s timeout, adjustable 0.62V power-fail comparator (PFI/PFO), and manual reset input. It monitors +3.3V systems with 2.97V to 3.17V V_TH threshold (R-suffix), guarantees reset validity down to V_CC = 1V, and targets critical µP power monitoring in white goods and networking equipment.

For engineers reviewing the MAX6705ARKA+T datasheet, MAX6705ARKA+T pinout, MAX6705ARKA+T application, or MAX6705ARKA+T equivalent, this page delivers verified functional identity, exact pin roles, confirmed reset timing (140ms timeout), power-fail detection capability (0.62V threshold), and validated alternative options for industrial embedded designs requiring reliable brownout and watchdog supervision.

Technical Context

The MAX6705ARKA+T implements a dedicated reset generator with internal voltage reference and precision comparator circuitry to assert RESET when V_CC falls below its factory-trimmed 3.08V threshold (R-suffix, -40°C to +125°C). Its watchdog timer operates independently of the reset path and triggers WDO low after 1.6s of no WDI edge transition.

It integrates a high-impedance PFI input referenced to a stable 0.62V internal bandgap, enabling external resistor-divider configuration for secondary supply monitoring; PFO provides active-low open-drain or push-pull output synchronized to PFI crossing that threshold. MR features internal 50kΩ pullup and supports debounced manual reset assertion.

Key Specifications

Pinout & Package

MAX6705ARKA+T is housed in an 8-pin SOT23 package (package code K8+2), measuring 2.9mm × 1.6mm × 1.1mm, RoHS-compliant and lead-free (indicated by "+T" suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with MAX6705MTA+T, the MAX6705ARKA+T provides tighter threshold alignment for 3.3V systems but shares identical watchdog and power-fail architecture; versus TPS3808G33DBVR, it delivers extended functionality (PFI/PFO, WDI/WDO) at the cost of larger footprint and higher BOM count.

Availability

MAX6705ARKA+T is available at Aetrix Electronics and suitable for industrial networking equipment, smart home white goods, telecom base station controllers, and embedded industrial controllers requiring stable component supply across extended temperature ranges.

Supply support for MAX6705ARKA+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 demanding industrial, communications, and computing applications.

The MAX6701–MAX6708 family was designed specifically for multivoltage microprocessor supervision in space-constrained, thermally harsh environments-emphasizing precision threshold accuracy, low-power operation, and integrated watchdog/power-fail functionality.

FAQ

What is the exact reset threshold voltage for MAX6705ARKA+T?

The MAX6705ARKA+T has a factory-trimmed reset threshold of 3.08V (typical) with a guaranteed range of 2.97V to 3.17V over the full –40°C to +125°C operating temperature range. This R-suffix variant is optimized for reliable supervision of +3.3V power rails, and the threshold is specified at V_CC falling conditions with 10mV/µs slew rate.

Does MAX6705ARKA+T support independent watchdog and reset outputs?

Yes, the MAX6705ARKA+T provides fully independent WDO and RESET outputs. WDO asserts low on watchdog timeout (1.6s) or V_CC undervoltage, while RESET responds to V_CC brownout, MR assertion, or watchdog timeout (in A-version). Both are active-low push-pull drivers, enabling concurrent NMI signaling and hard reset without shared timing dependencies.

How does the power-fail comparator work on MAX6705ARKA+T?

The MAX6705ARKA+T includes a dedicated 0.62V internal reference connected to the inverting input of a comparator. The noninverting input is exposed as the PFI pin. By connecting PFI to a resistor divider from a monitored supply, the comparator asserts PFO low when the divided voltage drops below 0.62V-providing early warning of impending power loss before the main rail collapses.

What is the function of the MR pin on MAX6705ARKA+T?

The MR (Manual Reset) pin on MAX6705ARKA+T is an active-low CMOS input with internal 50kΩ pullup to V_CC. Pulling MR low forces a reset pulse for the full timeout period (≥140ms) and clears the watchdog timer. It can be driven by a pushbutton switch or external logic signal, and is essential for system-level reset initiation and watchdog recovery sequences.

Is MAX6705ARKA+T compatible with 1.8V logic systems?

No, the MAX6705ARKA+T is not rated for 1.8V logic compatibility. Its MR, WDI, and PFI inputs require VIH ≥ 0.7×V_CC and VIL ≤ 0.3×V_CC, and its minimum operating V_CC is 1.2V. While it functions down to V_CC = 1.2V, interfacing with 1.8V logic domains requires level translation, as the device lacks native 1.8V-tolerant input thresholds.