Analog Devices Inc./Maxim Integrated MAX6808SA46+T

Overview

MAX6808SA46+T from Maxim Integrated is a precision 4.6V ±2% active-low open-drain voltage detector IC for microprocessor power-supply monitoring. It asserts reset when VCC falls below 4.508V (min) at +25°C, guarantees RESET validity down to VCC = 1.0V, draws only 35µA typical supply current, and features internal hysteresis to prevent chatter during brownout conditions - deployed in battery-powered bar-code scanners and critical µP systems.

For engineers reviewing the MAX6808SA46+T datasheet, MAX6808SA46+T pinout, MAX6808SA46+T application, or MAX6808SA46+T equivalent, key selection criteria include its open-drain output architecture, 4.6V factory-trimmed threshold with ±2% accuracy over -40°C to +85°C, immunity to sub-100µs negative VCC transients, and compatibility with multi-rail reset bus designs requiring external pull-up.

Technical Context

The MAX6808SA46+T implements a precision bandgap-based voltage comparator with built-in hysteresis (VHYST = 0.02 × VTH⁻ to 0.03 × VTH⁻), enabling stable reset assertion/deassertion across temperature. Its open-drain RESET output requires an external pull-up resistor and supports interfacing to bidirectional µP reset pins without contention.

It operates across VCC = 1.0V to 5.5V, with guaranteed reset assertion for VCC falling below 4.508V (min) and deassertion only after VCC rises above VTH⁺ ≈ 4.692V (max), delivering deterministic power-up sequencing in portable equipment where supply rails ramp slowly or experience noise.

Key Specifications

Pinout & Package

MAX6808SA46+T is supplied in an 8-pin SO (Small Outline) package with standard 150-mil width and 0.050" pitch. Pin 1 is RESET (active-low open-drain), Pin 4 is GND, Pin 5 is VCC, and Pins 2, 3, 6–8 are no-connect (N.C.).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6808SA46+T, MAX6315US46D3+T offers tighter threshold tolerance but lacks open-drain flexibility, while TLV803EB26DBZR targets lower-voltage domains entirely - making MAX6808SA46+T the only option among the three that combines 4.6V precision, open-drain drive, and 1.0V operational floor for legacy 5V µP supervision.

Availability

MAX6808SA46+T is available at Aetrix Electronics and suitable for portable/battery-powered equipment, intelligent instruments, critical µP and µC systems, and bar-code scanners requiring stable component supply and long-term industrial availability.

Supply support for MAX6808SA46+T 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, and communications applications.

The MAX6808SA46+T belongs to Maxim's voltage supervisor product line, engineered specifically for accurate, low-power power-on reset and brownout detection in resource-constrained embedded systems.

FAQ

What is the exact reset threshold voltage range for MAX6808SA46+T at room temperature?

The MAX6808SA46+T has a factory-trimmed nominal reset threshold of 4.6V, with a guaranteed range of 4.508V to 4.692V at +25°C (VCC falling). This ±2% tolerance is specified over the full operating temperature range (-40°C to +85°C), and the device includes internal hysteresis to ensure clean transitions. The MAX6808SA46+T does not require external calibration to meet this specification.

Does MAX6808SA46+T support operation down to 1.0V supply voltage, and what happens to RESET output below that?

Yes, MAX6808SA46+T guarantees valid RESET output down to VCC = 1.0V - meaning it will actively sink current and hold RESET low until VCC drops below 1.0V. Below 1.0V, the output becomes high-impedance (open-circuit), so a 100kΩ pulldown resistor is recommended if RESET must remain defined all the way to ground. This behavior is explicitly characterized in the MAX6808SA46+T datasheet under "Ensuring a Valid Reset Output Down to VCC = Ground".

Why does MAX6808SA46+T use an open-drain output instead of push-pull, and how should it be connected?

MAX6808SA46+T uses an open-drain RESET output to enable wired-OR reset buses, level translation across different supply domains (e.g., 3.3V µP with 5V peripherals), and safe interfacing with bidirectional µP reset pins. It must be connected with an external pull-up resistor to a compatible voltage rail (up to 6V); a 100kΩ resistor is sufficient for high-impedance loads. This architecture avoids contention and supports multi-source reset coordination - a key design distinction of the MAX6808SA46+T versus MAX6806/MAX6807 variants.

Can MAX6808SA46+T replace MAX6806SA46 or MAX6807SA46 in an existing design?

No, MAX6808SA46+T is not a direct replacement for MAX6806SA46 (active-low push-pull) or MAX6807SA46 (active-high push-pull) due to fundamental output architecture differences. Swapping requires adding an external pull-up resistor and verifying timing margins, as the open-drain output introduces RC-dependent rise time. The MAX6808SA46+T is selected specifically for applications needing wired-OR capability or bidirectional µP interface - not as a drop-in substitute. Board-level changes are necessary to accommodate its open-drain behavior.

What package and pin configuration does MAX6808SA46+T use, and are all pins functional?

MAX6808SA46+T is packaged in an 8-pin SO (Small Outline) outline with 150-mil width. Pin 1 is RESET (open-drain), Pin 4 is GND, Pin 5 is VCC, and Pins 2, 3, 6–8 are no-connect (N.C.) - internally unconnected and must remain unconnected on the PCB. This pinout matches the 8-pin µMAX variant electrically but differs mechanically from 3-pin SOT23/SC70 or 4-pin SOT143 versions. The MAX6808SA46+T datasheet confirms N.C. status for those pins in the "Pin Description" table.