Analog Devices Inc./Maxim Integrated MAX811SEUS+T

Overview

MAX811SEUS+T from Maxim Integrated is a low-power microprocessor supervisory circuit that monitors 3.08V supply voltage and asserts an active-low reset signal for ≥140ms after VCC rises above threshold; it features manual reset input, guaranteed RESET validity down to VCC = 1V, and operates in -40°C to +85°C industrial temperature range for embedded μP power monitoring.

For engineers reviewing the MAX811SEUS+T datasheet, MAX811SEUS+T pinout, MAX811SEUS+T application, or MAX811SEUS+T equivalent, key selection criteria include reset threshold accuracy (±0.05V over temp), 2.7µA typical supply current at 3.6V, SOT143-4 package compatibility, and manual reset debouncing without external components.

Technical Context

The MAX811SEUS+T implements a precision bandgap-based voltage comparator with internal 140ms reset timeout timer and integrated 20kΩ MR pull-up resistor. Its reset assertion logic guarantees active-low output state for VCC ≥1V and ignores transients ≤100ns on MR or ≤40µs (at 125mV overdrive) on VCC.

Designed for single-supply operation, it supports only 3.08V nominal reset threshold (suffix 'T'), requires no external components for basic supervision, and delivers glitch-immune reset control in portable and battery-powered systems where supply stability is critical during brownout or power-up sequences.

Key Specifications

Pinout & Package

MAX811SEUS+T is housed in a 4-pin SOT143 (U4+1) surface-mount package measuring 2.9mm × 1.6mm × 1.1mm, optimized for space-constrained PCB layouts in portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G30DBVR and ADM6806-3ARTZ-R7, the MAX811SEUS+T uniquely combines 3.08V precision threshold, integrated MR debouncing, ultra-low 2.7µA ICC, and guaranteed RESET validity down to 1V-all in a 4-pin SOT143 footprint-making it optimal for space- and power-constrained 3.3V systems requiring robust manual and power-fail reset control.

Availability

MAX811SEUS+T is available at Aetrix Electronics and suitable for industrial controllers, portable medical devices, smart energy meters, and IoT edge sensors requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX811SEUS+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 high-performance analog and mixed-signal semiconductor solutions for industrial, automotive, communications, and computing markets.

The MAX811/MAX812 product line delivers compact, low-power voltage supervisors targeting μP-based systems needing precise, glitch-immune power monitoring and manual reset capability in minimal footprint.

FAQ

What is the exact reset threshold voltage for MAX811SEUS+T?

The MAX811SEUS+T has a nominal reset threshold voltage of 3.08V, with guaranteed limits of 3.00V (min) to 3.15V (max) over the full -40°C to +85°C operating temperature range. This value is factory-trimmed and specified in the Electrical Characteristics table of the official datasheet. The 'T' suffix in MAX811SEUS+T explicitly denotes the 3.08V threshold variant, making it suitable for monitoring 3.3V ±5% power supplies.

Does MAX811SEUS+T provide manual reset functionality, and how is it implemented?

Yes, MAX811SEUS+T includes a dedicated manual reset (MR) input on Pin 3. It is an active-low input with an internal 20kΩ pull-up resistor, allowing direct connection to a normally open pushbutton switch between MR and GND-no external components needed. A logic-low pulse ≥10µs on MR asserts RESET low for at least 140ms after MR returns high. This feature enables field service reset, test-mode entry, or emergency recovery without modifying the host μP firmware.

What is the supply current consumption of MAX811SEUS+T, and under what conditions is it measured?

The MAX811SEUS+T draws 2.7µA typical supply current at VCC = 3.6V and TA = +25°C, with a maximum of 10µA over the full -40°C to +85°C temperature range. This ultra-low ICC is measured with RESET unloaded and is critical for extending battery life in portable applications. The datasheet confirms this value applies specifically to the 'T' (3.08V) variant, distinguishing it from higher-current L/M versions used with 5V supplies.

Can MAX811SEUS+T operate reliably when VCC drops below 1V, and what happens to the RESET output?

Below VCC = 1V, the MAX811SEUS+T RESET output ceases to sink current and transitions to a high-impedance (open-circuit) state. While the device remains functional down to VCC = 1.2V per absolute ratings, the RESET signal is no longer actively driven low. For applications requiring valid reset signaling down to 0V, a 100kΩ pulldown resistor on the RESET pin is recommended to prevent floating logic states-this design detail is explicitly documented in the "Ensuring a Valid RESET Output Down to VCC = 0V" section of the MAX811SEUS+T datasheet.

Is MAX811SEUS+T pin-compatible with other members of the MAX811/MAX812 family, such as MAX811LEUS+T?

Yes, all MAX811 variants-including MAX811SEUS+T and MAX811LEUS+T-share identical 4-pin SOT143 (U4+1) packaging and pinout: Pin 1 = GND, Pin 2 = RESET, Pin 3 = MR, Pin 4 = VCC. The only differences lie in reset threshold voltage (3.08V vs. 4.63V) and corresponding electrical parameters like supply current and overdrive response. This uniform footprint allows direct substitution in existing layouts when changing threshold requirements, provided system-level timing and voltage margins remain valid.