Control Design and Realization of a Fast Transient Response, High-Reliability DC-DC Converter With a Secondary- Side Control Circuit

• Main Authors: Cong Ma, Kai Wang, Jun-Feng Wang
• Format: Article
• Language: English
• Published: IEEE 2021-01-01
• Series: IEEE Access
• Subjects: High-reliability; secondary-side control; bias-power supply; peak-current-mode-control; small-signal modeling; thick-film process
• Online Access: https://ieeexplore.ieee.org/document/9366880/

In high-reliability applications, DC/DC converters should realize high-efficiency and fast-transient in harsh environments. Thus, the circuit parameter design and the reliability design are both critical. The secondary-side control circuit has a faster transient and a simpler gate-drive than the primary-side control circuit, which has been used for over twenty years. However, the detailed design procedure and analysis of the high-reliability secondary-side control circuit have not been presented in the literature. This article introduces a secondary-side control circuit design and its small-signal modeling procedure with a peak-current-mode-control (PCMC) forward converter. The reliability design and evaluation for thick-film converter are demonstrated. A 100-watt prototype is manufactured, and its steady-state waveforms and transient waveforms are tested and then compared with other high-reliability products. The experimental results show that the peak efficiency reaches 90.6%; the load transient response is 330mV/560μs; and the mean-time-between-failure (MTBF) value is 481 kilo-hours, proving the fast-transient and high-reliability features of the secondary-side control circuit.