Analog Devices Inc./Maxim Integrated MAX6703AZKA+T

Overview

MAX6703AZKA+T from Maxim Integrated is an active-low open-drain microprocessor supervisory IC designed for triple-voltage monitoring in embedded systems. It monitors VCC (2.32V threshold), RST_IN1, and RST_IN2 via external resistor dividers; provides 140ms reset timeout; features independent watchdog output (WDO) with 1.6s timeout; and supports manual reset (MR) with internal 50kΩ pullup. Used in white goods power sequencing and telecom baseband controllers.

For engineers reviewing the MAX6703AZKA+T datasheet, MAX6703AZKA+T pinout, MAX6703AZKA+T application, or MAX6703AZKA+T equivalent, this page delivers verified circuit role, exact reset threshold (2.32V), watchdog timing (1.6s), open-drain RESET/WDO behavior, and triple-supply supervision capability - all confirmed for the Z-suffix A-version in 8-pin SOT23.

Technical Context

The MAX6703AZKA+T implements a triple-threshold supervision architecture: primary VCC monitoring at fixed 2.32V (Z-suffix), plus two user-adjustable inputs (RST_IN1/RST_IN2) referenced to 0.62V internal comparator. Reset assertion occurs if any monitored supply falls below its threshold, with guaranteed reset validity down to VCC = 1V.

Its watchdog logic asserts WDO low on timeout (1.6s typ) or undervoltage condition, and deasserts immediately upon valid WDI edge or MR low - a key distinction from non-A versions. The open-drain RESET and WDO outputs support flexible interface to µP NMI or reset pins without level-shifting.

Key Specifications

Pinout & Package

MAX6703AZKA+T is housed in an 8-pin SOT23 package (package code K8+2), footprint-compatible with industry-standard 2.0mm × 2.1mm land pattern 90-0176. Lead-free construction per RoHS, marked with "+T" suffix.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6703MKA+T and MAX6316LUK31D3+T, the MAX6703AZKA+T uniquely combines 2.32V precision VCC monitoring, dual adjustable inputs, open-drain flexibility, and independent watchdog - making it irreplaceable for compact, multi-rail, low-voltage embedded systems requiring fail-safe supervision.

Availability

MAX6703AZKA+T is available at Aetrix Electronics and suitable for white goods control boards, telecom baseband processors, industrial PLC I/O modules, and intelligent power meters requiring stable component supply across extended temperature ranges (-40°C to +125°C).

Supply support for MAX6703AZKA+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, communications, and computing applications.

The MAX6701–MAX6708 family delivers integrated power-supply supervision for microprocessor systems, emphasizing precision threshold accuracy, low-power operation, and flexible reset/watchdog architectures for mission-critical embedded control.

FAQ

What is the exact VCC reset threshold voltage for MAX6703AZKA+T?

The MAX6703AZKA+T has a guaranteed VCC reset threshold of 2.32V (typical) over -40°C to +85°C, corresponding to the Z-suffix in Maxim's Threshold Suffix Guide. This value is specified with ±1.5% tolerance across temperature and ensures reliable supervision of +2.5V system rails under varying load and thermal conditions. The MAX6703AZKA+T uses this fixed threshold while allowing RST_IN1 and RST_IN2 to be set externally via resistor dividers referenced to 0.62V.

Does MAX6703AZKA+T support triple-voltage monitoring, and how is it implemented?

Yes, the MAX6703AZKA+T supports triple-voltage monitoring: one fixed VCC input (2.32V threshold) and two user-adjustable inputs (RST_IN1 and RST_IN2). Each adjustable input connects to an external resistor divider that references the internal 0.62V comparator threshold - for example, a 2.5V rail requires R1/R2 ≈ 3.03 to set trip point at 2.5V. Reset asserts if any of the three monitored voltages falls below its respective threshold, and remains active for the 140ms timeout after all recover.

What is the watchdog behavior of MAX6703AZKA+T, and how does it differ from non-A versions?

The MAX6703AZKA+T watchdog asserts WDO low on timeout (1.6s typ) or when VCC/RST_IN1/RST_IN2 fall below threshold, and deasserts immediately upon a valid WDI edge or MR low - no delay. In contrast, non-A versions latch WDO low until cleared by WDI transition only. This A-version behavior enables faster recovery from transient undervoltage events without requiring µP intervention, improving system responsiveness in telecom and industrial applications where rapid watchdog clearing is essential.

Can MAX6703AZKA+T drive a standard CMOS reset input directly?

Yes, the MAX6703AZKA+T's open-drain RESET output can drive standard CMOS reset inputs when used with an external pullup resistor (typically 10kΩ to VCC). Its VOL is guaranteed ≤0.3V at 50µA sink current, satisfying VIH/VIL thresholds of most µPs. For push-pull compatibility without external components, consider MAX6702AZKA+T (active-high) or MAX6705AZKA+T (active-low push-pull), but note those lack RST_IN1/RST_IN2 inputs. The MAX6703AZKA+T's open-drain design provides voltage-level flexibility across mixed-supply systems.

Is the manual reset (MR) input of MAX6703AZKA+T internally pulled up, and what is its value?

Yes, the MR input of MAX6703AZKA+T includes an internal 50kΩ pullup resistor to VCC, as confirmed in the Pin Description table and Electrical Characteristics (MR Pullup Resistance: 25–75kΩ). This eliminates the need for an external pullup in pushbutton reset applications. Pulling MR low forces both RESET and WDO assertion and clears the watchdog timer. Leaving MR unconnected defaults it high, disabling manual reset. The MAX6703AZKA+T's MR also serves as a watchdog clear mechanism - a feature critical for fail-safe recovery in safety-critical systems.