Analog Devices Inc./Maxim Integrated MAX6302ESA+

Overview

MAX6302ESA+ from Maxim Integrated is an adjustable low-power microprocessor supervisory circuit with active-high open-drain reset output, 4µA supply current, 1.31V to 5.5V operating voltage range, and configurable reset/watchdog timeout via external capacitors. It monitors power rails in battery-powered embedded controllers and portable medical instruments where brownout immunity and ultra-low quiescent current are critical.

For engineers reviewing the MAX6302ESA+ datasheet, MAX6302ESA+ pinout, MAX6302ESA+ application, or MAX6302ESA+ equivalent, this page delivers verified electrical parameters, exact pin functions, real-world timing behavior (including 500× watchdog extension), thermal stability data across –40°C to +85°C, and validated alternative options for reset supervision in space-constrained industrial designs.

Technical Context

The MAX6302ESA+ implements a precision bandgap reference (1.22V) driving dual comparators: one for reset threshold detection on RESET IN, another for watchdog timeout monitoring via SRT/SWT current sources. Its reset logic asserts active-high RESET only when VIN falls below VRST = 1.22 × (R1 + R2)/R2, then holds for programmable tRP = 2.67 × CSRT (µs).

Watchdog operation supports two modes: normal (WDS = GND, tWD = 2.67 × CSWT µs) and extended (WDS = VCC, tWD × 500 up to ~22 minutes). WDI accepts sub-30ns pulses; internal driver in extended mode enables watchdog disable via high-impedance WDI, while leakage remains <1µA in both modes.

Key Specifications

Pinout & Package

MAX6302ESA+ uses an 8-pin SO (Small Outline) package per Maxim's S8-2 outline (Outline No. 21-0041), RoHS-compliant with lead-free finish indicated by the "+" suffix.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6304ESA+, MAX6302ESA+ offers open-drain flexibility for shared reset buses but requires an external pull-up; versus TPS3808G125DBVR, it provides full adjustability and watchdog extension at higher pin count and quiescent current - making it optimal for design-in where configurability and robustness outweigh size/cost constraints.

Availability

MAX6302ESA+ is available at Aetrix Electronics and suitable for medical portable monitors, battery-powered data loggers, and industrial embedded controllers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6302ESA+ 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, medical, and communications applications, emphasizing low power, high reliability, and integration.

The MAX6301–MAX6304 family was engineered specifically for ultra-low-power microprocessor supervision in battery-critical and thermally challenging environments, delivering adjustable reset/watchdog functions in miniature packages without sacrificing accuracy or noise immunity.

FAQ

What is the minimum operating voltage for MAX6302ESA+ to guarantee valid RESET assertion?

The MAX6302ESA+ guarantees active-high RESET assertion down to VCC = 1.31V, as specified in its Electrical Characteristics table. Below this voltage, reset functionality is not assured. This threshold ensures reliable operation during deep brownout conditions common in single-cell Li-ion systems, where VCC may dip to 2.8V–3.0V under load - well above the 1.31V limit. The device remains functional across its full –40°C to +85°C industrial temperature range at this minimum supply.

Can MAX6302ESA+ monitor a 3.3V supply with a 2.9V reset threshold?

Yes, MAX6302ESA+ can monitor a 3.3V supply with a 2.9V reset threshold using an external resistor divider on RESET IN. With VRST = 1.22 × (R1 + R2)/R2, selecting R2 = 1MΩ and R1 ≈ 1.38MΩ yields VRST ≈ 2.9V. The high-impedance input (±1nA leakage) ensures minimal loading, preserving accuracy. This configuration is explicitly supported in the Typical Operating Circuit and Selector Guide, and is commonly used in 3.3V embedded controllers requiring brownout protection.

How does the 500× watchdog timeout extension work in MAX6302ESA+?

In MAX6302ESA+, asserting WDS = VCC activates extended watchdog mode, multiplying the base timeout (tWD = 2.67 × CSWT µs) by 500. For example, a 1µF capacitor on SWT yields ~22 minutes. Internally, the watchdog counter chain drives WDI with a brief pulse near timeout expiration - clearing the timer if WDI is left floating or three-stated, effectively disabling the watchdog. This mechanism is detailed in the Wake-Up Timer application and Figure 5, enabling low-power sleep cycling without additional components.

Is MAX6302ESA+ pin-compatible with MAX6301ESA+?

No, MAX6302ESA+ is not pin-compatible with MAX6301ESA+ despite identical pinout numbering. While both use the same 8-pin SO package and share pin positions (e.g., RESET IN on Pin 1, RESET on Pin 7), their RESET output polarity differs: MAX6302ESA+ provides active-high open-drain, whereas MAX6301ESA+ provides active-low open-drain. Swapping them without circuit modification would invert reset logic and cause system failure. The Selector Guide confirms this functional distinction across the MAX6301–MAX6304 family.

What capacitor type is required for SRT and SWT on MAX6302ESA+?

MAX6302ESA+ requires low-leakage ceramic capacitors for SRT and SWT, with leakage <10nA, as stated in Note 3 of the Electrical Characteristics. Standard X7R or C0G ceramics meet this requirement and are recommended in the Applications Information section. Electrolytic or tantalum capacitors are unsuitable due to higher leakage, which would cause significant timeout drift - e.g., a 100nA leak could shift tRP by >20%. Layout best practices also mandate short, isolated traces to minimize stray capacitance and noise coupling.