Analog Devices Inc./Maxim Integrated MAX6326UR28

Overview

MAX6326UR28 from Maxim Integrated is an ultra-low-power, active-low push-pull microprocessor supervisory circuit designed to monitor 2.8V power supplies in embedded digital systems. It asserts a reset signal when VCC falls below 2.800V (±1.5% at +25°C), holds reset for ≥100ms after VCC recovers, draws ≤1µA supply current, and operates over –40°C to +85°C - enabling reliable brownout protection in battery-powered controllers and portable instrumentation.

For engineers reviewing the MAX6326UR28 datasheet, MAX6326UR28 pinout, MAX6326UR28 application, or MAX6326UR28 equivalent, this page delivers verified technical context, precise reset threshold behavior, SOT23-3 package integration details, and validated alternative options for µP reset design validation and BOM optimization.

Technical Context

The MAX6326UR28 implements a precision bandgap-based voltage comparator with factory-trimmed 2.800V reset threshold (±1.5% at +25°C, ±2.5% over –40°C to +85°C) and 9.5mV hysteresis. Its reset timeout is guaranteed ≥100ms after VCC rises above VTH, with immunity to transients <200µs at 100mV overdrive.

This device uses a push-pull output stage capable of sourcing 500µA (VOH ≥0.8·VCC) and sinking 1.6mA (VOL ≤0.4V), eliminating external pull-up resistors. It remains fully functional down to VCC = 1V and requires no external components for basic reset supervision.

Key Specifications

Pinout & Package

MAX6326UR28 is housed in a 3-pin SOT23-3 package (JEDEC MO-178AA), footprint-compatible with industry-standard µP reset ICs and optimized for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326UR28, MAX809TR28D3T1G offers longer reset hold time but consumes 60% more quiescent current, while TPS3808G125DBVR introduces threshold inaccuracy and external component dependency - making MAX6326UR28 optimal for fixed 2.8V precision and minimal power budget.

Availability

MAX6326UR28 is available at Aetrix Electronics and suitable for industrial controllers, portable medical devices, and automotive body electronics requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6326UR28 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, sensing, and interface applications in industrial, automotive, and computing markets.

The MAX6326 family delivers ultra-low-power, factory-trimmed reset supervision for microprocessor-based systems where reliability, small size, and minimal quiescent current are critical design constraints.

FAQ

What is the exact reset threshold voltage of MAX6326UR28 and how tightly is it specified?

The MAX6326UR28 has a factory-trimmed reset threshold of 2.800V, specified as ±1.5% at +25°C and ±2.5% over the full –40°C to +85°C operating range. This precision enables robust brownout detection on 2.8V power rails without calibration. The MAX6326UR28's 9.5mV hysteresis further prevents chatter near the trip point. All tolerance values are production-tested per Maxim's datasheet.

Does MAX6326UR28 require any external components to function as a reset supervisor?

No, MAX6326UR28 requires zero external components. Its push-pull output drives the reset line directly, eliminating the need for pull-up resistors. The internal voltage reference, comparator, and timing circuitry are fully integrated. This simplifies layout, reduces BOM cost, and improves reliability - a key advantage confirmed in the MAX6326UR28 datasheet's "No External Components" feature.

What is the maximum supply current of MAX6326UR28 and at what conditions is it measured?

The MAX6326UR28 draws ≤1µA maximum supply current (ICC), tested at VCC = 5.5V, TA = –40°C to +85°C, with no load on the RESET pin. Typical current is lower (e.g., ~0.3µA at +25°C, VCC = 3.3V). This ultra-low ICC is critical for battery-powered applications where MAX6326UR28 enables multi-year operation on primary cells - a specification explicitly guaranteed in the Electrical Characteristics table.

How does MAX6326UR28 behave during fast VCC transients, and what is its immunity level?

MAX6326UR28 ignores fast negative-going VCC transients up to 200µs in duration when the overdrive (VTH – VCC) is 100mV, as shown in the "Maximum Transient Duration vs. Reset Threshold Overdrive" graph. This transient immunity prevents false resets during switching noise or load-dump events. The internal comparator architecture and filtering ensure only sustained undervoltage conditions trigger the MAX6326UR28's reset output.

Is MAX6326UR28 pin-compatible with other common reset ICs, and which packages does it support?

MAX6326UR28 is pin-compatible with the MAX803/MAX809/MAX810 series in the SOT23-3 package. It is offered exclusively in the 3-pin SOT23-3 outline (JEDEC MO-178AA), with identical pad layout and mechanical dimensions. This allows drop-in replacement in existing designs targeting 2.8V reset supervision - a compatibility explicitly stated in the MAX6326UR28 datasheet's "Pin Compatible with…" feature list.