A pseudo-noise coded constant-off-time (PNC-COT) control switching converter with maximum 18.7 dBm peak spur reduction and 92% efficiency in 40 nm CMOS

A pseudo-noise coded constant-off-time (PNC-COT) controlled switching converter is proposed in the power module to provide fast envelope tracking and reduced voltage ripple of the supply for radio-frequency power amplifier. The proposed spread spectrum frequency controller (SSFC) conquers the difficulty in spread spectrum realization for the COT control owing to the lack of clock signal. With pseudo-noise coded controlled, low electromagnetic interference is accomplished by softly spreading the switching frequency. Thus, fast voltage tracking, highest 92% efficiency, 35 mV voltage ripple and a 18.7 dBm peak spur reduction can be achieved in a fabricated SS embedded power module with an active area of 0.476mm² in 40nm CMOS process.