Analog Devices Inc./Maxim Integrated MAX6837VXSD3

Overview

The MAX6837VXSD3 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 210ms 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, it guarantees valid reset down to VCC = 0.55V and consumes only 7.5µA typical supply current.

For engineers reviewing the MAX6837VXSD3 datasheet, MAX6837VXSD3 pinout, MAX6837VXSD3 application, or MAX6837VXSD3 equivalent, this device serves as a precision voltage detector and reset generator for low-power embedded systems requiring stable, low-threshold supervision with manual reset debouncing and immunity to short VCC transients.

Technical Context

The MAX6837VXSD3 implements a precision bandgap-based reset comparator with ±2.5% threshold accuracy over -40°C to +85°C, paired with a fixed 210ms timeout timer. Its internal 20kΩ MR pullup enables direct connection of a momentary switch without external debounce components.

This variant belongs to the MAX6834–MAX6840 open-drain subgroup and features a 4-pin SC70-4 package with pins assigned as VCC, GND, MR, and open-drain RESET. It does not monitor RESET-IN - unlike MAX6838–MAX6840 - and relies solely on VCC monitoring with factory-trimmed threshold.

Key Specifications

Pinout & Package

MAX6837VXSD3 is housed in a 4-pin SC70-4 package (2.0mm × 2.1mm, 0.65mm pitch), optimized for space-constrained portable designs. The package is RoHS-compliant and available in lead-free (+T) configuration.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6837VXSD3, MAX6837HXSD3 shifts detection earlier for lower-voltage rails, while MAX6835VXSD3 trades open-drain flexibility for simplified drive strength and removes MR debounce - neither is pin-compatible, and both require PCB revision for substitution.

Availability

MAX6837VXSD3 is available at Aetrix Electronics and suitable for battery-powered medical sensors, low-voltage industrial controllers, and portable test equipment requiring stable component supply, long-term lifecycle support, and guaranteed RoHS compliance.

Supply support for MAX6837VXSD3 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, mixed-signal, and power management ICs for demanding industrial, automotive, and computing applications.

The MAX6832–MAX6840 family was developed specifically for ultra-low-voltage µP supervision in portable and energy-constrained systems, emphasizing minimal quiescent current, small SC70 packaging, and factory-trimmed accuracy without external components.

FAQ

What is the exact reset threshold voltage of the MAX6837VXSD3?

The MAX6837VXSD3 has a factory-set reset threshold of 1.575V, with ±2.5% accuracy over the full -40°C to +85°C operating temperature range. This value is laser-trimmed during production and specified in the Electrical Characteristics table under "Reset Threshold (VTH)" for the "V" suffix. It is designed for reliable supervision of 1.6V nominal supply rails.

Does the MAX6837VXSD3 support manual reset, and how is it implemented?

Yes, the MAX6837VXSD3 includes a debounced manual reset input (MR) with an internal 20kΩ pullup resistor to VCC. Pulling MR low forces an immediate reset, which remains asserted for the full 210ms timeout after MR returns high. No external debounce circuitry is needed, and MR accepts CMOS-level signals or open-drain switches directly.

What package type and pin count does the MAX6837VXSD3 use?

The MAX6837VXSD3 is supplied in a 4-pin SC70-4 package (2.0mm × 2.1mm footprint, 0.65mm lead pitch). Pin 1 is VCC, Pin 2 is GND, Pin 3 is MR, and Pin 4 is the open-drain active-low RESET output. This compact, surface-mount package supports high-density PCB layouts in portable electronics.

Can the MAX6837VXSD3 be used with supply voltages below 1.2V?

Yes - the MAX6837VXSD3 operates with VCC as low as 0.55V and guarantees valid reset output down to that level. However, its 1.575V reset threshold means it will assert reset whenever VCC falls below that point; it is not intended to supervise sub-1.2V rails. For lower thresholds, consider MAX6837HXSD3 (1.313V) or MAX6837IXSD3 (1.388V).

Is a pullup resistor required for the MAX6837VXSD3's RESET output?

Yes - because the MAX6837VXSD3 features an open-drain active-low RESET output, an external pullup resistor is mandatory. It can connect to any voltage rail from 0V to 6V (including higher than VCC), enabling level-shifting. Typical values range from 10kΩ to 100kΩ depending on bus capacitance and rise-time requirements.