Analog Devices Inc./Maxim Integrated MAX603EPA+

Overview

MAX603EPA+ from Maxim Integrated is a 5V fixed-output, low-dropout linear regulator with P-channel MOSFET pass transistor, 500mA output capability, 320mV dropout at 5V/500mA, 15μA typical quiescent current, and -40°C to +85°C operating temperature range. It serves as a primary voltage source in battery-powered portable instruments requiring stable 5V rail under variable load and input conditions.

For engineers reviewing the MAX603EPA+ datasheet, MAX603EPA+ pinout, MAX603EPA+ application, or MAX603EPA+ equivalent, key selection criteria include dropout performance at full load, reverse-current protection threshold (6–20mV), thermal shutdown behavior (160°C), Dual Mode™ configurability, and SOIC-8 vs. DIP-8 package thermal derating (1.8W vs. 727mW).

Technical Context

The MAX603EPA+ employs a 1.20V bandgap reference and error amplifier driving a P-channel MOSFET pass transistor - eliminating base-drive current and enabling ultra-low IQ independent of load. Its Dual Mode™ comparator selects internal feedback (5V fixed) when SET ≤ 80mV or external resistor network for adjustable 1.25V–11V output.

Reverse-current protection activates when VIN falls 6–20mV below VOUT, switching substrate bias to the more positive node and limiting reverse leakage to ≤10μA. Foldback current limiting delivers 350mA short-circuit protection below 0.8V output and 1.2A limit above 0.8V with VIN–VOUT > 0.7V.

Key Specifications

Pinout & Package

MAX603EPA+ is housed in an 8-pin plastic DIP (Dual In-line Package) with through-hole mounting, rated for 727mW continuous power dissipation at TA = +70°C (derated 9.09mW/°C above). GND pins (2,3,6,7) are electrically common but serve as thermal conduction paths; all must be soldered to PCB ground planes 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 TPS76350DBVT, the MAX603EPA+ uniquely combines 500mA output, 15μA IQ, reverse-current protection, and shutdown control in a through-hole DIP package - making it optimal for rugged, battery-backed industrial and portable instrumentation where reliability and thermal margin outweigh footprint constraints.

Availability

MAX603EPA+ is available at Aetrix Electronics and suitable for portable medical instruments, solar-powered data loggers, industrial handheld terminals, and low-power IoT edge nodes requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX603EPA+ 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 MAX603EPA+ belongs to Maxim's low-dropout linear regulator product line, engineered specifically for battery-powered portable equipment requiring ultra-low quiescent current, reverse-current isolation, and wide-input-voltage operation without sacrificing output accuracy or thermal robustness.

FAQ

What is the maximum continuous output current for MAX603EPA+ at 5V output?

The MAX603EPA+ delivers up to 500mA continuous output current when VIN ≥ 5.32V (5V + 320mV dropout). At higher input voltages, power dissipation limits apply: in its 8-pin plastic DIP package, continuous power must stay ≤727mW at +70°C ambient, derating 9.09mW/°C above that. For example, at VIN = 9V and VOUT = 5V, max sustainable current is ~180mA to avoid exceeding thermal limits.

Does MAX603EPA+ support adjustable output voltage, and how is it configured?

Yes, the MAX603EPA+ supports adjustable output from 1.25V to 11V via its Dual Mode™ architecture. To enable adjustable mode, disconnect the SET pin from GND and connect it to a resistor divider between OUT and GND. The output voltage follows VOUT = 1.20V × (1 + R1/R2), where R2 connects to GND. The SET pin draws <±10nA, allowing high-value resistors (e.g., R2 = 100kΩ, R1 = 317kΩ for 5V) without accuracy loss.

How does reverse-current protection work in MAX603EPA+, and what is its activation threshold?

MAX603EPA+ monitors the differential voltage between OUT and IN. When VOUT exceeds VIN by ≥6mV (typical) or 20mV (max), its internal protection circuit switches substrate bias to the more positive node and turns off the P-channel pass transistor, limiting reverse current to ≤10μA. This prevents backfeed from backup supplies or charged capacitors into a failing main input - critical in dual-source systems like battery + supercapacitor.

What capacitor values are required for stable operation of MAX603EPA+?

For stable operation across temperature and load, MAX603EPA+ requires a minimum 10μF output capacitor (tantalum or low-ESR electrolytic) and 0.1μF–10μF input capacitor. Using <3.3μF output capacitance risks oscillation. The 10μF output cap ensures adequate phase margin, load-transient suppression, and PSRR enhancement above 10kHz. Input caps >1μF improve line-transient response and supply-noise rejection.

Can MAX603EPA+ be used in automotive applications, and what is its qualified temperature range?

MAX603EPA+ is rated for -40°C to +85°C operation (E-grade), meeting requirements for under-hood and cabin electronics in non-safety-critical automotive subsystems. However, it is not AEC-Q200 qualified, lacks automotive-specific screening, and has no guaranteed performance at 125°C junction temperature. For automotive use, consider AEC-Q200 qualified alternatives unless full qualification is waived per customer design validation.