Analog Devices Inc./Maxim Integrated MAX6327UR23

Overview

MAX6327UR23 from Maxim Integrated is an active-high push-pull microprocessor supervisory circuit designed to monitor 2.3V power supplies in embedded systems. It asserts a high-level reset signal when VCC falls below 2.32V (±1.5% at +25°C), holds reset for ≥100ms after VCC recovers, draws ≤1µA supply current at 3.3V, and operates across –40°C to +85°C - enabling reliable brownout protection in portable battery-powered µP systems.

For engineers reviewing the MAX6327UR23 datasheet, MAX6327UR23 pinout, MAX6327UR23 application, or MAX6327UR23 equivalent, this device serves as a low-power, factory-trimmed reset supervisor with precise 2.32V threshold, push-pull output, SOT23-3 packaging, and immunity to fast VCC transients - critical for space-constrained industrial controllers and automotive ECUs requiring stable power-on sequencing.

Technical Context

The MAX6327UR23 integrates a precision bandgap reference and comparator to detect VCC drops below its factory-set 2.32V threshold, with hysteresis of 9.5mV and temperature coefficient of 40ppm/°C. Its reset timeout is guaranteed ≥100ms after VCC rises above VTH, and it remains functional down to VCC = 1V.

Designed for direct interface with µP reset inputs, the active-high push-pull RESET output sources ≥800µA at VOH = 0.8·VCC (VCC ≥2.1V) and sinks ≥1.2mA at VOL ≤0.4V, eliminating need for external pull-up resistors. The device rejects transients up to 200µs duration when VCC dips 100mV below VTH.

Key Specifications

Pinout & Package

MAX6327UR23 is housed in a 3-pin SOT23-3 package (JEDEC MO-178AA), with 1.3mm × 2.9mm footprint and 1.45mm height - compatible with standard pick-and-place equipment and 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 MAX809TR23D3T and TPS3808G12DBVR, the MAX6327UR23 delivers lowest ICC (≤1µA), smallest footprint (SOT23-3), and guaranteed push-pull drive - making it optimal for ultra-low-power, space-constrained designs where fixed 100ms reset timing is acceptable.

Availability

MAX6327UR23 is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, portable medical monitors, smart energy meters, and battery-backed data loggers requiring stable component supply with long-term lifecycle assurance.

Supply support for MAX6327UR23 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, automotive, and communications markets.

The MAX6326/MAX6327/MAX6328 family was designed specifically for ultra-low-power microprocessor reset supervision in battery-critical and space-constrained embedded systems - prioritizing sub-1µA ICC, factory-trimmed thresholds, and minimal external component count.

FAQ

What is the exact reset threshold voltage of MAX6327UR23 and how tightly is it specified?

The MAX6327UR23 has a factory-trimmed reset threshold of 2.32V, with ±1.5% tolerance at +25°C and ±2.5% over –40°C to +85°C. This value is confirmed in Table 1 of the datasheet and corresponds to the "R23" suffix. The device also features 9.5mV of built-in hysteresis to prevent oscillation near the trip point, and its tempco is 40ppm/°C - ensuring predictable behavior across temperature.

Does MAX6327UR23 require any external components to function?

No, the MAX6327UR23 requires zero external components. Its active-high push-pull RESET output drives the microprocessor reset pin directly without needing a pull-up resistor, and its internal precision reference and comparator eliminate trimming or calibration circuitry. This simplifies layout, reduces BOM cost, and improves reliability - a key advantage over open-drain or active-low alternatives like MAX6328UR23.

What is the maximum VCC transient duration that MAX6327UR23 can ignore without asserting reset?

The MAX6327UR23 ignores negative-going VCC transients up to 200µs in duration when the overdrive (VTH – VCC) is 100mV, as shown in Figure MAX6326-04 of the datasheet. For larger overdrives (e.g., 200mV), the allowable transient duration decreases to ~100µs. This immunity prevents spurious resets caused by switching noise or load dump events in automotive and industrial environments.

Is MAX6327UR23 pin-compatible with other members of the MAX632x family?

Yes, MAX6327UR23 shares identical SOT23-3 pinout and footprint with all MAX6326/MAX6327/MAX6328 variants, including MAX6326UR23 and MAX6328UR23. Pin 1 is GND, Pin 2 is RESET (active-high push-pull), and Pin 3 is VCC. This allows drop-in replacement within the same threshold group when changing reset polarity or output type - provided the host system's reset logic accepts active-high signaling.

What is the minimum VCC voltage at which MAX6327UR23 guarantees correct reset state?

The MAX6327UR23 guarantees correct reset assertion and deassertion behavior down to VCC = 1.0V, as stated in the General Description and Absolute Maximum Ratings sections. This ensures reliable operation during deep brownout conditions and power-down sequences - critical for fail-safe behavior in safety-critical systems where partial power loss must still trigger controlled shutdown via reset.