Analog Devices Inc./Maxim Integrated MAX604ESA-T

Overview

MAX604ESA-T from Maxim Integrated is a 3.3V fixed-output, low-dropout linear regulator with internal P-channel MOSFET pass transistor, delivering up to 500mA output current, 240mV typical dropout at 200mA, and 15μA typical quiescent current. It operates from 2.7V to 11.5V input and features Dual Mode™ operation for adjustable output (1.25V–11V) via external resistors - used in battery-powered portable instruments and solar-powered sensors where ultra-low IQ and reverse-current protection are critical.

For engineers reviewing the MAX604ESA-T datasheet, MAX604ESA-T pinout, MAX604ESA-T application, or MAX604ESA-T equivalent, key selection considerations include its -40°C to +85°C industrial temperature range, SO-8 package thermal performance (1.8W dissipation), shutdown mode (<2μA), and reverse-current protection threshold (6–20mV).

Technical Context

The MAX604ESA-T implements a 1.20V bandgap reference, error amplifier, MOSFET driver, and dual-mode comparator to select between internal fixed feedback (3.3V) and external resistor-based adjustable regulation. Its P-channel pass transistor eliminates base-drive current, enabling stable 15μA quiescent current across load and temperature.

Shutdown is active-low on the OFF pin with voltage-dependent thresholds (e.g., VIH ≥ 4.0V at VIN = 11.5V); reverse-current protection activates when VIN falls 6–20mV below VOUT, switching substrate bias to limit reverse leakage to ≤10μA. Thermal shutdown triggers at +160°C with 10°C hysteresis.

Key Specifications

Pinout & Package

MAX604ESA-T is housed in an 8-pin SOIC (Small Outline Integrated Circuit) package with exposed thermal pad capability, rated for 1.8W continuous power dissipation at TA = +70°C (derated 23.6mW/°C above). All four GND pins (2, 3, 6, 7) serve as thermal conduction paths and must be soldered to large copper planes for reliable high-current operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-IQ, adjustable LDO applications.

Compared with TPS76333QDBVRQ1 and MCP1825-3302E/DB, the MAX604ESA-T uniquely combines 500mA capability, 15μA IQ, reverse-current protection, and Dual Mode™ adjustability in a thermally robust SO-8 package - making it optimal for battery longevity, fault resilience, and design flexibility in portable instrumentation.

Availability

MAX604ESA-T is available at Aetrix Electronics and suitable for portable medical sensors, solar-powered environmental monitors, and industrial handheld scanners requiring stable component supply with guaranteed industrial temperature range (-40°C to +85°C) and long-term availability.

Supply support for MAX604ESA-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 demanding industrial, medical, and communications applications.

The MAX603/MAX604 family was engineered specifically for battery-powered systems needing ultra-low quiescent current, reverse-current blocking, and flexible fixed/adjustable outputs - targeting portable instrumentation, pagers, and solar-harvested devices.

FAQ

What is the guaranteed output voltage tolerance for MAX604ESA-T over temperature and load?

The MAX604ESA-T guarantees 3.15V to 3.45V output voltage across -40°C to +85°C ambient temperature and 20μA to 300mA load current, per its Electrical Characteristics table. This ±150mV (±4.5%) tolerance ensures compatibility with 3.3V logic families and ADC references in portable instrumentation where thermal drift must remain bounded.

Can MAX604ESA-T operate with input voltage below 3.3V?

No - the MAX604ESA-T requires minimum 2.7V input, but cannot regulate 3.3V output if VIN falls below VOUT + dropout. At 200mA load, dropout is 240mV typ, so VIN must stay ≥3.54V for stable 3.3V output. Below that, output collapses linearly; the device does not enter "dropout hold-up" mode like some bipolar regulators.

How does the SET pin determine fixed vs. adjustable mode on MAX604ESA-T?

The MAX604ESA-T uses an internal dual-mode comparator: if SET voltage is ≤80mV, it selects internal 3.3V feedback; if ≥150mV, it switches to external resistor divider. A direct GND connection satisfies the ≤80mV condition. Pulling SET to OUT (1.20V reference) enables adjustable mode with VOUT = 1.20V × (1 + R1/R2).

What thermal design is required to sustain 500mA output from MAX604ESA-T?

To sustain 500mA continuously, the MAX604ESA-T SO-8 package requires a minimum 1.3 cm² copper ground pad (per Figure 4) and airflow or board-level heatsinking to maintain junction temperature ≤+125°C. At VIN = 6V and VOUT = 3.3V, power dissipation is 1.35W - demanding full 1.8W SO-8 rating with proper PCB layout.

Does MAX604ESA-T provide reverse-voltage protection on the IN pin?

No - the MAX604ESA-T does not protect against reverse polarity on IN. Its reverse-current protection only activates when VIN falls *below* VOUT (e.g., backup battery takeover), limiting reverse conduction to ≤10μA. External reverse-polarity protection (e.g., series Schottky diode or ideal diode controller) is required if IN may be connected backward.