Analog Devices Inc./Maxim Integrated MAX6348UR45+T

Overview

MAX6348UR45+T from Maxim Integrated is an open-drain, active-low microprocessor supervisory circuit designed to monitor 4.5V power supplies in embedded systems. It asserts reset when VCC falls below 4.500V (±1.5% at +25°C, ±2.5% over -40°C to +85°C), maintains reset for ≥100ms after VCC recovery, draws ≤1µA supply current, and operates down to 1.2V VCC - ideal for battery-powered µP reset management in portable instrumentation.

For engineers reviewing the MAX6348UR45+T datasheet, MAX6348UR45+T pinout, MAX6348UR45+T application, or MAX6348UR45+T equivalent, key selection criteria include its factory-trimmed 4.5V reset threshold, SOT23-3 open-drain output with 0.3V VOL at 1.6mA sink, 100ms minimum reset timeout, immunity to fast VCC transients, and compatibility with bidirectional µP reset pins such as Motorola 68HC11.

Technical Context

The MAX6348UR45+T implements a precision bandgap-based reset comparator with 40ppm/°C tempco and 9.5mV hysteresis, ensuring stable threshold behavior across temperature. Its open-drain RESET output requires an external pull-up and supports bidirectional reset arbitration in systems where the microcontroller may also drive the reset line.

It features transient immunity: negative-going VCC glitches shorter than ~200µs (at 100mV overdrive) do not trigger false resets. The device guarantees correct reset state down to VCC = 1.2V and includes internal ESD protection rated per JEDEC JS-001.

Key Specifications

Pinout & Package

MAX6348UR45+T is housed in a 3-pin SOT23-3 package (outline 21-0051, land pattern 90-0179), RoHS-compliant, tape-and-reel packaged.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6348UR45+T, the MAX6348UR46+T offers a higher reset threshold for tighter 5V rail margining, while the TPS3808G33DBVR provides superior ESD robustness but lacks open-drain flexibility and requires different voltage monitoring - neither is pin-compatible, and both demand schematic review for reset topology alignment.

Availability

MAX6348UR45+T is available at Aetrix Electronics and suitable for portable medical monitors, industrial PLC I/O modules, legacy 68HC11 controllers, and low-power IoT edge sensors requiring stable component supply with guaranteed long-term sourcing.

Supply support for MAX6348UR45+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, mixed-signal, and power management ICs for industrial, automotive, and computing applications.

The MAX63xx family delivers ultra-low-power, factory-trimmed µP supervisors targeting space-constrained, battery-operated, and high-reliability embedded systems requiring deterministic reset behavior.

FAQ

What is the exact reset threshold voltage of MAX6348UR45+T and how tightly is it specified?

The MAX6348UR45+T has a nominal reset threshold of 4.500V, factory-trimmed with ±1.5% tolerance at +25°C and ±2.5% over the full -40°C to +85°C operating range. This specification is guaranteed per datasheet Electrical Characteristics table and applies directly to the MAX6348UR45+T - no binning or post-manufacture adjustment is required.

Does MAX6348UR45+T support operation during brownout conditions below typical logic supply levels?

Yes, MAX6348UR45+T guarantees correct reset state down to VCC = 1.2V, and its internal circuitry remains functional even as supply voltage drops below standard 2.5V or 3.3V logic thresholds. This ensures reliable reset assertion during deep brownout - a confirmed capability documented in the Absolute Maximum Ratings and Electrical Characteristics sections for MAX6348UR45+T.

Can MAX6348UR45+T interface directly with a microcontroller that has a bidirectional reset pin?

Yes, MAX6348UR45+T's open-drain RESET output is explicitly designed for this use case. As stated in the Applications Information section, it interfaces directly with bidirectional µP reset pins like those on the Motorola 68HC11 using only a single external pull-up resistor - no additional logic or isolation is needed, and this functionality is verified for MAX6348UR45+T in the datasheet Figure 1.

What is the maximum allowable duration of a VCC transient before MAX6348UR45+T triggers an unintended reset?

At a 100mV overdrive (i.e., VCC falling 100mV below 4.500V), the MAX6348UR45+T rejects transients up to approximately 200µs, as shown in the "Maximum Transient Duration vs. Reset Threshold Overdrive" graph (Figure MAX6326 toc04). This immunity is inherent to the MAX6348UR45+T design and prevents false resets from short noise spikes on the supply rail.

Is MAX6348UR45+T available in lead-free packaging and what does the '+T' suffix signify?

Yes, the '+T' suffix in MAX6348UR45+T explicitly denotes lead-free, RoHS-compliant packaging per Maxim Integrated's ordering conventions. The device is supplied in tape-and-reel format only, and the '+' replaces '-' to indicate lead-free finish - a confirmed marking convention documented in the Ordering Information section of the MAX6348UR45+T datasheet.