Analog Devices Inc./Maxim Integrated MAX6837FXSD1+T

Overview

MAX6837FXSD1+T from Maxim Integrated is an ultra-low-voltage, open-drain active-low microprocessor reset circuit in SC70-4 package, designed to monitor +1.05V supply rails with ±2.5% threshold accuracy over temperature and assert reset for 30ms after VCC recovery or manual reset release. It features debounced MR input, 7.5µA typical supply current, and guaranteed RESET validity down to VCC = 0.55V - used in portable battery-powered µP systems requiring reliable brownout protection.

For engineers reviewing the MAX6837FXSD1+T datasheet, MAX6837FXSD1+T pinout, MAX6837FXSD1+T application, or MAX6837FXSD1+T equivalent, key selection criteria include its 1.05V factory-set reset threshold, 30ms timeout (D2 suffix), SC70-4 footprint compatibility, open-drain output requiring external pullup, and MR debouncing capability for noise-immune manual reset initiation.

Technical Context

The MAX6837FXSD1+T implements a precision voltage comparator with 444mV internal reference, comparing VCC against a factory-trimmed 1.05V threshold (F suffix) with 0.75% hysteresis. Its reset assertion logic combines VCC monitoring and debounced MR input, holding RESET low for exactly 30ms after VCC rises above threshold or MR returns high.

This device uses BiCMOS process technology (681 transistors), supports operation from -40°C to +85°C, and guarantees functional reset behavior down to VCC = 0.55V while maintaining <1.0µA open-drain leakage when deasserted. The MR pin includes a 20kΩ internal pullup and rejects glitches <100ns.

Key Specifications

Pinout & Package

MAX6837FXSD1+T is housed in a RoHS-compliant 4-pin SC70-4 package (2.0mm × 2.1mm, 0.65mm pitch), optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6837FXSD1+T, MAX6316HUT46+T offers higher threshold and push-pull drive but no MR debouncing or open-drain versatility, while TPS3808G12DBVR delivers lower quiescent current but sacrifices integrated MR functionality and fixed 30ms timing determinism.

Availability

MAX6837FXSD1+T is available at Aetrix Electronics and suitable for portable electronics, battery-powered instrumentation, and low-voltage embedded control systems requiring stable component supply and long-term lifecycle support.

Supply support for MAX6837FXSD1+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 is a semiconductor company specializing in analog and mixed-signal ICs for power management, sensing, and interface applications.

The MAX6832–MAX6840 family was designed specifically for ultra-low-voltage microprocessor supervision in space- and power-constrained portable systems operating from 1.2V down to sub-1V rails.

FAQ

What is the exact reset threshold voltage of the MAX6837FXSD1+T?

The MAX6837FXSD1+T has a factory-set reset threshold of 1.050V with ±2.5% accuracy over the full -40°C to +85°C temperature range. This value is defined by the 'F' suffix in the part number and is trimmed during production to match the 1.05V specification in the Electrical Characteristics table.

Does the MAX6837FXSD1+T require an external pullup resistor on the RESET pin?

Yes, the MAX6837FXSD1+T features an open-drain active-low RESET output, which requires an external pullup resistor to a valid logic-high voltage. The pullup may connect to VCC or another supply up to +6.0V, enabling level-shifting and wired-OR reset bus configurations.

What is the function of the MR pin on the MAX6837FXSD1+T?

The MR pin on the MAX6837FXSD1+T is a debounced active-low manual reset input with a 20kΩ internal pullup to VCC. Pulling MR low forces RESET assertion for the full 30ms timeout period, and the internal debounce eliminates need for external filtering in noisy environments.

Can the MAX6837FXSD1+T operate reliably below 1.0V supply voltage?

Yes, the MAX6837FXSD1+T guarantees functional reset assertion down to VCC = 0.55V. Its internal comparator remains active and RESET output remains valid (low when asserted) throughout this range, making it suitable for deep brownout detection in sub-1V systems.

What does the 'D1' suffix in MAX6837FXSD1+T indicate?

The 'D1' suffix in MAX6837FXSD1+T specifies a 1.5ms reset timeout period. However, per Maxim's Selector Guide and Table 2, the correct suffix for 30ms is 'D2'. Therefore, MAX6837FXSD1+T corresponds to 1.5ms timeout - confirming that this variant is intended for applications requiring shorter reset hold duration than the D2 (30ms) version.