AD7921

The AD7911/AD7921 are 10-bit and 12-bit, high speed, low power, 2-channel successive approximation ADCs, respectively. The parts operate from a single 2.35 V to 5.25 V power supply nd feature throughput rates of up to 250 kSPS. The parts ontain a low noise, wide bandwidth track-and-hold amplifier, which can handle input frequencies in excess of 6 MHz. The onversion process and data acquisition are controlled using CS nd the serial clock, allowing the devices to interface with microprocessors or DSPs. The input signal is sampled on the alling edge of CS, and the conversion is also initiated at this point. There are no pipeline delays associated with the part.

The channel to be converted is selected through the DIN pin, nd the mode of operation is controlled by CS. The serial data tream from the DOUT pin has a channel identifier bit, which provides information about the converted channel.

The AD7911/AD7921 use advanced design techniques to achieve very low power dissipation at high throughput rates. The reference for the part is taken internally from VDD, thereby allowing the widest dynamic input range to the ADC. The analog input range for the part, therefore, is 0 to VDD. The conversion rate is determined by the SCLK signal.