Analog Devices Inc./Maxim Integrated MAX6837VXSD3-T

Overview

MAX6837VXSD3-T from Maxim Integrated is an ultra-low-voltage, open-drain active-low microprocessor reset circuit in SC70-4 package, designed to monitor +1.575V supply rails with ±2.5% threshold accuracy over temperature and assert reset for 210ms 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 - ideal for battery-powered µP systems requiring reliable brownout protection.

For engineers reviewing the MAX6837VXSD3-T datasheet, MAX6837VXSD3-T pinout, MAX6837VXSD3-T application, or MAX6837VXSD3-T equivalent, key selection criteria include its 1.575V factory-set reset threshold, 210ms timeout period (D3 suffix), open-drain active-low output requiring external pullup, debounced manual reset input, and SC70-4 footprint compatibility with space-constrained portable designs.

Technical Context

The MAX6837VXSD3-T implements a precision voltage comparator with 444mV internal reference, comparing VCC against a factory-trimmed threshold (1.575V) to detect brownout conditions. Its reset assertion logic includes fixed 210ms timeout after VCC rises above threshold or MR deassertion, with immunity to transients <100ns on MR and <60µs negative VCC glitches at 100mV overdrive.

It uses BiCMOS process technology (681 transistors), supports VCC from 0.55V to 3.6V, and guarantees open-drain RESET sink capability of 200µA at VCC ≥ 1.5V with VOL ≤ 0.2V. The debounced MR input includes a 20kΩ internal pullup and accepts CMOS-level signals without external filtering.

Key Specifications

Pinout & Package

MAX6837VXSD3-T is housed in a 4-pin SC70-4 package (1.25mm × 0.8mm, 0.65mm pitch), with gull-wing leads suitable for reflow soldering. Pin 1 is marked by a dot or beveled edge.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6837VXSD3-T, MAX6381XR29D3-T removes MR functionality and simplifies output drive but loses system-level reset flexibility; TPS3123E15DBVR offers superior threshold accuracy and lower current but increases PCB area and requires external debounce, making MAX6837VXSD3-T optimal for compact, manually serviceable embedded systems.

Availability

MAX6837VXSD3-T is available at Aetrix Electronics and suitable for battery-powered wearables, industrial sensor nodes, medical handhelds, automotive body electronics, and portable instrumentation requiring stable component supply with guaranteed long-term continuity.

Supply support for MAX6837VXSD3-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 (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MAX6832–MAX6840 family was designed specifically for ultra-low-voltage microprocessor supervision in space- and power-constrained systems, emphasizing factory-trimmed accuracy, minimal external components, and robust transient immunity.

FAQ

What is the exact reset threshold voltage and tolerance for MAX6837VXSD3-T?

The MAX6837VXSD3-T 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 confirmed in the Electrical Characteristics table under "Reset Threshold (VTH)" for the "V" suffix variant. The tolerance ensures reliable detection of brownout on 1.6V nominal supplies across environmental stress conditions.

Does MAX6837VXSD3-T require an external pullup resistor on the RESET pin?

Yes, MAX6837VXSD3-T requires an external pullup resistor on the RESET pin because it features an open-drain active-low output. The datasheet specifies that the pullup may connect to any voltage between 0V and 6V - including supplies higher than VCC - enabling level-shifting. Typical values range from 10kΩ to 100kΩ depending on rise-time and bus loading requirements.

What is the function of the MR pin on MAX6837VXSD3-T and how is it used?

The MR (Manual Reset) pin on MAX6837VXSD3-T is an active-low, internally debounced input with a 20kΩ pullup to VCC. Pulling MR to GND forces a reset regardless of VCC level, and reset remains asserted for the full 210ms timeout after MR is released. It eliminates need for external RC debounce, supporting direct connection to momentary switches or logic outputs in field-serviceable designs.

Can MAX6837VXSD3-T operate reliably when VCC drops below 1.0V?

Yes, MAX6837VXSD3-T guarantees valid reset operation down to VCC = 0.55V for active-low output functionality. Below this, the open-drain output transitions to high-impedance, but the 210ms timeout and threshold comparison remain functional throughout the 0.55V–3.6V range. This ensures supervision integrity during deep brownout scenarios common in battery-depleted portable devices.

Is MAX6837VXSD3-T pin-compatible with other devices in the MAX6832–MAX6840 family?

MAX6837VXSD3-T shares the same SC70-4 pinout (GND, VCC, MR, RESET) with MAX6835 and MAX6836 variants, differing only in reset threshold (V = 1.575V) and timeout (D3 = 210ms). It is not pin-compatible with SC70-3 variants (MAX6832–MAX6834) or RESET-IN variants (MAX6838–MAX6840), which have different pin assignments and functions.