Many of today's portable devices (smartphones and tablets) are powered by single-cell lithium-ion batteries that deliver approximately 4.2V at full charge. However, when connected to interfaces that require 5V output, such as USB, HDMI, and audio amplifiers for speakers, a DC/DC converter is needed to boost the voltage. At the same time, longer battery life and greater efficiency are required in a small form factor.
In response, the BD1865GWL features a minimum operating voltage of 2.5V, extending battery life in devices by allowing operation down to the conventional 2.7V. Furthermore, two operating modes are integrated: PWM/PFM mode and the original ROHM PWM mix mode. The former ensures 90% efficiency across all load regions, while the latter eliminates unwanted switching noise in audio applications. The BD1865GWL is also capable of delivering output currents up to 2A in a compact 1.6mm x 1.6mm package, contributing to further miniaturization of the final product.
Key Features
1. Low Voltage Extends Battery Life
When the remaining battery level is low, the input voltage to the system (battery output voltage) decreases. Utilizing 
industry-leading analog design technology developed over many years, ROHM is able to supply a stable 5V output even at low input voltages of 2.5V, significantly extending battery life.
2. Two control modes improve efficiency and performance
• PFM / PWM mode
This mode automatically switches between PFM and PWM modes based on the load, ensuring high efficiency across the entire load range.
• Mixing PWM mode:
An original control method that offers greater efficiency than typical PWM at light loads and avoids unwanted audible noise generated during switching, making it ideal for high-fidelity audio systems.
3. High Power in a Space-Efficient Surface Mount Package:
Typically, two or more ICs and one large IC are required to achieve a 2A output current. However, increasing the IC size and/or overall board area can be problematic, especially in portable devices that demand smaller components. The BD1865GWL delivers a 5V/2A output in a compact 1.6mm x 1.6mm package.
An evaluation board is also available, allowing for immediate evaluation (please inquire).
