Analog Devices Inc./Maxim Integrated MAX6326UR29

Overview

MAX6326UR29 from Maxim Integrated is an ultra-low-power, active-low push-pull microprocessor supervisory circuit designed to monitor 2.93V power supplies and assert a reset signal during brownout, power-up, or power-down events. It delivers 1µA max supply current, 100ms min reset timeout, ±1.5% reset threshold accuracy at +25°C, and operates from VCC = 1.2V to 5.5V over –40°C to +85°C. It is used in portable battery-powered µP systems requiring reliable, low-cost power monitoring.

For engineers reviewing the MAX6326UR29 datasheet, MAX6326UR29 pinout, MAX6326UR29 application, or MAX6326UR29 equivalent, key selection criteria include its factory-trimmed 2.93V reset threshold, SOT23-3 package, push-pull active-low RESET output, guaranteed reset assertion down to VCC = 1V, and immunity to fast VCC transients.

Technical Context

The MAX6326UR29 implements a precision bandgap-based voltage comparator with hysteresis (6.3mV) to detect when VCC falls below its 2.93V nominal threshold. Its internal timing circuit ensures a minimum 100ms reset pulse width after VCC recovers above threshold, independent of supply ramp rate.

It features a push-pull RESET output capable of sourcing 500µA at 0.8·VCC and sinking 1.6mA at ≤0.3V, eliminating external pull-up components. The device remains fully functional and maintains correct reset state for VCC as low as 1V, enabling robust operation during deep brownout conditions.

Key Specifications

Pinout & Package

MAX6326UR29 is housed in a 3-pin SOT23-3 package (package code U3-1), with 0.95mm pitch, 2.9mm × 1.6mm footprint, and exposed pad not connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD3-T and TPS3808G33DBVR, MAX6326UR29 offers tighter threshold accuracy (±1.5%), lower supply current (1µA vs. ≥1.8µA), guaranteed functionality down to 1V, and integrated 100ms timing-making it optimal for space-constrained, battery-critical, and deep-brownout-resilient designs.

Availability

MAX6326UR29 is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, smart meter battery backup systems, and POS terminal power sequencing requiring stable component supply across long production lifecycles.

Supply support for MAX6326UR29 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 is a semiconductor company specializing in analog and mixed-signal ICs for power, sensing, and connectivity applications.

The MAX6326 family is part of Maxim's ultra-low-power supervisory product line, engineered specifically for reliable, component-free reset generation in battery-powered and brownout-prone µP systems.

FAQ

What is the exact reset threshold voltage of MAX6326UR29 and how tightly is it specified?

The MAX6326UR29 has a nominal reset threshold of 2.93V, factory-trimmed with ±1.5% tolerance at +25°C and ±2.5% over the full –40°C to +85°C operating range. This precision eliminates the need for external calibration and ensures consistent brownout detection across temperature and unit-to-unit variation. The 6.3mV hysteresis further prevents chatter near the trip point.

Does MAX6326UR29 remain functional when VCC drops below 2.0V?

Yes, MAX6326UR29 is guaranteed to maintain correct reset state and assert RESET appropriately down to VCC = 1.0V. This capability is explicitly specified in the datasheet and enables reliable operation during deep brownout events where other supervisors may fail or behave unpredictably. Its internal circuitry remains fully functional across the entire 1.2V–5.5V VCC range.

What type of RESET output does MAX6326UR29 provide, and what are its drive capabilities?

MAX6326UR29 provides an active-low push-pull RESET output. It can source up to 500µA while asserting high (VOH ≥ 0.8·VCC) and sink up to 1.6mA while asserting low (VOL ≤ 0.3V at ISINK = 1.6mA, VCC > 2.1V). This eliminates the need for an external pull-up resistor and ensures direct compatibility with standard µP reset inputs.

How long does the RESET signal stay asserted after VCC rises above the threshold?

The MAX6326UR29 guarantees a minimum reset timeout of 100ms after VCC rises above the 2.93V threshold. Typical timeout is 185ms, with a maximum of 280ms over temperature. This built-in delay ensures the microprocessor has sufficient time to stabilize clocks and peripherals before release, removing dependency on external RC timing networks.

Is MAX6326UR29 susceptible to false resets caused by short VCC transients?

No, MAX6326UR29 incorporates transient immunity circuitry that rejects fast negative-going VCC glitches. For example, a 100mV overdrive (i.e., VCC dipping 100mV below 2.93V) is ignored if duration is under ~20µs. This behavior is characterized in the "Maximum Transient Duration vs. Reset Threshold Overdrive" graph and ensures robust operation in electrically noisy environments.