Analog Devices Inc./Maxim Integrated MAX6378UR44

Overview

MAX6378UR44 from Maxim Integrated is an ultra-low-power, active-low voltage detector in SOT23-3 package, with factory-trimmed 4.38V threshold (±2.5% over temperature), 500nA supply current, and push-pull output. It monitors VCC in battery-powered systems and asserts OUT low when supply drops below threshold-used for precision brownout detection in portable medical devices and IoT edge sensors.

For engineers reviewing the MAX6378UR44 datasheet, MAX6378UR44 pinout, MAX6378UR44 application, or MAX6378UR44 equivalent, key selection criteria include reset threshold accuracy, transient immunity, supply current at 1V VCC operation, and compatibility with 3.3V/5V logic interfaces without external pull-ups.

Technical Context

The MAX6378UR44 implements a precision bandgap reference and comparator with internally trimmed resistors to set its 4.38V trip point. Its push-pull output drives logic-low directly during undervoltage events without requiring external components.

It guarantees correct output state down to VCC = 1V and rejects fast transients via built-in hysteresis (9.5µs propagation delay) and threshold overdrive filtering-enabling reliable operation in noisy power rails of wearables and remote sensors.

Key Specifications

Pinout & Package

MAX6378UR44 is housed in a 3-pin SOT23-3 package (JEDEC MO-178AA), footprint-compatible with SC70-3 but with higher power dissipation rating (320mW at +70°C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV803EB33DBZR and TPS3808G33DBVR, the MAX6378UR44 uniquely delivers 4.38V precision detection, 500nA supply current, and SOT23-3 push-pull output in a single, no-compromise solution for 4.2V–4.4V Li-ion or regulated 5V rail monitoring.

Availability

MAX6378UR44 is available at Aetrix Electronics and suitable for battery-powered wearables, industrial sensor nodes, medical handhelds, and smart meter backup systems requiring stable component supply with long-lifecycle support.

Supply support for MAX6378UR44 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 power, sensing, and connectivity in harsh, space-constrained environments.

The MAX6375–MAX6380 family was engineered specifically for ultra-low-power voltage monitoring in portable and battery-critical systems-prioritizing nanoscale ICC, factory-trimmed accuracy, and minimal external component count.

FAQ

What is the exact reset threshold voltage of MAX6378UR44 and how tightly is it specified?

The MAX6378UR44 has a nominal reset threshold of 4.38V, with ±2.5% accuracy guaranteed over the full -40°C to +85°C operating temperature range. This specification is factory-trimmed and does not require external calibration. The device also exhibits 40ppm/°C tempco and 100mV hysteresis to prevent oscillation near the trip point. These parameters are fully characterized and production-tested per Maxim's datasheet.

Does MAX6378UR44 require an external pull-up resistor on its output?

No, MAX6378UR44 features an active-low push-pull output, meaning it actively drives the OUT pin low during undervoltage conditions and high-impedance otherwise-no external pull-up is needed. This distinguishes it from open-drain variants like MAX6380 and simplifies interface to microcontrollers or FPGAs with standard reset inputs. The push-pull structure ensures robust logic-level transitions without additional components.

Can MAX6378UR44 operate reliably when the supply voltage drops below 2.0V?

Yes, MAX6378UR44 guarantees correct output logic state down to VCC = 1.0V, and its functional operating range starts at 1.2V. This makes it suitable for deep brownout detection in systems with aging batteries or unregulated supplies. The internal bandgap reference and comparator remain stable and responsive even at sub-2V levels, ensuring deterministic reset assertion before critical logic fails.

How does MAX6378UR44 handle fast voltage transients on the VCC line?

MAX6378UR44 incorporates inherent transient immunity: its internal architecture filters out negative-going VCC glitches shorter than ~200µs at 100mV overdrive, as shown in the "Maximum Transient Duration vs. Threshold Overdrive" graph in the datasheet. This prevents false resets caused by switching noise, motor commutation spikes, or hot-plug events-critical for reliability in portable and industrial equipment.

What package options are available for MAX6378UR44 and are they interchangeable on PCB?

MAX6378UR44 is offered exclusively in the 3-pin SOT23-3 package (JEDEC MO-178AA). While the MAX6378XR44 variant uses the pin-compatible SC70-3 package, the UR suffix denotes SOT23-3 only. The two packages share identical pinout (GND-OUT-VCC) and footprint outline but differ in thermal performance (320mW vs. 174mW dissipation) and solder profile-PCB land patterns are not interchangeable without layout review.