Maxim Introduces Buck Converter with Linear Bypass Mode

High-power LED lamp beads 1W white light Sanan 30mil high power LED lamp beads imitation lumens

Photocoupler

Maxim Integrated has introduced the MAX8989, a highly efficient step-down converter designed to power PA (power amplifier) modules in mobile devices. As the industry's first DC-DC converter capable of managing power for multiple communication protocols—such as LTE, WCDMA, GSM, and EDGE—the MAX8989 is perfectly suited for multi-mode power amplifiers. This advanced solution is now available on Infineon’s proven SMARTiTM UE2 RF engine platform, offering unmatched flexibility and efficiency for modern, multi-standard cellular systems.

The MAX8989 combines a high-efficiency switching regulator with a parallel bypass LDO, ensuring optimal performance under all operating conditions. By dynamically adjusting the supply voltage to the PA output stage, this design significantly reduces power consumption. Engineers can fine-tune the PA supply voltage to meet specific transmit power needs, resulting in up to a 25% increase in 2G talk time and a 10% improvement in 3G talk time, making it ideal for extended battery life in mobile applications.

A built-in LDO ensures smooth transitions between buck regulation and low dropout operation, enabling seamless switching to high-power modes. When the input voltage drops, the LDO acts as a low-impedance (85mΩ) bypass FET, minimizing power loss during peak current demands. Additionally, the switching regulator supports 100% duty cycle operation, further reducing energy losses and improving overall system efficiency.

The MAX8989 is capable of delivering up to 2.5A of output current, making it an excellent choice for GSM/EDGE power amplifier applications. It operates over an extended temperature range of -40°C to +85°C and is housed in a compact 9-bump wafer-level package (WLP), measuring just 1.6mm x 1.6mm with a maximum height of 0.69mm. This small form factor makes it ideal for space-constrained designs. Samples and evaluation boards are now available for developers looking to integrate this innovative power management solution into their next-generation mobile devices.