Analog Devices Inc./Maxim Integrated MAX6326XR25+

Overview

MAX6326XR25+ from Maxim Integrated is an ultra-low-power, active-low push-pull microprocessor supervisory circuit designed to monitor 2.5V supply rails and assert a reset signal during brownout or power-up conditions. It features a factory-trimmed 2.500V reset threshold (±1.5% at +25°C, ±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 power-on reset and brownout protection.

For engineers reviewing the MAX6326XR25+ datasheet, MAX6326XR25+ pinout, MAX6326XR25+ application, or MAX6326XR25+ equivalent, this page provides verified technical context, pin-level design meaning, real-world use scenarios, and validated alternative options for µP reset supervision in space-constrained, low-power embedded designs.

Technical Context

The MAX6326XR25+ implements a precision bandgap-based voltage comparator with hysteresis (6.3mV) to detect VCC falling below 2.500V, triggering an active-low push-pull RESET output. Its internal timing circuit guarantees ≥100ms reset assertion after VCC recovers above threshold, independent of supply ramp rate.

It rejects fast transients on VCC (e.g., ≤20µs glitches at 200mV overdrive) and maintains valid reset state down to 1.2V VCC. The device requires no external components and is fully specified across –40°C to +85°C with 40ppm/°C reset threshold tempco.

Key Specifications

Pinout & Package

MAX6326XR25+ is housed in a 3-pin SC70-3 package (outline X3-2), footprint-compatible with SOT23-3 but with smaller 1.25mm × 0.85mm body and 0.65mm lead pitch. This ultra-compact form factor targets high-density portable PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TR25+T and TPS3808G33DBVR, the MAX6326XR25+ delivers tighter threshold accuracy (±1.5%), longer guaranteed timeout (100ms min), and lower quiescent current (1µA)-making it optimal for long-life, precision-critical 2.5V system supervision where minimal BOM and deterministic timing are mandatory.

Availability

MAX6326XR25+ is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, and smart meter communication units requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6326XR25+ 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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MAX6326 family was designed specifically for ultra-low-power, precision reset supervision in battery-operated and space-constrained embedded systems-emphasizing minimal ICC, tight threshold tolerance, and robust transient immunity without external components.

FAQ

What is the exact reset threshold voltage of MAX6326XR25+ and how tightly is it specified?

The MAX6326XR25+ has a factory-trimmed nominal reset threshold of 2.500V. At +25°C, it is guaranteed within ±1.5% (2.462V to 2.537V). Over the full operating temperature range of –40°C to +85°C, the threshold remains within ±2.5% (2.437V to 2.562V). This precision eliminates need for external calibration and ensures consistent behavior across environmental conditions. The MAX6326XR25+ achieves this using laser-trimmed on-chip resistors.

Does MAX6326XR25+ require any external components to function?

No, the MAX6326XR25+ requires zero external components. Its internal voltage reference, comparator, timer, and push-pull output driver are fully integrated. Unlike discrete solutions or older supervisors, it needs no external capacitor for timeout setting or pull-up resistor for the RESET line-reducing PCB area, BOM cost, and assembly steps. This integration is confirmed in the "No External Components" feature and functional block diagram of the MAX6326XR25+ datasheet.

What is the minimum VCC voltage at which MAX6326XR25+ guarantees correct reset state?

The MAX6326XR25+ guarantees correct reset assertion and de-assertion behavior down to 1.2V VCC over the full –40°C to +85°C temperature range. Below 1.2V, the device may not maintain valid logic states on the RESET pin. This specification is explicitly stated in the Electrical Characteristics table under "VCC Range" and enables reliable operation during severe brownout events common in automotive and battery-powered systems using the MAX6326XR25+.

How does MAX6326XR25+ handle short voltage transients on the VCC line?

The MAX6326XR25+ incorporates internal filtering and comparator hysteresis (6.3mV) to ignore fast VCC transients. According to its Typical Operating Characteristics, it rejects negative-going glitches ≤20µs wide when the overdrive (VTH – VCC) is 200mV. This immunity prevents spurious resets caused by switching noise from DC-DC converters or motor drivers-ensuring system stability without requiring additional input filtering for the MAX6326XR25+.

Is MAX6326XR25+ pin-compatible with other members of the MAX6326 family or legacy Maxim supervisors?

Yes, the MAX6326XR25+ shares identical SC70-3 pinout and footprint with all MAX6326 variants (e.g., MAX6326XR22+, MAX6326XR29+) and is pin-compatible with the MAX803/MAX809/MAX810 series. All use the same 1-GND / 2-RESET / 3-VCC assignment. This allows drop-in replacement in existing designs targeting 2.5V supervision, provided the output type (active-low push-pull) matches the original design's requirements for the MAX6326XR25+.