Mixed-Signal Front-End (MxFE™) Baseband
Transceiver for Broadband Applications
AD9863
FEATURES
FUNCTIONAL BLOCK DIAGRAM
Receive path includes dual 12-bit, 50 MSPS analog-to-digital
converters with internal or external reference
Transmit path includes dual 12-bit, 200 MSPS digital-to-
analog converters with 1×, 2×, or 4× interpolation and
programmable gain control
VIN+A
ADC
ADC
DATA
MUX
AND
Rx DATA
VIN–A
VIN+B
LATCH
VIN–B
I/O
INTERFACE
CONTROL
I/O
Internal clock distribution block includes a programmable
phase-locked loop and timing generation circuitry,
allowing single-reference clock operation
INTERFACE
CONFIGURATION
BLOCK
FLEXIBLE
I/O BUS
[0:23]
LOW-PASS
INTERPOLATION
FILTER
IOUT+A
DATA
LATCH
AND
24-pin flexible I/O data interface allows various interleaved
or noninterleaved data transfers in half-duplex mode and
interleaved data transfers in full-duplex mode
DAC
DAC
IOUT–A
IOUT+B
Tx DATA
DEMUX
IOUT–B
Configurable through register programmability or
optionally limited programmability through mode pins
Independent Rx and Tx power-down control pins
64-lead LFCSP package (9 mm × 9 mm footprint)
ADC CLOCK
DAC CLOCK
CLKIN1
CLKIN2
CLOCK
GENERATION
BLOCK
PLL
AD9863
APPLICATIONS
Broadband access
Figure 1.
Broadband LAN
Communications (modems)
GENERAL DESCRIPTION
The AD9863 is a member of the MxFE family—a group of
integrated converters for the communications market. The
AD9863 integrates dual 12-bit analog-to-digital converters
(ADC) and dual 12-bit digital-to-analog converters (TxDAC®).
The AD9863 ADCs are optimized for ADC sampling of 50 MSPS
and less. The dual TxDACs operate at speeds up to 200 MHz
and include a bypassable 2× or 4× interpolation filter. The
AD9863 is optimized for high performance, low power, and
small form factor to provide a cost-effective solution for the
broadband communications market.
In half-duplex systems, the interface supports 24-bit parallel
transfers or 12-bit interleaved transfers. In full-duplex systems,
the interface supports a 12-bit interleaved ADC bus and a
12-bit interleaved TxDAC bus. The flexible I/O bus reduces pin
count, also reducing the required package size on the AD9863
and the device to which it connects.
The AD9863 can use either mode pins or a serial programma-
ble interface (SPI) to configure the interface bus, operate the
ADC in a low power mode, configure the TxDAC interpolation
rate, and control ADC and TxDAC power-down. The SPI
provides more programmable options for both the TxDAC path
(for example, coarse and fine gain control and offset control for
channel matching) and the ADC path (for example, the internal
duty cycle stabilizer and twos complement data format).
The AD9863 uses a single input clock pin (CLKIN) or two
independent clocks for the Tx path and the Rx path. The ADC
and TxDAC clocks are generated within a timing generation
block that provides user programmable options such as divide
circuits, PLL multipliers, and switches.
The AD9863 is packaged in a 64-lead LFCSP (low profile, fine
pitched, chip scale package). The 64-lead LFCSP footprint is
only 9 mm × 9 mm and is less than 0.9 mm high, fitting into
such tightly spaced applications as PCMCIA cards.
A flexible, bidirectional 24-bit I/O bus accommodates a variety
of custom digital back ends or open market DSPs.
Rev. A
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 that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
www.analog.com
© 2005 Analog Devices, Inc. All rights reserved.