Analog Devices Inc./Maxim Integrated MAX809TEUR

Overview

MAX809TEUR from Maxim Integrated is a 3-pin SOT23-3 microprocessor supervisory circuit with push-pull active-low RESET output, precision 3.08V reset threshold (±0.5% over temperature), 140ms minimum reset timeout, 12µA supply current at +25°C, and guaranteed operation down to VCC = +1V. It monitors +3.3V digital systems in portable equipment, industrial controllers, and automotive ECUs.

For engineers reviewing the MAX809TEUR datasheet, MAX809TEUR pinout, MAX809TEUR application, or MAX809TEUR equivalent, this page delivers verified electrical parameters, package dimensions, thermal performance across -40°C to +105°C, reset timing behavior under brownout conditions, and validated alternative parts for design continuity.

Technical Context

The MAX809TEUR implements a precision bandgap-based voltage comparator with 30ppm/°C tempco to detect VCC falling below 3.08V, asserting an active-low RESET signal until VCC rises above threshold and remains stable for ≥140ms. Its push-pull output drives CMOS inputs directly without external pull-up components.

Designed for single-supply monitoring, it rejects fast transients up to 100mV overdrive for ≤20µs (at +25°C) and maintains valid logic states down to VCC = 1V - enabling reliable reset assertion during slow power-down sequences in battery-powered systems.

Key Specifications

Pinout & Package

MAX809TEUR is housed in a RoHS-compliant 3-pin SOT23-3 package (JEDEC MO-178AA), with 1.9mm pitch, 0.95mm max height, and thermal pad omitted. Pin 1 = RESET (active-low push-pull), Pin 2 = GND, Pin 3 = VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TEUR, MAX809SEUR offers tighter alignment to 3.0V rails but reduces noise margin; TPS3808G30DBVR adds manual reset capability at the cost of larger package and non-drop-in replacement.

Availability

MAX809TEUR is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, and portable medical devices requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX809TEUR 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 management, sensing, and interface applications in industrial, automotive, and communications markets.

The MAX809TEUR belongs to Maxim's microprocessor supervisory product line, engineered specifically for deterministic power-on reset generation in space-constrained, battery-sensitive embedded systems operating from 1.2V to 5.5V supplies.

FAQ

What is the exact reset threshold voltage of the MAX809TEUR and how stable is it over temperature?

The MAX809TEUR has a nominal reset threshold of 3.08V with ±0.5% tolerance over the full operating temperature range of -40°C to +105°C. Its temperature coefficient is 30ppm/°C, meaning threshold drift is limited to ±3.6mV across a 120°C span - ensuring consistent brownout detection in automotive and industrial environments where ambient temperature varies widely. This stability is confirmed in the device's Electrical Characteristics table under "Reset Threshold (SOT only)" for the "T" suffix variant.

Does the MAX809TEUR require external components to function?

No, the MAX809TEUR operates autonomously with no external components required. Its push-pull active-low RESET output drives standard CMOS inputs directly, eliminating the need for pull-up resistors or RC networks. This simplifies BOM, reduces PCB area, and removes tuning variables - all verified in the "No External Components" feature and Typical Operating Circuit diagrams of the MAX809TEUR datasheet.

Can the MAX809TEUR be used with a 2.5V supply rail?

Yes, the MAX809TEUR supports VCC from 1.2V to 5.5V, including 2.5V operation. However, its 3.08V reset threshold means it will assert RESET continuously when VCC = 2.5V, making it unsuitable for monitoring 2.5V rails. It is specifically designed for +3.3V systems (where 3.08V provides ~7% headroom). For 2.5V monitoring, use MAX809ZEUR (2.32V threshold) instead - confirmed in the Selector Guide and Absolute Maximum Ratings tables.

How does the MAX809TEUR handle fast power supply transients?

The MAX809TEUR rejects negative-going VCC transients up to 100mV in magnitude for durations ≤20µs at +25°C, as specified in the "Power-Down Reset Delay vs. Temperature" graphs and Electrical Characteristics table. This immunity prevents false resets caused by switching noise or coupling spikes. A 0.1µF ceramic capacitor placed adjacent to the VCC pin further enhances robustness - details are provided in the Applications Information section on "Negative-Going VCC Transients."

What is the minimum VCC voltage at which the MAX809TEUR guarantees correct RESET logic state?

The MAX809TEUR guarantees correct RESET logic state down to VCC = +1V. Below this, the output enters high-impedance state and no longer actively drives low. This is explicitly stated in the General Description ("outputs are guaranteed to be in the correct logic state for VCC down to 1V") and verified in the "Ensuring a Valid Reset Output Down to VCC = 0" subsection, which recommends a pull-down resistor only for operation below 1V - confirming 1V as the functional lower limit.