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 and feature throughput rates up to 250 kSPS. The parts contain a low-noise, wide bandwidth track/hold amplifier, which can handle input frequencies in excess of 6 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 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 and the mode of operation is controlled by CS. The serial data stream from the DOUT pin has a channel identifier bit, which provides information about the channel converted.
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. 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.
### Features and Benefits
Specified for VDD of 2.35 V to 5.25 V
Low Power:
4 mW typ at 250 kSPS with 3 V Supplies
13.5 mW typ at 250 kSPS with 5 V Supplies
Wide Input Bandwidth:
71.5 dB Minimum SNR at 100 kHz Input Frequency
Flexible Power/Serial Clock Speed Management
Throughput Rate: 250 kSPS
No Pipeline Delays
High Speed Serial Interface SPI®/QSPI™ /MICROWIRE™ /DSP Compatible
