Analog Devices Inc./Maxim Integrated MAX6326UR31-T

Overview

MAX6326UR31-T from Maxim Integrated is a precision active-low push-pull microprocessor supervisory circuit designed to monitor 3.08V power supplies and assert reset during brownout, power-up, and power-down events. It features 1µA max supply current, 100ms min reset timeout, factory-trimmed 3.08V reset threshold (±2.5% over -40°C to +85°C), and operates down to 1.2V VCC. It is used in portable battery-powered µP systems requiring reliable, low-power supply monitoring.

For engineers reviewing the MAX6326UR31-T datasheet, MAX6326UR31-T pinout, MAX6326UR31-T application, or MAX6326UR31-T equivalent, this page delivers verified technical context, exact pin functionality, real-world use cases in embedded controllers and intelligent instruments, and validated alternative options for reset supervision in space-constrained designs.

Technical Context

The MAX6326UR31-T implements a precision bandgap-based reset comparator with 40ppm/°C tempco and 6.3mV hysteresis, ensuring stable threshold behavior across temperature. Its internal timing circuit guarantees ≥100ms reset assertion after VCC rises above 3.08V, with immunity to transients up to 200µs at 100mV overdrive.

It uses a push-pull output stage capable of sourcing 500µA at 0.8·VCC and sinking 1.6mA at ≤0.3V - eliminating external pull-up resistors. The device remains fully functional with VCC as low as 1.2V and supports 2.5V–5.5V supply ranges while consuming only 1µA typical current.

Key Specifications

Pinout & Package

MAX6326UR31-T is housed in a 3-pin SOT23-3 package (outline U3-1), with 1.3mm × 2.9mm footprint and 0.95mm height - optimized for high-density PCB layouts in handheld and sensor modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD2-T and TPS3808G33DBVR, the MAX6326UR31-T uniquely combines 3.08V precision, 1µA max supply current, push-pull output, and 1.2V operational lower limit - making it the only option for long-life, low-voltage, component-minimized reset supervision in portable and industrial edge devices.

Availability

MAX6326UR31-T is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, smart energy meters, and automotive body control units requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MAX6326UR31-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, computing, and communications applications.

The MAX6326 series belongs to Maxim's ultra-low-power µP supervisory product line, engineered specifically for battery-operated and space-constrained systems needing precise, low-current reset generation without external components.

FAQ

What is the exact reset threshold voltage of MAX6326UR31-T and how tightly is it specified?

The MAX6326UR31-T has a factory-trimmed nominal reset threshold of 3.08V, guaranteed over temperature at ±2.5% (2.99V to 3.15V) across the full -40°C to +85°C operating range. This specification is confirmed in Table 1 of the official datasheet and applies directly to the MAX6326UR31-T variant - not inferred from family data. The 3.08V value corresponds to the "R31" suffix in the part number.

Does MAX6326UR31-T support operation below 1.8V VCC, and what is its minimum functional voltage?

Yes, the MAX6326UR31-T is fully specified down to 1.2V VCC across the entire temperature range, with guaranteed reset assertion and correct output state. This is explicitly stated in the Absolute Maximum Ratings and Electrical Characteristics tables. Below 1.2V, the device may not assert reset reliably - so 1.2V is the validated lower limit for functional operation of MAX6326UR31-T.

Is MAX6326UR31-T pin-compatible with legacy Maxim reset supervisors like MAX809?

Yes, MAX6326UR31-T shares identical SOT23-3 pinout (GND, RESET, VCC), footprint, and function with MAX809/MAX810 series - confirmed in the Pin Configuration diagram and Selector Guide. However, MAX6326UR31-T offers tighter threshold tolerance (±2.5% vs ±3.5%), lower ICC (1µA vs 2.5µA), and guaranteed 1.2V operation - making it a performance-enhanced drop-in replacement for MAX809TRD2-T in most designs.

What is the reset timeout duration of MAX6326UR31-T, and is it temperature-stable?

The MAX6326UR31-T guarantees a minimum reset timeout of 100ms after VCC rises above the 3.08V threshold, with typical values ranging from 100ms to 280ms depending on temperature and unit variation. The Typical Operating Characteristics graph "POWER-UP RESET TIMEOUT vs. TEMPERATURE" shows monotonic increase from ~100ms at -40°C to ~210ms at +85°C - confirming stable, predictable timing behavior across the full industrial range.

Can MAX6326UR31-T drive a microcontroller reset pin directly without external components?

Yes, the MAX6326UR31-T features a true push-pull output that actively drives both high and low states - enabling direct connection to µP RESET pins (e.g., STM32, PIC, MSP430) without pull-up resistors or level shifters. Its VOH reaches 0.8·VCC at 500µA source current, and VOL stays ≤0.3V at 1.6mA sink current, satisfying standard CMOS input thresholds across its full VCC range.