The AD9957 functions as a universal I/Q modulator and agileupconverter for communications systems where cost, size, powerconsumption, and dynamic performance are critical. TheAD9957 integrates a high speed, direct digital synthesizer(DDS), a high performance, high speed, 14-bit digital-to-analogconverter (DAC), clock multiplier circuitry, digital filters, andother DSP functions onto a single chip. It provides basebandupconversion for data transmission in a wired or wirelesscommunications system.

The AD9957 is the third offering in a family of quadraturedigital upconverters (QDUCs) that includes the AD9857 andAD9856. It offers performance gains in operating speed, powerconsumption, 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 asa 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 formultiplication of the reference clock frequency.

The user interface to the control functions includes a serial porteasily configured to interface to the SPORT of the Blackfin^®DSP and profile pins to enable fast and easy shift keying of anysignal parameter (phase, frequency, or amplitude).

Applications

• HFC data, telephony, and video modems
• Wireless base station transmissions
• Broadband communications transmissions
• Internet telephony

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.