This work provides an all-digital smart temperature sensor with dual-mode transceiver chipset for wireless body area network (WBAN). The measurement results show that the proposed temperature sensor achieves a maximum temperature error<0.6°C within the range from 20°C to 50°C. And a phase-frequency tunable clock generator (PFTCG) is designed with frequency and phase tuning capability on the fly. This chip is manufactured on a standard 90 nm CMOS process. The supply voltage to the chip core is globally applied at 0.5 V with 12 powerdomain partitions for sleep-active and voltage-scaling management. The transceiver chipset provides maximum 7 Mbps data rate, resulting in 97.7% efficiency improvement in baseband circuit processing.