Analog Devices Inc./Maxim Integrated MAX6808SA46+

Overview

MAX6808SA46+ from Maxim Integrated is a precision 4.6V active-low open-drain voltage detector IC designed for power-supply monitoring in microprocessor-based systems. It asserts reset when VCC falls below 4.508V (±2% threshold accuracy), features 35µA supply current, guarantees RESET validity down to VCC = 1.0V, and operates across –40°C to +85°C in an 8-pin SO package.

For engineers reviewing the MAX6808SA46+ datasheet, MAX6808SA46+ pinout, MAX6808SA46+ application, or MAX6808SA46+ equivalent, key selection considerations include its open-drain output architecture, immunity to VCC transients up to 100mV overdrive, hysteresis of 0.02–0.03×VTH−, manual-reset capability (in SOT143 variants), and compatibility with bidirectional µP reset pins.

Technical Context

The MAX6808SA46+ implements a precision bandgap-based voltage comparator with internal hysteresis (VHYST = VTH+ − VTH−) to prevent output oscillation during supply brownouts. Its reset assertion is triggered solely by VCC crossing the falling threshold (VTH− = 4.60V ±2%), with no timeout delay-output responds within 30µs at 1mV/µs slew rate.

As an open-drain device, MAX6808SA46+ requires an external pullup resistor (e.g., 100kΩ to ≤6V) to interface with multiple supply domains or bidirectional µP reset I/O. It lacks internal MR functionality in the SO package; manual reset is exclusive to the 4-pin SOT143 variant.

Key Specifications

Pinout & Package

MAX6808SA46+ is housed in an 8-pin SO (Small Outline) package with 1.27mm pitch. 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.). No manual reset (MR) input is provided in this SO variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6808SA46+, MAX6315US46D3+ offers tighter threshold accuracy and lower ICC but sacrifices SO package compatibility and higher noise immunity, while TLV803EA46DBZR achieves nanoamp ICC in SOT23 but omits hysteresis specification and SO packaging-making MAX6808SA46+ optimal for industrial SO-based designs requiring proven transient immunity and 35µA ICC.

Availability

MAX6808SA46+ is available at Aetrix Electronics and suitable for computers, intelligent instruments, critical µP/µC power monitoring, and bar-code scanners requiring stable component supply, long-term industrial lifecycle support, and RoHS-compliant sourcing.

Supply support for MAX6808SA46+ 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 power-management ICs for industrial, computing, and communications applications.

The MAX680x family delivers precision voltage detection for microprocessor supervisory functions, targeting cost-sensitive, space-constrained systems needing factory-trimmed thresholds and minimal external components.

FAQ

What is the reset threshold voltage of the MAX6808SA46+?

The MAX6808SA46+ has a factory-preset nominal reset threshold of 4.60V with ±2% accuracy, meaning the actual falling threshold (VTH−) is guaranteed between 4.508V and 4.692V at +25°C. This threshold is optimized for 5V ±5% power supplies and ensures reset assertion before downstream 5V ICs fall outside their specified operating range. The MAX6808SA46+ uses internal bandgap reference circuitry to maintain stability across temperature.

Does the MAX6808SA46+ support manual reset functionality?

No, the MAX6808SA46+ in the 8-pin SO package does not include a manual reset (MR) input. Manual reset is only available in the 4-pin SOT143 package variant (e.g., MAX6808US46-T). The SO package has pins 1 (RESET), 2 (VCC), and 4 (GND) active, while pins 3 and 5–8 are N.C. For designs requiring MR, the SOT143 version must be selected-not the MAX6808SA46+.

What external components are required for the MAX6808SA46+ open-drain output?

The MAX6808SA46+ requires an external pullup resistor on the RESET pin to define the high logic state. A 100kΩ resistor to any supply up to 6V is recommended for high-impedance loads; lower values (e.g., 4.7kΩ) may be used for faster rise times or heavier capacitive loads. No other external components-such as capacitors or voltage dividers-are needed, as the MAX6808SA46+ integrates precision threshold reference and hysteresis.

How does the MAX6808SA46+ behave when VCC drops below 1.0V?

Below VCC = 1.0V, the MAX6808SA46+ RESET output ceases sinking current and becomes a high-impedance open circuit. This means the RESET line will float unless externally pulled down. In most systems, operation is already invalid below 1.0V, so floating is acceptable. However, if deterministic low-state is required down to ground, a 100kΩ pulldown resistor should be added-this ensures RESET remains low regardless of leakage currents, preserving system safety during full power collapse.

Is the MAX6808SA46+ pin-compatible with legacy supervisory ICs like the MC34064?

Yes, the MAX6808SA46+ in the 8-pin SO package is pin-compatible with the MC33064, MC33164, MC34064, and MC34164 families. Pin 1 is RESET, Pin 2 is VCC, and Pin 4 is GND-matching the standard SO-8 supervisory IC pinout. However, unlike those older parts, MAX6808SA46+ provides superior ±2% threshold accuracy, 35µA ICC, and guaranteed operation down to VCC = 1.0V, making it a direct functional upgrade without PCB changes.