Analog Devices Inc./Maxim Integrated MAX6837HXSD0+T

Overview

MAX6837HXSD0+T from Maxim Integrated is an ultra-low-voltage, open-drain active-low microprocessor reset circuit in SC70-4 package, designed to monitor +1.313V supply rails with ±2.5% threshold accuracy over temperature. It features a 210ms reset timeout period, 7.5µA typical supply current, and operates across -40°C to +85°C. Used for reliable power-on reset assertion in battery-powered microcontroller systems.

For engineers reviewing the MAX6837HXSD0+T datasheet, MAX6837HXSD0+T pinout, MAX6837HXSD0+T application, or MAX6837HXSD0+T equivalent, key selection criteria include its open-drain RESET output requiring external pullup, debounced MR input, 210ms fixed timeout, and compatibility with low-voltage (1.2V–1.8V) digital systems.

Technical Context

The MAX6837HXSD0+T implements a precision voltage comparator with 444mV internal reference, comparing VCC against factory-trimmed 1.313V threshold (H suffix). Its reset logic asserts active-low RESET when VCC falls below threshold or MR is pulled low, holding assertion for exactly 210ms after recovery - no external timing components required.

It integrates a 20kΩ internal MR pullup resistor, supports CMOS-level MR drive, rejects <100ns glitches on MR, and guarantees valid RESET output down to VCC = 0.55V. The open-drain output allows level-shifting and bidirectional µP reset pin interfacing without contention.

Key Specifications

Pinout & Package

MAX6837HXSD0+T is housed in a 4-pin SC70 package (2.0mm × 2.1mm, 0.65mm pitch), optimized for high-density portable designs. Pin 1 = GND, Pin 2 = RESET (open-drain active-low), Pin 3 = MR (debounced manual reset input), Pin 4 = VCC (monitored supply).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6837HXSD0+T, MAX6381XR22D3+T offers identical timing but targets 2.2V systems and eliminates pullup design overhead, while TPS3123E13DBVR trades MR support and accuracy for broader vendor availability and lower unit cost in non-critical applications.

Availability

MAX6837HXSD0+T is available at Aetrix Electronics and suitable for portable medical devices, industrial wireless sensors, smart metering systems, and BLE peripherals requiring stable component supply across extended product lifecycles.

Supply support for MAX6837HXSD0+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) designs precision analog and mixed-signal ICs for power management, sensing, and interface applications in industrial, automotive, and consumer markets.

The MAX6832–MAX6840 family delivers ultra-low-voltage reset supervision for sub-1.8V digital systems, targeting battery-powered and energy-efficient embedded controllers where size, current, and accuracy are critical.

FAQ

What is the exact reset threshold voltage of the MAX6837HXSD0+T?

The MAX6837HXSD0+T has a factory-trimmed reset threshold of 1.313V, specified with ±2.5% accuracy over the full -40°C to +85°C operating temperature range. This value corresponds to the "H" suffix in the part number and is validated per Maxim's Electrical Characteristics table. The threshold remains stable across VCC variations from 0.55V to 3.6V, making MAX6837HXSD0+T suitable for precise low-voltage monitoring in 1.3V core applications.

Does the MAX6837HXSD0+T require an external pullup resistor on the RESET pin?

Yes, the MAX6837HXSD0+T features an open-drain active-low RESET output and requires an external pullup resistor to a defined logic-high voltage. Typical values range from 10kΩ to 100kΩ, connected to either VCC or another compatible supply (up to +6.0V). Without this pullup, the RESET signal cannot achieve a valid HIGH state, rendering MAX6837HXSD0+T unable to release the reset condition properly in most µP interfaces.

What is the function of the MR pin on the MAX6837HXSD0+T?

The MR (Manual Reset) pin on MAX6837HXSD0+T is an active-low, debounced input with an internal 20kΩ pullup resistor to VCC. Pulling MR low forces an immediate reset assertion, independent of VCC level, and reset remains active for the full 210ms timeout after MR returns high. This enables hardware-initiated resets via pushbutton or external logic, and MAX6837HXSD0+T's built-in debounce eliminates need for external filtering components.

Can the MAX6837HXSD0+T operate with VCC below 1.0V?

Yes, the MAX6837HXSD0+T is fully specified to operate with VCC as low as 0.55V, and it guarantees valid reset assertion down to that level. Its internal comparator and logic remain functional, and the open-drain RESET output can sink up to 200µA while asserted. However, below 0.55V, MAX6837HXSD0+T ceases to guarantee RESET validity - a design consideration for ultra-deep brownout scenarios.

What does the "D3" suffix in MAX6837HXSD0+T indicate?

The "D3" suffix in MAX6837HXSD0+T specifies a nominal reset timeout period of 210ms. This is the duration for which the RESET signal remains asserted after VCC rises above the 1.313V threshold or after the MR pin transitions from low to high. The D3 timing is factory-fixed and requires no external components, ensuring predictable µP initialization timing across all units of MAX6837HXSD0+T without calibration or variation.