When the MODE bit in the Config register is set to 1b, the ADS111x-Q1 enter a power-down state, and operate in single-shot mode. This power-down state is the default state for the ADS111x-Q1 when power is first applied. Although powered down, the devices still respond to commands. The ADS111x-Q1 remain in this power-down state until a 1b is written to the operational status (OS) bit in the Config register. When the OS bit is asserted, the device powers up in approximately 25 μs, resets the OS bit to 0b, and starts a single conversion. When conversion data are ready for retrieval, the device powers down again. Writing a 1b to the OS bit while a conversion is ongoing has no effect. To switch to continuous-conversion mode, write a 0b to the MODE bit in the Config register.