Analog Devices Inc./Maxim Integrated MAX6837VXSD0

Overview

The MAX6837VXSD0 from Maxim Integrated is an ultra-low-voltage microprocessor supervisory circuit with open-drain active-low reset output, factory-set 1.575V reset threshold, and 1.5ms reset timeout period. It monitors +1.2V to +1.8V supply rails in portable and battery-powered systems, asserting reset during power-up, brownout, or manual reset events. Designed for critical µP power monitoring in space-constrained applications, it operates down to VCC = 0.55V and consumes only 7.5µA typical supply current.

For engineers reviewing the MAX6837VXSD0 datasheet, MAX6837VXSD0 pinout, MAX6837VXSD0 application, or MAX6837VXSD0 equivalent, key selection considerations include its SC70-4 open-drain RESET output requiring external pullup, debounced MR input, ±2.5% reset threshold accuracy over temperature, and immunity to short negative VCC transients-critical for reliable embedded system startup and fault recovery.

Technical Context

The MAX6837VXSD0 implements a precision voltage comparator with 444mV internal reference, comparing VCC against a factory-trimmed threshold (1.575V) to trigger reset assertion when supply drops below that level. Its reset timeout is fixed at 1.5ms (D1 suffix), generated by an on-chip RC timing network independent of external components.

It features a debounced manual reset input (MR) with internal 20kΩ pullup and 2µs minimum pulse width requirement, and guarantees valid reset output down to VCC = 0.55V. The open-drain RESET output supports level-shifting and bidirectional µP reset interfaces, sinking up to 200µA at VCC ≥ 1.5V with VOL ≤ 0.2V.

Key Specifications

Pinout & Package

MAX6837VXSD0 is housed in a 4-pin SC70-4 package (2.0mm × 2.1mm, 0.5mm pitch), optimized for high-density PCB layouts in portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6837VXSD0, MAX6835VXSD0 simplifies BOM by eliminating the pullup resistor but sacrifices interface flexibility, while MAX6316HPU29D3-T offers lower power but cannot supervise 1.6V rails-making MAX6837VXSD0 uniquely suited for modern ultra-low-voltage portable designs.

Availability

MAX6837VXSD0 is available at Aetrix Electronics and suitable for battery-powered wearables, low-power IoT sensor nodes, and industrial handheld terminals requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6837VXSD0 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, computing, and consumer applications.

The MAX6832–MAX6840 family was designed specifically to address ultra-low-voltage µP supervision needs in portable and energy-sensitive systems, replacing discrete reset solutions with integrated, SC70-packaged circuits offering precision thresholds and minimal quiescent power.

FAQ

What is the reset threshold voltage of the MAX6837VXSD0?

The MAX6837VXSD0 has a factory-set reset threshold of 1.575V, with ±2.5% accuracy over the full operating temperature range (-40°C to +85°C). This value is laser-trimmed during production and applies specifically to the 'V' suffix variant. The threshold remains stable across VCC variations from 0.55V to 3.6V, ensuring consistent brownout detection for 1.6V nominal supply rails.

Does the MAX6837VXSD0 require an external pullup resistor on the RESET pin?

Yes, the MAX6837VXSD0 features an open-drain active-low RESET output and requires an external pullup resistor to a valid logic-high voltage. The pullup may connect to VCC or a higher supply (up to +6.0V), enabling level-shifting. Typical values range from 10kΩ to 100kΩ depending on rise-time and bus loading requirements. Without this resistor, RESET cannot achieve a defined HIGH state.

What is the function of the MR pin on the MAX6837VXSD0?

The MR (Manual Reset) pin on the MAX6837VXSD0 is an active-low, debounced input with an internal 20kΩ pullup resistor to VCC. Pulling MR low forces an immediate reset assertion, which remains active for the full 1.5ms timeout after MR returns high. This allows hardware-initiated resets via pushbutton or external logic without additional debounce circuitry, and MR may be left unconnected if unused.

Can the MAX6837VXSD0 operate with supply voltages below 1.2V?

Yes, the MAX6837VXSD0 is specified to operate down to VCC = 0.55V and guarantees valid reset output behavior at that level. However, its reset threshold of 1.575V means it will assert reset whenever VCC falls below that value-so sustained operation below 1.575V triggers reset. The device remains functional (e.g., MR input responsive) down to 0.55V, supporting graceful shutdown sequences in ultra-low-power systems.

Is the MAX6837VXSD0 pin-compatible with other devices in the MAX6832–MAX6840 family?

Yes, the MAX6837VXSD0 shares identical SC70-4 pinout and footprint with all other 4-pin variants in the MAX6832–MAX6840 family, including MAX6835, MAX6836, MAX6838–MAX6840. Pin 1 is GND, Pin 2 is RESET, Pin 3 is MR (or RESET-IN on MAX6838/MAX6839/MAX6840), and Pin 4 is VCC. This allows drop-in substitution within the same package configuration when functional requirements align.