Analog Devices Inc./Maxim Integrated MAX6705AMKA

Overview

MAX6705AMKA 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 +5.0V/+3.3V/+3.0V/+2.5V supplies and guarantees valid reset down to VCC = 1V for reliable µP startup in industrial controllers and embedded systems.

For engineers reviewing the MAX6705AMKA datasheet, MAX6705AMKA pinout, MAX6705AMKA application, or MAX6705AMKA equivalent, key selection criteria include its fixed reset threshold variant (M-suffix = 4.38V), push-pull active-low RESET output, independent WDO assertion on watchdog timeout or undervoltage, and compatibility with noisy power-rail monitoring via external resistor dividers on PFI and RST_IN pins.

Technical Context

The MAX6705AMKA integrates a precision voltage monitor with 60ppm/°C temperature coefficient, a 1.6s watchdog timer cleared by WDI edges or reset events, and a separate 0.62V reference-based power-fail comparator with 1µs propagation delay. Its reset generator holds RESET low for 140–300ms after VCC, PFI, or MR transitions, with immunity to sub-100ns glitches on MR and guaranteed operation at VCC ≥ 1.0V.

Unlike MAX6704/MAX6708, it features independent WDO output (not tied to RESET), and unlike MAX6701(A)/MAX6702(A)/MAX6703(A), it lacks dual adjustable reset inputs - it monitors only VCC and PFI/RST_IN1 (shared pin function). The A-version ensures WDO deasserts immediately when VCC recovers above threshold, without timeout delay.

Key Specifications

Pinout & Package

MAX6705AMKA uses an 8-pin SOT23-8 package (JEDEC MO-178 BA, 3.00 × 1.75 mm body, 0.65 mm pitch) with exposed pad not connected internally. Pin 1 marked by dot; pins 1–8 arranged counterclockwise from top-left in top view.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6705MKA, the MAX6705AMKA offers faster WDO recovery after VCC recovery and eliminates need for WDI toggling to clear latched faults. Against TPS3808G33DBVR, it delivers three integrated functions (reset + watchdog + power-fail) in one SOT23-8 package, reducing board space and enabling advanced power sequencing.

Availability

MAX6705AMKA is available at Aetrix Electronics and suitable for industrial automation, automotive electronics, and medical device applications requiring stable component supply, extended temperature operation (-40°C to +125°C), and long-term lifecycle support.

Supply support for MAX6705AMKA 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, automotive, and communications applications.

The MAX6701–MAX6708 family was designed to replace discrete reset circuits and multiple supervisory ICs with a single, small-footprint solution offering precision voltage monitoring, watchdog supervision, and power-fail warning - targeting space-constrained µP systems.

FAQ

What is the reset threshold voltage for MAX6705AMKA?

The MAX6705AMKA has a nominal reset threshold of 4.38V (M-suffix), with guaranteed tolerance of ±1.5% over -40°C to +125°C. This value is factory-trimmed and specified in the Electrical Characteristics table under "VCC Reset Threshold (VCC falling)". The threshold applies to the VCC pin and determines when RESET asserts during power-down or brownout conditions.

Does MAX6705AMKA support monitoring of voltages other than VCC?

Yes, MAX6705AMKA supports monitoring of secondary voltages via its PFI pin, which connects to an internal 0.62V comparator. By using an external resistor divider between the target supply and GND, designers can scale any voltage (e.g., 3.3V, 2.5V, 1.8V) to trip at 0.62V on PFI. The PFO output then provides an active-low signal indicating impending power failure.

How does the watchdog timer in MAX6705AMKA differ from the non-A version?

The MAX6705AMKA watchdog timer asserts WDO low on timeout (1.6s typ) or when VCC drops below threshold, but deasserts WDO immediately upon VCC recovery - no timeout delay required. In contrast, the non-A MAX6705MKA requires a WDI edge or MR low to clear latched WDO, making it suitable for persistent fault signaling.

Can MAX6705AMKA drive heavy capacitive loads on its RESET output?

Yes, MAX6705AMKA's RESET output is push-pull and rated to sink 3.2mA at VCC ≥ 4.25V (VOL ≤ 0.4V), enabling direct driving of µP reset inputs with up to 1000pF capacitance. Its low VOL and high drive strength eliminate need for external pull-up resistors, simplifying layout and improving noise immunity in high-speed digital systems.

Is MAX6705AMKA RoHS-compliant and available in lead-free packaging?

MAX6705AMKA is offered in both leaded and lead-free variants. The standard MAX6705AMKA uses leaded packaging; the lead-free version is designated MAX6705AMKA+ (replacing "-T" with "+T" in ordering code). Both meet RoHS Directive 2011/65/EU requirements and are qualified for industrial temperature range (-40°C to +125°C).