Analog Devices Inc./Maxim Integrated MAX6808UA32

Overview

MAX6808UA32 from Maxim Integrated is a precision voltage detector IC designed for power-supply monitoring in microprocessor-based systems. It features a factory-preset 3.2V ±2% reset threshold, active-low open-drain RESET output, and guaranteed operation down to VCC = 1.0V. Used in portable equipment and critical µP power monitoring, it eliminates external components while providing stable reset assertion during brownout and power-down events.

For engineers reviewing the MAX6808UA32 datasheet, MAX6808UA32 pinout, MAX6808UA32 application, or MAX6808UA32 equivalent, key selection criteria include its 3.2V threshold accuracy, open-drain output compatibility with bidirectional µP reset pins, immunity to VCC transients, and support for low-voltage operation down to 1V.

Technical Context

The MAX6808UA32 implements a precision bandgap-based voltage comparator with internal hysteresis (VHYST = 0.02–0.03 × VTH−), ensuring noise-immune switching between rising and falling VCC thresholds. Its open-drain RESET output requires an external pullup resistor and supports interfacing with multiple supply domains up to 6V.

It operates across −40°C to +85°C, draws only 35µA typical supply current at 3.6V, and maintains valid reset signaling even as VCC declines to 1.0V - enabling reliable system initialization and shutdown sequencing in battery-powered and low-voltage embedded applications.

Key Specifications

Pinout & Package

MAX6808UA32 is housed in an 8-pin µMAX package (package code UA), pin-compatible with MC33064/MC33164 series. The µMAX footprint supports high-density PCB layouts while maintaining thermal performance up to 362mW at +70°C.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage detector applications.

Compared with MAX6808UA32, MAX6326UT32D3+ offers significantly lower supply current but sacrifices hysteresis assurance and open-drain flexibility; TPS3808G33DBVR provides tighter threshold tolerance and lower ICC but requires redesign for push-pull interface and lacks native support for bidirectional µP reset pins.

Availability

MAX6808UA32 is available at Aetrix Electronics and suitable for portable/battery-powered equipment, bar-code scanners, critical µP and µC power monitoring, and intelligent instruments requiring stable component supply and long-term industrial availability.

Supply support for MAX6808UA32 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 semiconductor company specializing in analog, mixed-signal, and high-reliability ICs for industrial, computing, and communications markets.

The MAX680x family was designed specifically for precision, low-power voltage monitoring in space- and power-constrained digital systems - emphasizing threshold accuracy, minimal external components, and robust operation across voltage and temperature extremes.

FAQ

What is the exact reset threshold voltage of MAX6808UA32 and how is it specified?

The MAX6808UA32 has a nominal reset threshold voltage of 3.20V, with guaranteed accuracy of ±2% over temperature (−40°C to +85°C). This value corresponds to VTH− (falling VCC threshold) and is factory-trimmed. Electrical Characteristics table specifies min/typ/max: 3.136V / 3.20V / 3.264V at +25°C. The threshold is referenced directly to VCC and does not require external resistors or calibration.

Why does MAX6808UA32 use an open-drain RESET output instead of push-pull?

The open-drain RESET output of MAX6808UA32 enables wired-OR connectivity, level shifting across different supply domains (up to 6V), and safe interfacing with microprocessors that have bidirectional reset I/O pins (e.g., Motorola 68HC11). Unlike push-pull outputs, it avoids bus contention and allows flexible pullup placement - a key design advantage confirmed in the MAX6808's Applications Information section.

Can MAX6808UA32 operate reliably below 1.8V, and what is its minimum functional VCC?

Yes - MAX6808UA32 is fully specified down to VCC = 1.0V. Its RESET output remains valid (guaranteed logic low) for VCC ≥ 1.0V, and supply current remains stable (35µA typ at 1.0V). Below 1.0V, the output becomes high-impedance; for ground-referenced validity, a 100kΩ pulldown resistor is recommended per Figure 4 in the datasheet.

Is MAX6808UA32 pin-compatible with other devices in the MAX680x family or legacy supervisors?

MAX6808UA32 in the 8-pin µMAX package is pin-compatible with MAX6806UAxx and MAX6807UAxx variants, and also with MC33064/MC33164/MC34064/MC34164 in the same SO and µMAX footprints. Pin 1 is (RESET), Pin 2 is VCC, and Pins 3–8 are N.C. - confirmed in Pin Configurations and Ordering Information sections.

Does MAX6808UA32 include hysteresis, and how does it affect reset behavior?

Yes - MAX6808UA32 includes internal hysteresis (VHYST = 0.02–0.03 × VTH−), creating distinct rising (VTH+) and falling (VTH−) thresholds. This prevents output oscillation during slow or noisy VCC transitions near the trip point. Hysteresis magnitude is fixed and non-adjustable, and its presence is explicitly documented in both Electrical Characteristics and Detailed Description sections.