MAX857CPA

Overview

The MAX857CPA is a step-up DC-DC converter manufactured by Analog Devices Inc./Maxim Integrated. It operates with an input voltage range of 0.8V to 6V and provides a fixed output voltage of either 3.3V or 5V, or an adjustable output. The device delivers an output current of 150mA and switches at a frequency of 500kHz. It is housed in an 8-pin SOIC package and functions within a temperature range of -40°C to +85°C.

Feature Summary

• Boost topology for efficient voltage step-up conversion
• Fixed or adjustable output voltage options
• High switching frequency for compact external component size

Applications

• Portable battery-powered equipment
• Cellular phones
• Personal digital assistants (PDAs)
• Laptop computers

Procurement Notes

Verify the specific suffix 'CPA' indicates the commercial temperature grade and DIP packaging variant. Confirm RoHS compliance status as '+T' variants are often lead-free while non-suffixed or older parts may differ. Ensure the distributor source provides official documentation matching the exact part number to avoid confusion with similar MAX85x series components.

Selection Notes

Select this component when a boost regulator is required for low-voltage single-cell lithium-ion or alkaline battery applications. The 150mA output current suits moderate load requirements. Consider the 500kHz switching frequency for balancing efficiency and passive component size. Verify that the 8-pin DIP package fits the target PCB layout constraints compared to surface-mount alternatives.

Part Context

The MAX857 belongs to Maxim's family of high-efficiency step-up converters designed for portable electronics. It integrates a power switch and control circuitry to minimize external component count. The device is part of the broader PMIC portfolio used in mobile communication devices and handheld instruments requiring reliable voltage regulation from low-input sources.

Replacement Considerations

Check for MAX857ESA+T for surface-mount SOIC packaging with potentially different thermal characteristics. Verify if MAX856 serves as a compatible alternative if fixed 3.3V/5V outputs are sufficient and pinout compatibility is confirmed. Consult official substitution guides for any functional differences in shutdown current or ripple specifications.