A fast digital chip is designed and fabricated successfully to implement the algorithm for estimating blood pressure (BP) in real time by a non-invasive cuffless photoplethysmogram (PPG) Sensor. The fast response accomplished by this digital computation chip is made possible by one-time calibration only and the Taiwan Semiconductor Manufacturing (TSMC) T18 process to realize the chip in an area of 3.97 mm2. The experimental result shows that the overall power consumption of the chip is 15.62 mW. Finally, the blood pressure measurement platform has been developed with a user interface (UI) for long-term continuous cuffless BP measurement. The non-invasive blood pressure sensor is applied to the wrist arteries of 44 subjects for sensing the PPG pulsation of the blood vessel, and then estimating BPs (blood pressures). Measurement results shows that the maximum error in the BP measurement is ± 6 mmHg. Which is less than 8 mmHg, defined by the Advancement of Medical Instrumentation (AAMI) and British Hypertension Society (BHS) standard.