Analog Devices Inc./Maxim Integrated MAX6334UR18D3+

Overview

MAX6334UR18D3+ from Maxim Integrated is an ultra-low-voltage, open-drain microprocessor reset supervisor IC designed for 1.8V power supply monitoring in space-constrained embedded systems. It asserts an active-low RESET signal when VCC falls below 1.80V (±1.8% at +25°C, ±3% over -40°C to +125°C), maintains reset for ≥100ms after VCC recovers, draws only 3.0–6.0µA at 1.8V, and operates down to VCC = 1.0V with guaranteed output validity - used in portable equipment and critical μP power monitoring.

For engineers reviewing the MAX6334UR18D3+ datasheet, MAX6334UR18D3+ pinout, MAX6334UR18D3+ application, or MAX6334UR18D3+ equivalent, key selection factors include its 1.8V factory-trimmed reset threshold, 100ms minimum timeout, open-drain output architecture for bidirectional reset interfacing, SOT23-3 package compatibility, and guaranteed operation down to 1.0V VCC.

Technical Context

The MAX6334UR18D3+ implements a precision bandgap-based voltage comparator with hysteresis to detect VCC drops below 1.80V, coupled with a temperature-stable RC-based timeout generator delivering ≥100ms reset assertion after recovery. Its open-drain RESET output enables wired-OR configurations and direct interface with microcontrollers featuring bidirectional reset pins (e.g., Motorola 68HC11), requiring only an external pull-up resistor.

Reset propagation delay is ≤24µs during VCC falling edge (10V/ms), and the device rejects transients up to ~100µs depending on overdrive magnitude. It is fully specified across -40°C to +125°C, with supply current varying from 3.0µA (1.8V, +25°C) to 7.0µA (2.5V, +25°C), and RESET leakage current ≤0.5µA when not asserted.

Key Specifications

Pinout & Package

MAX6334UR18D3+ is housed in a RoHS-compliant 3-pin SOT23-3 package (outline 21-0051, land pattern 90-0179), with 1.0mm pitch, 2.92mm × 1.3mm footprint, and thermal pad omitted. Pin 1 = GND, Pin 2 = RESET (open-drain), Pin 3 = VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6334UR18D3+, MAX6333UR18D3+ offers lower minimum VCC (0.7V vs. 1.0V) but lacks open-drain flexibility, while TPS3808G18DBVR adds enable functionality and longer timeout at the cost of higher current and non-pin-compatible packaging.

Availability

MAX6334UR18D3+ is available at Aetrix Electronics and suitable for portable/battery-powered equipment, critical μP/μC power monitoring, intelligent instruments, and controllers requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for MAX6334UR18D3+ 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, automotive, communications, and computing applications.

The MAX633x family delivers ultra-low-voltage, low-power supervisory circuits optimized for reliable reset generation in 1.8V–3.3V digital systems - targeting space-constrained, battery-sensitive, and thermally demanding applications.

FAQ

What is the factory-trimmed reset threshold voltage for MAX6334UR18D3+?

The MAX6334UR18D3+ has a factory-trimmed reset threshold of 1.80V, with a tolerance of ±1.8% at +25°C and ±3% over the full operating temperature range of -40°C to +125°C. This precise threshold is laser-trimmed during manufacturing and requires no external components or calibration, making it ideal for stable 1.8V supply monitoring in MAX6334UR18D3+ applications.

Does MAX6334UR18D3+ support operation below 1.8V supply voltage?

Yes, MAX6334UR18D3+ is guaranteed to maintain correct reset output behavior down to VCC = 1.0V, unlike the MAX6332/MAX6333 variants which operate down to 0.7V. Below 1.0V, the internal circuitry may become indeterminate, so MAX6334UR18D3+ is not recommended for use below this minimum - a key design boundary confirmed in its Absolute Maximum Ratings and Electrical Characteristics tables.

What is the minimum reset timeout period specified for MAX6334UR18D3+?

The MAX6334UR18D3+ provides a minimum reset timeout period of 100ms, corresponding to the "D3" suffix in its part number. This value is guaranteed over temperature and supply voltage, ensuring sufficient time for microprocessor initialization and clock stabilization before release - a critical timing parameter explicitly defined in the Electrical Characteristics table for MAX6334UR18D3+.

Why does MAX6334UR18D3+ use an open-drain RESET output instead of push/pull?

The open-drain RESET output in MAX6334UR18D3+ enables wired-OR connectivity and direct interfacing with microcontrollers that have bidirectional reset pins (e.g., Motorola 68HC11), where either the supervisor or the μP can assert reset. This architecture requires only an external pull-up resistor and avoids contention - a functional distinction clearly documented in the MAX6334UR18D3+ datasheet's Pin Description and Applications Information sections.

Is MAX6334UR18D3+ compatible with the same PCB footprint as MAX809 or MAX6326?

Yes, MAX6334UR18D3+ is pin-compatible with MAX809/MAX810 and MAX6326/MAX6327/MAX6328 in the SOT23-3 package, sharing identical pinout (GND, RESET, VCC) and footprint. This compatibility is explicitly stated in the Benefits and Features section of the MAX6334UR18D3+ datasheet and verified in the Pin Configuration diagram, enabling drop-in replacement in legacy designs using those parts.