Analog Devices Inc./Maxim Integrated MAX603CPA+

Overview

The MAX603CPA+ from Maxim Integrated is a 5V fixed-output, low-dropout linear regulator with P-channel MOSFET pass transistor, delivering up to 500mA output current, 320mV dropout at 5V/500mA, and 15μA typical quiescent current. It operates from 2.7V to 11.5V input and features shutdown (2μA off mode), reverse-current protection, and thermal overload protection - ideal for battery-powered instrumentation and portable 5V systems.

For engineers reviewing the MAX603CPA+ datasheet, MAX603CPA+ pinout, MAX603CPA+ application, or MAX603CPA+ equivalent, key selection considerations include its fixed 5V output, SO-8-compatible DIP-8 package, dropout behavior under load, shutdown threshold voltage vs. VIN, and compatibility with 10μF output capacitance for stability.

Technical Context

The MAX603CPA+ 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 ultra-low IQ independent of load. Its dual-mode comparator selects between internal feedback (5V preset) and external resistor-adjustable mode (1.25V–11V) based on SET pin voltage (<80mV for fixed mode).

Reverse-current protection activates when VIN falls 6–20mV below VOUT, switching substrate bias to limit reverse leakage to ≤10μA. Foldback current limiting engages at 350mA during short-circuit (VOUT < 0.8V) and up to 1.2A in normal operation, while thermal shutdown triggers at +160°C with 10°C hysteresis.

Key Specifications

Pinout & Package

MAX603CPA+ is housed in an 8-pin plastic DIP (dual in-line package) with 0.3-inch width, rated for 727mW continuous power dissipation at +70°C ambient and derated above that temperature. GND pins (2,3,6,7) serve as electrical ground and thermal conduction paths; all must be soldered to PCB copper for reliable thermal performance.

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#PBF and TPS76350DBVR, the MAX603CPA+ uniquely combines 500mA output, ultra-low 15μA IQ, active shutdown, and reverse-current protection in a through-hole DIP-8 package - making it optimal for rugged, long-life, battery-backed instrumentation where reliability and efficiency are co-prioritized.

Availability

MAX603CPA+ is available at Aetrix Electronics and suitable for portable medical sensors, industrial data loggers, solar-powered IoT nodes, and handheld test equipment requiring stable component supply with long-term manufacturability and RoHS-compliant sourcing.

Supply support for MAX603CPA+ 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 MAX603CPA+ belongs to Maxim's low-dropout linear regulator product line, engineered specifically for battery-powered systems requiring extended runtime, robust fault protection, and seamless input failure recovery.

FAQ

What is the maximum continuous output current for MAX603CPA+?

The MAX603CPA+ delivers up to 500mA continuous output current when thermal limits permit - specifically, when power dissipation (I_OUT × (V_IN − V_OUT)) stays within the 727mW package limit at +70°C ambient. At higher ambient temperatures or larger input-output differentials, derating applies per the 9.09mW/°C thermal derating curve. The MAX603CPA+ datasheet specifies 600mA absolute maximum short-circuit current, but sustained operation is capped at 500mA under typical conditions.

Does MAX603CPA+ support adjustable output voltage?

Yes, the MAX603CPA+ supports adjustable output from 1.25V to 11V using external resistors connected to the SET pin - enabled by its Dual Mode™ architecture. When SET is grounded, it defaults to fixed 5V output. For adjustable mode, connect R1 between OUT and SET, and R2 between SET and GND; output follows V_OUT = 1.20V × (1 + R1/R2). The MAX603CPA+'s SET pin draws only ±10nA, allowing high-value resistors to minimize quiescent power loss.

What is the dropout voltage specification for MAX603CPA+ at 500mA?

The MAX603CPA+ has a typical dropout voltage of 320mV at 5V output and 500mA load, with a maximum of 550mV. Dropout is defined as the minimum VIN − VOUT required to maintain VOUT within 100mV of nominal (i.e., ≥4.90V). This means the MAX603CPA+ can regulate down to ~5.32V input at full load - a critical parameter for maximizing battery utilization in 5V systems.

How does reverse-current protection work in MAX603CPA+?

The MAX603CPA+ monitors the differential between OUT and IN voltages; when VIN falls 6–20mV below VOUT, its internal protection circuit switches substrate bias to the more positive rail and turns off the P-channel pass transistor. This limits reverse current to ≤10μA, preserving backup power sources (e.g., supercapacitors or secondary batteries) during main supply failure - a feature not found in most standard LDOs.

Can MAX603CPA+ be used with ceramic output capacitors?

Yes, the MAX603CPA+ is stable with ceramic output capacitors of 10μF or greater, provided they meet the 10μF minimum requirement and have adequate voltage rating (≥6.3V for 5V output). Unlike some older LDOs, it does not require ESR-based damping, so low-ESR ceramics are fully compatible - improving transient response and reducing board area versus tantalum or aluminum electrolytics. Always verify stability under worst-case load steps per the MAX603CPA+ load-transient plots.