Analog Devices Inc./Maxim Integrated MAX6703TKA-T

Overview

MAX6703TKA-T from Maxim Integrated is a precision microprocessor supervisory IC in an 8-pin SOT23 package, providing triple-voltage monitoring (one fixed + two adjustable thresholds), active-low open-drain reset output, manual reset input, and independent watchdog timer with 1.6s timeout. It guarantees valid reset operation down to V_CC = 1V and supports critical µP power monitoring in white goods and networking equipment.

For engineers reviewing the MAX6703TKA-T datasheet, MAX6703TKA-T pinout, MAX6703TKA-T application, or MAX6703TKA-T equivalent, key selection criteria include its dual adjustable reset inputs for 3-supply systems, 0.62V power-fail comparator threshold, 140ms reset timeout, open-drain RESET output configuration, and guaranteed operation across –40°C to +125°C.

Technical Context

The MAX6703TKA-T implements a triple-threshold supervision architecture: primary V_CC monitoring with factory-set threshold (T-suffix = 3.08V nominal), plus two user-adjustable inputs (RST_IN1/RST_IN2) referenced to a 0.62V internal bandgap. All three comparators feed a single reset generator with 140ms timeout.

Its watchdog circuit asserts WDO low after 1.6s of no WDI edge transition, and WDO deasserts immediately upon valid WDI toggle or MR pull-low - a defining behavior of the "A" version. The open-drain RESET output requires external pull-up and remains asserted during brownout, power-down, or manual reset events.

Key Specifications

Pinout & Package

Package: 8-pin SOT23 (lead-free, RoHS-compliant, -T suffix). Compact footprint (2.9mm × 1.6mm) suitable for space-constrained embedded PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6703TKA-T, MAX6703TKA+T offers identical electrical and thermal performance in lead-free packaging, while MAX6705TKA-T reduces supervision scope to single-rail but retains the same 3.08V threshold and A-version watchdog behavior - making it a functional subset for simplified applications.

Availability

MAX6703TKA-T is available at Aetrix Electronics and suitable for computers, networking equipment, white goods, and telecommunications infrastructure requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6703TKA-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) designs high-performance analog and mixed-signal ICs for demanding industrial, automotive, and communications applications.

The MAX6701–MAX6708 family delivers integrated µP supervision with triple-voltage monitoring, watchdog, and power-fail detection in ultra-small SOT23 packages - engineered for reliability in harsh environments and space-constrained embedded systems.

FAQ

What is the reset threshold voltage of the MAX6703TKA-T?

The MAX6703TKA-T has a factory-trimmed V_CC reset threshold of 3.08V (nominal), with ±3% tolerance over –40°C to +125°C. This T-suffix designation targets +3.3V supply supervision. The device also supports two additional user-adjustable reset inputs (RST_IN1/RST_IN2) referenced to a precise 0.62V internal bandgap, enabling triple-supply monitoring in a single IC.

How does the watchdog behavior of the MAX6703TKA-T differ from non-A versions?

The MAX6703TKA-T is an "A" version, meaning its WDO output deasserts immediately upon a valid WDI edge transition or MR pull-low - with no timeout delay. In contrast, standard MAX6703T versions latch WDO low until the next WDI edge occurs *after* the timeout expires. This A-version behavior enables faster recovery from firmware hangs and simplifies watchdog-driven reset loops in the MAX6703TKA-T design.

Can the MAX6703TKA-T monitor three different supply voltages simultaneously?

Yes. The MAX6703TKA-T monitors V_CC (3.08V threshold), plus two user-defined supplies via RST_IN1 and RST_IN2 pins. Each uses an external resistor divider to scale the target voltage down to the internal 0.62V reference. Reset asserts if *any* of the three monitored voltages falls below its respective threshold, making the MAX6703TKA-T ideal for multi-rail systems like industrial controllers or telecom base stations.

What is the function of the PFI and PFO pins on the MAX6703TKA-T?

PFI is a high-impedance input for an external resistor divider connected to a secondary supply; it's compared against the 0.62V internal reference. PFO is the corresponding open-drain output that goes low when PFI drops below threshold - providing early power-fail warning. In the MAX6703TKA-T, PFI/PFO operate independently of the main reset path, allowing preemptive µP interrupt handling before full supply collapse.

Is the MAX6703TKA-T compatible with 1.8V or 2.5V microcontrollers?

Yes. The MAX6703TKA-T operates from V_CC = 1.0V to 5.5V and guarantees valid reset output down to 1V. Its CMOS-compatible MR, WDI, and PFI inputs accept logic levels referenced to local V_CC, and the open-drain RESET/WDO/PFO outputs can be pulled up to any voltage ≤6.0V - enabling seamless interfacing with 1.8V, 2.5V, 3.3V, or 5V µCs without level shifters.