Analog Devices Inc./Maxim Integrated MAX811REUS-T

Overview

MAX811REUS-T from Maxim Integrated is an active-low microprocessor supervisory circuit in SOT143-4 package, designed to monitor 3.08V supply voltage with ±1.5% threshold accuracy, 6µA quiescent current, and 140ms minimum reset timeout. It asserts RESET low during power-up, brownout, or manual reset for embedded controllers and portable battery-powered systems.

For engineers reviewing the MAX811REUS-T datasheet, MAX811REUS-T pinout, MAX811REUS-T application, or MAX811REUS-T equivalent, key selection criteria include guaranteed RESET validity down to VCC = 1V, MR input with 20kΩ internal pull-up, immunity to ≤40µs VCC transients (125mV overdrive), and compatibility with 3V/3.3V digital logic interfaces.

Technical Context

The MAX811REUS-T implements a precision bandgap-based voltage comparator with hysteresis-free threshold detection at 3.08V nominal, coupled to a monostable timer that guarantees ≥140ms RESET assertion after VCC recovery. Its MR input accepts TTL/CMOS logic levels and initiates reset on low assertion, with internal 20kΩ pull-up enabling switch-to-GND operation without external components.

Reset timing is temperature-stable (±30ppm/°C tempco) and validated across –40°C to +85°C. The device ignores fast VCC transients ≤40µs (for 125mV overdrive), ensuring robust operation in noisy power environments while maintaining deterministic reset behavior during brownout recovery.

Key Specifications

Pinout & Package

SOT143-4 surface-mount package (4.0mm × 2.0mm × 1.1mm height), lead-free per RoHS, with gull-wing leads and exposed pad not connected internally.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with TPS3123E18DBVR and ADM6710L30ARTZ-R7, the MAX811REUS-T provides optimal balance of 3.08V accuracy, minimal 4-pin SOT143 footprint, and guaranteed 1V RESET validity-making it ideal for cost-sensitive, space-constrained 3V systems where exact threshold alignment and layout simplicity are critical.

Availability

MAX811REUS-T is available at Aetrix Electronics and suitable for industrial controllers, portable medical devices, smart energy meters, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX811REUS-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, communications, and computing applications.

The MAX811/MAX812 family delivers ultra-low-power, single-function voltage supervision for microprocessor systems-optimized for 3V/3.3V/5V rails with minimal external components and guaranteed timing performance.

FAQ

What is the exact reset threshold voltage of the MAX811REUS-T?

The MAX811REUS-T has a nominal reset threshold voltage of 3.08V with ±1.5% initial accuracy over temperature. This value is laser-trimmed at wafer test and verified across –40°C to +85°C, making it suitable for monitoring 3.0V systems with ±5% supply tolerance. The 'T' suffix in MAX811REUS-T specifically denotes the 3.08V threshold variant per Maxim's ordering guide.

Does the MAX811REUS-T require external components for basic operation?

No, the MAX811REUS-T operates autonomously with no external components required. Its MR input features a built-in 20kΩ pull-up resistor, and the open-drain RESET output only needs an external pull-up resistor (typically 10kΩ to VCC) for interfacing with µP reset inputs. No capacitors, resistors, or trimming elements are needed for core supervision functionality.

How does the MAX811REUS-T behave when VCC drops below 1V?

The MAX811REUS-T guarantees RESET remains a valid logic-low output for VCC ≥1V. Below 1V, the RESET output transitions to high-impedance (open-circuit) and no longer actively sinks current. In applications requiring defined logic state down to 0V, a 100kΩ pull-down resistor on the RESET pin ensures it stays low during deep undervoltage conditions.

What is the maximum allowable VCC transient duration the MAX811REUS-T can ignore?

For a 125mV overdrive (VCC dipping 125mV below the 3.08V threshold), the MAX811REUS-T ignores transients ≤40µs in duration. This immunity is specified for the R/S/T variants (including MAX811REUS-T) and ensures reliable operation in environments with switching noise or relay-induced spikes without generating spurious resets.

Is the MAX811REUS-T pin-compatible with other MAX811 variants like MAX811LEUS-T?

Yes, all MAX811 variants-including MAX811REUS-T, MAX811LEUS-T, and MAX811MEUS-T-share identical SOT143-4 pinout and package dimensions. The only differences are reset threshold voltage (3.08V vs. 4.63V vs. 4.38V) and corresponding marking codes; electrical timing, MR functionality, and RESET drive strength remain consistent across the family.