AD6654/PCB Analog Devices Inc, AD6654/PCB Datasheet - Page 5

• Manufacturer Part Number: AD6654/PCB
• Description: BOARD EVALUATION FOR AD6654
• Manufacturer: Analog Devices Inc

Specifications of AD6654/PCB

• Module/board Type: Evaluation Board
• For Use With/related Products: AD6554
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

can perform. It can also allow complex filtering operations to be
achieved in the programmable filters.
The digital AGC provides the user with scaled digital outputs
based on the rms level of the signal present at the output of the
digital filters. The user can set the requested level and time
constant of the AGC loop for optimum performance of the
postprocessor. This is a critical function in the base station for
CDMA application, where the power level must be well
controlled going into the RAKE receivers. It has programmable
clipping and rounding control to provide different output
resolutions.
The overall filter response for the AD6654 is the composite of
all the combined filter stages. Each successive filter stage is
capable of narrower transition bandwidths, but requires a
greater number of CLK cycles to calculate the output. The
AD6654 features a fractional clock multiplier that uses the ADC
clock (which is slower than the DDC’s processing speed) to
produce a DDC master clock up to 200 MHz. This feature
allows fractional multiplication of the input clock to allow the
DDC to function at maximum speed while maintaining edge
identity to the ADC clock.
More decimation in the first filter stage minimizes overall
power consumption. Data from the device is interfaced to a
DSP/FPGA/baseband processor via high speed parallel ports
(preferred), or a DSP-compatible microprocessor interface.
The AD6654 is available in 4-channel and 6-channel versions.
The primary focus of the data sheet is on the 6-channel part.
The only difference between the 6-channel and 4-channel
devices is that, on the 4-channel version, Channel 4 and
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Channel 5 are not available (see Figure 1). The 4-channel device
has the same DDC input port features, output ports, and
memory map as the 6-channel device. On the 4-channel
version, the memory map section for Channel 4 and Channel 5
can be programmed and read back, but the two extra channels
are disabled internally.
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Integrated 14-bit, 92.16 MSPS ADC.
Track-and-hold amplifier analog input for excellent IF
sampling up to 200 MHz.
Four or six independent digital filtering channels.
RMS/peak power monitoring of the ADC data port and
96 dB range AGCs before the output ports.
Three programmable RAM coefficient filters, three half-
band filters, two fixed coefficient filters, and one fifth-
order CIC filter per channel.
Complex filtering by combining filtering capability of
multiple channels.
Three 16-bit parallel output ports operating at up to
200 MHz clock.
Blackfin®- and TigerSHARC®-compatible, 8-/16-bit
microprocessor port.
Synchronous serial communications port is compatible
with most serial interface standards: SPORT, SPI, and SSR.
AD6654