CMOS 180 MHz Quadrature Digital Upconverter ad Preliminary Technical Information AD985 FEATURES Universal low-cost solution for HFC network Low power: 400 mW@ rradack speed return-channel Tx function Space-saving surface-mount packaging Up to 70 MHz output bandwidth Bi-directional control bus interface Integrated 12-bit D/A converter Supports burst and continuous Tx modes Programmable sample rate interpolation filter 4 stored pin-selectable modulator profiles Programmable reference clock multiplier Direct interface to AD8320 PGA cable driver Internal SINX/X Compensation filter APPLICATIONS >52 dB SFDR @40 MHz Analog DAC Out . >48 dB SFDR @70 MHz Analog DAC Out Winclone Telepneny. and Video nogems >80 dB narrowband SFDR @ 70 MHz Aout reless and satelle communications +3.3V Single Supply Operation 4X/8X 3&3 Pe Programmable 4 p 1X to 64x = : rogrammable o|2 5 interpolating Interpolator : Complex [J 22 5 Halfbands saxl, [aap : Data In Hee x TAT pac PO 5-70 MHz Output Pxe 1 {oo 4X/8X OP LAProgrammable H4 1X to 64x : | : Programmable DAC nterpolating : Halfbands Interpolation : Rset a SINE COSINE : Prog. Clock : SPI Interface to AD8320 Multiplier + DDS and Control Functions H+q Programmable Cable | : Driver Amplifier i i Master di ; . Ref Clock In Profile Profile Bi-directional SP! Control Interface: Tx Enable Select Select Feset 32-bit frequency tuning word (VQ Sync) 1-2 3-4 Frequency Update Interpolation filter coefficients Ref clock multiplier coefficients Output phase inversion enable Cable driver amplifier control FUNCTIONAL BLOCK DIAGRA GENERAL DESCRIPTION The AD9856 integrates a high-speed direct-digital synthesi (DDS), a high-performance, high-speed 12-bit Digital, An converter (DAC), clock multiplier circuitry, digital.fi other DSP functions onto a single chip, t quadrature digital upconverter device. TI intended to function as a universal upstreg fabricated on an advanced CMOS process and it ceptional level of mixed signal performance. The ides a precision digital modulation and upconvert jth a direct interface port to the AD83Aigitally- > cable driver amplifier. The AD9853/AD8320 ms aighly- integrated, low-power, small footprint, and -ffective solution for the HFC return-path Tx requirement. cost, size, power dissipation, and dynapcformance are critical attributes. The AD9856 is available in a space-saving surface mount package and is specified to operate overetttended industrial temperature range of -40 to+85 C. This Advanced Datasheet describes a product which is in the development stage. Specifications and pin-out are subject to change without notice. For additional information please contact Analog Devices, High-speed Converter Group, 7910 Triad Center Drive, Greensboro, NC, 27409 Tel: 336/605-4365 REV. 6/2/98