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