Analog Devices Inc./Maxim Integrated MAX6705TKA

Overview

The MAX6705TKA 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 rails and guarantees valid reset down to VCC = 1V - used in automotive control modules requiring reliable brownout detection and fail-safe restart.

For engineers reviewing the MAX6705TKA datasheet, MAX6705TKA pinout, MAX6705TKA application, or MAX6705TKA equivalent, this page delivers verified functional identity, exact pin roles, confirmed timing parameters (140ms reset timeout, 1.6s watchdog), real-world supervision use cases, and two validated alternative parts with documented technical and application differences.

Technical Context

The MAX6705TKA implements a dedicated reset generator with voltage threshold detection on VCC and an independent 0.62V reference-based power-fail comparator. Its watchdog circuit asserts WDO low after 1.6s of no WDI edge transition and clears only on rising/falling WDI edges or MR assertion - not on VCC recovery alone in non-A versions, but deasserts without delay upon VCC recovery in A-version (confirmed for MAX6705A).

It features dual independent comparators: one for VCC reset (threshold set by suffix 'K' = 3.08V per Threshold Suffix Guide), and another for PFI monitoring with 6mV hysteresis. The reset output remains asserted for ≥120ms after all fault conditions clear, and RESET is guaranteed low ≤0.4V at ISINK = 3.2mA when VCC ≥ 4.25V.

Key Specifications

Pinout & Package

Package: 8-pin SOT23-8 (3.00mm × 1.75mm × 1.30mm body, 0.65mm pitch), lead-free option available as MAX6705TKA+T.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6705TSA, the MAX6705TKA offers higher reset threshold margin for +3.3V rails; compared with TPS3808G33DBVR, it delivers full feature parity (PFI/PFO, WDO, MR) in same footprint - enabling drop-in replacement where 3.08V threshold meets design margin.

Availability

MAX6705TKA is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLC I/O modules, and medical infusion pump controllers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6705TKA 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 demanding industrial, automotive, and medical applications - emphasizing reliability, low power, and high integration.

The MAX6701–MAX6708 family targets space-constrained µP systems needing multirail supervision, power-fail warning, and watchdog safety - with MAX6705TKA optimized for +3.3V applications requiring A-version watchdog behavior and push-pull reset.

FAQ

What is the exact reset threshold voltage of MAX6705TKA and how is it determined?

The MAX6705TKA has a fixed VCC reset threshold of 3.08V (min 2.97V, max 3.17V over -40°C to +125°C), defined by the 'K' suffix in its part number per Maxim's Threshold Suffix Guide. This value is laser-trimmed during production and applies specifically to the VCC input; the PFI comparator retains its independent 0.62V threshold. The MAX6705TKA datasheet confirms this in the Electrical Characteristics table under "VCC Reset Threshold".

Does MAX6705TKA support watchdog functionality, and what is its timeout behavior?

Yes, MAX6705TKA includes a watchdog timer with a typical timeout of 1.6s (0.96–2.52s over temperature). It asserts the open-drain WDO pin low if the WDI input sees no rising or falling edge within that period. As an A-version part, WDO deasserts immediately upon VCC recovery above threshold - unlike non-A versions which require a WDI edge. This behavior is explicitly documented in the Standard- vs. A-Version Comparison section.

Can MAX6705TKA monitor voltages other than VCC, and how is that implemented?

Yes, MAX6705TKA monitors secondary voltages via its PFI pin, which connects to an internal 0.62V comparator. An external resistor divider scales the target voltage (e.g., 5V, 12V, or -48V rail) to 0.62V at PFI; when the scaled voltage drops below threshold, PFO goes low. The MAX6705TKA datasheet provides the exact divider formula in Figure 8 and confirms PFI leakage ≤±200nA - enabling high-impedance, low-power monitoring without loading the source rail.

What output drive capability does the MAX6705TKA RESET pin provide?

The MAX6705TKA RESET pin is an active-low push-pull output capable of sinking 3.2mA while maintaining VOL ≤ 0.4V at VCC ≥ 4.25V, and sinking 1.2mA with VOL ≤ 0.3V at VCC ≥ 2.55V. It sources up to 800µA with VOH ≥ 0.8×VCC. These values are measured and guaranteed in the Electrical Characteristics table - confirming direct drive of µP reset inputs without external buffers or pull-ups.

Is MAX6705TKA compatible with lead-free PCB assembly processes?

Yes, MAX6705TKA is available in lead-free packaging - ordered as MAX6705TKA+T (replacing '-T' with '+T' per Maxim's Ordering Information). The device meets JEDEC J-STD-020 moisture sensitivity level 1 and withstands peak reflow temperatures up to 260°C. Package dimensions and soldering profiles align with standard SOT23-8 reflow guidelines, and the datasheet confirms compatibility in the Package Information section.