Analog Devices Inc./Maxim Integrated MAX812TEUS+T

Overview

MAX812TEUS+T from Maxim Integrated is an active-high microprocessor supervisory circuit designed to monitor 3.08V power supplies in embedded systems. It asserts a reset signal when VCC drops below 3.08V (±0.08V over temperature), maintains reset for ≥140ms after recovery, and features a debounced manual reset input (MR) with 20kΩ internal pull-up. Used in battery-powered controllers and intelligent instruments for reliable power-on initialization.

For engineers reviewing the MAX812TEUS+T datasheet, MAX812TEUS+T pinout, MAX812TEUS+T application, or MAX812TEUS+T equivalent, this page delivers verified electrical parameters, SOT143 package mapping, reset timing behavior under brownout, MR interface design guidance, and validated alternative options for 3V-system voltage monitoring.

Technical Context

The MAX812TEUS+T implements a precision bandgap-based reset comparator with 30ppm/°C tempco and guaranteed operation from VCC = 1.2V to 3.6V. Its internal timer enforces a minimum 140ms reset timeout after VCC rises above the 3.08V threshold, and it ignores transients ≤20µs at 125mV overdrive.

MR input accepts TTL/CMOS logic or switch-to-ground activation, asserting reset while low and holding it for tRP (140–560ms) after release. The active-high RESET output drives loads up to 1.2mA sink (VOL ≤0.3V at VCC = VTH(MAX)) and sources 500µA with VOH ≥0.8×VCC.

Key Specifications

Pinout & Package

MAX812TEUS+T is housed in a 4-pin SOT143 (U4+1) surface-mount package, 1.3mm × 2.1mm footprint, 0.95mm height, RoHS-compliant lead(Pb)-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3123E18DBVR and ADM6710LAKSZ-RL, the MAX812TEUS+T delivers optimal balance of ultra-low ICC (2.7µA), guaranteed 3.08V threshold accuracy, integrated MR, and minimal footprint-making it the preferred choice for cost-sensitive, battery-constrained 3V systems without watchdog requirements.

Availability

MAX812TEUS+T is available at Aetrix Electronics and suitable for industrial controller monitoring, battery-powered data loggers, and medical point-of-care devices requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX812TEUS+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, with emphasis on power management and reliability-critical functions.

The MAX811/MAX812 family was engineered specifically for low-power microprocessor supervision in space-constrained, battery-operated systems requiring guaranteed reset behavior across −40°C to +85°C.

FAQ

What is the exact reset threshold voltage of MAX812TEUS+T and how stable is it over temperature?

The MAX812TEUS+T has a nominal reset threshold of 3.08V, with guaranteed limits of 3.00V to 3.15V over the full −40°C to +85°C operating range. Its 30ppm/°C temperature coefficient ensures total drift remains within ±15mV across temperature, meeting tight system-level brownout margins for 3V logic families.

Does MAX812TEUS+T support manual reset, and what are the drive requirements for the MR pin?

Yes, MAX812TEUS+T includes a dedicated MR pin with internal 20kΩ pull-up to VCC. To assert reset, MR must be driven below 0.25×VCC (e.g., <0.75V at VCC = 3.0V). It accepts TTL/CMOS logic levels and can be directly connected to a momentary switch to ground-no external components required.

Can MAX812TEUS+T operate reliably at VCC = 1.2V, and what happens to the RESET output at low supply?

Yes, MAX812TEUS+T is fully specified down to VCC = 1.2V. At VCC < 1.2V, RESET remains high (active state) until VCC falls below the functional limit; the device guarantees correct logic state throughout its rated operating range, ensuring no undefined reset behavior during deep brownout.

What is the minimum reset pulse width guaranteed by MAX812TEUS+T, and is it affected by temperature?

MAX812TEUS+T guarantees a minimum reset timeout period (tRP) of 140ms after VCC rises above the threshold or after MR is released. This value is specified over temperature (−40°C to +85°C) and does not degrade at extremes-maximum tRP is 560ms, providing robust margin for slow-rising supplies.

How does MAX812TEUS+T handle power supply transients, and what transient rejection is documented?

MAX812TEUS+T rejects negative-going VCC transients ≤20µs in duration when the overdrive (VTH − VCC) is 125mV-verified per Figure 1 in the datasheet. This immunity eliminates need for external RC filtering in noisy environments like motor-driven industrial equipment.