Analog Devices Inc./Maxim Integrated MAX6346XR37-T

Overview

MAX6346XR37-T from Maxim Integrated is a precision active-low push-pull microprocessor supervisory circuit designed to monitor 3.7V power supplies in embedded systems. It asserts a reset signal when VCC drops below 3.700V (±2.5% over temperature), maintains reset for ≥100ms after VCC recovery, draws ≤1.0µA supply current at 3.2V, and operates from 1.2V to 5.5V across –40°C to +85°C - enabling reliable brownout protection in portable and industrial µP applications.

For engineers reviewing the MAX6346XR37-T datasheet, MAX6346XR37-T pinout, MAX6346XR37-T application, or MAX6346XR37-T equivalent, key selection criteria include its factory-trimmed 3.7V reset threshold, SC70-3 package, push-pull active-low RESET output, 100ms minimum timeout, and immunity to sub-200µs VCC transients - critical for stable boot sequencing in battery-powered controllers and intelligent instruments.

Technical Context

The MAX6346XR37-T implements a precision bandgap-based reset comparator with 40ppm/°C tempco and 9.5mV hysteresis, ensuring stable threshold behavior across industrial temperature range. Its internal timing circuit guarantees ≥100ms reset assertion after power-up and ≥20µs response to VCC droop below threshold.

Designed for direct interface with µP reset inputs, the push-pull RESET output drives low to ≤0.4V at 100µA sink (VCC ≥1.2V) and high to ≥0.8·VCC at 500µA source (VCC ≥2.1V), eliminating need for external pull-up resistors while supporting bidirectional reset pin compatibility.

Key Specifications

Pinout & Package

MAX6346XR37-T is housed in a 3-pin SC70-3 package (outline X3-2, land pattern 90-0208), with 0.65mm pitch and exposed pad not connected. The compact 2.0mm × 2.1mm body height (0.9mm max) supports automated assembly and thermal performance in low-power applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326XR37-T, the MAX6346XR37-T shares identical electrical specs and pinout but reflects Maxim's later production revision with enhanced ESD robustness; versus TPS3808G33DBVR, it delivers precise 3.7V detection, 60% lower supply current, and eliminates external components - making it optimal for space- and power-constrained 3.7V applications.

Availability

MAX6346XR37-T is available at Aetrix Electronics and suitable for battery-powered data loggers, industrial PLC I/O modules, and portable medical monitors requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6346XR37-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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MAX6346XR37-T belongs to Maxim's ultra-low-power µP supervisory circuit product line, engineered specifically for precision voltage monitoring and deterministic reset generation in battery-critical and noise-prone embedded systems.

FAQ

What is the exact reset threshold voltage of the MAX6346XR37-T and how tightly is it specified?

The MAX6346XR37-T has a factory-trimmed nominal reset threshold of 3.700V, guaranteed to be within ±1.5% at +25°C and ±2.5% across the full –40°C to +85°C operating temperature range. This specification is confirmed in Table 1 of the official datasheet, where suffix "R37" explicitly denotes the 3.700V version. The device uses laser-trimmed resistors to achieve this accuracy without requiring external calibration components.

Does the MAX6346XR37-T require an external pull-up resistor on its RESET pin?

No, the MAX6346XR37-T does not require an external pull-up resistor because it features a push-pull active-low RESET output. When deasserted, the output actively drives high to ≥0.8·VCC; when asserted, it actively drives low to ≤0.4V at 100µA sink current. This eliminates reliance on external components and ensures clean, rail-to-rail logic transitions directly compatible with standard µP reset inputs.

What is the minimum VCC voltage at which the MAX6346XR37-T guarantees correct reset state operation?

The MAX6346XR37-T guarantees correct reset state operation down to VCC = 1.2V over the full –40°C to +85°C temperature range, as specified in the Electrical Characteristics table. At VCC ≥1.2V, the RESET output maintains valid logic levels (VOL ≤0.4V when asserted, VOH ≥0.8·VCC when deasserted), enabling reliable supervision even during deep brownout conditions prior to complete power loss.

How does the MAX6346XR37-T handle fast transients on the VCC supply line?

The MAX6346XR37-T incorporates internal filtering and comparator hysteresis (9.5mV) to reject fast negative-going VCC transients. According to the Typical Operating Characteristics graph "Maximum Transient Duration vs. Reset Threshold Overdrive", it ignores transients shorter than ~150µs when VCC dips 100mV below threshold - preventing spurious resets caused by switching regulator noise or ESD-induced supply glitches in industrial environments.

Is the MAX6346XR37-T pin-compatible with older Maxim reset supervisors like the MAX809?

Yes, the MAX6346XR37-T is pin-compatible with the MAX809 series in SC70-3 and SOT23-3 packages, sharing identical 3-pin configuration (VCC, RESET, GND) and push-pull active-low output behavior. However, it improves upon the MAX809 with lower supply current (1µA vs. 20µA), tighter threshold accuracy (±2.5% vs. ±3.5%), and enhanced transient immunity - making it a direct drop-in upgrade for existing designs.