Analog Devices Inc./Maxim Integrated MAX6837IXSD2+

Overview

MAX6837IXSD2+ from Maxim Integrated is an ultra-low-voltage, open-drain active-low microprocessor reset circuit in SC70-4 package, designed to monitor +1.388V supply rails with ±2.5% threshold accuracy over temperature and assert reset for 30ms after VCC recovery or manual reset release. It features a 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 MAX6837IXSD2+ datasheet, MAX6837IXSD2+ pinout, MAX6837IXSD2+ application, or MAX6837IXSD2+ equivalent, key selection criteria include its 1.388V factory-set reset threshold, 30ms timeout (D2 suffix), SC70-4 footprint compatibility, open-drain output requiring external pullup, and MR debounce capability - all critical for low-power embedded power sequencing and reset integrity validation.

Technical Context

The MAX6837IXSD2+ implements a precision voltage comparator with 444mV internal reference, comparing VCC against a factory-trimmed threshold derived from that reference. Its reset assertion logic combines VCC monitoring and debounced manual reset (MR) input, with fixed 30ms timeout generated by an on-chip RC timing circuit.

It uses BiCMOS process technology (681 transistors), supports operation from VCC = 0.55V to 3.6V, and maintains reset assertion during fast negative VCC transients up to 100ns at 20mV overdrive - confirmed by transient immunity characterization curves in the datasheet.

Key Specifications

Pinout & Package

MAX6837IXSD2+ is housed in a 4-pin SC70-4 package (2.0mm × 2.1mm, 0.65mm pitch), compatible with standard reflow profiles and space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6837IXSD2+, MAX6837VXSD2+ shifts threshold upward for higher-supply systems, while MAX6835IXSD2+ replaces open-drain with push-pull output - both retain identical timeout, MR debounce, and SC70-4 footprint, enabling direct substitution only when threshold or output topology aligns with system requirements.

Availability

MAX6837IXSD2+ is available at Aetrix Electronics and suitable for portable medical devices, industrial sensor nodes, and battery-powered instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6837IXSD2+ 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 computing markets.

The MAX6832–MAX6840 family delivers ultra-low-voltage reset supervision for battery-powered and energy-sensitive systems, emphasizing minimal quiescent current, small SC70 packaging, and factory-trimmed accuracy - targeting portable and embedded µP power integrity.

FAQ

What is the exact reset threshold voltage of the MAX6837IXSD2+?

The MAX6837IXSD2+ has a factory-set reset threshold of 1.388V, with ±2.5% accuracy over the full operating temperature range (-40°C to +85°C). This value is defined by the 'I' suffix in the part number and is trimmed during production using Maxim's BiCMOS process. The threshold is referenced to an internal 444mV bandgap, scaled precisely for 1.4V nominal supply monitoring - no external adjustment is possible.

Does the MAX6837IXSD2+ require an external pullup resistor on the RESET pin?

Yes, the MAX6837IXSD2+ features an open-drain active-low RESET output, which requires an external pullup resistor to function correctly. The datasheet specifies typical values between 10kΩ and 100kΩ, connected to VCC or a higher voltage rail (up to +6.0V). Without this pullup, RESET cannot transition high and will remain indeterminate, preventing proper µP reset release.

What is the purpose of the MR pin on the MAX6837IXSD2+?

The MR (Manual Reset) pin on the MAX6837IXSD2+ is an active-low, debounced input with a 20kΩ internal pullup to VCC. Pulling MR low forces an immediate reset regardless of VCC level, and reset remains asserted for the full 30ms timeout after MR is released. This enables hardware-initiated resets via pushbuttons or external logic without added filtering components.

Can the MAX6837IXSD2+ operate reliably below 1.0V supply voltage?

Yes, the MAX6837IXSD2+ is specified to operate down to VCC = 0.55V and guarantees valid reset assertion down to that level. Its internal comparator and timing circuitry remain functional, and the open-drain RESET output continues sinking current until VCC drops below 0.55V. Below that, RESET becomes high-impedance - a pulldown resistor may be added if reset state must be held low to ground.

How does the 30ms reset timeout (D2 suffix) affect system startup timing?

The D2 suffix on MAX6837IXSD2+ configures a fixed 30ms reset timeout period, meaning RESET remains asserted for exactly 30ms after VCC rises above 1.388V or after MR is released. This ensures µPs and peripheral ICs have sufficient time to stabilize their internal clocks and power domains before execution begins - eliminating race conditions common in low-voltage, fast-ramping systems.