Advantages and Disadvantages of Using Composite Amplifiers
Advancements in Composite Amplifiers Transform Power Amplifiers for Electronic PCB Design
Composite amplifiers, a combination of multiple operational amplifiers, are revolutionizing power amplifiers in electronic Printed Circuit Board (PCB) design. These innovative amplifiers offer several key benefits, including improved efficiency, enhanced performance, and increased integration.
One of the primary advantages of composite amplifiers is their ability to provide an efficient slew-rate boost, as the gain of the feedback amplifier is multiplied by the slew-rate. This makes them particularly suitable for microwave and RF applications, where high-speed performance is crucial.
The use of composite amplifiers in power amplifiers can remove errors caused by thermal feedback loops, particularly self-heating. This is achieved through the feedback loop in composite amplifiers, which improves DC accuracy and removes noise within the circuit. As a result, composite amplifiers offer better DC output-offset, which is not affected by the excess load placed on output transistors.
Composite op-amps exhibit properties such as higher gain, boosted slew rates, and lower distortion. They also offer advantages in DC performance, retaining the DC characteristics of the first input amplifier. The feedback loops in composite amplifiers are negative and are also known as nested-feedback amplifiers. However, it is worth noting that a negative feedback loop in composite amplifiers can cause a weakening of the signal at the output.
Recent advancements in composite amplifiers are closely tied to developments in device materials, packaging, and circuit design techniques that enhance performance, efficiency, and integration. One such development is the use of Gallium Nitride (GaN) devices, which offer high power density, high efficiency, and superior thermal performance compared to traditional silicon-based components.
New GaN FET components, such as the EPC2304, are developed with very low on-resistance, enabling compact designs that handle high current and high switching frequencies. These devices improve efficiency and reduce switching losses in power amplifiers embedded on PCBs, as demonstrated in high-performance motor drive inverters for medium-voltage applications.
Advances in packaging, including thermally optimized QFN packages, allow for better heat dissipation directly on PCB layouts, offering robust thermal management without bulky heatsinks. This supports prototyping and production-ready power amplifiers with clean waveforms and minimal ringing in real-world scenarios.
Modern PCB designs for composite amplifiers incorporate wideband transmission lines for broad frequency operation and improved gain flatness. This can include dual-orthogonal mode structures for duplexing and advanced matching networks to maintain amplifier efficiency and bandwidth.
Recent power amplifiers such as the Qorvo TGA2578-CP operate over broad frequency ranges, delivering saturated output power of 30 W with power-added efficiency greater than 30% and gain exceeding 26 dB. These advancements facilitate the development of smaller, higher-frequency, and more efficient power amplifiers for applications like mobile communications, autonomous vehicles, robotics, and motor control drives.
As we look towards the future, the increasing adoption of composite op-amps in power amplifiers is expected to drive product demand over the coming years. This trend is supported by emerging PCB technologies—including embedded components and flexible substrates—which enable miniaturization and improved electrical performance.
In summary, recent composite amplifier advancements in PCB-based power amplifiers focus on GaN technology, improved thermal and electrical design, high switching frequencies, integration of digital distortion correction, and enhanced efficiency and power output. These crucial advancements are paving the way for evolving high-frequency, high-power applications across automotive, mobile, and industrial sectors.
For those interested in learning more about PCB design, the Design for Manufacturing Handbook is a valuable resource. This comprehensive guide covers topics such as annular rings, vias, trace width and space, solder mask, and silkscreen, providing must-knows about these essential aspects of PCB design.
Technology plays a significant role in the field of electronic PCB design, with advancements in composite amplifiers revolutionizing power amplifiers. These innovative composite amplifiers, characterized by their high efficiency, enhanced performance, and increased integration, are particularly beneficial in microwave and RF applications due to their ability to provide efficient slew-rate boosts.
Recent advancements in composite amplifiers, such as the use of Gallium Nitride (GaN) devices and improvements in packaging and circuit design techniques, are driving the development of smaller, higher-frequency, and more efficient power amplifiers for various applications like mobile communications, autonomous vehicles, robotics, and motor control drives.
