Analog Devices Inc./Maxim Integrated MAX6327UR30

Overview

MAX6327UR30 from Maxim Integrated is an active-high push-pull microprocessor supervisory circuit designed to monitor 3.0V power supplies and assert a reset signal during brownout, power-up, and power-down events. It features a factory-trimmed 3.00V reset threshold (±1.5% at +25°C, ±2.5% over –40°C to +85°C), 100ms minimum reset timeout, ultra-low 1µA max supply current, and guaranteed operation down to 1.2V VCC. It is used in portable battery-powered systems requiring reliable, low-power power-on reset functionality.

For engineers reviewing the MAX6327UR30 datasheet, MAX6327UR30 pinout, MAX6327UR30 application, or MAX6327UR30 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 MAX6327UR30 implements a precision bandgap-based voltage comparator with hysteresis (6.3mV) to detect VCC falling below its 3.00V threshold and hold RESET high for ≥100ms after recovery. Its push-pull output drives high actively (VOH ≥ 0.8·VCC at ISOURCE = 500µA, VCC ≥ 2.1V) and low passively (VOL ≤ 0.4V at ISINK = 3.2mA, VCC ≥ 4.5V), eliminating external pull-up components.

It operates across –40°C to +85°C with full specification of reset timing, threshold accuracy, and supply current (0.5–1.0µA typical at 3V). The device ignores fast VCC transients (up to 100V/µs slew rate) and maintains correct reset state down to 1.2V VCC - enabling robust supervision even during deep brownout conditions.

Key Specifications

Pinout & Package

MAX6327UR30 is housed in a 3-pin SOT23-3 package (package code U3-1), footprint-compatible with industry-standard 3-pin supervisory 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 supervision applications.

Compared with MAX6327UR30, the MAX6327XR30-T offers identical performance in a smaller footprint but requires tighter assembly control, while the MAX809TR30-T trades ultra-low power and deep-brownout robustness for lower unit cost in fixed-line-powered systems.

Availability

MAX6327UR30 is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, smart meter data loggers, and automotive body control units requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MAX6327UR30 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/MAX6327/MAX6328 family delivers ultra-low-power, factory-trimmed µP reset supervision for battery-critical and space-constrained embedded systems - prioritizing reliability, minimal external components, and wide VCC operating range.

FAQ

What is the exact reset threshold voltage of MAX6327UR30 and how does it vary with temperature?

The MAX6327UR30 has a factory-trimmed nominal reset threshold of 3.00V. At +25°C, this is guaranteed within ±1.5% (2.955V to 3.045V). Over the full operating temperature range of –40°C to +85°C, the threshold varies by ±2.5%, resulting in a min/max span of 2.925V to 3.075V. Its 40ppm/°C tempco ensures predictable, linear drift - critical for designs requiring consistent brownout behavior across environmental conditions. This specification is fully tested and guaranteed per the datasheet.

Does MAX6327UR30 require any external components to function as a reset supervisor?

No, the MAX6327UR30 requires zero external components. Its active-high push-pull RESET output drives directly to µP reset pins without needing a pull-up resistor. The internal voltage reference, comparator, timer, and output driver are fully integrated. This eliminates BOM cost, layout area, and potential failure points associated with discrete R/C networks - a key advantage over older reset ICs like the MAX809 series.

Can MAX6327UR30 operate reliably during deep brownout conditions below 2.0V?

Yes, the MAX6327UR30 is fully specified down to 1.2V VCC and guaranteed to maintain correct reset state (asserting RESET high) throughout that range. Unlike many supervisory ICs that cease functioning below 1.8V, this capability ensures reliable reset assertion during severe brownouts - protecting flash memory writes and preventing MCU state corruption in battery-powered systems nearing end-of-life.

What is the maximum transient duration the MAX6327UR30 can ignore on the VCC line?

The MAX6327UR30 suppresses reset assertion for VCC transients up to 20µs in duration when the overdrive (VTH – VCC) is 100mV, as confirmed by the "Maximum Transient Duration vs. Reset Threshold Overdrive" graph in the datasheet. This immunity prevents spurious resets caused by switching noise, EFT bursts, or load-step-induced dips - making it suitable for electrically noisy environments such as motor drives or automotive power distribution systems.

Is MAX6327UR30 pin-compatible with legacy Maxim reset ICs like the MAX809?

Yes, the MAX6327UR30 is pin-compatible with the MAX809 series in the SOT23-3 package: Pin 1 = GND, Pin 2 = RESET (active-high push-pull), Pin 3 = VCC. However, note that MAX809 variants typically feature open-drain outputs and different threshold tolerances. While footprint and basic connectivity match, direct substitution requires verification of reset polarity, timing, and VCC operating range compatibility in the target application.