Analog Devices Inc./Maxim Integrated MAX6346XR33-T

Overview

MAX6346XR33-T from Maxim Integrated is a precision 3.3V microprocessor supervisory circuit in SC70-3 package, featuring active-low push-pull reset output, 1µA max supply current, ±1.5% reset threshold accuracy at +25°C, and guaranteed operation down to VCC = 1.2V over -40°C to +85°C. It monitors 3.3V power rails in portable embedded systems and asserts reset for ≥100ms after VCC recovers above 3.30V.

For engineers reviewing the MAX6346XR33-T datasheet, MAX6346XR33-T pinout, MAX6346XR33-T application, or MAX6346XR33-T equivalent, this device delivers ultra-low-power voltage monitoring with factory-trimmed 3.30V reset threshold, transient-immune brownout detection, and direct compatibility with µP reset interfaces requiring active-low push-pull drive without external components.

Technical Context

The MAX6346XR33-T implements a precision bandgap-based reset comparator with 9.5mV hysteresis and 40ppm/°C tempco, ensuring stable 3.30V threshold across temperature. Its internal timing circuit guarantees minimum 100ms reset timeout after power-up, independent of VCC slew rate.

Designed for single-supply monitoring, it operates from 1.2V to 5.5V and maintains valid reset state down to 1V - enabling reliable supervision during deep brownout conditions. The push-pull output drives low (≤0.3V @ 1.6mA) when asserted and high (≥0.8·VCC) when released, eliminating need for external pull-up resistors.

Key Specifications

Pinout & Package

MAX6346XR33-T is housed in a 3-pin SC70-3 package (outline X3-2), measuring 2.0mm × 2.1mm × 0.95mm, with gull-wing leads optimized for high-density PCB layouts and reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326XR33-T and TPS3123QDBVRQ1, MAX6346XR33-T uniquely combines 5.5V VCC tolerance, push-pull output, and 1µA max ICC across full voltage range - making it optimal for cost-sensitive, space-constrained industrial and portable 3.3V systems where layout simplicity and wide supply headroom matter.

Availability

MAX6346XR33-T is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical monitors, smart energy meters, and IoT edge sensors requiring stable component supply with no long lead times.

Supply support for MAX6346XR33-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 and mixed-signal ICs for industrial, communications, and consumer applications, with emphasis on power management and reliability-critical functions.

The MAX6346XR33-T belongs to the MAX63xx family of ultra-low-power µP supervisory circuits, engineered specifically for battery-operated and space-constrained embedded systems needing accurate, low-current voltage monitoring without external components.

FAQ

What is the exact reset threshold voltage of MAX6346XR33-T and how tightly is it specified?

The MAX6346XR33-T has a nominal reset threshold of 3.30V, with ±1.5% tolerance at +25°C and ±2.5% over the full -40°C to +85°C operating range. This specification is factory-trimmed and guaranteed per device - not typical - ensuring consistent 3.3V rail supervision without calibration. The 9.5mV hysteresis further prevents chatter near threshold. MAX6346XR33-T meets this spec across its entire qualified temperature and voltage range.

Does MAX6346XR33-T require an external pull-up resistor on its RESET pin?

No, MAX6346XR33-T features an active-low push-pull output, meaning it actively drives both high and low states without needing an external pull-up resistor. When reset is asserted, it sinks up to 1.6mA at ≤0.3V; when released, it sources current to maintain VOH ≥0.8·VCC. This eliminates board space, BOM count, and potential noise coupling from external resistors - a key advantage over open-drain alternatives like MAX6348XR33-T. MAX6346XR33-T is fully self-contained for reset signaling.

Can MAX6346XR33-T operate reliably below 2.5V supply voltage?

Yes, MAX6346XR33-T is fully specified to operate from VCC = 1.2V to 5.5V and guarantees correct reset state down to 1.0V. Its internal bandgap reference and comparator remain functional at sub-2.5V levels, enabling robust brownout detection in low-voltage battery systems. At 1.2V, supply current remains ≤1.0µA and reset timeout holds ≥100ms. MAX6346XR33-T maintains all key specifications across this extended range.

How does MAX6346XR33-T handle fast transients on the VCC line?

MAX6346XR33-T incorporates transient immunity circuitry that ignores negative-going VCC glitches shorter than ~100µs (depending on overdrive magnitude), as shown in the "Maximum Transient Duration vs. Reset Threshold Overdrive" graph in its datasheet. For example, a 200mV dip below threshold is rejected if duration is <20µs. This prevents false resets during switching noise or ESD events. MAX6346XR33-T's design ensures only sustained brownouts trigger reset - critical for noisy industrial environments.

Is MAX6346XR33-T pin-compatible with legacy Maxim reset ICs like MAX809?

Yes, MAX6346XR33-T is explicitly pin-compatible with MAX809, MAX803, and MAX810 in SC70-3 and SOT23-3 packages, sharing identical 3-pin VCC–RESET–GND topology and push-pull active-low output behavior. Layouts designed for those parts can use MAX6346XR33-T without modification. However, MAX6346XR33-T improves upon them with lower ICC (1µA vs. 15–25µA), tighter threshold tolerance (±1.5% vs. ±2.5%), and enhanced transient rejection. MAX6346XR33-T serves as a drop-in upgrade for existing designs.