Analog Devices Inc./Maxim Integrated MAX6704SKA+

Overview

MAX6704SKA+ from Maxim Integrated is a single-supply microprocessor supervisory IC in an 8-pin SOT23 package, providing dual active-low/active-high push-pull reset outputs, an adjustable power-fail comparator (PFI/PFO), manual reset input (MR), and a reset-based watchdog timer with 1.6s timeout. It monitors +2.93V supply (S-suffix threshold), guarantees reset validity down to VCC = 1V, and supports critical µP power monitoring in white goods and networking equipment.

For engineers reviewing the MAX6704SKA+ datasheet, MAX6704SKA+ pinout, MAX6704SKA+ application, or MAX6704SKA+ equivalent, this page delivers verified functional identity, exact pin roles, confirmed reset timing (140ms timeout), PFI threshold (618mV typ), and validated alternatives for multivoltage supervision where complementary reset polarity and power-fail warning are required.

Technical Context

The MAX6704SKA+ implements a dual-stage reset generator with independent assertion logic for VCC and PFI inputs, enabling simultaneous active-low and active-high reset signaling without external inverters. Its reset timeout is fixed at 140ms (min) with 200ms typical, and its power-fail comparator features 6mV hysteresis and sub-1µs propagation delay.

Unlike the MAX6701–MAX6703(A) family, it lacks RST_IN1/RST_IN2 inputs and does not provide independent WDO output; instead, watchdog overflow directly triggers the RESET pulse for the full timeout period. The MR input includes internal 50kΩ pullup and 100ns glitch rejection.

Key Specifications

Pinout & Package

MAX6704SKA+ uses an 8-pin SOT23 package (package code K8+2, outline 21-0078), with 0.65mm pitch, 2.9mm × 1.6mm footprint, and RoHS-compliant lead-free construction (+T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6704SKA+, MAX6708SKA+ removes watchdog functionality while retaining identical supervision accuracy and dual-reset capability, whereas MAX6705SKA+ trades complementary reset for independent watchdog output and simplified reset architecture-enabling trade-offs between safety coverage, PCB routing complexity, and firmware integration effort.

Availability

MAX6704SKA+ is available at Aetrix Electronics and suitable for computers, networking equipment, white goods, and intelligent instruments requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6704SKA+ 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 power management, sensing, and interface applications in industrial, automotive, and communications systems.

The MAX6701–MAX6708 family targets cost-sensitive, space-constrained µP systems requiring reliable power-on reset, brownout protection, power-fail warning, and optional watchdog supervision-all in sub-3mm² SOT23 packages.

FAQ

What is the exact reset threshold voltage for MAX6704SKA+?

The MAX6704SKA+ has a nominal VCC reset threshold of 2.93V, with guaranteed min/max values of 2.85V and 3.00V respectively across −40°C to +125°C. This corresponds to the 'S' suffix in the part number and is optimized for +3.0V supply rails. The threshold exhibits a temperature coefficient of 60ppm/°C, ensuring stability over wide operating conditions. MAX6704SKA+ maintains this specification without requiring external calibration.

Does MAX6704SKA+ provide an independent watchdog output (WDO)?

No, MAX6704SKA+ does not feature an independent watchdog output. Instead, its watchdog timer is reset-based: when the WDI input fails to toggle within 1.6s, the device asserts both RESET and RESET outputs for the full 140ms timeout period. This eliminates the need for external logic to convert WDO assertion into a reset pulse, distinguishing it from MAX6701–MAX6707 variants that include dedicated WDO pins.

How is the power-fail warning implemented on MAX6704SKA+?

MAX6704SKA+ implements power-fail warning via the PFI (power-fail input) and PFO (power-fail output) pins. PFI is a high-impedance input referenced to an internal 0.62V bandgap; connecting it to a resistor divider on a monitored rail allows setting a custom trip point. When PFI falls below threshold, PFO asserts low within 1µs. This enables early warning of impending supply collapse-critical for orderly shutdown in systems like networking gear or white goods.

Can MAX6704SKA+ monitor multiple supply voltages simultaneously?

No, MAX6704SKA+ monitors only a single supply voltage (VCC) for reset generation. Unlike the MAX6701–MAX6703(A) series, it does not include RST_IN1 or RST_IN2 inputs for triple-voltage supervision. Its design focuses on simplicity and dual-reset polarity for single-rail systems. For multivoltage monitoring, engineers should consider MAX6701SKA+ or MAX6702SKA+, which support two additional adjustable inputs alongside VCC.

What is the function of the two RESET pins on MAX6704SKA+?

MAX6704SKA+ provides two physically separate RESET pins: Pin 7 is active-low RESET, and Pin 8 is active-high RESET. Both are push-pull outputs driven from the same internal reset generator. This complementary arrangement allows direct connection to µPs or FPGAs requiring both polarities-e.g., nRESET and RESET inputs-without external inverters or level shifters. The outputs remain synchronized and share identical timing characteristics including 140ms timeout and 1V minimum VCC operation.