Analog Devices Inc./Maxim Integrated MAX6346XR46

Overview

The MAX6346XR46 from Maxim Integrated is a precision 3-pin microprocessor supervisory circuit with active-low push-pull reset output, factory-trimmed reset threshold of 4.63V (±1.5% at +25°C), 100ms minimum reset timeout, and ultra-low 1µA max supply current. It monitors VCC in 2.5V–5V digital systems and asserts reset during power-up, brownout, or power-down events - used in battery-powered controllers and automotive ECUs requiring reliable, low-power reset supervision.

For engineers reviewing the MAX6346XR46 datasheet, MAX6346XR46 pinout, MAX6346XR46 application, or MAX6346XR46 equivalent, key selection criteria include its 4.63V reset threshold tolerance, SC70-3 package footprint, push-pull active-low RESET drive capability, and immunity to sub-200µs VCC transients at 100mV overdrive - critical for stable µP initialization in noisy industrial environments.

Technical Context

The MAX6346XR46 implements a precision bandgap-based voltage comparator with internal hysteresis (9.5mV typical) to detect VCC drops below 4.63V, holding RESET asserted until VCC rises above threshold and remains stable for ≥100ms. Its reset logic is fully specified from –40°C to +85°C with 40ppm/°C tempco.

No external components are required: the device integrates reference, comparator, timer, and push-pull output driver. Reset assertion is immune to fast VCC transients ≤200µs (at 100mV overdrive), and operation is guaranteed down to VCC = 1V - enabling robust supervision even during deep brownout conditions.

Key Specifications

Pinout & Package

MAX6346XR46 is housed in a 3-pin SC70-3 package (2.0mm × 2.1mm × 0.9mm), compatible with SOT23-3 PCB footprints and reflow assembly. The package supports leaded and lead-free soldering (order with "+T" suffix for RoHS-compliant).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor reset supervision applications.

Compared with MAX809TR46D3T, MAX6346XR46 offers lower ICC and guaranteed 1V operation; versus TPS3808G33DBVR, it delivers exact 4.63V threshold without external components - making it optimal for 5V-system brownout protection where pin count, power, and precision are critical.

Availability

MAX6346XR46 is available at Aetrix Electronics and suitable for automotive engine control units, portable medical monitors, industrial PLC I/O modules, smart energy meters, and battery-powered instrumentation requiring stable component supply and long-term lifecycle support.

Supply support for MAX6346XR46 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, automotive, communications, and computing applications.

The MAX63xx family targets ultra-low-power, high-accuracy microprocessor reset supervision - optimized for systems where supply stability, minimal BOM, and guaranteed behavior under brownout are essential design requirements.

FAQ

What is the exact reset threshold voltage of the MAX6346XR46 and how tightly is it specified?

The MAX6346XR46 has a factory-trimmed reset threshold of 4.63V, with ±1.5% tolerance at +25°C and ±2.5% over the full –40°C to +85°C temperature range. This specification is guaranteed by production testing, not just design simulation, ensuring consistent brownout detection across all units shipped. The MAX6346XR46 uses laser trimming to achieve this accuracy without external components.

Does the MAX6346XR46 require any external components to operate?

No, the MAX6346XR46 requires zero external components. It integrates the voltage reference, comparator, reset timer, and push-pull output driver into a single SC70-3 package. Unlike many reset ICs that need pull-up resistors or timing capacitors, the MAX6346XR46 delivers a complete, self-contained reset solution - reducing bill-of-materials cost and PCB area while improving reliability.

What is the minimum VCC voltage at which the MAX6346XR46 remains functional and asserts reset correctly?

The MAX6346XR46 is guaranteed to maintain correct reset state down to VCC = 1.0V. Below this, the internal circuitry may become undefined. This 1V minimum enables reliable operation during deep brownout events - for example, when a 5V supply collapses rapidly during automotive cold-crank. The MAX6346XR46 continues asserting RESET until VCC recovers above 4.63V and remains stable for ≥100ms.

How does the MAX6346XR46 handle fast voltage transients on the VCC line?

The MAX6346XR46 rejects fast negative-going VCC transients up to 200µs in duration when the overdrive (VTH – VCC) is 100mV, per the Typical Operating Characteristics graph in the datasheet. This built-in immunity prevents false resets caused by switching noise, relay bounce, or EFT events. The MAX6346XR46 achieves this through internal filtering and comparator hysteresis (9.5mV typical), eliminating need for external RC snubbers.

Is the MAX6346XR46 pin-compatible with other members of the MAX63xx family?

Yes, the MAX6346XR46 shares identical SC70-3 pinout and function mapping with all MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX6348 variants - including MAX6326UR46-T and MAX6346UR46-T. All use Pin 1 = GND, Pin 2 = RESET (active-low push-pull), Pin 3 = VCC. This allows direct substitution within the same package type, provided the output polarity and threshold match the system requirement. The MAX6346XR46 is not pin-compatible with open-drain or active-high variants like MAX6348XR46-T.