Analog Devices Inc./Maxim Integrated MAX604CSA+T

Overview

MAX604CSA+T from Maxim Integrated is a 3.3V fixed-output, low-dropout linear regulator with P-channel MOSFET pass transistor, delivering up to 500mA output current, 240mV dropout at 200mA, and 15μA typical quiescent current. It operates from 2.7V to 11.5V input and features shutdown mode (2μA), reverse-current protection, and thermal overload protection - ideal for battery-powered portable instruments and solar-powered devices.

For engineers reviewing the MAX604CSA+T datasheet, MAX604CSA+T pinout, MAX604CSA+T application, or MAX604CSA+T equivalent, key selection considerations include dropout voltage vs. load, shutdown threshold behavior across input voltage range, reverse-current protection activation threshold (6–20mV), Dual Mode™ feedback configuration, and SO-8 thermal derating (1.8W at +70°C).

Technical Context

The MAX604CSA+T implements a 1.20V bandgap reference, error amplifier, and MOSFET driver controlling an internal 500mA P-channel pass transistor. Its Dual Mode™ comparator selects between internal fixed feedback (3.3V) when SET ≤ 80mV or external adjustable feedback (1.25V–11V) when SET ≥ 150mV.

Reverse-current protection actively switches substrate bias between IN and OUT pins to limit reverse conduction when VIN falls below VOUT by ≥6mV. Thermal shutdown activates at +160°C with 10°C hysteresis, forcing pulsed operation under sustained overload.

Key Specifications

Pinout & Package

MAX604CSA+T is housed in an 8-pin SOIC (SO-8) package with exposed thermal pad design rated for 1.8W continuous dissipation at +70°C ambient. Ground pins (2, 3, 6, 7) serve dual roles as electrical ground and thermal heatsinks - all must be soldered to large copper planes for reliable power handling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS76333DBVR and MCP1700T-3302E/MB, the MAX604CSA+T delivers higher output current (500mA), integrated reverse-current blocking, programmable Dual Mode™ feedback, and robust thermal/foldback protection - making it suitable for mission-critical portable systems where reliability and flexibility outweigh footprint savings.

Availability

MAX604CSA+T is available at Aetrix Electronics and suitable for battery-powered devices, portable instruments, and solar-powered instruments requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX604CSA+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, automotive, and communications markets.

The MAX603/MAX604 product line was engineered specifically for ultra-low-power, high-reliability battery-operated systems - emphasizing minimal quiescent current, robust fault protection, and flexible output configuration without external components.

FAQ

What is the maximum continuous output current for MAX604CSA+T under typical conditions?

The MAX604CSA+T delivers up to 500mA continuous output current when the input-to-output differential voltage remains within thermal limits. At 3.3V output and 200mA load, dropout is 240mV; at 400mA, it rises to 480mV. Power dissipation must stay below 1.8W (SO-8 package at +70°C), so actual current depends on VIN, ambient temperature, and PCB copper area. The device includes foldback current limiting to protect against shorts.

How does the SET pin function in MAX604CSA+T, and what happens if left floating?

The SET pin on MAX604CSA+T determines operating mode: grounding it selects the factory-trimmed 3.3V output; connecting it to an external resistor divider enables adjustable output (1.25V–11V). If left floating, leakage currents may cause the voltage at SET to exceed the 80mV threshold, resulting in unpredictable switching between modes or regulation instability. Maxim specifies impedance to ground must be <10kΩ in fixed mode to ensure reliable operation.

Does MAX604CSA+T support reverse-current protection, and how does it behave during input failure?

Yes, MAX604CSA+T features active reverse-current protection that activates when VIN falls 6–20mV below VOUT. At that point, internal circuitry switches substrate bias to the more positive of IN or OUT, turning off the pass transistor and limiting reverse current to ≤0.01μA. This allows backup sources (e.g., supercapacitors or secondary batteries) to maintain VOUT uninterrupted during primary supply failure - a key advantage over standard LDOs.

What is the recommended capacitor configuration for stable operation of MAX604CSA+T?

For stable operation across temperature and load, MAX604CSA+T requires a minimum 10μF output capacitor (low-ESR tantalum or ceramic) and 0.1μF–10μF input capacitor. Capacitors smaller than 3.3μF on the output risk oscillation. Larger output capacitance improves load-transient response and PSRR above 10kHz. Input capacitance enhances line-transient rejection and noise filtering - especially important when powering from noisy switchers or long traces.

Can MAX604CSA+T be used in automotive applications, and what temperature grades are available?

The MAX604CSA+T is rated for 0°C to +70°C operation (C-grade) and is not qualified for automotive AEC-Q100 stress testing. For extended temperature ranges, Maxim offers the MAX604ESA (–40°C to +85°C) and MAX604MSA (–55°C to +125°C) variants in the same SO-8 package. These versions maintain identical electrical specifications but undergo additional screening for harsh-environment reliability - required for under-hood or industrial control applications.