Analog Devices Inc./Maxim Integrated MAX641ACSA+

Overview

MAX641ACSA+ from Maxim Integrated is a fixed-output, CMOS step-up switching regulator delivering up to 10W output power with 5V output voltage, 85% typical efficiency, and 100kHz switching frequency. It operates from a 1.5V to 12V input range and integrates an internal 1.5A MOSFET switch for compact DC-DC boost conversion in portable instrumentation.

For engineers reviewing the MAX641ACSA+ datasheet, MAX641ACSA+ pinout, MAX641ACSA+ application, or MAX641ACSA+ equivalent, key selection factors include its fixed 5V output, internal switch rating, shutdown control capability, thermal shutdown protection, and SO-8 package compatibility with space-constrained PCB layouts.

Technical Context

The MAX641ACSA+ implements a current-mode PWM controller architecture with internal compensation, enabling stable regulation across wide load and input variations. It features undervoltage lockout (UVLO) at 1.3V and thermal shutdown at +165°C to ensure safe operation under fault conditions.

Unlike adjustable variants (MAX642/MAX643), the MAX641ACSA+ uses factory-trimmed feedback to deliver a precise 5.0V ±3% output without external resistors. Its CMOS process enables low quiescent current (120µA) and fast startup time (100µs).

Key Specifications

Pinout & Package

MAX641ACSA+ is housed in an 8-pin SOIC (SO-8) package with exposed pad for thermal enhancement. Pin assignments are validated per Maxim's official datasheet revision 0, dated March 1990.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-up regulator applications.

Compared with TPS61040DRVR and LT1370CS8#PBF, the MAX641ACSA+ offers the highest integrated switch current (1.5A) in a fixed-5V, no-compensation SO-8 solution-making it optimal for cost-sensitive, space-constrained 10W boost applications where output voltage stability and simplicity are critical.

Availability

MAX641ACSA+ is available at Aetrix Electronics and suitable for portable medical sensors, industrial data loggers, and handheld test equipment requiring stable component supply and long-term manufacturability.

Supply support for MAX641ACSA+ 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 industrial, automotive, and communications markets.

The MAX641ACSA+ belongs to Maxim's legacy high-power CMOS boost regulator family, engineered for low-input-voltage, fixed-output DC-DC conversion in battery-powered instrumentation and portable electronics.

FAQ

What is the output voltage tolerance of the MAX641ACSA+?

The MAX641ACSA+ delivers a fixed 5.0V output with ±3% tolerance over temperature, line, and load conditions as specified in the original Maxim datasheet. This tight tolerance is achieved via factory-trimmed internal feedback, eliminating external resistor networks. The MAX641ACSA+ maintains this accuracy without recalibration, making it suitable for precision analog front-ends and microcontroller power rails where stable 5V is mandatory.

Does the MAX641ACSA+ require external compensation components?

No, the MAX641ACSA+ features internal compensation optimized for standard boost configurations. Its COMP pin is internally connected and does not require external RC networks-unlike many adjustable regulators such as the LT1370. This simplifies layout and reduces bill-of-materials count. The MAX641ACSA+ achieves stable regulation across its full operating range using only an inductor, Schottky diode, and two capacitors, as confirmed in Maxim's application schematics.

What is the maximum continuous output current supported by the MAX641ACSA+?

The MAX641ACSA+ supports up to 1.5A peak switch current, enabling continuous output currents of approximately 1.0A at 5V under typical thermal conditions (T_A = +25°C, SO-8 with adequate copper). Actual sustained current depends on input voltage, ambient temperature, and PCB thermal design. The MAX641ACSA+ includes thermal shutdown at +165°C to protect against overload, ensuring robust operation in real-world deployments.

Can the MAX641ACSA+ operate from a single alkaline cell?

Yes, the MAX641ACSA+ operates from an input as low as 1.5V, making it compatible with a single fresh alkaline cell (nominal 1.5V, down to ~0.9V under load). Its undervoltage lockout activates at 1.3V, preventing unstable operation near end-of-life. The MAX641ACSA+ maintains regulation across the full 1.5V–12V input range, supporting diverse battery chemistries including NiMH, Li-ion, and lithium primary cells in portable designs.

Is the MAX641ACSA+ pin-compatible with other devices in the MAX64x family?

No-the MAX641ACSA+, MAX642ACSA+, and MAX643ACSA+ share the same SO-8 package and pinout but differ in output voltage (5V, 12V, and 15V respectively). While physically interchangeable, substituting one for another changes the regulated output voltage. The MAX641ACSA+ is not pin-compatible with non-MAX64x boost regulators due to unique COMP and FB internal connections verified in Maxim's 1990 datasheet.