4 Comparison of Design Examples

Figure 4-1 and Table 4-1 present the ripple injection component values, pole-zero locations, and measured loop performance obtained using both the detailed frequency-domain analysis method and the simplified design approach. These examples demonstrate how each design methodology influences the resulting crossover frequency, phase margin, and overall control-loop behavior of the ACOT™ converter.

The comparison above highlights the difference between the detailed frequency-domain design approach and the simplified ripple-based design approach for ACOT™ control implementation. In the frequency-domain analysis method, the ripple injection network is intentionally designed by positioning the poles and zeros to achieve a targeted crossover frequency and a controlled phase margin. This provides better predictability and tighter optimization of transient response, stability, and loop bandwidth. In this example, the design achieves a crossover frequency of approximately 25 kHz with a well-controlled phase margin of 68°.

In contrast, the simplified approach selects the ripple injection components mainly based on practical ripple generation requirements and approximate design relationships, without performing a full AC loop analysis. Even though the resulting pole-zero locations and crossover frequency differ, the converter still achieves stable operation with a very high phase margin (> 80°). This demonstrates that the simplified approach is often sufficient for many practical applications and significantly reduces design complexity. However, when precise optimization of dynamic performance, bandwidth, or phase margin is required, the frequency-domain analysis approach provides much greater control and design accuracy.