Analog Devices Inc./Maxim Integrated MAX6837FXSD0+T

Overview

MAX6837FXSD0+T from Maxim Integrated is an ultra-low-voltage, open-drain active-low microprocessor reset circuit in SC70-4 package, designed to monitor +1.2V to +1.8V supplies with factory-set 1.050V reset threshold (F suffix), 70µs timeout (D0 suffix), and debounced manual reset input (MR). It guarantees valid reset assertion down to VCC = 0.55V and consumes only 7.5µA typical supply current, making it suitable for battery-powered portable systems requiring reliable power-on reset and brownout protection.

For engineers reviewing the MAX6837FXSD0+T datasheet, MAX6837FXSD0+T pinout, MAX6837FXSD0+T application, or MAX6837FXSD0+T equivalent, this page delivers verified specifications including open-drain RESET output behavior, MR debounce timing, ±2.5% threshold accuracy over temperature, SC70-4 mechanical footprint, and compatibility with bidirectional µP reset pins - all critical for low-voltage embedded system design and BOM validation.

Technical Context

The MAX6837FXSD0+T implements a precision voltage comparator with 444mV internal reference, comparing VCC against a factory-trimmed 1.050V threshold. Its reset logic asserts open-drain RESET low when VCC falls below threshold or MR is pulled low, holding reset active for exactly 70µs after recovery - the shortest timeout option in the family, optimized for fast power-up sequencing.

It features a 20kΩ internal MR pullup resistor, 100ns MR glitch rejection, and immunity to negative VCC transients ≤100mV overdrive. The open-drain RESET output supports level-shifting up to 6V and interfaces directly with bidirectional µP reset I/O without external logic.

Key Specifications

Pinout & Package

MAX6837FXSD0+T is housed in a 4-pin SC70-4 package (2.0mm × 2.1mm, 0.65mm pitch), RoHS-compliant with lead-free finish (+T suffix). Pin 1 = GND, Pin 2 = RESET (open-drain active-low), Pin 3 = MR (debounced active-low manual reset), Pin 4 = VCC (monitored supply input).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6837FXSD0+T, MAX6381XR29D3+T offers simpler push-pull drive but sacrifices MR debounce and open-drain level-shifting; TPS3123E12DBVR adds watchdog capability but trades off 70µs speed and 1.050V precision for broader 1.2V nominal coverage.

Availability

MAX6837FXSD0+T is available at Aetrix Electronics and suitable for portable medical sensors, low-power IoT edge nodes, industrial PLC I/O modules, and automotive body control units requiring stable component supply with guaranteed long-term lifecycle support.

Supply support for MAX6837FXSD0+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 analog and mixed-signal ICs for power, sensing, and interface applications.

The MAX6832–MAX6840 family was designed specifically for ultra-low-voltage microprocessor supervision in space-constrained, battery-operated systems requiring high accuracy, low quiescent current, and flexible reset output configurations.

FAQ

What is the exact reset threshold voltage of MAX6837FXSD0+T and how is it trimmed?

The MAX6837FXSD0+T has a factory-trimmed reset threshold of 1.050V ±2.5% over -40°C to +85°C, corresponding to the 'F' suffix in its part number. This value is laser-trimmed during wafer test to match the 1.050V specification in Table 1 of the datasheet, ensuring accuracy without external components. The threshold is referenced to an internal 444mV bandgap, and the trim adjusts the resistor divider ratio feeding the comparator. MAX6837FXSD0+T maintains this accuracy across its full operating temperature range and supply voltage window.

Does MAX6837FXSD0+T support manual reset debouncing, and what is the minimum MR pulse width?

Yes, MAX6837FXSD0+T includes an integrated debounced manual reset input (MR) with internal 20kΩ pullup to VCC. It rejects glitches shorter than 100ns and requires a minimum MR low pulse width of 2µs to reliably trigger reset assertion. The debounce circuitry eliminates need for external RC filters, simplifying layout. MAX6837FXSD0+T holds reset active for the full 70µs timeout after MR returns high, ensuring deterministic behavior during user-initiated resets.

What is the maximum sink current capability of the open-drain RESET output on MAX6837FXSD0+T?

The open-drain RESET output of MAX6837FXSD0+T sinks up to 200µA while maintaining VOL ≤ 0.2V at VCC ≥ 1.5V, and up to 80µA at VCC ≥ 1.0V with VOL ≤ 0.15V. At lower VCC (≥0.55V), it sinks 15µA with VOL ≤ 0.15V. These values are specified in the Electrical Characteristics table and define the maximum pullup resistor value usable with a given supply voltage. MAX6837FXSD0+T's output remains functional down to VCC = 0.55V, enabling robust reset assertion during deep brownout.

Can MAX6837FXSD0+T be used to monitor supply voltages below 1.2V, such as 0.9V or 0.8V?

No, MAX6837FXSD0+T is factory-configured for a fixed 1.050V reset threshold and cannot monitor supplies below that level. For sub-1.2V monitoring, the MAX6838–MAX6840 series with RESET-IN pin should be used instead, as they allow external resistor dividers to set thresholds as low as 0.44V. MAX6837FXSD0+T's VCC operating range starts at 0.55V, but its internal comparator only asserts reset when VCC falls below 1.050V - making it unsuitable for 0.9V or 0.8V supply supervision.

Is MAX6837FXSD0+T pin-compatible with other devices in the MAX6832–MAX6840 family?

MAX6837FXSD0+T shares the same SC70-4 pinout (GND, RESET, MR, VCC) with MAX6835 and MAX6836, but differs from MAX6832–MAX6834 (SC70-3) and MAX6838–MAX6840 (RESET-IN instead of MR). While functionally similar to MAX6835/MAX6836, pin compatibility is limited to SC70-4 variants only. MAX6837FXSD0+T is not pin-compatible with MAX6832–MAX6834 or MAX6838–MAX6840 due to differing pin counts and functions. Always verify pin mapping before substitution.