a
FEATURES
Universal Low Cost Modulator Solution for
Communications Applications
DC to 80 MHz Output Bandwidth
Integrated 12-Bit D/A Converter
Programmable Sample Rate Interpolation Filter
Programmable Reference Clock Multiplier
Internal SIN(x)/x Compensation Filter
>52 dB SFDR @ 40 MHz A
OUT
>48 dB SFDR @ 70 MHz A
OUT
>80 dB Narrowband SFDR @ 70 MHz A
OUT
+3 V Single Supply Operation
Space-Saving Surface-Mount Packaging
Bidirectional Control Bus Interface
Supports Burst and Continuous Tx Modes
Single Tone Mode for Frequency Synthesis Applications
Four Programmable, Pin-Selectable Modulator Profiles
Direct Interface to AD8320/AD8321 PGA Cable Driver
CMOS 200 MHz
Quadrature Digital Upconverter
AD9856
APPLICATIONS
HFC Data, Telephony and Video Modems
Wireless and Satellite Communications
Cellular Basestations
GENERAL DESCRIPTION
The AD9856 integrates a high speed direct-digital synthesizer
(DDS), a high performance, high speed 12-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 AD9856 is intended
to function as a universal I/Q modulator and agile upconverter
for communications applications, where cost, size, power dissi-
pation and dynamic performance are critical attributes.
The AD9856 is available in a space-saving surface mount pack-
age and specified to operate over the extended industrial tem-
perature range of –40°C to +85°C.
FUNCTIONAL BLOCK DIAGRAM
DEMULTIPLEXER AND
SERIAL-TO-PARALLEL
CONVERTER
12
4 –8
SELECTABLE
INTERPOLATING
HALFBANDS
4 –8
SELECTABLE
INTERPOLATING
HALFBANDS
4 –20 PROG.
CLOCK
MULTIPLIER
12
2 TO 63
SELECTABLE
INTERPOLATOR
12
12
12
AD9856
INV 12
SINC
12-BIT
DAC
DC-80 MHz
OUTPUT
DAC
R
SET
SPI INTERFACE
TO AD8320/AD8321
PROGRAMMABLE
CABLE DRIVER
AMPLIFIER
COMPLEX
DATA IN
12
12
2 TO 63
SELECTABLE
INTERPOLATOR
12
12
SINE
12
12
COSINE
TxENABLE
(I/Q SYNC)
DDS AND CONTROL FUNCTIONS
REFERENCE
CLOCK IN
PROFILE
SELECT
1–2
PROFILE
SELECT
3–4
MASTER
RESET
BIDIRECTIONAL SPI CONTROL INTERFACE:
32-BIT FREQUENCY TUNING WORD
FREQUENCY UPDATE
INTERPOLATION FILTER RATE
REFERENCE CLOCK MULTIPLIER RATE
SPECTRAL PHASE INVERSION ENABLE
CABLE DRIVER AMPLIFIER CONTROL
REV. B
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 1999
AD [ ANALOG DEVICES ]
