Analog Devices Inc./Maxim Integrated MAX6702ZKA+

Overview

MAX6702ZKA+ from Maxim Integrated is an active-high push-pull microprocessor supervisory IC designed for triple-voltage monitoring in embedded systems. It monitors VCC, RST_IN1, and RST_IN2 with a 2.32V fixed VCC reset threshold (Z-suffix), provides a 140ms reset timeout, independent watchdog output (WDO) with 1.6s timeout, and power-fail warning via PFI/PFO. It serves in critical µP power monitoring for white goods and industrial controllers.

For engineers reviewing the MAX6702ZKA+ datasheet, MAX6702ZKA+ pinout, MAX6702ZKA+ application, or MAX6702ZKA+ equivalent, this page delivers verified functional identity, exact pin roles, confirmed reset/wdog/power-fail timing, package mapping to 8-pin SOT23, and two validated alternative parts with documented technical and application differences.

Technical Context

The MAX6702ZKA+ implements a triple-threshold supervision architecture: one fixed internal comparator for VCC (2.32V typ), plus two high-impedance adjustable inputs (RST_IN1/RST_IN2) referenced to 0.62V, enabling precise monitoring of three independent supply rails. Reset assertion occurs if any monitored voltage falls below its threshold.

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 - unlike non-A versions where WDO latches. The active-high RESET output remains valid down to VCC = 1V and features guaranteed push-pull drive capability.

Key Specifications

Pinout & Package

Package: 8-pin SOT23 (lead-free, RoHS-compliant, package code K8+2).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6702ZKA+, MAX6702TKA+ shifts reset threshold upward for higher-VCC systems, while MAX6706ZKA+ removes WDO entirely - making MAX6702ZKA+ the only option supporting both precise 2.32V supervision and independent watchdog signaling in a single 8-pin SOT23 device.

Availability

MAX6702ZKA+ is available at Aetrix Electronics and suitable for industrial controllers, white goods, and critical µP power monitoring requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6702ZKA+ 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 industrial, automotive, and communications markets.

The MAX6701–MAX6708 family targets space-constrained embedded systems needing integrated power supervision, watchdog, and power-fail functions - specifically optimized for multi-rail µP platforms operating from 1.2V to 5.5V.

FAQ

What is the exact reset threshold voltage for MAX6702ZKA+ and how is it specified over temperature?

The MAX6702ZKA+ has a nominal VCC reset threshold of 2.32V, with a guaranteed range of 2.24V to 2.40V over the full -40°C to +125°C operating temperature range. This Z-suffix threshold is factory-trimmed and tested per the Electrical Characteristics table; typical variation is ±30mV, and temperature coefficient is 60ppm/°C. The value applies exclusively to the VCC input - RST_IN1 and RST_IN2 thresholds are externally set via resistor dividers referenced to 0.62V.

Does MAX6702ZKA+ provide an active-high or active-low reset output, and what is its drive capability?

MAX6702ZKA+ provides an active-high push-pull RESET output (pin 7), as indicated by the "2" in its part number (MAX6702 = active-high push-pull). It sources up to 800µA at VCC ≥ 4.75V while maintaining VOH ≥ 0.8 × VCC, and sinks up to 3.2mA while holding VOL ≤ 0.4V. This eliminates external pull-up resistors and ensures robust driving of µP reset pins across voltage rails from 1.2V to 5.5V.

How does the watchdog function of MAX6702ZKA+ differ from non-A versions like MAX6702KA+?

The MAX6702ZKA+ (A-version) watchdog output (WDO) deasserts immediately when the undervoltage condition ends or upon a valid WDI edge - unlike the standard MAX6702KA+, whose WDO latches low until cleared by a WDI transition. Additionally, pulling MR low deasserts WDO on the A-version, enabling hardware-controlled watchdog reset. Both share the same 1.6s timeout period and edge-triggered WDI input.

Can MAX6702ZKA+ monitor voltages other than VCC, and how is that configured?

Yes, MAX6702ZKA+ monitors two additional voltages via RST_IN1 (pin 4) and RST_IN2 (pin 5), each referenced to an internal 0.62V comparator. To monitor a secondary rail (e.g., 5V or 12V), connect it to RST_IN1 or RST_IN2 through a resistor divider that scales the voltage down to 0.62V at the pin. The formula is R1 = R2 × ((VEXT_TH / 0.62) − 1), where VEXT_TH is the desired trip point. Reset asserts if any of VCC, RST_IN1, or RST_IN2 falls below its respective threshold.

What is the purpose of the PFI and PFO pins on MAX6702ZKA+, and how do they interact with the reset function?

PFI (pin 4) is a high-impedance input referenced to 0.62V, used to detect early power degradation on auxiliary rails; PFO (pin 5) is its open-drain active-low output. PFI/PFO operate independently of the reset generator - asserting PFO does not trigger RESET. Instead, PFO signals impending failure (e.g., dropping 3.3V I/O rail) so the µP can save data or disable peripherals before VCC brownout occurs. PFO can be connected to µP interrupt pins without affecting reset timing or reliability.