AD9957 Datasheet | Analog Devices

FEATURES 1 GSPS internal clock speed (up to 400 MHz analog output) Integrated 1 GSPS 14-bit DAC 250 MSPS input data rate Phase noise ≤ - 125 d Bc/Hz (400 MHz carrier @ 1 k Hz offset) Excellent dynamic performance >80 d B narrow-band SFDR 8 programmable profiles for shift keying Sin(x)/(x) correction (inverse sinc filter) Reference clock multiplier Internal oscillator for a single crystal operation Software and hardware controlled power-down Integrated RAM Phase modulation capability Multichip synchronization Easy interface to Blackfin SPORT Interpolation factors from 4× to 252× Interpolation DAC mode Gain control DAC Internal divider allows references up to 2 GHz 1.8 V and 3.3 V power supplies 100-lead TQFP_EP package APPLICATIONS HFC data, telephony, and video modems Wireless base station transmissions Broadband munications transmissions Internet telephony GENERAL DESCRIPTION The AD9957 functions as a universal I/Q modulator and agile upconverter for munications systems where cost, size, power consumption, and dynamic performance are critical. The AD9957 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. It provides baseband upconversion for data transmission in a wired or wireless munications system. The AD9957 is the third offering in a family of quadrature digital upconverters (QDUCs) that includes the AD9857 and AD9856. It offers performance gains in operating speed, power consumption, and spectral performance. Unlike its predecessors, it supports a 16-bit serial input mode for I/Q baseband data. The device can alternatively be programmed to operate either as a single tone, sinusoidal source or as an interpolating DAC. The reference clock input circuitry includes a crystal oscillator, a high speed, divide-by-two input, and a low noise PLL for multiplication of the reference clock frequency. The...