Analog Devices Inc./Maxim Integrated MAX6834HXRD3+

Overview

MAX6834HXRD3+ from Maxim Integrated is an ultra-low-voltage, open-drain active-low microprocessor reset circuit in SC70-3 package, designed to monitor +1.313V supply (H suffix), assert reset during brownout or power-down, and maintain reset for 210ms after recovery. It operates down to VCC = 0.55V, consumes 7.5µA typical supply current, and supports manual reset via MR pin - used in portable battery-powered µP systems requiring reliable low-voltage supervision.

For engineers reviewing the MAX6834HXRD3+ datasheet, MAX6834HXRD3+ pinout, MAX6834HXRD3+ application, or MAX6834HXRD3+ equivalent, key selection criteria include its 1.313V factory-set threshold, 210ms timeout (D3 suffix), open-drain RESET output requiring external pullup, -40°C to +85°C operation, and compatibility with bidirectional µP reset pins in low-power embedded designs.

Technical Context

The MAX6834HXRD3+ implements a precision voltage comparator with ±2.5% threshold accuracy over temperature and 0.75% hysteresis, monitoring VCC directly without external components. Its reset assertion logic responds to VCC falling below 1.313V or MR pin being pulled low, with fixed 210ms timeout after recovery.

As an open-drain active-low device, it requires an external pullup resistor on RESET - enabling level-shifting across supplies (e.g., 1.2V monitored rail to 3.3V or 5V reset logic) and seamless interfacing with bidirectional µP reset I/O. Immunity to short negative VCC transients (<100ns at 100mV overdrive) ensures robust operation in noisy environments.

Key Specifications

Pinout & Package

MAX6834HXRD3+ is housed in a 3-pin SC70 package (1.25mm × 0.8mm, 0.65mm pitch), optimized for high-density PCB layouts in portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809HTR and TPS3808G13DBVR, the MAX6834HXRD3+ offers unique open-drain output in ultra-small SC70-3, enabling compact bidirectional reset interfaces and multi-rail level shifting - while delivering lowest quiescent current among 1.3V supervisors in 3-pin packages.

Availability

MAX6834HXRD3+ is available at Aetrix Electronics and suitable for portable medical devices, battery-powered wearables, low-voltage microcontroller systems, and energy-harvesting IoT endpoints requiring stable component supply across extended production lifecycles.

Supply support for MAX6834HXRD3+ 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 is a semiconductor company specializing in analog and mixed-signal ICs for power management, sensing, and interface applications - acquired by Analog Devices in 2021 but maintaining distinct product branding and support infrastructure.

The MAX6832–MAX6840 family was engineered specifically for ultra-low-voltage µP reset supervision in space- and power-constrained portable electronics, addressing the growing need for reliable 1.2V–1.8V rail monitoring without external components.

FAQ

What is the exact reset threshold voltage of the MAX6834HXRD3+?

The MAX6834HXRD3+ has a factory-set reset threshold of 1.313V, with ±2.5% accuracy over the full -40°C to +85°C operating temperature range. This value is defined by the 'H' suffix in the part number and is guaranteed by design - not adjustable. The threshold remains stable due to integrated bandgap reference and hysteresis of 0.75% of VTH, preventing chatter near trip point.

Does the MAX6834HXRD3+ require an external pullup resistor on the RESET pin?

Yes, the MAX6834HXRD3+ features an open-drain active-low RESET output and absolutely requires an external pullup resistor. The resistor can 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. Without this pullup, RESET remains floating and nonfunctional.

What is the reset timeout period for the MAX6834HXRD3+?

The MAX6834HXRD3+ provides a fixed reset active timeout period of 210ms, indicated by the 'D3' suffix. This duration begins when VCC rises above 1.313V (or MR is released) and ends when RESET deasserts. It is internally trimmed and guaranteed over temperature, ensuring sufficient hold time for microcontroller boot sequences, PLL locking, and memory initialization in low-power embedded systems.

Can the MAX6834HXRD3+ monitor supply voltages below 1.313V?

No - the MAX6834HXRD3+ is a fixed-threshold device configured only for 1.313V detection and cannot monitor lower voltages. For sub-1.3V supervision (e.g., 0.8V or 0.6V rails), consider the MAX6838/MAX6839/MAX6840 series with RESET-IN input, which uses an external resistor divider to set thresholds as low as 0.44V. The MAX6834HXRD3+ monitors only its own VCC pin and does not support adjustable threshold functionality.

Is the MAX6834HXRD3+ compatible with bidirectional microprocessor reset pins?

Yes, the open-drain active-low RESET output of the MAX6834HXRD3+ is explicitly designed for interoperability with bidirectional µP reset I/O. By connecting RESET directly to the µP's reset pin with a single external pullup, either device can assert reset - the µP during software-initiated resets, and the MAX6834HXRD3+ during power faults. This eliminates need for OR-ing diodes or additional logic gates in the reset path.