Low power IEEE 802.11n single input single output (SISO) wireless LAN (WLAN) baseband LSI has been developed for mobile applications. The multiple low power technologies such as on-chip power gating and high throughput technologies for expanding idle time are applied to the LSI. By minimizing always-on circuits and implementing them using thick gate-oxide transistors, 7uW stand-by power consumption is achieved with negligible shutdown/restart transition time. The built-in wake-up timer and on-chip CPU enables continuous transmit/receive operation without an external intervention.