Analog Devices Inc./Maxim Integrated MAX6466XR29+T

Overview

MAX6466XR29+T from Maxim Integrated is a micropower supervisory circuit with open-drain active-low reset output, factory-set 2.9V lower trip threshold (VTH−), 150ms minimum reset timeout, ±2.5% threshold accuracy over −40°C to +125°C, and 1.0µA supply current at 3.6V - used for reliable power-on reset generation in battery-powered medical sensors and portable instrumentation.

For engineers reviewing the MAX6466XR29+T datasheet, MAX6466XR29+T pinout, MAX6466XR29+T application, or MAX6466XR29+T equivalent, key selection criteria include guaranteed 150ms reset assertion after VCC recovery, immunity to sub-20µs VCC transients, open-drain compatibility with mixed-voltage logic domains, and SC70-3 footprint suitability for space-constrained PCB layouts.

Technical Context

The MAX6466XR29+T implements a precision bandgap reference and comparator with internally trimmed resistor networks to set VTH− = 2.900V (±2.5%) and VTH+ = 3.031V (5% hysteresis). Its open-drain output requires an external pullup and asserts low when VCC falls below VTH−, holding low for ≥150ms after VCC rises above VTH+.

This device belongs to the MAX6464–MAX6466 µP supervisory subgroup, distinguished from voltage detectors (MAX6461–MAX6463) by its built-in reset timeout function and absence of propagation delay specification - instead guaranteeing minimum assertion duration under all operating conditions.

Key Specifications

Pinout & Package

MAX6466XR29+T is housed in a 3-pin SC70-3 package with exposed pad (not electrically connected). Pin 1 = OUT (open-drain active-low), Pin 2 = GND, Pin 3 = VCC. The package supports reflow soldering per JEDEC J-STD-020 and operates up to +125°C ambient.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar µP supervisory applications.

Compared with MAX6466XR29+T, MAX6466UR29+T offers identical functionality in a thermally robust SOT23-3 package, while TPS3808G33DBVR provides longer timeout and lower cost but sacrifices threshold flexibility and open-drain interoperability - making MAX6466XR29+T optimal for size-critical, multi-rail portable designs requiring precise 2.9V supervision.

Availability

MAX6466XR29+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered data loggers, and industrial handheld terminals requiring stable component supply with guaranteed long-term availability and lead-free compliance.

Supply support for MAX6466XR29+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 and mixed-signal ICs for power management, sensing, and connectivity applications - emphasizing ultra-low power, high reliability, and small form factors.

The MAX6461–MAX6466 family was engineered specifically for space- and energy-constrained systems requiring deterministic power-on reset without external components - targeting portable instrumentation, wearables, and industrial edge nodes.

FAQ

What is the exact reset threshold voltage of MAX6466XR29+T and how does it vary with temperature?

The MAX6466XR29+T has a nominal lower trip threshold (VTH−) of 2.900V at +25°C, with guaranteed tolerance of ±2.5% across the full −40°C to +125°C operating range. At temperature extremes, VTH− remains between 2.828V (min at −40°C) and 2.973V (max at +125°C), as confirmed in Table 1a of the datasheet. This tight drift ensures consistent reset behavior in automotive and industrial environments where thermal stability is critical. The MAX6466XR29+T achieves this via on-chip bandgap reference and laser-trimmed resistors.

Does MAX6466XR29+T require any external components to function as a reset supervisor?

No, the MAX6466XR29+T operates autonomously with no external components required for basic reset supervision. Its internal bandgap reference, comparator, trimmed resistor network, and hysteresis circuit eliminate the need for external voltage dividers or timing capacitors. However, because it features an open-drain output, an external pullup resistor (typically 10kΩ to logic rail) is mandatory to establish a defined HIGH state when the output is not asserted. This pullup enables level-shifting and is the only external component needed for full functionality of the MAX6466XR29+T.

How does the 150ms reset timeout of MAX6466XR29+T behave during power-up and brownout recovery?

The MAX6466XR29+T asserts its open-drain output LOW whenever VCC falls below 2.900V (VTH−), and holds it LOW for a minimum of 150ms after VCC rises above 3.031V (VTH+). This timeout is internally generated and guaranteed across −40°C to +125°C - it does not depend on external RC networks or supply slew rate. During power-up, the device remains in reset until VCC exceeds VTH+ and then sustains reset for ≥150ms. During brownout recovery, the same timing applies, ensuring reliable MCU initialization regardless of supply dynamics. This behavior is intrinsic to the MAX6466XR29+T's architecture.

Can MAX6466XR29+T interface with a 1.8V microcontroller reset input while powered from a 3.3V supply?

Yes, the MAX6466XR29+T's open-drain output enables seamless interfacing with 1.8V logic. When powered from a 3.3V VCC, connect the OUT pin to a 1.8V pullup resistor (e.g., 10kΩ). The MAX6466XR29+T will sink current to assert LOW (≤0.4V at 9mA load), satisfying 1.8V logic LOW requirements, and release the line to be pulled HIGH to 1.8V - fully compliant with 1.8V I/O thresholds. This level-shifting capability is a core design feature of the MAX6466XR29+T and eliminates external translators.

What is the maximum transient immunity of MAX6466XR29+T and how is it verified?

The MAX6466XR29+T is immune to VCC transients ≤20µs in duration when the overdrive (VTH− − VCC) is 100mV, as shown in Figure 4 (MAX6461 toc04) of the datasheet. Immunity degrades logarithmically with increasing overdrive - e.g., at 200mV overdrive, maximum tolerable pulse width drops to ~5µs. This specification is validated through characterization across temperature and process corners, ensuring robust operation against switching regulator noise, ESD-induced supply dips, and load-dump events. The MAX6466XR29+T's internal hysteresis and comparator design inherently provide this transient rejection without external filtering.