The EPC91106 evaluation board is an advanced synchronous buck and boost converter, designed to deliver high power density in a compact form. Equipped with the 100V-rated, 11 mΩ RDS(on) EPC23104 eGaN® IC, this evaluation board provides a high-performance, space-saving solution for diverse applications. In this post, we’ll explore the design, key features, performance metrics, and experimental validation of the EPC91106, providing insights into its potential applications and suitability for power management solutions.

Key Features and Highlights of the EPC91106 Evaluation Board

Key Features and Highlights of the EPC91106 Evaluation Board

1. Key Features and Highlights of the EPC91106 Evaluation Board
   Measuring only 21 x 13 mm, the core circuit of the EPC91106 evaluation board is compact enough for applications where space is critical, such as high-density computing, automotive, and industrial electronics. In addition, its 3 mm low-profile inductor enables compliance with the stringent profile restrictions of modern electronic packaging.

2. Flexible Power Conversion Capabilities
   The EPC91106 operates as both a buck or boost converter, providing users with flexibility in handling a range of voltage and current requirements.

3. Thermal Management Solutions
   The evaluation board can accommodate a heat spreader and heatsink to manage thermal loads for higher-power operations.

4. Enhanced Digital Control
   Digital control features allow for advanced power management techniques, enabling users to achieve optimized performance and energy efficiency in addition to flexible voltage and current settings that can be adjusted during operation.

Performance Characteristics of the EPC91106

The EPC91106 evaluation board has been designed to ensure optimal performance under various operating conditions. Here’s a breakdown of the key performance metrics based on experimental validation:

1. Efficiency

   The EPC91106 was configured with an average-current mode buck controller, set to a 12 V output with a 720 kHz switching frequency and 10 ns dead time. Tests were performed with various input voltages from 24 V through 48 V. Figure 1 shows the measured efficiency for the various supply voltages, under two operating conditions; 1) natural convention (solid line) and 2) 400 LFM forced airflow (dashed line). Both tests were conducted without a heatsink installed.

   

• Efficiency Observations

  • The board displayed consistently high efficiency, even at higher output currents.

  • The converter achieves over 97% peak efficiency, despite its small size. Advanced GaN technology makes it possible to operate at higher switching frequency while maintaining low switching loss.

  • Using force air cooling extended the power range capability of the board.

2. Switch-Node and Output Ripple Voltage Waveforms

   The switch-node voltage waveform was measured with a 48 V input, 12 V output, and 10 A load current (Figure 2) and shows a clean transition between states. The switch-node waveform also demonstrates a very short dead time of about 10 ns. This is made possible by EPC23104’s precisely zero delay matching time between high-side and low-side FETs along with fast switching rising and falling time. Consequently, the EPC91106 can be safely operated with a dead time of 10 ns or less.

   

   Figure 3 presents the output ripple voltage at a 1 A load, showing a peak-to-peak ripple voltage of approximately 75 mV. The ability to operate at higher switching frequency reduces the size of the output capacitors while still achieving low output ripple voltage.

   

3. Transient Response

   The transient response was measured with a 48 V input, 12 V output, under a load change from 1.5A to 13 A and back, and is shown in figure 4. This fast recovery to voltage regulation showcases the EPC91106’s ability to handle dynamic loads in real-time.

   

Thermal Performance of the EPC91106

Thermal management is crucial in high-power-density converters, and the EPC91106 has been tested for thermal performance under multiple conditions without a heatsink and with 400 LFM airflow. Figure 5 shows the thermal image of the board operating at 48 V input, delivering an output of 12 V and 13 A load current. Even without a heatsink, the EPC91106 exhibited only moderate temperature increases. The thermal performance of the board suggests that it can operate reliably under high-power loads in environments where passive cooling may be limited.

Applications of the EPC91106 Evaluation Board

• Consumer Electronics: The compact design and efficient power management make the EPC91106 ideal for consumer devices such as laptops, gaming consoles, and high-end audio equipment, which require reliable DC-DC conversion in limited space with minimal heat generation.
• High-Density Computing: The EPC91106's compact form factor and efficient power conversion make it ideal for data centers and high-performance computing systems. It can be used in server systems as auxiliary power supplies to support the PSU and internal electronics, enabling reliable power management in densely packed hardware environments.

Conclusion

The EPC91106 evaluation board represents an efficient, compact solution for high-density, low-profile power conversion needs. With its advanced GaN technology, flexible power modes, and robust thermal performance, the EPC91106 stands out as a versatile choice for engineers. Its capacity to deliver efficient, stable power management in space-limited applications makes it an excellent tool for fields such as high-density computing, consumer, and industrial power systems.

For more information on ordering or learning about the EPC91106, Ask a GaN Expert.

Parinda Chantarasereekul,