GENERAL DESCRIPTION The AD9857 integrates a high speed direct digital synthesizer (DDS), a high performance, high speed, 14-bit digital-to-analog converter (DAC), clock multiplier circuitry, digital filters, and other DSP functions onto a single chip, to form a complete quadrature digital upconverter device. The AD9857 is intended to function as a universal I/Q modulator and agile upconverter, single-tone DDS, or interpolating DAC for communications applications, where cost, size, power dissipation, and dynamic performance are critical attributes. FEATURES 200 MHz internal clock rate 14-bit data path Excellent dynamic performance: 80 dB SFDR @ 65 MHz (±100 kHz) AOUT 4× to 20× programmable reference clock multiplier Reference clock multiplier PLL lock detect indicator Internal 32-bit quadrature DDS FSK capability 8-bit output amplitude control Single-pin power-down function Four programmable, pin-selectable signal profiles SIN(x)/x correction (inverse SINC function) Simplified control interface 10 MHz serial, 2-wire or 3-wire SPI®-compatible 3.3 V single supply Single-ended or differential input reference clock 80-lead LQFP surface-mount packaging Three modes of operation: Quadrature modulator mode Single-tone mode Interpolating DAC mode APPLICATIONS HFC data, telephony, and video modems Wireless base station Agile, LO frequency synthesis Broadband communications
|