Analog Devices Inc./Maxim Integrated MAX6837HXSD0

Overview

MAX6837HXSD0 from Maxim Integrated is an ultra-low-voltage microprocessor supervisory circuit with open-drain active-low reset output, factory-set 1.313V reset threshold, 30ms reset timeout period (D2 suffix), and 7.5µA typical supply current. It monitors +1.2V to +1.8V power supplies in portable and battery-powered systems, asserting reset during brownout or manual reset events while maintaining guaranteed reset validity down to VCC = 0.55V.

For engineers reviewing the MAX6837HXSD0 datasheet, MAX6837HXSD0 pinout, MAX6837HXSD0 application, or MAX6837HXSD0 equivalent, key selection criteria include its SC70-4 open-drain reset architecture, debounced MR input, ±2.5% threshold accuracy over temperature, and compatibility with bidirectional µP reset pins in low-power embedded designs.

Technical Context

The MAX6837HXSD0 implements a precision voltage comparator with 444mV internal reference and hysteresis of 0.75% of VTH to reject fast VCC transients. Its reset logic asserts RESET low when VCC falls below 1.313V and holds it for exactly 30ms after VCC recovers above threshold or after MR deassertion.

It features a debounced manual reset input (MR) with internal 20kΩ pullup and 2µs minimum pulse width requirement, and supports external noise immunity via optional 0.1µF capacitor to ground. The open-drain RESET output requires an external pullup and can interface to higher-voltage rails up to 6V.

Key Specifications

Pinout & Package

MAX6837HXSD0 is housed in a 4-pin SC70-4 package (2.0mm × 2.1mm, 0.65mm pitch), optimized for space-constrained portable PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6837HXSD0, the V-suffix variant raises reset trip point by 262mV for higher-supply systems, while the F-suffix lowers it by 263mV for ultra-low-voltage domains-both retain identical timing, packaging, and MR functionality, enabling drop-in replacement within their respective voltage windows.

Availability

MAX6837HXSD0 is available at Aetrix Electronics and suitable for battery-powered IoT sensor nodes, portable medical devices, and low-voltage microcontroller systems requiring stable component supply across extended production lifecycles.

Supply support for MAX6837HXSD0 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 consumer markets.

The MAX6832–MAX6840 product line delivers ultra-low-voltage supervisory circuits targeting portable and battery-operated equipment where minimal quiescent current and small footprint are mandatory design constraints.

FAQ

What is the exact reset threshold voltage of MAX6837HXSD0 and how accurate is it over temperature?

The MAX6837HXSD0 has a factory-set reset threshold of 1.313V with ±2.5% accuracy over the full operating temperature range of -40°C to +85°C. This specification is guaranteed by design and verified across temperature extremes-not just at +25°C-ensuring consistent brownout detection in real-world portable equipment environments where ambient temperature fluctuates significantly.

Does MAX6837HXSD0 require an external pullup resistor on its RESET pin, and what voltage can it tolerate?

Yes, MAX6837HXSD0 requires an external pullup resistor on its open-drain RESET output. The pullup may connect to any voltage between 0V and 6.0V, including rails higher than VCC (e.g., 3.3V or 5V), enabling level-shifting for interfacing with µPs powered by different supplies. Typical values range from 10kΩ to 100kΩ depending on rise-time and drive strength requirements.

How does the manual reset (MR) input on MAX6837HXSD0 behave, and is external debouncing needed?

The MR input on MAX6837HXSD0 is active-low with an internal 20kΩ pullup to VCC and built-in hardware debouncing-no external RC network or firmware delay is required. A momentary switch from MR to GND generates a clean reset pulse, and the device holds RESET active for the full 30ms timeout after MR returns high, ensuring robust operation in noisy or mechanically unstable environments.

Can MAX6837HXSD0 operate reliably when VCC drops below 1.0V, and what is its minimum functional supply voltage?

MAX6837HXSD0 guarantees valid reset assertion down to VCC = 0.55V-well below typical 1.0V logic thresholds. Below this, the internal circuitry ceases sinking current on RESET, but the open-drain structure allows an external pulldown (e.g., 100kΩ to GND) to maintain LOW state. Its absolute minimum supply for reset functionality is 0.55V, making it suitable for deep-brownout protection in fading battery scenarios.

Is MAX6837HXSD0 pin-compatible with other members of the MAX6832–MAX6840 family, and which variants share the same SC70-4 footprint?

Yes, MAX6837HXSD0 is pin-compatible with all SC70-4 variants in the MAX6832–MAX6840 family-including MAX6835, MAX6836, MAX6838, MAX6839, and MAX6840-sharing identical 4-pin SC70-4 layout, GND/RESET/MR/VCC pin assignments, and thermal pad configuration. This allows direct substitution within the same package variant when adjusting reset threshold or output polarity without PCB redesign.