Analog Devices Inc./Maxim Integrated MAX6808SA32

Overview

MAX6808SA32 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 - enabling reliable brownout detection in battery-powered instrumentation and portable equipment.

For engineers reviewing the MAX6808SA32 datasheet, MAX6808SA32 pinout, MAX6808SA32 application, or MAX6808SA32 equivalent, key selection criteria include its 3.2V threshold accuracy, open-drain output compatibility with bidirectional µP reset pins, immunity to negative-going VCC transients up to 100µs, and support for manual reset via SOT143 package variants (though MAX6808SA32 uses SO-8).

Technical Context

The MAX6808SA32 implements a comparator-based reset circuit with internal hysteresis (VHYST = 0.02–0.03 × VTH−), ensuring stable switching during supply voltage transitions. Its open-drain RESET output requires an external pullup resistor and supports level-shifting across supplies up to 6V.

It operates over −40°C to +85°C with 35µA typical supply current at VCC = 3.6V and maintains valid reset assertion while VCC ≥ 1.0V. The device is immune to short-duration negative-going VCC transients (e.g., ≤100µs at 100mV overdrive), eliminating false resets in noisy power environments.

Key Specifications

Pinout & Package

MAX6808SA32 is housed in an 8-pin SO (Small Outline) package with exposed pad (RoHS-compliant, lead-free). Pinout matches industry-standard µP supervisory footprints and is pin-compatible with MC33064/MC34064 families.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6808SA32, MAX6326UT32D3+ offers superior current efficiency but lacks SO-8 packaging and manual reset capability; TPS3808G33DBVR improves accuracy and ICC but cannot replace MAX6808SA32 in bidirectional reset interfaces without redesign.

Availability

MAX6808SA32 is available at Aetrix Electronics and suitable for portable/battery-powered equipment, bar-code scanners, and critical µP and µC power monitoring requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for MAX6808SA32 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 MAX6806/MAX6807/MAX6808 family delivers cost-effective, high-accuracy voltage supervision for microprocessor systems - prioritizing threshold stability, low ICC, and robust transient immunity over programmability or watchdog functionality.

FAQ

What is the exact reset threshold voltage of MAX6808SA32 and how is it specified?

The MAX6808SA32 has a nominal reset threshold voltage of 3.20V, with guaranteed accuracy of ±2% over temperature (−40°C to +85°C). This means the actual falling-threshold (VTH−) is specified between 3.136V and 3.264V at +25°C, and the device asserts RESET when VCC drops below this range. The threshold is factory-trimmed and does not require external calibration.

Why does MAX6808SA32 use an open-drain RESET output instead of push-pull?

The MAX6808SA32 uses an active-low open-drain RESET output to enable safe interfacing with microprocessors that have bidirectional reset I/O pins (e.g., Motorola 68HC11), avoiding bus contention. It also allows multiple supervisors to share a common reset line using wired-OR logic and supports level-shifting with external pullup resistors up to 6V - a capability not possible with push-pull outputs.

Does MAX6808SA32 support manual reset functionality?

No, MAX6808SA32 in the 8-pin SO package does not include a manual reset (MR) input. Manual reset is only available on the 4-pin SOT143 variants (e.g., MAX6808US32-T), which dedicate pin 2 to MR. The SO-8 pinout of MAX6808SA32 has pins 3–7 as N.C., and no internal MR circuitry is connected in this variant.

What is the minimum supply voltage at which MAX6808SA32 guarantees valid RESET assertion?

MAX6808SA32 guarantees valid RESET assertion down to VCC = 1.0V. Below this voltage, the internal circuitry ceases to sink current and the open-drain output becomes high-impedance. For applications requiring RESET to remain asserted all the way to ground, a pull-down resistor (e.g., 100kΩ) must be added externally to hold the line low.

How does MAX6808SA32 handle power-supply transients, and what is its immunity specification?

MAX6808SA32 is immune to short-duration negative-going VCC transients: it will not falsely assert RESET for pulses ≤100µs when the overdrive (VTH− − VCC) is 100mV. Immunity decreases as transient depth increases - e.g., at 200mV overdrive, maximum allowable pulse width drops to ~30µs. A 0.1µF ceramic capacitor placed close to the VCC pin further enhances transient rejection.