Can TPS51220 be used by 99% ?

Hi Yusuke,

Please contact Shuichi Ishikawa in Japan directly. His email address: s-ishikawa@ti.com.

Thanks,

Nancy

Hi Yusuke,

Ishikawa-san in Japan is the system engineer for this part. The designer for this part is also in Japan. He will give you good support. I am not quite sure if this part can work for your condition. The typical min off time is 290ns in the datasheet. If you set frequency to 200kHz, the period becomes 5us. So it sounds max duty cycle is 94.2%. However, TPS51220 skips pulses if higher duty cycle is needed. It skips 5 pulses at transient and 3 pulses at steady state. So instead, the actual switching frequency can become 1/4 of its setting frequency and the switching period becomes 20us. Thus the typical max duty cycle becomes 98.6%(round up to 99%). That is the reason we claim 99% duty cycle in the datasheet. Please contact Ishikawa-san directly for your further question.

Thanks,

Nancy