Analog Devices Inc./Maxim Integrated MAX604CPA

Overview

The MAX604CPA 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 MAX604CPA datasheet, MAX604CPA pinout, MAX604CPA application, or MAX604CPA equivalent, key selection considerations include its fixed 3.3V output, 8-pin PDIP package, dual-mode capability (fixed/adjustable), dropout behavior under load, and thermal derating in plastic DIP.

Technical Context

The MAX604CPA 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 feedback path based on SET pin voltage: ≤80mV enables internal 3.3V regulation; >150mV enables external resistor-adjustable output (1.25V–11V).

Reverse-current protection activates when VIN falls 6–20mV below VOUT, switching substrate bias to limit reverse leakage to ≤10μA. Foldback current limiting responds to short-circuit conditions (<0.8V output) by capping current at 350mA, while thermal shutdown engages at +160°C with 10°C hysteresis.

Key Specifications

Pinout & Package

MAX604CPA is housed in an 8-pin plastic DIP (dual in-line package) with through-hole mounting and no exposed thermal pad. GND pins (2,3,6,7) are electrically common and serve as primary heat conduction paths; all must be soldered to large copper areas for rated 727mW dissipation at +70°C ambient.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2936MP-3.3/NOPB and TPS76333DBVR, the MAX604CPA offers uniquely low 15μA quiescent current, integrated shutdown control, reverse-current isolation, and dual-mode configurability - making it superior for long-life, battery-critical, and flexible-voltage applications despite its larger PDIP footprint.

Availability

MAX604CPA is available at Aetrix Electronics and suitable for battery-powered portable instruments, solar-powered remote sensors, and low-power industrial data loggers requiring stable component supply with long-term manufacturability and legacy support.

Supply support for MAX604CPA 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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MAX603/MAX604 family was designed specifically for ultra-low-power, battery-critical systems requiring reliable 3.3V/5V regulation with minimal quiescent draw and robust fault protection - targeting portable instrumentation and energy-harvesting applications.

FAQ

What is the maximum continuous output current for MAX604CPA?

The MAX604CPA delivers up to 500mA output current under specified conditions: input voltage ≥4.3V, ambient temperature ≤+70°C, and adequate PCB copper area for thermal dissipation. At higher temperatures or in the plastic DIP package, derating applies - continuous power dissipation is limited to 727mW at +70°C, decreasing by 9.09mW/°C above that point. The device also features foldback current limiting to protect against shorts.

Does MAX604CPA support adjustable output voltage?

Yes, the MAX604CPA supports adjustable output from 1.25V to 11V using external resistors connected to the SET pin - enabled when SET voltage exceeds 150mV. In preset mode (SET = GND), it regulates to 3.3V. This Dual Mode™ functionality is intrinsic to the MAX604CPA silicon and does not require external components beyond R1/R2 for adjustment.

What is the purpose of the OFF pin on MAX604CPA?

The OFF pin on MAX604CPA is an active-low shutdown control that disables the entire regulator circuitry, reducing supply current to ≤2μA. When pulled low (≤0.4V), it turns off the pass transistor, reference, error amplifier, and bias networks. For normal operation, OFF must be tied to IN. Fast CMOS/TTL logic is recommended to avoid indeterminate states during transition.

How does reverse-current protection work in MAX604CPA?

MAX604CPA's reverse-current protection activates when the input voltage (IN) falls 6–20mV below the output voltage (OUT), triggering internal substrate switching to isolate the input from the output. This limits reverse leakage to ≤10μA, preventing backup power sources (e.g., secondary batteries or supercaps) from discharging through the regulator - a critical feature for systems with multiple power domains.

What capacitor values are required for stable operation of MAX604CPA?

For stable operation across temperature and load, MAX604CPA requires a minimum 10μF output capacitor (low-ESR tantalum or ceramic) and 0.1μF–10μF input capacitor. Using <3.3μF output capacitance risks oscillation. Larger output capacitors improve load-transient response and PSRR; input capacitance ≥1μF enhances line-transient rejection and noise filtering - especially important in battery-fed or noisy supply environments.