资 源 简 介
The AD97091 is a dual-port， high speed， 2-channel， 8-bit CMOS DAC. It integrates two high quality 8-bit TxDAC+® cores， a voltage reference， and digital interface circuitry into a small 48-lead LQFP package. The AD9709 offers excepTIonal ac and dc performance while supporTIng update rates of up to 125 MSPS. The AD9709 has been opTImized for processing I and Q data in communicaTIons applications. The digital interface consists of two double-buffered latches as well as control logic. Separate write inputs allow data to be written to the two DAC ports independent of one another. Separate clocks control the update rate of the DACs. A mode control pin allows the AD9709 to interface to two separate data ports， or to a single interleaved high speed data port. In interleaving mode， the input data stream is demuxed into its original I and Q data and then latched. The I and Q data is then converted by the two DACs and updated at half the input data rate. The GAINCTRL pin allows two modes for setting the full-scale current （IOUTFS） of the two DACs. IOUTFS for each DAC can be set independently using two external resistors， or IOUTFS for both DACs can be set by using a single external resistor. See the Gain Control Mode section for important date code information on this feature. The DACs utilize a segmented current source architecture combined with a proprietary switching technique to reduce glitch energy and to maximize dynamic accuracy. Each DAC provides differential current output， thus supporting singleended or differential applications. Both DACs can be simultaneously updated and provide a nominal full-scale current of 20 mA. The full-scale currents between each DAC are matched to within 0.1%. 1 Patent pending. The AD9709 is manufactured on an advanced low-cost CMOS process. It operates from a single supply of 3.3 V or 5 V and consumes 380 mW of power.
