Analog Devices Inc./Maxim Integrated MAX6326UR27-T

Overview

MAX6326UR27-T from Maxim Integrated is an ultra-low-power, active-low push-pull microprocessor supervisory circuit designed to monitor VCC supply voltage and assert a reset signal during power-up, brownout, or power-down events. It features a factory-trimmed 2.70V reset threshold (±2.5% over -40°C to +85°C), 100ms minimum reset timeout, 1µA max supply current at 3V, and operates down to 1.2V VCC. It is used in portable battery-powered systems requiring reliable, low-quiescent-power reset supervision.

For engineers reviewing the MAX6326UR27-T datasheet, MAX6326UR27-T pinout, MAX6326UR27-T application, or MAX6326UR27-T equivalent, key selection criteria include its SOT23-3 package, push-pull active-low RESET output, guaranteed operation down to 1.2V VCC, immunity to fast VCC transients, and compatibility with 2.5V/3V/3.3V/5V digital systems.

Technical Context

The MAX6326UR27-T implements a precision bandgap-based reset comparator with 40ppm/°C temperature coefficient and 6.3mV hysteresis to prevent chatter near the 2.70V threshold. Its internal timing circuit ensures a minimum 100ms reset assertion after VCC rises above VTH, independent of supply ramp rate.

Designed for direct interface with µP reset inputs, the push-pull output drives low (≤0.3V at 1.6mA) when asserted and high (≥0.8·VCC) when released, eliminating external pull-up components. The device ignores VCC transients shorter than ~100µs at 100mV overdrive, enhancing noise immunity in noisy power environments.

Key Specifications

Pinout & Package

MAX6326UR27-T is housed in a 3-pin SOT23-3 package (outline 21-0051), with 0.95mm pitch, 2.9mm × 1.6mm footprint, and gull-wing leads compatible with standard reflow processes.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD3-T and TPS3808G12DBVR, the MAX6326UR27-T delivers guaranteed 100ms reset hold time without external components, lower ICC, and tighter threshold accuracy-making it optimal for space-constrained, battery-sensitive designs where deterministic reset behavior is critical.

Availability

MAX6326UR27-T is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, smart utility meters, and automotive body control units requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MAX6326UR27-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, mixed-signal, and power management ICs for industrial, computing, communications, and consumer applications.

The MAX6326 family delivers ultra-low-power, pin-compatible µP reset supervisors optimized for battery-operated and space-constrained systems where reliability, accuracy, and zero-component count are essential design requirements.

FAQ

What is the exact reset threshold voltage of MAX6326UR27-T and how does it vary with temperature?

The MAX6326UR27-T has a factory-trimmed nominal reset threshold of 2.70V at +25°C, with ±1.5% tolerance at room temperature and ±2.5% over the full –40°C to +85°C operating range. Its temperature coefficient is 40ppm/°C, meaning the threshold drifts by approximately ±0.011V across the full temperature span. This ensures predictable brownout detection in industrial and automotive environments where supply rails fluctuate with ambient conditions. The MAX6326UR27-T maintains this specification without external calibration.

Does MAX6326UR27-T require any external components to function?

No, the MAX6326UR27-T requires zero external components. Its internal precision voltage reference, comparator, and timing circuit generate a fully specified 100ms minimum reset pulse width upon power-up or brownout. Unlike many reset ICs that need external capacitors for delay setting or pull-up resistors for open-drain outputs, the MAX6326UR27-T's push-pull active-low RESET output drives directly into the µP reset pin, reducing BOM count and PCB area. This integration is confirmed in the device's "No External Components" feature list and electrical characteristics table.

What is the supply current consumption of MAX6326UR27-T under typical operating conditions?

The MAX6326UR27-T draws a maximum supply current of 1.0µA at VCC = 3.0V and +25°C, with typical consumption of 0.5µA. At 5.5V, ICC remains ≤1.75µA. This ultra-low quiescent current is guaranteed across the full –40°C to +85°C temperature range and enables multi-year operation from primary lithium or coin-cell batteries. The value is measured with no load on the RESET pin and is explicitly specified in the Electrical Characteristics table under "Supply Current (ICC)" for the MAX6326 series.

How does MAX6326UR27-T handle fast voltage transients on the VCC line?

The MAX6326UR27-T incorporates built-in immunity to fast VCC transients: its reset comparator is designed to ignore negative-going glitches shorter than ~100µs when the overdrive (VTH – VCC) is 100mV, as shown in the "Maximum Transient Duration vs. Reset Threshold Overdrive" graph. This prevents spurious resets caused by switching noise, ESD coupling, or load-dump events. The device achieves this through internal filtering and comparator hysteresis (6.3mV), ensuring robust operation in electrically noisy environments without requiring external RC filters.

Is MAX6326UR27-T pin-compatible with other common reset ICs like MAX809 or MAX810?

Yes, the MAX6326UR27-T is pin-compatible with the MAX803/MAX809/MAX810 families in the SOT23-3 package, sharing identical pin 1 (GND), pin 2 (RESET), and pin 3 (VCC) assignments. However, unlike the MAX809 (open-drain) or MAX810 (push-pull active-high), the MAX6326UR27-T provides active-low push-pull output. This allows direct drop-in replacement in circuits designed for active-low reset, but requires verification that the host µP accepts active-low signaling and that no external pull-up conflicts exist. Compatibility is explicitly stated in the datasheet's "Pin Compatible with…" feature bullet.