Implantable biomedical device supplying by a 28nm CMOS self-calibration DC-DC buck converter with 97% output voltage accuracy. - Te-Fu Yang; Ru-Yu Huang; Yi-Ping Su; Balakumar; Ke-Horng Chen; Tsung-Yen Tsai; Jian-Ru Lin; Ying-Hsi Lin; Chao-Cheng Lee; Pei-Ling Tseng (ISCAS, 2015)