The ADS79xx devices offer a power-down feature to save power when not in use. There are two ways to power down the device. It can be powered down by writing DI05 = 1 in the Mode Control register (refer to Table 1, Table 2 and Table 5); in this case the device powers down on the 16th falling edge of SCLK in the next data frame. Another way to powerdown the device is through GPIO. GPIO3 can act as a PD input (refer to Table 11, for assigning this functionality to GPIO3). This is an asynchronous and active low input. The device powers down instantaneously after GPIO3 (PD) = 0. The device will powerup again on the CS falling edge while DI05 = 0 in the Mode Control register and GPIO3 (PD) = 1.