Dual, 16-Bit, 1000 MSPS, TxDAC+ Digital-to-Analog Converter

The AD9125 is a dual, 16-bit, high dynamic range TxDAC+® digital-to-analog converter (DAC) that provides a sample rate of 1000 MSPS, permitting a multicarrier generation up to the Nyquist frequency. It includes features optimized for direct conversion transmit applications, including complex digital modulation, and gain and offset compensation. The DAC outputs are optimized to interface seamlessly with analog quadrature modulators, such as the ADL537x F-MOD series from Analog Devices, Inc. A 4-wire serial port interface allows programming/readback of many internal parameters. Full-scale output current can be programmed over a range of 8.7 mA to 31.7 mA. The AD9125 comes in a 72-lead LFCSP.

Product Highlights

* Ultralow noise and intermodulation distortion (IMD)

enable high quality synthesis of wideband signals from

baseband to high intermediate frequencies.

* A proprietary DAC output switching technique enhances

dynamic performance.

* The current outputs are easily configured for various

single-ended or differential circuit topologies.

* Flexible CMOS digital interface allows the standard 32-wire bus to be reduced to a 16-wire bus.

Applications

* Wireless infrastructure

* W-CDMA, CDMA2000, TD-SCDMA, WiMAX, GSM, LTE

* Digital high or low IF synthesis

* Transmit diversity

* Wideband communications: LMDS/MMDS, point-to-point

* Cable modem termination systems

* Flexible CMOS interface allows dual-word, word, or byte load

* Single-carrier W-CDMA ACLR = 80 dBc @ 122.88 MHz IF

* Analog output: adjustable 8.7 mA to 31.7 mA, RL = 25 Ω to 50 Ω

* Novel 2×/4×/8× interpolator/complex modulator allows carrier placement anywhere in the DAC bandwidth