Analog Devices Inc./Maxim Integrated MAX16037PLA31+T

Overview

The MAX16037PLA31+T from Maxim Integrated is an 8-pin μDFN low-power supervisory circuit for microprocessor systems, featuring debounced manual-reset input (MR), active-low push-pull reset output, 3.08V factory-set reset threshold, 140ms minimum reset timeout, and battery switchover with <2µA backup current at +25°C. It ensures reliable SRAM retention during brownout in portable POS terminals.

For engineers reviewing the MAX16037PLA31+T datasheet, MAX16037PLA31+T pinout, MAX16037PLA31+T application, or MAX16037PLA31+T equivalent, key selection considerations include its 3.08V reset threshold accuracy over -40°C to +85°C, MR input with internal 20kΩ pullup, push-pull RESET capable of sinking 20mA, and integrated power-fail comparator with 1.235V PFI threshold.

Technical Context

The MAX16037PLA31+T implements a precision voltage-monitoring architecture with a bandgap-referenced 3.08V reset comparator, independent 1.235V power-fail comparator (PFI/PFO), and debounced MR input with 120ns propagation delay. Its internal MOSFET-based battery switchover path delivers <4.6Ω VCC-to-OUT on-resistance at 2.5V and maintains OUT regulation down to 1.2V supply.

This variant belongs to the MAX16033–MAX16040 family's 8-pin μDFN configuration and excludes watchdog (WDI), chip-enable gating (CEIN/CEOUT), and auxiliary RESETIN functions - retaining only MR, PFI, RESET, PFO, GND, VCC, OUT, and BATT terminals for compact battery-backup supervision.

Key Specifications

Pinout & Package

Package: 2mm × 2mm, 8-pin μDFN (exposed pad), RoHS-compliant, tape-and-reel (T).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar supervisory circuit applications.

Compared with MAX16037PLA29+T, the MAX16037PLA31+T provides higher reset threshold for improved noise immunity in 3.3V systems; compared with TPS3808G33DBVR, it adds critical battery switchover and dual-threshold monitoring - essential for SRAM retention and predictive power failure response.

Availability

MAX16037PLA31+T is available at Aetrix Electronics and suitable for portable POS terminals, industrial data loggers, set-top boxes, and medical infusion pump controllers requiring stable component supply and long-term lifecycle support.

Supply support for MAX16037PLA31+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 power management, sensing, and interface applications in industrial, computing, and communications markets.

The MAX16033–MAX16040 product line delivers ultra-low-power supervisory circuits with integrated battery switchover, targeting portable and battery-critical systems where SRAM data integrity must survive extended power loss.

FAQ

What is the factory-set reset threshold voltage for the MAX16037PLA31+T?

The MAX16037PLA31+T has a factory-set reset threshold of 3.08V, with guaranteed limits of 3.00V (minimum) and 3.15V (maximum) over the full -40°C to +85°C operating range. This value is laser-trimmed during production and applies specifically to the "A31" suffix variant. The MAX16037PLA31+T uses this threshold to assert RESET when VCC falls below specification, ensuring robust brownout protection for 3.3V microprocessor systems.

Does the MAX16037PLA31+T support battery switchover, and what is its backup current consumption?

Yes, the MAX16037PLA31+T supports automatic battery switchover from VCC to BATT when VCC drops below the reset threshold and VBATT exceeds VCC by at least 40mV. In battery backup mode with VCC = 0V and VBATT = 2.8V, the MAX16037PLA31+T draws only 1µA (typical) at +25°C and 2µA (maximum) across -40°C to +85°C - enabling multi-year operation on standard coin cells. This low current is achieved through optimized internal MOSFET biasing and leakage control.

What type of RESET output does the MAX16037PLA31+T provide, and what are its drive capabilities?

The MAX16037PLA31+T provides an active-low push-pull RESET output, denoted by the "L" in its part number suffix. It can sink up to 20mA while asserting low (VOL ≤ 0.3V at ISINK = 1.6mA), and outputs a valid high level of ≥0.8×VCC when deasserted (VOH ≥ 0.8×VCC at ISOURCE = 500µA). This eliminates the need for an external pullup resistor and ensures direct compatibility with standard microprocessor reset inputs, including those requiring driven-high release timing.

Can the MAX16037PLA31+T monitor a secondary power supply, and how is that implemented?

Yes, the MAX16037PLA31+T includes a dedicated power-fail input (PFI) with a precise 1.235V threshold comparator. To monitor a secondary supply (e.g., 5V or 12V), connect a resistive divider from the rail to PFI such that the divided voltage equals 1.235V at the desired trip point. The resulting PFO output asserts low on threshold breach and can be used to trigger interrupts or feed into MR for cascaded reset action. The MAX16037PLA31+T's PFI input draws only ±100nA, minimizing divider error.

Is the manual-reset input (MR) of the MAX16037PLA31+T debounced, and does it require external components?

Yes, the MR input of the MAX16037PLA31+T is internally debounced and includes a 20kΩ (minimum) pullup resistor to VCC. This allows direct connection of a normally open momentary switch between MR and GND - no external RC network or Schmitt-trigger buffer is required. The MAX16037PLA31+T detects MR transitions with 120ns propagation delay and holds RESET asserted for ≥140ms after MR returns high, satisfying most μP reset timing requirements without additional circuitry.