A Compact Wide-Input-Range Time-Domain Buck Converter with Fast Transient Response for Industrial Applications

Time-domain control in DC-DC converters represents an effective strategy to reduce the controller area occupation without introducing the quantization error typical of digital approaches. Because of the absence of the PWM ramp generator, however, the implementation of line feed-forward compensation in a time-domain controller is not straightforward. This paper introduces a time-domain-controlled buck converter with a line feed-forward and an adaptive loop gain compensation. A 1.4-A prototype converter with 6-to-24-V input voltage range and 3.3-V output, is fabricated in a 180-nm BCD process. Experimental results show a 3x reduction in the line transient response and a control loop bandwidth with limited dependence on input voltage variations. The die area is 1.78 $\mathrm{m}\mathrm{m}^{2}$, while the time-domain controller occupies only 0.28 $\mathrm{m}\mathrm{m}^{2}.$