AD7910/AD7920,pdf datasheet (A

The AD7910/AD79201 are, respectively, 10-bit and 12-bit, high speed, low power, successive approximation ADCs. The parts operate from a single 2.35 V to 5.25 V power supply and feature throughput rates up to 250 kSPS. The parts contain a low noise, wide bandwidth track-and-hold amplifier that can handle input frequencies in excess of 13 MHz.
The conversion process and data acquisition are controlled using CS and the serial clock, allowing the devices to interface with microprocessors or DSPs. The input signal is sampled on the falling edge of CS and the conversion is initiated at this point. There are no pipeline delays associated with the part.
The AD7910/AD7920 use advanced design techniques to achieve very low power dissipation at high throughput rates.
The reference for the part is taken internally from VDD. This allows the widest dynamic input range to the ADC. Thus, the analog input range for the part is 0 to VDD. The conversion rate is determined by the SCLK.