Analog Devices Inc./Maxim Integrated MAX603CSA+T

Overview

The MAX603CSA+T from Maxim Integrated is a 5V fixed-output, low-dropout linear regulator with P-channel MOSFET pass transistor, 500mA output current capability, 15μA typical quiescent current, and 320mV dropout at 5V/500mA - designed for battery-powered instrumentation and portable electronics requiring stable low-power voltage regulation.

For engineers reviewing the MAX603CSA+T datasheet, MAX603CSA+T pinout, MAX603CSA+T application, or MAX603CSA+T equivalent, this page delivers verified electrical parameters, thermal behavior, Dual Mode™ configuration options, reverse-current protection threshold, and SO-8 package layout guidance - all confirmed from Maxim's official Rev 1 (4/17) datasheet.

Technical Context

The MAX603CSA+T implements a 1.20V bandgap reference, error amplifier, MOSFET driver, and dual-mode comparator to regulate output via internal feedback (5V fixed) or external resistor network (1.25V–11V adjustable). Its P-channel pass transistor eliminates base-drive current, enabling ultra-low IQ independent of load.

Shutdown logic disables all circuitry below 2μA when OFF pin is pulled low; reverse-current protection activates at ∆V = V_OUT − V_IN ≥ 6mV (typ), switching substrate bias to limit reverse leakage to 0.01μA. Thermal shutdown triggers at +160°C with 10°C hysteresis.

Key Specifications

Pinout & Package

MAX603CSA+T uses an 8-pin SOIC (SO-8) package rated for 1.8W power dissipation at +70°C ambient, with four dedicated GND pins serving as thermal conduction paths - requires soldering to large copper planes for thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT1763CS8-5#TRPBF and TLS850F0TESA1, the MAX603CSA+T delivers superior battery runtime due to its 15μA IQ and unique reverse-current protection - critical for systems with backup power sources or intermittent input, while retaining full configurability via the SET pin.

Availability

MAX603CSA+T is available at Aetrix Electronics and suitable for battery-powered instrumentation, portable medical sensors, solar-powered remote monitors, and industrial data loggers requiring stable component supply with guaranteed long-term availability.

Supply support for MAX603CSA+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 MAX603CSA+T belongs to Maxim's low-dropout linear regulator product line, engineered specifically for ultra-low-power, battery-critical systems where extended runtime, thermal resilience, and reverse-current isolation are mandatory design requirements.

FAQ

What is the maximum continuous output current of the MAX603CSA+T?

The MAX603CSA+T delivers 500mA continuous output current when operated within its safe operating area - defined by input-output differential voltage, ambient temperature, and PCB thermal design. At 5V output and 500mA load, dropout is 320mV; exceeding this differential or ambient temperature may trigger thermal shutdown. The datasheet specifies 600mA absolute maximum for short durations.

Does the MAX603CSA+T support adjustable output voltage?

Yes, the MAX603CSA+T supports adjustable output from 1.25V to 11V using external resistors connected to the SET pin. When SET is grounded, it defaults to 5V fixed output. The internal 1.20V reference and zero-bias SET input enable precise resistor-based programming without loading errors - confirmed in the MAX603/MAX604 datasheet Figure 3 and Output Voltage Selection section.

What is the purpose of the four GND pins on the MAX603CSA+T SO-8 package?

The four GND pins (pins 2, 3, 6, 7) on the MAX603CSA+T serve dual roles: providing low-impedance return paths and acting as thermal conduction channels. Maxim explicitly states they "function as heatsinks" and must be soldered to large copper pads or planes to achieve the rated 1.8W power dissipation at +70°C ambient - critical for sustaining 500mA output without thermal derating.

How does reverse-current protection work in the MAX603CSA+T?

The MAX603CSA+T monitors V_IN and V_OUT and switches its internal substrate bias to the more positive node when V_IN falls below V_OUT by ≥6mV (typ). This turns off the P-channel pass transistor and limits reverse leakage to 0.01μA - enabling safe operation in systems with backup batteries or redundant supplies. This behavior is documented in the Reverse-Current Protection section and Electrical Characteristics table (parameter ∆VRTH).

Can the MAX603CSA+T be used with input voltages below 2.7V?

No - the absolute minimum input voltage for the MAX603CSA+T is 2.7V, as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. Operation below this violates the device's functional specification; attempting to regulate at lower VIN risks unstable output, increased dropout, or failure to maintain regulation. For sub-2.7V applications, consider alternative regulators such as the MAX1726 or TPS7A05.