Analog Devices Inc./Maxim Integrated MAX6386LT33D4+T

Overview

MAX6386LT33D4+T from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 3.3V reset threshold (±2.5% over -40°C to +125°C), and 1120ms minimum VCC reset timeout. It features a debounced manual reset input (MR) with internal 63kΩ pullup and operates down to VCC = 1.0V. Used in battery-powered controllers and embedded systems requiring reliable power-on reset and brownout protection.

For engineers reviewing the MAX6386LT33D4+T datasheet, MAX6386LT33D4+T pinout, MAX6386LT33D4+T application, or MAX6386LT33D4+T equivalent, key selection criteria include reset threshold accuracy, MR timing behavior, open-drain drive capability (3.2mA sink at 4.5V), guaranteed reset validity down to 1V supply, and compatibility with dual-voltage monitoring architectures.

Technical Context

The MAX6386LT33D4+T implements a precision bandgap-based voltage comparator for VCC monitoring and a digital timeout counter triggered on threshold violation. Its MR input is synchronized and debounced internally, eliminating external RC networks. The open-drain RESET output requires an external pullup and supports wired-OR configurations across multiple supervisors.

Reset assertion occurs when VCC falls below 3.3V (nominal) or MR is pulled low; deassertion follows a fixed 1120ms timeout after VCC recovery or MR release. The device guarantees correct logic state of RESET down to VCC = 1.0V and exhibits immunity to negative-going VCC transients ≤35µs at 100mV overdrive.

Key Specifications

Pinout & Package

MAX6386LT33D4+T is packaged in a 4-pin SC70 (package code X4+1, outline 21-0098), measuring 1.3mm × 1.7mm × 0.95mm. This RoHS-compliant, lead-free package supports high-density PCB layouts and reflow soldering per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6386LT33D4+T, the /V+T variant adds automotive qualification without altering timing or electrical behavior, while TPS3808G33DBVR reduces supply current by ~50% but removes MR integration-requiring additional components for field-service reset capability.

Availability

MAX6386LT33D4+T is available at Aetrix Electronics and suitable for industrial PLC controllers, battery-powered data loggers, dual-voltage embedded systems, and automotive body control modules requiring stable component supply and long-term manufacturability.

Supply support for MAX6386LT33D4+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 precision analog and mixed-signal ICs for industrial, automotive, and computing applications, emphasizing low power, high reliability, and small form factors.

The MAX6381–MAX6390 family delivers single/dual-supply microprocessor supervisory circuits optimized for low-voltage, low-power embedded systems where reset accuracy, timing predictability, and minimal quiescent current are critical.

FAQ

What is the exact reset threshold voltage of MAX6386LT33D4+T and how does it vary with temperature?

The MAX6386LT33D4+T has a nominal reset threshold of 3.3V, with guaranteed tolerance of ±2.5% over the full operating temperature range of -40°C to +125°C. At +25°C, the threshold is specified as 3.3V ±1.5%. The tempco is 60ppm/°C, meaning drift is linear and predictable-e.g., at +125°C, deviation remains within the ±2.5% band. This performance is confirmed in the Electrical Characteristics table on page 3 of the official datasheet.

Does MAX6386LT33D4+T support manual reset functionality, and what are the timing requirements?

Yes, MAX6386LT33D4+T includes a debounced manual reset input (MR) with an internal 63kΩ pullup resistor. Driving MR low asserts RESET immediately, and RESET remains low for the full 1120ms VCC reset timeout period after MR is released. The MR input accepts standard TTL/CMOS logic levels and rejects glitches <100ns. No external debounce components are required, as confirmed in the "Manual Reset Input" section on page 6 of the datasheet.

What is the output configuration of the RESET pin on MAX6386LT33D4+T, and what external components are needed?

The RESET pin on MAX6386LT33D4+T is an open-drain active-low output. It requires an external pullup resistor to the target logic rail (e.g., 3.3V or 5V) to generate a valid high-level signal when deasserted. The device can sink up to 3.2mA at VCC ≥4.5V. Typical pullup values range from 4.7kΩ to 100kΩ depending on bus capacitance and rise-time requirements. This configuration is explicitly defined in the Pin Description table on page 6 and Figure 2 on page 7 of the datasheet.

Can MAX6386LT33D4+T operate reliably at very low supply voltages, and what is the minimum functional VCC?

Yes, MAX6386LT33D4+T guarantees correct RESET output logic state down to VCC = 1.0V, as stated in the Absolute Maximum Ratings and Electrical Characteristics tables. Below 1.0V, the internal comparator and timer may become indeterminate. This feature ensures deterministic reset behavior during deep brownout conditions-critical for preventing undefined MCU states. The specification is validated across temperature and process corners, not just typical conditions.

Is MAX6386LT33D4+T pin-compatible with legacy Maxim reset ICs like MAX809 or MAX6326?

Yes, MAX6386LT33D4+T is pin-compatible with MAX809, MAX810, MAX803, MAX6326–MAX6328, MAX6346–MAX6348, and MAX6711–MAX6713 in the 4-pin SC70 package. This compatibility is explicitly documented in the Features list on page 1 of the datasheet. However, note that MAX6386LT33D4+T uses open-drain output while MAX809 uses push-pull-so pullup resistors must be added if replacing a push-pull device in an existing design.