The HSP50216 Quad Programmable Digital Downconverter
(QPDC) is designed for high dynamic range applications
such as cellular basestations where multiple channel
processing is required in a small physical space. The QPDC
combines into a single package, a set of four channels which
include: digital mixers, a quadrature carrier NCO, digital
filters, a resampling filter, a Cartesian-to-polar coordinate
converter and an AGC loop.
The HSP50216 accepts four channels of 16-bit real digitized IF
samples which are mixed with local quadrature sinusoids. Each
channel carrier NCO frequency is set independently by the
microprocessor. The output of the mixers are filtered with a CIC
and FIR filters, with a variety of decimation options. Gain
adjustment is provided on the filtered signal. The digital AGC
provides a gain adjust range of up to 96dB with programmable
thresholds and slew rates. A cartesian to polar coordinate
converter provides magnitude and phase outputs. A frequency
discriminator provides a frequency output via the FIR filter.
Selectable outputs include I samples, Q samples, Magnitude,
Phase, Frequency and AGC gain. The output resolution is
selectable from 4-bit fixed point to 32-bit floating point.
The maximum output bandwidth achievable using a single
channel is at least 1MHz.

Features
• Up to 70MSPS Input
• Four Independently Programmable Downconverter
Channels in a single package
• Four Parallel 16-Bit Inputs - Fixed or Floating Point Format
• 32-Bit Programmable Carrier NCO with >115dB SFDR
• 110dB FIR Out of Band Attenuation
• Decimation from 8 to >65536
• 24-bit Internal Data Path
• Digital AGC with up to 96dB of Gain Range
• Filter Functions
- 1 to 5 Stage CIC Filter
- Halfband Decimation and Interpolation FIR Filter
- Programmable FIR Filter
- Resampling FIR Filter
• Cascadable Filtering for Additional Bandwidth
• Four Independent Serial Outputs
• 3.3V Operation
• Pb-Free Available (RoHS Compliant)

Applications
• Narrow-Band TDMA through IS-95 CDMA Digital Software
Radio and Basestation Receivers
• Wide-Band Applications: W-CDMA and UMTS Digital
Software Radio and Basestation Receivers