AD9765

The AD9765 is a dual port, high speed, two channel, 12-bit CMOS DAC. It integrates two high quality 12-bit TxDAC+cores, a voltage reference and digital interface circuitry into a small 48-lead LQFP package. The AD9765 offers exceptional ac and dc performance while supporting update rates up to 125 MSPS.

The AD9765 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 AD9765 to interface to two separate data ports, or to a single interleaved high speed data port. In inter-leaving mode the input data stream is demuxed into its original I and Q data and then latched. The I and Q data is then con-verted 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 both2 DACs can be set by using a single external resistor. The DACs utilize a segmented current source architecture com-bined with a proprietary switching technique to reduce glitch
energy and to maximize dynamic accuracy. Each DAC provides differential current output thus supporting single-ended or dif-ferential applications. Both DACs can be simultaneously updated

TxDAC+ is a registered trademark of Analog Devices, Inc.
1Patent pending.
2Please see GAINCTRL Mode section, for important date code information on
this feature.