A dedicated ultra-low power arterial pulse wave (APW) sensor for wrist watch type system is implemented in 0.18-μm CMOS technology with 1.8-V supply. A duty cycle controlled (DCC) current source (CS) enables low-power consuming current injection with 98% power reduction. A DC balanced amplifier reduces settling time by 72%, enabling fast APW signal acquisition when motion artifact is occurred. The simulated 2.125-mm2 single chip APW sensor consumes only 54-μW.