Analog Devices Inc./Maxim Integrated MAX6302EPA

Overview

MAX6302EPA from Maxim Integrated is an active-high, open-drain microprocessor supervisory circuit designed for reliable reset and watchdog monitoring in industrial and embedded systems. It features adjustable reset threshold (≥1.22V), adjustable reset timeout (2.8–5.2 ms with 1500pF), adjustable watchdog timeout (2.8–5.2 ms normal / 1.4–2.6 s extended), 500× watchdog multiplier via WDS pin, and 4µA supply current at +25°C. It operates across –40°C to +85°C and supports VCC down to 1.31V.

For engineers reviewing the MAX6302EPA datasheet, MAX6302EPA pinout, MAX6302EPA application, or MAX6302EPA equivalent, key selection criteria include its active-high open-drain RESET output, extended-mode watchdog timing scalability, power-supply transient immunity, and compatibility with low-voltage µP systems requiring guaranteed reset assertion above VCC = 1.31V.

Technical Context

The MAX6302EPA implements a precision bandgap-based reset comparator with 20mV hysteresis and a programmable reset timeout using a 500nA current source into the SRT pin. Its watchdog timer uses the same current-source architecture on SWT and supports two discrete modes-normal (WDS = GND) and extended (WDS = VCC)-with the latter multiplying timeout by 500 via internal counter scaling.

Reset assertion is triggered when RESET IN voltage falls below the externally set threshold (VRST = 1.22 × (R1 + R2)/R2), and deassertion occurs after the timeout period following VRST crossing. The open-drain RESET output requires an external pullup and remains high during fault conditions, enabling bidirectional reset arbitration with µPs like the 68HC11.

Key Specifications

Pinout & Package

MAX6302EPA is housed in an 8-pin plastic DIP (PDIP) package with 0.3-inch body width and through-hole mounting. Pin spacing is 0.1 inch, compatible with standard PCB layouts and socketing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6302ESA, the MAX6302EPA offers identical electrical performance and temperature rating but differs in mechanical form factor and assembly method; compared with TPS3808G12DBVR, it trades fixed-threshold simplicity for full adjustability of both reset and watchdog timing-critical for designs spanning multiple voltage rails or requiring adaptive sleep/wake behavior.

Availability

MAX6302EPA is available at Aetrix Electronics and suitable for medical infusion pumps, industrial PLC I/O modules, and portable ECG monitors requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX6302EPA 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, medical, and communications applications.

The MAX6301–MAX6304 family was designed specifically for low-power microprocessor supervision in battery-operated and thermally demanding environments, emphasizing configurability, transient resilience, and wide supply voltage tolerance.

FAQ

What is the minimum VCC required for guaranteed reset assertion in MAX6302EPA?

The MAX6302EPA guarantees valid RESET assertion for VCC ≥ 1.31V. Below this voltage, the internal circuitry cannot maintain specified output drive strength or timing accuracy. This threshold is confirmed in the Electrical Characteristics table under "Operating Voltage Range" for MAX6302/MAX6304 variants. For applications requiring operation below 1.31V, the MAX6303EPA or MAX6304EPA should be evaluated instead.

How does the WDS pin affect watchdog behavior in MAX6302EPA?

In MAX6302EPA, the WDS pin selects between two watchdog modes: when tied to GND, it enables normal-mode timeout (e.g., 4.0ms with 1500pF); when tied to VCC, it activates extended mode, multiplying the timeout by 500 (e.g., 2.0s). A transition on WDS also clears and restarts the watchdog timer. This dual-mode capability allows one MAX6302EPA design to serve both real-time monitoring and low-power wake-up functions.

Can MAX6302EPA monitor voltages other than VCC?

Yes, MAX6302EPA can monitor any DC voltage via the RESET IN pin using an external resistor divider. The monitored voltage (VIN) connects to RESET IN, and the threshold VRST is calculated as 1.22 × (R1 + R2)/R2. This enables supervision of 1.8V, 2.5V, or 3.3V rails independent of VCC, provided VIN stays within absolute maximum ratings (–0.3V to VCC + 0.3V) and the divider draws negligible current relative to the 10nA input leakage.

What capacitor type is recommended for SRT and SWT pins in MAX6302EPA?

Ceramic capacitors with low leakage (<10nA) are recommended for both SRT and SWT pins in MAX6302EPA. These pins source/sink a precision 500nA current, so high-leakage dielectrics (e.g., standard electrolytic or certain Y5V ceramics) introduce timing errors. X7R or C0G/NP0 types in 0805 or smaller packages minimize parasitic capacitance and board leakage, ensuring accurate reset and watchdog timeout periods per the formula t = 2.67 × C (pF → µs).

Is MAX6302EPA pin-compatible with other members of the MAX6301–MAX6304 family?

Yes, MAX6302EPA is fully pin-compatible with MAX6301EPA, MAX6303EPA, and MAX6304EPA in the same 8-pin PDIP package. All share identical pinout, supply range, timing architecture, and thermal specifications. The only functional differences lie in reset polarity (active-high vs. active-low) and output structure (open-drain vs. push-pull), which are defined by part number-not pin assignment-so PCB layout reuse is possible across the family with only firmware or external pullup adjustments.