12-Bit, 300 MSPS High Speed TxDAC+ D/A Converter

The AD9753 is a dual, muxed port, ultrahigh speed, single-channel, 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 2× 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 VP-P. The DAC utilizes a segmented current source architecture combined with a proprietary switching technique to reduce glitch energy and to maximize dynamic accuracy. Differential current outputs support single-ended or differential applications. The differential outputs each provide a nominal full-scale current from 2 mA to 20 mA.

The AD9753 is manufactured on an advanced low cost 0.35 µm CMOS process. It operates from a single supply of 3.0 V to 3.6 V and consumes 155 mW of power.

PRODUCT HIGHLIGHTS

* The AD9753 is a member of a pin compatible family of high

speed TxDAC+s providing 10-, 12-, and 14-bit resolution.

* Ultrahigh Speed 300 MSPS Conversion Rate.

* Dual 12-Bit Latched, Multiplexed Input Ports. The AD9753

features a flexible digital interface allowing high speed data

conversion through either a single or dual port input.

* Low Power. Complete CMOS DAC function operates on

155 mW from a 3.0 V to 3.6 V single supply. The DAC full-scale current can be reduced for lower power operation.

* On-Chip Voltage Reference. The AD9753 includes a 1.20 V

temperature-compensated band gap voltage reference.

APPLICATIONS

* Communications: LMDS, LMCS, MMDS

* Base Stations

* Digital Synthesis

* QAM and OFDM

* 12-Bit Dual Muxed Port DAC

* 300 MSPS Output Update Rate

* Excellent SFDR and IMD Performance

* SFDR to Nyquist @ 25 MHz Output: 69 dB

* Internal Clock Doubling PLL