Analog Devices Inc./Maxim Integrated MAX604ESA

Overview

The MAX604ESA from Maxim Integrated is a low-dropout, low-quiescent-current linear regulator with fixed 3.3V output and adjustable mode capability (1.25V–11V), featuring an internal 500mA P-channel MOSFET pass transistor, 240mV dropout at 200mA/3.3V, and 15μA typical quiescent current - designed for battery-powered portable instruments and solar-powered devices requiring stable low-power regulation.

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

Technical Context

The MAX604ESA implements a bandgap-referenced error amplifier driving a P-channel MOSFET pass element, enabling ultra-low IQ independent of load. Its Dual Mode™ comparator selects between internal fixed-voltage feedback (SET ≤ 80mV → 3.3V) and external resistor-divider feedback (SET ≥ 150mV → adjustable output).

Reverse-current protection operates by dynamically switching the substrate and power bus to the more positive of IN or OUT pins, limiting reverse leakage to ≤10μA when VIN falls below VOUT by ≥6mV. Thermal shutdown activates at TJ = +160°C with 10°C hysteresis, forcing pulsed operation under sustained overload.

Key Specifications

Pinout & Package

MAX604ESA is housed in an 8-pin SOIC (Small Outline Integrated Circuit) package with exposed thermal pad structure, rated for 1.8W continuous power dissipation at TA = +70°C (derated 23.6mW/°C above). Four GND pins (2,3,6,7) serve dual roles: electrical ground reference and primary thermal conduction paths - all must be soldered to large copper planes for reliable operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout, low-IQ linear regulator applications.

Compared with TPS76333QDBVRQ1 and MCP1702T-3302E/MB, the MAX604ESA uniquely combines 300mA capability, sub-250mV dropout, reverse-current protection, and Dual Mode™ configurability in a thermally robust SO-8 package - making it optimal for industrial portable equipment requiring both efficiency and fault resilience.

Availability

MAX604ESA 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 long-term manufacturability and consistent parametric performance.

Supply support for MAX604ESA 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 MAX603/MAX604 product line was engineered specifically for battery-constrained systems demanding ultra-low quiescent current, low dropout, and intelligent protection - targeting portable instrumentation, pagers, and solar-harvesting devices.

FAQ

What is the maximum continuous output current for MAX604ESA?

The MAX604ESA delivers up to 300mA continuously under specified thermal conditions (SO-8 package, adequate PCB copper, TA ≤ +70°C). At 500mA, operation is limited to short-duration pulses due to power dissipation constraints - the absolute maximum continuous output current is defined by (TJ − TA)/(θJB + θBA), not just the 500mA pass transistor rating. Always verify junction temperature in final layout using the 42°C/W θJB value.

Does MAX604ESA support adjustable output voltage, and how is it configured?

Yes, MAX604ESA supports adjustable output from 1.25V to 11V using external resistors connected to the SET pin. When SET voltage exceeds 150mV, the internal comparator selects external feedback mode; the output follows VOUT = 1.20V × (1 + R1/R2). The SET pin draws only ±10nA, enabling high-value resistors (up to 1.5MΩ for R2) to minimize power loss while maintaining accuracy.

What is the purpose of the four GND pins on MAX604ESA, and how should they be connected?

The four GND pins (2, 3, 6, 7) on MAX604ESA serve as both electrical ground references and primary thermal conduction paths. All must be soldered directly to a large copper ground plane - not individual traces - to achieve the rated 1.8W power dissipation. Inadequate grounding causes thermal derating, increased dropout, and premature thermal shutdown. The SO-8 package's thermal performance depends entirely on this multi-pin ground connection.

How does reverse-current protection work in MAX604ESA, and what is its activation threshold?

MAX604ESA's reverse-current protection activates when VIN falls 6mV to 20mV below VOUT, at which point internal circuitry switches the substrate and power bus to the more positive node (OUT), turning off the P-channel pass transistor. This limits reverse leakage to ≤0.01μA, preventing backup batteries or supercapacitors from discharging through the regulator when the main supply fails - critical for energy-harvesting and dual-source systems.

Can MAX604ESA be used with input voltages below 2.7V?

No, MAX604ESA is not specified or guaranteed for operation below 2.7V input. The absolute minimum input voltage is 2.7V (for C/E grade), and attempting to operate below this risks loss of regulation, increased dropout, or undefined behavior. For sub-2.7V applications, consider dedicated ultra-low-input LDOs such as the TPS7A05, which supports down to 1.4V input while delivering 3.3V output.