PRODUCT DESCRIPTION:

The AD9755 is a dual, muxed port, ultrahigh speed, singlechannel, 14-bit CMOS DAC. It integrates a high quality 14-bitTxDAC+ core, a voltage reference, and digital interface circuitryinto a small 48-lead LQFP package. The AD9755 offers exceptional ac and dc performance while supporting update rates upto 300 MSPS.The AD9755 has been optimized for ultrahigh speed applications up to 300 MSPS where data rates exceed those possible ona single data interface port DAC. The digital interface consistsof two buffered latches as well as control logic. These latchescan 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 thetwo input channels. The resulting output data rate is twice thatof the two input channels. With the PLL disabled, an external2× clock may be supplied and divided by two internally.The CLK inputs (CLK+/CLK–) can be driven either differentiallyor single-ended, with a signal swing as low as 1 V p-p.The DAC utilizes a segmented current source architecture combined with a proprietary switching technique to reduce glitchenergy and maximize dynamic accuracy. Differential currentoutputs support single-ended or differential applications. Thedifferential outputs each provide a nominal full-scale currentfrom 2 mA to 20 mA.The AD9755 is manufactured on an advanced low cost 0.35 µmCMOS process. It operates from a single supply of 3.0 V to 3.6 Vand consumes 155 mW of power.

PRODUCT HIGHLIGHTS:

1. The AD9755 is a member of a pin compatible family of highspeed TxDAC+s providing 10-, 12-, and 14-bit resolution.

2. Ultrahigh Speed 300 MSPS Conversion Rate.

3. Dual 14-Bit Latched, Multiplexed Input Ports. The AD9755features a flexible digital interface allowing high speed dataconversion through either a single or dual port input.

4. Low Power. Complete CMOS DAC function operates on155 mW from a 3.0 V to 3.6 V single supply. The DAC fullscale current can be reduced for lower power operation.

5. On-Chip Voltage Reference. The AD9755 includes a 1.20 Vtemperature compensated band gap voltage reference.

FEATURES:

14-Bit Dual Muxed Port DAC

300 MSPS Output Update Rate

Excellent SFDR and IMD Performance

SFDR to Nyquist @ 25 MHz Output: 71 dB

Internal Clock Doubling PLL

Differential or Single-Ended Clock Input

On-Chip 1.2 V Reference

Single 3.3 V Supply Operation

Power Dissipation: 155 mW @ 3.3 V

48-Lead LQFP

APPLICATIONS:

Communications: LMDS, LMCS, MMDS

Base Stations

Digital Synthesis

QAM and OFDM