Analog Devices Inc./Maxim Integrated MAX6301CPA+

Overview

The MAX6301CPA+ from Maxim Integrated is an 8-pin PDIP-packaged, low-power microprocessor supervisory circuit with adjustable reset threshold (≥1.22V), adjustable reset timeout (via external capacitor on SRT), and adjustable watchdog timeout (via SWT + WDS pin-selectable 500× extension). It features open-drain active-low RESET output, 4µA supply current, and guaranteed RESET assertion down to VCC = 1V - used in battery-powered medical instruments and embedded controllers for brownout detection and software hang recovery.

For engineers reviewing the MAX6301CPA+ datasheet, MAX6301CPA+ pinout, MAX6301CPA+ application, or MAX6301CPA+ equivalent, this page delivers verified electrical parameters, exact PDIP-8 terminal roles, real-world timing behavior (e.g., tRP = 2.67 × CSRT), and two validated alternative parts with documented functional and interface differences.

Technical Context

The MAX6301CPA+ implements a precision bandgap-based reset comparator with 1.22V internal reference, enabling externally adjustable reset thresholds via resistor divider on RESET IN. Its reset timeout is generated by a 500nA current source charging CSRT, while watchdog timing uses an identical current source on SWT, with WDS selecting either normal mode (tWD ≈ 2.67 × CSWT in µs) or extended mode (tWD × 500).

It operates across 2V–5.5V supply range, draws only 4µA typical ICC, and guarantees RESET assertion at VCC ≥ 1V. The open-drain RESET output supports bidirectional µP reset pins and requires an external pullup; immunity to ≤50µs/100mV VCC transients is confirmed per Typical Operating Characteristics graphs.

Key Specifications

Pinout & Package

MAX6301CPA+ 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 MAX6303CPA+, the MAX6301CPA+ offers open-drain flexibility for shared reset buses but requires a pullup; versus TPS3808G12DBVR, it trades fixed-threshold simplicity for full configurability in brownout-prone or ultra-low-power systems.

Availability

MAX6301CPA+ is available at Aetrix Electronics and suitable for medical instrumentation, portable diagnostic equipment, and industrial embedded controllers requiring stable component supply across commercial temperature range and long-term production cycles.

Supply support for MAX6301CPA+ 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, sensing, and interface applications, with emphasis on reliability and low-power operation.

The MAX6301CPA+ belongs to the MAX6301–MAX6304 family of adjustable µP supervisors - engineered specifically for applications demanding customizable reset thresholds, programmable timeouts, and robust watchdog functionality in resource-constrained systems.

FAQ

What is the minimum supply voltage at which MAX6301CPA+ guarantees RESET assertion?

The MAX6301CPA+ guarantees RESET output remains asserted (low) for VCC ≥ 1V. Below 1V, output drive capability degrades significantly. This ensures reliable processor initialization during brownout conditions common in battery-powered systems. The MAX6301CPA+ achieves this via internal biasing that maintains comparator function down to 1V, unlike many competitors that require ≥1.8V for valid reset generation.

How do I calculate the reset timeout period for MAX6301CPA+?

The reset timeout period (tRP) for MAX6301CPA+ is calculated as tRP (µs) = 2.67 × CSRT (pF), where CSRT is the capacitor connected between SRT (pin 3) and GND. For example, a 1500pF capacitor yields tRP ≈ 4005µs (4.0ms). This linear relationship holds because the MAX6301CPA+ uses a precision 500nA current source to charge CSRT - no external timing resistors are needed.

Can MAX6301CPA+ monitor voltages other than VCC?

Yes, MAX6301CPA+ can monitor any DC voltage by connecting it to the RESET IN (pin 1) input through an external resistor divider. The monitored voltage (VIN) is scaled to match the internal 1.22V reference: VRST = 1.22 × (R1 + R2)/R2. This allows supervision of 1.8V, 2.5V, or 3.3V rails independently of VCC, enabling flexible system-level power monitoring in multi-rail designs.

What is the purpose of the WDS pin on MAX6301CPA+?

The WDS (Watchdog Select) pin on MAX6301CPA+ controls watchdog timer mode: logic low (GND) selects normal mode with basic timeout (tWD ≈ 2.67 × CSWT), while logic high (VCC) enables extended mode multiplying timeout by 500×. A state change on WDS immediately resets the watchdog counter - enabling dynamic timeout adjustment, such as extending timeout during sleep modes and shortening it during active firmware execution.

Does MAX6301CPA+ require an external pullup resistor on the RESET pin?

Yes, MAX6301CPA+ requires an external pullup resistor on the RESET (pin 7) output because it is open-drain. A typical value is 4.7kΩ to VCC. This configuration allows multiple devices (e.g., µP and FPGA) to share the same reset bus via wired-OR logic and supports bidirectional reset pins found on processors like the 68HC11 - a key advantage over push-pull alternatives like MAX6303CPA+.