Analog Devices Inc./Maxim Integrated MAX6461UR31+T

Overview

MAX6461UR31+T from Maxim Integrated is a precision ultra-low-power voltage detector IC designed for battery and power-supply monitoring in space-constrained portable systems. It features a fixed 3.1V lower trip threshold (VTH−), 5% internal hysteresis, ±2.5% threshold accuracy over −40°C to +125°C, and 1.0µA supply current at 3.6V - enabling reliable reset assertion in Li+-based medical devices and cordless phones.

For engineers reviewing the MAX6461UR31+T datasheet, MAX6461UR31+T pinout, MAX6461UR31+T application, or MAX6461UR31+T equivalent, key selection considerations include its SOT23-3 package, active-low push-pull output, 17µs propagation delay, and absence of external components - critical for low-voltage, low-power supervisory designs requiring guaranteed reset behavior during brownout conditions.

Technical Context

The MAX6461UR31+T implements a precision bandgap reference and comparator with internally trimmed resistor networks to set its factory-trimmed 3.100V (±2.5%) VTH− threshold. Its hysteresis circuit ensures VTH+ = VTH− × 1.05 (3.255V), preventing output chatter near the trip point.

This device operates as a voltage detector only (not a µP supervisor), with no internal timeout - output asserts low when VCC falls below VTH− and releases high only after VCC rises above VTH+, delivering deterministic 17µs propagation delay under 10mV/µs slew rate conditions.

Key Specifications

Pinout & Package

SOT23-3 package (3-pin, 1.3mm × 1.75mm × 0.95mm body, 0.95mm pitch), lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV803EB31DBZR and APX803S-31SA-7, the MAX6461UR31+T uniquely delivers 3.1V detection with 1.0µA ICC, ±2.5% accuracy over −40°C to +125°C, and active-low push-pull output - making it the only option meeting full industrial temperature and drive-strength requirements without external components.

Availability

MAX6461UR31+T is available at Aetrix Electronics and suitable for precision battery monitoring, noise-immune µP reset circuits, and portable medical devices requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX6461UR31+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, medical, and communications applications.

The MAX6461–MAX6466 family was engineered specifically for ultra-low-power voltage supervision in battery-operated and thermally demanding systems - emphasizing minimal ICC, factory-trimmed thresholds, and robust transient immunity without external components.

FAQ

What is the exact threshold voltage of MAX6461UR31+T and how is it specified?

The MAX6461UR31+T has a factory-trimmed lower trip threshold (VTH−) of 3.100V ±2.5% at +25°C, with guaranteed limits of 3.023V (min) to 3.178V (max) across −40°C to +125°C. Its upper threshold VTH+ is fixed at VTH− × 1.05 (3.255V nominal), providing 5% hysteresis to prevent output oscillation. This specification is confirmed in Table 1a of the official datasheet and applies exclusively to the "31" suffix variant.

Does MAX6461UR31+T include a reset timeout period?

No, MAX6461UR31+T does not include an internal reset timeout period. It is a voltage detector (not a µP supervisor), so its output asserts low when VCC falls below VTH− and releases high only after VCC rises above VTH+. In contrast, MAX6464–MAX6466 variants provide a minimum 150ms timeout. This distinction is explicitly defined in the Selector Guide and Functional Diagram sections of the MAX6461–MAX6466 datasheet.

What output configuration does MAX6461UR31+T use and how is it implemented?

MAX6461UR31+T uses an active-low push-pull output stage. Pin 1 (OUT) drives logic-low (≤0.3V at 1mA sink) when asserted and actively drives logic-high (≥0.8×VCC) when released - requiring no external pull-up resistor. This configuration is confirmed in the Pin Description table and Ordering Information, where "UR" denotes SOT23-3 package with push-pull active-low output.

Can MAX6461UR31+T operate from a 1.8V supply?

Yes, MAX6461UR31+T operates from 1.2V to 6.0V, including 1.8V. However, its 3.1V threshold means it will assert reset whenever VCC drops below ~3.02V - so at 1.8V supply, the output remains continuously asserted. It is intended to monitor higher rails (e.g., 3.3V) while powered from that same rail, not to supervise sub-threshold supplies.

Is MAX6461UR31+T pin-compatible with other members of the MAX6461–MAX6466 family in SOT23-3?

Yes, all MAX6461–MAX6466 variants in SOT23-3 (UR-series) share identical pinout: Pin 1 = OUT, Pin 2 = GND, Pin 3 = VCC. However, functionality differs - MAX6461/MAX6462/MAX6463 are voltage detectors (no timeout), while MAX6464–MAX6466 are µP supervisors (150ms timeout). Swapping requires verifying functional compatibility, not just pin alignment.