Analog Devices Inc./Maxim Integrated MAX6835IXSD0+T

Overview

MAX6835IXSD0+T from Maxim Integrated is a 4-pin SC70 ultra-low-voltage microprocessor reset circuit with push-pull active-low RESET output, 1.388V factory-set reset threshold, 70µs timeout period (D0), ±2.5% threshold accuracy over temperature, and 7.5µA typical supply current. It monitors +1.2V to +1.8V supplies in portable µP systems and asserts reset during brownout or power-up sequencing.

For engineers reviewing the MAX6835IXSD0+T datasheet, MAX6835IXSD0+T pinout, MAX6835IXSD0+T application, or MAX6835IXSD0+T equivalent, key selection criteria include guaranteed reset validity down to VCC = 0.55V, debounced manual reset input (MR), immunity to short negative VCC transients, and compatibility with low-power battery-operated embedded designs requiring precise voltage supervision.

Technical Context

The MAX6835IXSD0+T implements a precision bandgap-based voltage comparator with internal 20kΩ MR pullup and fixed 70µs reset timeout. Its reset assertion logic responds to VCC falling below 1.388V or MR being pulled low, holding RESET low for exactly 70µs after recovery - making it suitable for fast-boot digital systems where minimal reset hold time is critical.

This variant belongs to the MAX6835 subgroup featuring push-pull active-low RESET, debounced MR input, and no RESET-IN pin. Unlike MAX6838–MAX6840, it monitors VCC directly rather than an external divider network, and unlike MAX6832/MAX6834, it uses a 4-pin SC70-4 package to accommodate the dedicated MR terminal.

Key Specifications

Pinout & Package

MAX6835IXSD0+T is housed in a RoHS-compliant 4-pin SC70-4 package (2.0mm × 2.1mm, 0.65mm pitch), optimized for high-density portable PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6832VXRD0+T, MAX6835IXSD0+T adds MR functionality in a larger 4-pin package; compared with MAX6381XR29+T, it delivers 5x lower supply current and 21x shorter timeout - making it superior for ultra-low-power, fast-response applications where manual reset is essential.

Availability

MAX6835IXSD0+T is available at Aetrix Electronics and suitable for wearable health monitors, industrial sensor nodes, and portable medical diagnostics requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6835IXSD0+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, mixed-signal, and power management ICs for demanding industrial, medical, and communications applications.

The MAX6832–MAX6840 family was developed specifically for ultra-low-voltage µP supervision in space-constrained, battery-powered systems - emphasizing sub-1µA quiescent current, SC70 packaging, and factory-trimmed thresholds for 1.2V–1.8V rails.

FAQ

What is the exact reset threshold voltage of MAX6835IXSD0+T and how is it specified?

The MAX6835IXSD0+T has a factory-set reset threshold of 1.388V, with ±2.5% accuracy over the full operating temperature range of -40°C to +85°C. This value corresponds to the 'I' suffix in the Threshold Suffix Guide and is guaranteed by design - not just typical - meaning every unit meets this specification across temperature and process variation. The threshold is referenced to the monitored VCC supply and remains stable due to internal bandgap regulation.

Does MAX6835IXSD0+T support manual reset, and how is it implemented?

Yes, MAX6835IXSD0+T includes a debounced manual reset input (MR) on pin 3. It features an internal 20kΩ pullup resistor to VCC, allowing direct connection of a normally open momentary switch to ground. The device rejects glitches shorter than 100ns and provides built-in debounce - eliminating the need for external RC filters or firmware intervention. This makes MAX6835IXSD0+T suitable for field-serviceable or user-initiated reset functions in portable equipment.

What is the reset timeout period of MAX6835IXSD0+T and why is it significant?

The MAX6835IXSD0+T has a fixed 70µs reset timeout period (D0 option), the shortest in the MAX6832–MAX6840 family. This ensures the reset signal remains asserted just long enough to guarantee µP core initialization after power recovery - critical in fast-boot applications like sensor nodes and wearables. Unlike longer timeouts (e.g., 30ms or 210ms), the 70µs delay avoids unnecessary system latency while still meeting minimum reset pulse width requirements of modern low-voltage MCUs.

Can MAX6835IXSD0+T operate down to 0.55V VCC, and what happens to RESET output at that level?

Yes, MAX6835IXSD0+T guarantees functional reset assertion down to VCC = 0.55V. Below this voltage, the push-pull RESET output transitions to a high-impedance state (open circuit) rather than floating unpredictably. This behavior prevents undefined logic states on the reset line when the supply collapses fully - a key reliability feature for systems where µP reset integrity must be maintained until the last usable volt.

Is MAX6835IXSD0+T pin-compatible with other devices in the MAX6832–MAX6840 family?

MAX6835IXSD0+T is pin-compatible within its 4-pin SC70-4 subgroup (MAX6835/MAX6836/MAX6837), sharing identical pinout: GND (1), RESET (2), MR (3), VCC (4). However, it is not pin-compatible with 3-pin variants (e.g., MAX6832) or RESET-IN variants (e.g., MAX6838), which have different pin assignments and functions. Always verify pin mapping against the specific ordering suffix and configuration guide before PCB layout.