Analog Devices Inc./Maxim Integrated MAX604CSA-T

Overview

The 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 typical 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 its fixed 3.3V output, SO-8 package thermal performance, dropout behavior under load, shutdown threshold voltage variation with VIN, and compatibility with low-ESR ceramic output capacitors.

Technical Context

The MAX604CSA-T uses an internal 1.20V bandgap reference and error amplifier to regulate output via a P-channel MOSFET pass transistor - eliminating base-drive current and enabling stable 15μA quiescent current across load and temperature. Its dual-mode comparator selects between internal feedback (SET = GND → 3.3V) and external resistor network (1.25V–11V adjustable).

Reverse-current protection activates when VIN falls 6–20mV below VOUT, switching substrate bias to limit reverse leakage to ≤10μA. Foldback current limiting delivers 350mA short-circuit protection below 0.8V output and 1.2A limit above 0.8V with sufficient VIN–VOUT margin.

Key Specifications

Pinout & Package

MAX604CSA-T is housed in an 8-pin SOIC (SO-8) package with exposed thermal pad (1.8W power dissipation rating at TA = +70°C). All four GND pins (2,3,6,7) serve as both electrical ground and thermal conduction paths - must be soldered to large copper planes for reliable 500mA 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 TPS76333DBVR and MCP1700T-3302E/TT, the MAX604CSA-T uniquely combines 500mA output, 15μA IQ, reverse-current blocking, and thermal foldback in a thermally enhanced SO-8 package - making it the only option capable of sustaining full-rated load across automotive-grade temperature ranges with integrated fault resilience.

Availability

MAX604CSA-T is available at Aetrix Electronics and suitable for battery-powered devices, portable instruments, and solar-powered environmental monitors requiring stable component supply with guaranteed long-term availability and consistent parametric performance.

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, communications, and consumer applications.

The MAX603/MAX604 product line was designed specifically for battery-constrained systems requiring ultra-low quiescent current, low dropout, and robust fault protection - targeting portable medical, instrumentation, and remote sensing markets.

FAQ

What is the maximum continuous output current of the MAX604CSA-T?

The MAX604CSA-T delivers up to 500mA continuous output current under specified thermal conditions - provided the SO-8 package is mounted on a PCB with adequate copper pour (≥1.3 cm² ground pad per Figure 4) and ambient temperature remains ≤+70°C. At higher temperatures or reduced heatsinking, derating applies per the 1.8W power dissipation limit.

Does the MAX604CSA-T support adjustable output voltage?

Yes, the MAX604CSA-T supports adjustable output from 1.25V to 11V via external resistors connected to the SET pin, using the formula VOUT = 1.20V × (1 + R1/R2). When SET is grounded, it defaults to the factory-trimmed 3.3V output. The SET pin's ±10nA leakage ensures high-impedance resistor networks maintain accuracy.

How does reverse-current protection work in the MAX604CSA-T?

The MAX604CSA-T monitors the differential voltage between OUT and IN. When VOUT exceeds VIN by ≥6mV (up to 20mV), internal circuitry switches substrate bias to the more positive rail and turns off the P-channel pass transistor - limiting reverse current to ≤10μA. This enables safe backup power switchover without external diodes.

What is the recommended output capacitor for stable operation of the MAX604CSA-T?

A 10μF low-ESR ceramic or tantalum capacitor is recommended at the OUT pin for stable operation across temperature and load (20μA–300mA). Capacitors smaller than 3.3μF risk oscillation; larger values improve load-transient response and PSRR above 10kHz. Input capacitance of 0.1μF–10μF is also advised.

Can the MAX604CSA-T be used with 3.3V logic to control the OFF pin?

No - the OFF pin's high-threshold voltage increases with input supply (e.g., 4.0V minimum at VIN = 11.5V), so 3.3V logic cannot reliably enable the device across its full input range. Use VIN-referenced logic, level-shifting circuitry, or a dedicated supervisor IC to ensure OFF pin voltage exceeds the rising threshold under all operating conditions.