Analog Devices Inc./Maxim Integrated MAX6334UR16D2

Overview

MAX6334UR16D2 from Maxim Integrated is an open-drain, active-low microprocessor supervisory circuit designed to monitor 1.6V power supplies in ultra-low-voltage digital systems. It asserts reset when VCC falls below 1.60V (±3% over temperature), maintains reset for ≥20ms after VCC recovers, draws only 3.3µA at 2.5V, and operates down to VCC = 1.0V while guaranteeing valid RESET output-used in battery-powered controllers and portable instrumentation.

For engineers reviewing the MAX6334UR16D2 datasheet, MAX6334UR16D2 pinout, MAX6334UR16D2 application, or MAX6334UR16D2 equivalent, key selection criteria include its 1.6V factory-trimmed reset threshold, 20ms minimum timeout, open-drain output architecture for bidirectional µP reset pin interfacing, and guaranteed operation to 1.0V supply-critical for brownout detection in space-constrained embedded designs.

Technical Context

The MAX6334UR16D2 implements a precision voltage comparator with factory-trimmed 1.60V reset threshold (±1.8% at +25°C, ±3% over –40°C to +125°C) and built-in hysteresis to reject fast transients up to 24µs at 10V/ms slew rate. Its open-drain RESET output requires an external pull-up and supports wired-OR configurations with microcontrollers like the Motorola 68HC11.

Unlike push/pull variants (MAX6332/MAX6333), the MAX6334UR16D2's output stage is optimized for low-leakage (<0.5µA) deasserted-state operation and interfaces directly with high-impedance or bidirectional reset inputs-enabling flexible system-level reset arbitration without additional logic.

Key Specifications

Pinout & Package

The MAX6334UR16D2 is housed in a 3-pin SOT23 package (outline 21-0051, land pattern 90-0179), with gull-wing leads, RoHS-compliant lead-free finish (U3+1 code), and thermal pad omitted.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor reset supervision applications.

Compared with MAX6334UR16D2, MAX6326UR16D2 offers lower supply voltage operation but forfeits bus-sharing capability, while TPS3808G16DBVR adds automotive qualification and manual reset at the cost of higher quiescent current-making MAX6334UR16D2 optimal for cost-sensitive, space-constrained, battery-powered designs requiring open-drain flexibility.

Availability

MAX6334UR16D2 is available at Aetrix Electronics and suitable for battery-powered instrumentation, automotive body control modules, and industrial sensor nodes requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6334UR16D2 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 industrial, computing, and automotive applications.

The MAX633x family delivers ultra-low-voltage, low-power microprocessor supervisory circuits targeting space-constrained, battery-operated systems where supply monitoring reliability and minimal quiescent current are critical.

FAQ

What is the factory-trimmed reset threshold voltage for MAX6334UR16D2?

The MAX6334UR16D2 has a factory-trimmed reset threshold of 1.60V, with ±1.8% accuracy at +25°C and ±3% over the full operating temperature range of –40°C to +125°C. This value is confirmed in Table 1 of the datasheet and applies specifically to the "UR16" suffix. The MAX6334UR16D2 uses this precise threshold to detect brownout conditions in 1.8V and 2.5V digital systems without external components.

Does MAX6334UR16D2 support operation below 1.8V supply voltage?

Yes, the MAX6334UR16D2 is guaranteed to operate and assert a valid RESET signal down to VCC = 1.0V, unlike the MAX6332/MAX6333 variants which guarantee operation to 0.7V. This 1.0V minimum ensures reliable reset assertion during deep brownout events in low-voltage systems. The MAX6334UR16D2 achieves this while maintaining open-drain output functionality and <0.5µA leakage when deasserted.

What is the purpose of the "D2" suffix in MAX6334UR16D2?

The "D2" suffix in MAX6334UR16D2 indicates a factory-programmed nominal reset timeout period of 20ms minimum. Per the Ordering Information section, "D1" = 1ms min, "D2" = 20ms min, and "D3" = 100ms min. This timeout begins when VCC rises above the 1.60V threshold and ensures the microprocessor remains held in reset long enough to complete internal initialization-critical for reliable boot in ARM and RISC-based µCs.

Can MAX6334UR16D2 interface directly with a bidirectional microcontroller reset pin?

Yes, the MAX6334UR16D2's open-drain active-low RESET output is explicitly designed for direct interface with bidirectional µP reset pins such as those found on the Motorola 68HC11. When used with a single external pull-up resistor, either the MAX6334UR16D2 or the µP can assert reset on the shared line. This eliminates need for additional logic or level shifters-confirmed in the Applications Information section under "Interfacing to µPs with Bidirectional Reset Pins."

Is MAX6334UR16D2 available in lead-free packaging?

Yes, MAX6334UR16D2 is available in lead-free packaging. Per the Ordering Information, lead-free versions are denoted by replacing "-T" with "+T" in the part number (e.g., MAX6334UR16D2+T). The device uses RoHS-compliant terminations, and the package code "U3+1" confirms lead-free status. All standard versions-including MAX6334UR16D2-are supplied in tape-and-reel format only.