12-Bit, 300 MSPS
High Speed TxDAC+ D/A Converter
AD9753*
В® APPLICATIONS
Communications: LMDS, LMCS, MMDS
Base Stations
Digital Synthesis
QAM and OFDM GENERAL DESCRIPTION The AD9753 is a dual, muxed port, ultrahigh speed, singlechannel, 12-bit CMOS DAC. It integrates a high quality 12-bit
TxDAC+ core, a voltage reference, and digital interface circuitry
into a small 48-lead LQFP package. The AD9753 offers exceptional ac and dc performance while supporting update rates up
to 300 MSPS.
The AD9753 has been optimized for ultrahigh speed applications up to 300 MSPS where data rates exceed those possible on
a single data interface port DAC. The digital interface consists
of two buffered latches as well as control logic. These latches
can be time multiplexed to the high speed DAC in several ways.
This PLL drives the DAC latch at twice the speed of the externally applied clock and is able to interleave the data from the
two input channels. The resulting output data rate is twice that
of the two input channels. With the PLL disabled, an external
2Г— clock may be supplied and divided by two internally.
The CLK inputs (CLK+/CLK–) can be driven either differentially or single-ended, with a signal swing as low as 1 V p-p. FUNCTIONAL BLOCK DIAGRAM
DVDD PORT1 DCOM LATCH
MUX PORT2 CLK+
CLK– …