Analog Devices Inc./Maxim Integrated MAX6808SA26

Overview

MAX6808SA26 from Maxim Integrated is a precision voltage detector IC designed for power-supply monitoring in microprocessor-based systems. It features a factory-preset 2.6V ±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.

For engineers reviewing the MAX6808SA26 datasheet, MAX6808SA26 pinout, MAX6808SA26 application, or MAX6808SA26 equivalent, key selection considerations include its open-drain output topology, 2.6V threshold accuracy, 35µA supply current, and compatibility with multi-rail reset bus architectures requiring pull-up flexibility.

Technical Context

The MAX6808SA26 implements a precision bandgap-based voltage comparator with internal hysteresis (VHYST = 0.02–0.03 × VTH−), ensuring noise-immune switching between VTH+ (rising) and VTH− (falling) thresholds. Its open-drain RESET output requires an external pull-up resistor and supports interfacing with mixed-voltage logic buses up to 6V.

It operates across −40°C to +85°C with supply voltage range 1.0V to 5.5V, draws only 35µA typical supply current at 3.6V, and maintains valid RESET assertion even as VCC decays to 1.0V - enabling reliable low-voltage brownout detection before system logic fails.

Key Specifications

Pinout & Package

MAX6808SA26 is supplied in an 8-pin SO (Small Outline) package with exposed pad (RoHS-compliant, lead-free). Pin 1 is RESET (active-low open-drain), Pin 2 is VCC, Pin 4 is GND. Pins 3 and 5–8 are not internally connected (N.C.).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6808SA26, MAX6315US26D3-T adds manual reset but loses open-drain interoperability; TPS3808G33DBVR offers longer delay and different threshold, making it incompatible for direct 2.6V immediate-reset replacement.

Availability

MAX6808SA26 is available at Aetrix Electronics and suitable for portable/battery-powered equipment, bar-code scanners, and critical µP power monitoring requiring stable component supply across industrial temperature ranges and long-lifecycle programs.

Supply support for MAX6808SA26 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 management, sensing, and interface applications in industrial, computing, and portable systems.

The MAX6806/MAX6807/MAX6808 family delivers high-accuracy, low-power voltage supervision for microprocessor systems where deterministic reset timing and minimal external components are essential.

FAQ

What is the exact reset threshold voltage of MAX6808SA26 and how tightly is it specified?

The MAX6808SA26 has a nominal reset threshold of 2.60V, with guaranteed accuracy of ±2% over temperature (−40°C to +85°C). At +25°C, the electrical specification defines VTH− as 2.548V (min) to 2.652V (max). This tight tolerance eliminates need for external calibration and ensures consistent brownout detection across production units and operating conditions. The MAX6808SA26 uses factory laser-trimming to achieve this precision.

Why does MAX6808SA26 use an open-drain RESET output instead of push-pull?

The MAX6808SA26 uses an open-drain RESET output to enable wired-OR reset bus configurations, support level-shifting across different supply rails (e.g., pulling RESET to 5V while monitoring a 3.3V VCC), and interface safely with µPs having bidirectional reset pins. Unlike push-pull variants (MAX6806/MAX6807), the MAX6808SA26 avoids contention and allows multiple supervisors to share one reset line - a key requirement in complex embedded systems. This architecture is intrinsic to the MAX6808SA26 design.

Can MAX6808SA26 operate reliably below 1.8V, and what is its minimum functional VCC?

Yes, MAX6808SA26 is fully specified to operate down to VCC = 1.0V, with RESET output guaranteed to remain valid (logic low) throughout that range. Electrical characteristics confirm functionality at 1.0V (ICC = 35µA typ), and the device continues asserting RESET until VCC rises above the 2.6V threshold. Below 1.0V, the output becomes high-impedance - a known behavior documented in the MAX6808SA26 datasheet. This makes MAX6808SA26 suitable for deep-brownout detection in ultra-low-power systems.

What package type and pin count does MAX6808SA26 use, and are all pins electrically active?

MAX6808SA26 uses an 8-pin SO (Small Outline) package. Only three pins are electrically active: Pin 1 (RESET, open-drain), Pin 2 (VCC), and Pin 4 (GND). Pins 3 and 5–8 are Not Connected (N.C.) - they have no internal bond wire and must be left floating or tied to ground per PCB layout guidelines. This pinout matches industry-standard 8-pin SO footprints used for supervisory ICs, simplifying board reuse.

How does MAX6808SA26 handle power-supply transients, and what protection does it offer against false resets?

MAX6808SA26 is specifically designed to reject short-duration negative-going VCC transients - it will not assert RESET for pulses under 100ns wide when the dip magnitude is ≤100mV below the 2.6V threshold. Internal hysteresis (0.02–0.03 × VTH−) further prevents chatter during slow or noisy supply ramps. Adding a 0.1µF ceramic capacitor close to the VCC pin enhances transient immunity. These features are validated and specified in the MAX6808SA26 datasheet, making it robust in electrically noisy environments like motor-driven portable equipment.