Analog Devices Inc./Maxim Integrated MAX6835HXSD3+

Overview

MAX6835HXSD3+ from Maxim Integrated is a micropower voltage supervisor IC with push-pull active-low reset output, factory-set 1.313V reset threshold, and 210ms reset timeout period, designed to monitor +1.2V to +1.8V supply rails in low-voltage microprocessor systems and portable equipment.

For engineers reviewing the MAX6835HXSD3+ datasheet, MAX6835HXSD3+ pinout, MAX6835HXSD3+ application, or MAX6835HXSD3+ equivalent, this device delivers precise brownout detection, manual reset debouncing, ±2.5% threshold accuracy over temperature, ultra-low 7.5µA supply current, and guaranteed reset validity down to VCC = 0.55V - critical for reliable power sequencing in battery-powered embedded systems.

Technical Context

The MAX6835HXSD3+ implements a precision bandgap-based voltage comparator with hysteresis (0.75% of VTH) to reject fast VCC transients, paired with a fixed 210ms timeout monostable circuit triggered on VCC drop below 1.313V or MR assertion. Its internal 20kΩ MR pullup enables direct switch-to-ground connection without external components.

This variant belongs to the MAX6835 subgroup featuring debounced manual reset input (MR), push-pull active-low RESET output, and SC70-4 packaging - distinct from open-drain or adjustable-threshold variants like MAX6837 or MAX6839. It monitors VCC directly and does not support RESET-IN functionality.

Key Specifications

Pinout & Package

MAX6835HXSD3+ is housed in a 4-pin SC70-4 package (2.0mm × 2.1mm, 0.65mm pitch), optimized for space-constrained portable designs. Pin 1 is GND, Pin 2 is RESET, Pin 3 is MR, and Pin 4 is VCC - fully compatible with industry-standard SC70 footprint layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6835HXSD3+, the MAX6835VXSD3+ offers identical timing and interface but targets higher supply voltages, while the MAX6316HUT46+T trades MR integration for 80% lower supply current - making it preferable only when manual reset is omitted and minimal leakage dominates power budget.

Availability

MAX6835HXSD3+ is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, battery management units (BMUs), and low-power wireless gateways requiring stable component supply with guaranteed long-term manufacturability.

Supply support for MAX6835HXSD3+ 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 product line was engineered specifically for ultra-low-voltage microprocessor supervision in space- and power-constrained systems, emphasizing precision threshold accuracy, minimal quiescent current, and robust transient immunity.

FAQ

What is the exact reset threshold voltage of the MAX6835HXSD3+ and how stable is it over temperature?

The MAX6835HXSD3+ has a factory-set reset threshold of 1.313V with ±2.5% accuracy over the full -40°C to +85°C operating range. This specification is guaranteed by design and 100% production tested at +25°C. The normalized threshold variation versus temperature is less than ±0.5% across the range, as confirmed in Figure MAX6832-40 toc04 of the datasheet. This stability ensures deterministic reset behavior without derating in industrial environments.

Does the MAX6835HXSD3+ support manual reset, and what are the electrical requirements for the MR pin?

Yes, the MAX6835HXSD3+ features a debounced manual reset input (MR) on Pin 3. The MR pin has an internal 20kΩ pullup to VCC and requires a logic-low signal ≤0.3×VCC to assert reset. Minimum pulse width is 2µs, and it rejects glitches shorter than 100ns. No external components are needed - a normally open momentary switch from MR to ground suffices. The pin is compatible with CMOS logic and open-drain drivers.

What is the function of the RESET output on the MAX6835HXSD3+, and how should it be interfaced to a microcontroller?

The MAX6835HXSD3+ provides a push-pull active-low RESET output on Pin 2. When asserted, it actively pulls the line to GND; when deasserted, it drives HIGH to VCC. It interfaces directly to standard µP reset inputs without external pullups. For example, with a 1.3V core supply, RESET sinks ≥15µA at 0.15V (VOL) and sources ≥50µA at 0.8×VCC (VOH), meeting most ARM and RISC-V reset input thresholds.

Can the MAX6835HXSD3+ monitor supply voltages below 1.2V, and what is its minimum functional VCC?

No - the MAX6835HXSD3+ is designed to supervise nominal 1.2V to 1.8V supplies and does not support adjustable threshold (RESET-IN) functionality. Its minimum functional VCC is 0.55V: reset remains valid and asserted down to this level, but the device ceases sinking current below 0.55V. For sub-1.2V monitoring, consider the MAX6838/MAX6839/MAX6840 series with RESET-IN input and 444mV reference.

Is the MAX6835HXSD3+ pin-compatible with other supervisors in the MAX6832–MAX6840 family, and which variants share the same SC70-4 footprint?

Yes - the MAX6835HXSD3+ shares the identical 4-pin SC70-4 package and pinout (GND, RESET, MR, VCC) with MAX6835VXSD3+, MAX6835FXSD3+, MAX6836HXSD3+, MAX6837HXSD3+, and all MAX6838–MAX6840 variants. However, output polarity (active-low vs. active-high), MR presence, and RESET-IN capability differ across variants - electrical compatibility requires verification of reset logic level, timeout, and feature set per application.